diff options
Diffstat (limited to 'vendor/serde_derive/src/de.rs')
| -rw-r--r-- | vendor/serde_derive/src/de.rs | 3148 |
1 files changed, 0 insertions, 3148 deletions
diff --git a/vendor/serde_derive/src/de.rs b/vendor/serde_derive/src/de.rs deleted file mode 100644 index e3b737c..0000000 --- a/vendor/serde_derive/src/de.rs +++ /dev/null @@ -1,3148 +0,0 @@ -use crate::fragment::{Expr, Fragment, Match, Stmts}; -use crate::internals::ast::{Container, Data, Field, Style, Variant}; -use crate::internals::{attr, replace_receiver, ungroup, Ctxt, Derive}; -use crate::{bound, dummy, pretend, this}; -use proc_macro2::{Literal, Span, TokenStream}; -use quote::{quote, quote_spanned, ToTokens}; -use std::collections::BTreeSet; -use std::ptr; -use syn::punctuated::Punctuated; -use syn::spanned::Spanned; -use syn::{parse_quote, Ident, Index, Member}; - -pub fn expand_derive_deserialize(input: &mut syn::DeriveInput) -> syn::Result<TokenStream> { - replace_receiver(input); - - let ctxt = Ctxt::new(); - let cont = match Container::from_ast(&ctxt, input, Derive::Deserialize) { - 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 (de_impl_generics, _, ty_generics, where_clause) = split_with_de_lifetime(¶ms); - let body = Stmts(deserialize_body(&cont, ¶ms)); - let delife = params.borrowed.de_lifetime(); - 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 #de_impl_generics #ident #ty_generics #where_clause { - #vis fn deserialize<__D>(__deserializer: __D) -> #serde::__private::Result<#remote #ty_generics, __D::Error> - where - __D: #serde::Deserializer<#delife>, - { - #used - #body - } - } - } - } else { - let fn_deserialize_in_place = deserialize_in_place_body(&cont, ¶ms); - - quote! { - #[automatically_derived] - impl #de_impl_generics #serde::Deserialize<#delife> for #ident #ty_generics #where_clause { - fn deserialize<__D>(__deserializer: __D) -> #serde::__private::Result<Self, __D::Error> - where - __D: #serde::Deserializer<#delife>, - { - #body - } - - #fn_deserialize_in_place - } - } - }; - - Ok(dummy::wrap_in_const( - cont.attrs.custom_serde_path(), - impl_block, - )) -} - -fn precondition(cx: &Ctxt, cont: &Container) { - precondition_sized(cx, cont); - precondition_no_de_lifetime(cx, cont); -} - -fn precondition_sized(cx: &Ctxt, cont: &Container) { - if let Data::Struct(_, fields) = &cont.data { - if let Some(last) = fields.last() { - if let syn::Type::Slice(_) = ungroup(last.ty) { - cx.error_spanned_by( - cont.original, - "cannot deserialize a dynamically sized struct", - ); - } - } - } -} - -fn precondition_no_de_lifetime(cx: &Ctxt, cont: &Container) { - if let BorrowedLifetimes::Borrowed(_) = borrowed_lifetimes(cont) { - for param in cont.generics.lifetimes() { - if param.lifetime.to_string() == "'de" { - cx.error_spanned_by( - ¶m.lifetime, - "cannot deserialize when there is a lifetime parameter called 'de", - ); - return; - } - } - } -} - -struct Parameters { - /// Name of the type the `derive` is on. - local: syn::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, - - /// Lifetimes borrowed from the deserializer. These will become bounds on - /// the `'de` lifetime of the deserializer. - borrowed: BorrowedLifetimes, - - /// At least one field has a serde(getter) attribute, implying that the - /// remote type has a private field. - has_getter: bool, - - /// Type has a repr(packed) attribute. - is_packed: bool, -} - -impl Parameters { - fn new(cont: &Container) -> Self { - let local = cont.ident.clone(); - let this_type = this::this_type(cont); - let this_value = this::this_value(cont); - let borrowed = borrowed_lifetimes(cont); - let generics = build_generics(cont, &borrowed); - let has_getter = cont.data.has_getter(); - let is_packed = cont.attrs.is_packed(); - - Parameters { - local, - this_type, - this_value, - generics, - borrowed, - has_getter, - is_packed, - } - } - - /// Type name to use in error messages and `&'static str` arguments to - /// various Deserializer 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: Deserialize` for each generic -// field type that will be deserialized by us, plus a bound `T: Default` for -// each generic field type that will be set to a default value. -fn build_generics(cont: &Container, borrowed: &BorrowedLifetimes) -> syn::Generics { - let generics = bound::without_defaults(cont.generics); - - let generics = bound::with_where_predicates_from_fields(cont, &generics, attr::Field::de_bound); - - let generics = - bound::with_where_predicates_from_variants(cont, &generics, attr::Variant::de_bound); - - match cont.attrs.de_bound() { - Some(predicates) => bound::with_where_predicates(&generics, predicates), - None => { - let generics = match *cont.attrs.default() { - attr::Default::Default => bound::with_self_bound( - cont, - &generics, - &parse_quote!(_serde::__private::Default), - ), - attr::Default::None | attr::Default::Path(_) => generics, - }; - - let delife = borrowed.de_lifetime(); - let generics = bound::with_bound( - cont, - &generics, - needs_deserialize_bound, - &parse_quote!(_serde::Deserialize<#delife>), - ); - - bound::with_bound( - cont, - &generics, - requires_default, - &parse_quote!(_serde::__private::Default), - ) - } - } -} - -// Fields with a `skip_deserializing` or `deserialize_with` attribute, or which -// belong to a variant with a `skip_deserializing` or `deserialize_with` -// attribute, are not deserialized 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: Deserialize` bound where T is the type of the -// field. -fn needs_deserialize_bound(field: &attr::Field, variant: Option<&attr::Variant>) -> bool { - !field.skip_deserializing() - && field.deserialize_with().is_none() - && field.de_bound().is_none() - && variant.map_or(true, |variant| { - !variant.skip_deserializing() - && variant.deserialize_with().is_none() - && variant.de_bound().is_none() - }) -} - -// Fields with a `default` attribute (not `default=...`), and fields with a -// `skip_deserializing` attribute that do not also have `default=...`. -fn requires_default(field: &attr::Field, _variant: Option<&attr::Variant>) -> bool { - if let attr::Default::Default = *field.default() { - true - } else { - false - } -} - -enum BorrowedLifetimes { - Borrowed(BTreeSet<syn::Lifetime>), - Static, -} - -impl BorrowedLifetimes { - fn de_lifetime(&self) -> syn::Lifetime { - match *self { - BorrowedLifetimes::Borrowed(_) => syn::Lifetime::new("'de", Span::call_site()), - BorrowedLifetimes::Static => syn::Lifetime::new("'static", Span::call_site()), - } - } - - fn de_lifetime_param(&self) -> Option<syn::LifetimeParam> { - match self { - BorrowedLifetimes::Borrowed(bounds) => Some(syn::LifetimeParam { - attrs: Vec::new(), - lifetime: syn::Lifetime::new("'de", Span::call_site()), - colon_token: None, - bounds: bounds.iter().cloned().collect(), - }), - BorrowedLifetimes::Static => None, - } - } -} - -// The union of lifetimes borrowed by each field of the container. -// -// These turn into bounds on the `'de` lifetime of the Deserialize impl. If -// lifetimes `'a` and `'b` are borrowed but `'c` is not, the impl is: -// -// impl<'de: 'a + 'b, 'a, 'b, 'c> Deserialize<'de> for S<'a, 'b, 'c> -// -// If any borrowed lifetime is `'static`, then `'de: 'static` would be redundant -// and we use plain `'static` instead of `'de`. -fn borrowed_lifetimes(cont: &Container) -> BorrowedLifetimes { - let mut lifetimes = BTreeSet::new(); - for field in cont.data.all_fields() { - if !field.attrs.skip_deserializing() { - lifetimes.extend(field.attrs.borrowed_lifetimes().iter().cloned()); - } - } - if lifetimes.iter().any(|b| b.to_string() == "'static") { - BorrowedLifetimes::Static - } else { - BorrowedLifetimes::Borrowed(lifetimes) - } -} - -fn deserialize_body(cont: &Container, params: &Parameters) -> Fragment { - if cont.attrs.transparent() { - deserialize_transparent(cont, params) - } else if let Some(type_from) = cont.attrs.type_from() { - deserialize_from(type_from) - } else if let Some(type_try_from) = cont.attrs.type_try_from() { - deserialize_try_from(type_try_from) - } else if let attr::Identifier::No = cont.attrs.identifier() { - match &cont.data { - Data::Enum(variants) => deserialize_enum(params, variants, &cont.attrs), - Data::Struct(Style::Struct, fields) => { - deserialize_struct(params, fields, &cont.attrs, StructForm::Struct) - } - Data::Struct(Style::Tuple, fields) | Data::Struct(Style::Newtype, fields) => { - deserialize_tuple(params, fields, &cont.attrs, TupleForm::Tuple) - } - Data::Struct(Style::Unit, _) => deserialize_unit_struct(params, &cont.attrs), - } - } else { - match &cont.data { - Data::Enum(variants) => deserialize_custom_identifier(params, variants, &cont.attrs), - Data::Struct(_, _) => unreachable!("checked in serde_derive_internals"), - } - } -} - -#[cfg(feature = "deserialize_in_place")] -fn deserialize_in_place_body(cont: &Container, params: &Parameters) -> Option<Stmts> { - // Only remote derives have getters, and we do not generate - // deserialize_in_place for remote derives. - assert!(!params.has_getter); - - if cont.attrs.transparent() - || cont.attrs.type_from().is_some() - || cont.attrs.type_try_from().is_some() - || cont.attrs.identifier().is_some() - || cont - .data - .all_fields() - .all(|f| f.attrs.deserialize_with().is_some()) - { - return None; - } - - let code = match &cont.data { - Data::Struct(Style::Struct, fields) => { - deserialize_struct_in_place(params, fields, &cont.attrs)? - } - Data::Struct(Style::Tuple, fields) | Data::Struct(Style::Newtype, fields) => { - deserialize_tuple_in_place(params, fields, &cont.attrs) - } - Data::Enum(_) | Data::Struct(Style::Unit, _) => { - return None; - } - }; - - let delife = params.borrowed.de_lifetime(); - let stmts = Stmts(code); - - let fn_deserialize_in_place = quote_block! { - fn deserialize_in_place<__D>(__deserializer: __D, __place: &mut Self) -> _serde::__private::Result<(), __D::Error> - where - __D: _serde::Deserializer<#delife>, - { - #stmts - } - }; - - Some(Stmts(fn_deserialize_in_place)) -} - -#[cfg(not(feature = "deserialize_in_place"))] -fn deserialize_in_place_body(_cont: &Container, _params: &Parameters) -> Option<Stmts> { - None -} - -fn deserialize_transparent(cont: &Container, params: &Parameters) -> Fragment { - let fields = match &cont.data { - Data::Struct(_, fields) => fields, - Data::Enum(_) => unreachable!(), - }; - - let this_value = ¶ms.this_value; - let transparent_field = fields.iter().find(|f| f.attrs.transparent()).unwrap(); - - let path = match transparent_field.attrs.deserialize_with() { - Some(path) => quote!(#path), - None => { - let span = transparent_field.original.span(); - quote_spanned!(span=> _serde::Deserialize::deserialize) - } - }; - - let assign = fields.iter().map(|field| { - let member = &field.member; - if ptr::eq(field, transparent_field) { - quote!(#member: __transparent) - } else { - let value = match field.attrs.default() { - attr::Default::Default => quote!(_serde::__private::Default::default()), - attr::Default::Path(path) => quote!(#path()), - attr::Default::None => quote!(_serde::__private::PhantomData), - }; - quote!(#member: #value) - } - }); - - quote_block! { - _serde::__private::Result::map( - #path(__deserializer), - |__transparent| #this_value { #(#assign),* }) - } -} - -fn deserialize_from(type_from: &syn::Type) -> Fragment { - quote_block! { - _serde::__private::Result::map( - <#type_from as _serde::Deserialize>::deserialize(__deserializer), - _serde::__private::From::from) - } -} - -fn deserialize_try_from(type_try_from: &syn::Type) -> Fragment { - quote_block! { - _serde::__private::Result::and_then( - <#type_try_from as _serde::Deserialize>::deserialize(__deserializer), - |v| _serde::__private::TryFrom::try_from(v).map_err(_serde::de::Error::custom)) - } -} - -fn deserialize_unit_struct(params: &Parameters, cattrs: &attr::Container) -> Fragment { - let this_type = ¶ms.this_type; - let this_value = ¶ms.this_value; - let type_name = cattrs.name().deserialize_name(); - let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = - split_with_de_lifetime(params); - let delife = params.borrowed.de_lifetime(); - - let expecting = format!("unit struct {}", params.type_name()); - let expecting = cattrs.expecting().unwrap_or(&expecting); - - quote_block! { - #[doc(hidden)] - struct __Visitor #de_impl_generics #where_clause { - marker: _serde::__private::PhantomData<#this_type #ty_generics>, - lifetime: _serde::__private::PhantomData<&#delife ()>, - } - - impl #de_impl_generics _serde::de::Visitor<#delife> for __Visitor #de_ty_generics #where_clause { - type Value = #this_type #ty_generics; - - fn expecting(&self, __formatter: &mut _serde::__private::Formatter) -> _serde::__private::fmt::Result { - _serde::__private::Formatter::write_str(__formatter, #expecting) - } - - #[inline] - fn visit_unit<__E>(self) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - _serde::__private::Ok(#this_value) - } - } - - _serde::Deserializer::deserialize_unit_struct( - __deserializer, - #type_name, - __Visitor { - marker: _serde::__private::PhantomData::<#this_type #ty_generics>, - lifetime: _serde::__private::PhantomData, - }, - ) - } -} - -enum TupleForm<'a> { - Tuple, - /// Contains a variant name - ExternallyTagged(&'a syn::Ident), - /// Contains a variant name and an intermediate deserializer from which actual - /// deserialization will be performed - Untagged(&'a syn::Ident, TokenStream), -} - -fn deserialize_tuple( - params: &Parameters, - fields: &[Field], - cattrs: &attr::Container, - form: TupleForm, -) -> Fragment { - assert!(!cattrs.has_flatten()); - - let field_count = fields - .iter() - .filter(|field| !field.attrs.skip_deserializing()) - .count(); - - let this_type = ¶ms.this_type; - let this_value = ¶ms.this_value; - let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = - split_with_de_lifetime(params); - let delife = params.borrowed.de_lifetime(); - - // If there are getters (implying private fields), construct the local type - // and use an `Into` conversion to get the remote type. If there are no - // getters then construct the target type directly. - let construct = if params.has_getter { - let local = ¶ms.local; - quote!(#local) - } else { - quote!(#this_value) - }; - - let type_path = match form { - TupleForm::Tuple => construct, - TupleForm::ExternallyTagged(variant_ident) | TupleForm::Untagged(variant_ident, _) => { - quote!(#construct::#variant_ident) - } - }; - let expecting = match form { - TupleForm::Tuple => format!("tuple struct {}", params.type_name()), - TupleForm::ExternallyTagged(variant_ident) | TupleForm::Untagged(variant_ident, _) => { - format!("tuple variant {}::{}", params.type_name(), variant_ident) - } - }; - let expecting = cattrs.expecting().unwrap_or(&expecting); - - let nfields = fields.len(); - - let visit_newtype_struct = match form { - TupleForm::Tuple if nfields == 1 => { - Some(deserialize_newtype_struct(&type_path, params, &fields[0])) - } - _ => None, - }; - - let visit_seq = Stmts(deserialize_seq( - &type_path, params, fields, false, cattrs, expecting, - )); - - let visitor_expr = quote! { - __Visitor { - marker: _serde::__private::PhantomData::<#this_type #ty_generics>, - lifetime: _serde::__private::PhantomData, - } - }; - let dispatch = match form { - TupleForm::Tuple if nfields == 1 => { - let type_name = cattrs.name().deserialize_name(); - quote! { - _serde::Deserializer::deserialize_newtype_struct(__deserializer, #type_name, #visitor_expr) - } - } - TupleForm::Tuple => { - let type_name = cattrs.name().deserialize_name(); - quote! { - _serde::Deserializer::deserialize_tuple_struct(__deserializer, #type_name, #field_count, #visitor_expr) - } - } - TupleForm::ExternallyTagged(_) => quote! { - _serde::de::VariantAccess::tuple_variant(__variant, #field_count, #visitor_expr) - }, - TupleForm::Untagged(_, deserializer) => quote! { - _serde::Deserializer::deserialize_tuple(#deserializer, #field_count, #visitor_expr) - }, - }; - - let visitor_var = if field_count == 0 { - quote!(_) - } else { - quote!(mut __seq) - }; - - quote_block! { - #[doc(hidden)] - struct __Visitor #de_impl_generics #where_clause { - marker: _serde::__private::PhantomData<#this_type #ty_generics>, - lifetime: _serde::__private::PhantomData<&#delife ()>, - } - - impl #de_impl_generics _serde::de::Visitor<#delife> for __Visitor #de_ty_generics #where_clause { - type Value = #this_type #ty_generics; - - fn expecting(&self, __formatter: &mut _serde::__private::Formatter) -> _serde::__private::fmt::Result { - _serde::__private::Formatter::write_str(__formatter, #expecting) - } - - #visit_newtype_struct - - #[inline] - fn visit_seq<__A>(self, #visitor_var: __A) -> _serde::__private::Result<Self::Value, __A::Error> - where - __A: _serde::de::SeqAccess<#delife>, - { - #visit_seq - } - } - - #dispatch - } -} - -#[cfg(feature = "deserialize_in_place")] -fn deserialize_tuple_in_place( - params: &Parameters, - fields: &[Field], - cattrs: &attr::Container, -) -> Fragment { - assert!(!cattrs.has_flatten()); - - let field_count = fields - .iter() - .filter(|field| !field.attrs.skip_deserializing()) - .count(); - - let this_type = ¶ms.this_type; - let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = - split_with_de_lifetime(params); - let delife = params.borrowed.de_lifetime(); - - let expecting = format!("tuple struct {}", params.type_name()); - let expecting = cattrs.expecting().unwrap_or(&expecting); - - let nfields = fields.len(); - - let visit_newtype_struct = if nfields == 1 { - // We do not generate deserialize_in_place if every field has a - // deserialize_with. - assert!(fields[0].attrs.deserialize_with().is_none()); - - Some(quote! { - #[inline] - fn visit_newtype_struct<__E>(self, __e: __E) -> _serde::__private::Result<Self::Value, __E::Error> - where - __E: _serde::Deserializer<#delife>, - { - _serde::Deserialize::deserialize_in_place(__e, &mut self.place.0) - } - }) - } else { - None - }; - - let visit_seq = Stmts(deserialize_seq_in_place(params, fields, cattrs, expecting)); - - let visitor_expr = quote! { - __Visitor { - place: __place, - lifetime: _serde::__private::PhantomData, - } - }; - - let type_name = cattrs.name().deserialize_name(); - let dispatch = if nfields == 1 { - quote!(_serde::Deserializer::deserialize_newtype_struct(__deserializer, #type_name, #visitor_expr)) - } else { - quote!(_serde::Deserializer::deserialize_tuple_struct(__deserializer, #type_name, #field_count, #visitor_expr)) - }; - - let visitor_var = if field_count == 0 { - quote!(_) - } else { - quote!(mut __seq) - }; - - let in_place_impl_generics = de_impl_generics.in_place(); - let in_place_ty_generics = de_ty_generics.in_place(); - let place_life = place_lifetime(); - - quote_block! { - #[doc(hidden)] - struct __Visitor #in_place_impl_generics #where_clause { - place: &#place_life mut #this_type #ty_generics, - lifetime: _serde::__private::PhantomData<&#delife ()>, - } - - impl #in_place_impl_generics _serde::de::Visitor<#delife> for __Visitor #in_place_ty_generics #where_clause { - type Value = (); - - fn expecting(&self, __formatter: &mut _serde::__private::Formatter) -> _serde::__private::fmt::Result { - _serde::__private::Formatter::write_str(__formatter, #expecting) - } - - #visit_newtype_struct - - #[inline] - fn visit_seq<__A>(self, #visitor_var: __A) -> _serde::__private::Result<Self::Value, __A::Error> - where - __A: _serde::de::SeqAccess<#delife>, - { - #visit_seq - } - } - - #dispatch - } -} - -fn deserialize_seq( - type_path: &TokenStream, - params: &Parameters, - fields: &[Field], - is_struct: bool, - cattrs: &attr::Container, - expecting: &str, -) -> Fragment { - let vars = (0..fields.len()).map(field_i as fn(_) -> _); - - let deserialized_count = fields - .iter() - .filter(|field| !field.attrs.skip_deserializing()) - .count(); - let expecting = if deserialized_count == 1 { - format!("{} with 1 element", expecting) - } else { - format!("{} with {} elements", expecting, deserialized_count) - }; - let expecting = cattrs.expecting().unwrap_or(&expecting); - - let mut index_in_seq = 0_usize; - let let_values = vars.clone().zip(fields).map(|(var, field)| { - if field.attrs.skip_deserializing() { - let default = Expr(expr_is_missing(field, cattrs)); - quote! { - let #var = #default; - } - } else { - let visit = match field.attrs.deserialize_with() { - None => { - let field_ty = field.ty; - let span = field.original.span(); - let func = - quote_spanned!(span=> _serde::de::SeqAccess::next_element::<#field_ty>); - quote!(#func(&mut __seq)?) - } - Some(path) => { - let (wrapper, wrapper_ty) = wrap_deserialize_field_with(params, field.ty, path); - quote!({ - #wrapper - _serde::__private::Option::map( - _serde::de::SeqAccess::next_element::<#wrapper_ty>(&mut __seq)?, - |__wrap| __wrap.value) - }) - } - }; - let value_if_none = expr_is_missing_seq(None, index_in_seq, field, cattrs, expecting); - let assign = quote! { - let #var = match #visit { - _serde::__private::Some(__value) => __value, - _serde::__private::None => #value_if_none, - }; - }; - index_in_seq += 1; - assign - } - }); - - let mut result = if is_struct { - let names = fields.iter().map(|f| &f.member); - quote! { - #type_path { #( #names: #vars ),* } - } - } else { - quote! { - #type_path ( #(#vars),* ) - } - }; - - if params.has_getter { - let this_type = ¶ms.this_type; - let (_, ty_generics, _) = params.generics.split_for_impl(); - result = quote! { - _serde::__private::Into::<#this_type #ty_generics>::into(#result) - }; - } - - let let_default = match cattrs.default() { - attr::Default::Default => Some(quote!( - let __default: Self::Value = _serde::__private::Default::default(); - )), - attr::Default::Path(path) => Some(quote!( - let __default: Self::Value = #path(); - )), - attr::Default::None => { - // We don't need the default value, to prevent an unused variable warning - // we'll leave the line empty. - None - } - }; - - quote_block! { - #let_default - #(#let_values)* - _serde::__private::Ok(#result) - } -} - -#[cfg(feature = "deserialize_in_place")] -fn deserialize_seq_in_place( - params: &Parameters, - fields: &[Field], - cattrs: &attr::Container, - expecting: &str, -) -> Fragment { - let deserialized_count = fields - .iter() - .filter(|field| !field.attrs.skip_deserializing()) - .count(); - let expecting = if deserialized_count == 1 { - format!("{} with 1 element", expecting) - } else { - format!("{} with {} elements", expecting, deserialized_count) - }; - let expecting = cattrs.expecting().unwrap_or(&expecting); - - let mut index_in_seq = 0usize; - let write_values = fields.iter().map(|field| { - let member = &field.member; - - if field.attrs.skip_deserializing() { - let default = Expr(expr_is_missing(field, cattrs)); - quote! { - self.place.#member = #default; - } - } else { - let value_if_none = expr_is_missing_seq(Some(quote!(self.place.#member = )), index_in_seq, field, cattrs, expecting); - let write = match field.attrs.deserialize_with() { - None => { - quote! { - if let _serde::__private::None = _serde::de::SeqAccess::next_element_seed(&mut __seq, - _serde::__private::de::InPlaceSeed(&mut self.place.#member))? - { - #value_if_none; - } - } - } - Some(path) => { - let (wrapper, wrapper_ty) = wrap_deserialize_field_with(params, field.ty, path); - quote!({ - #wrapper - match _serde::de::SeqAccess::next_element::<#wrapper_ty>(&mut __seq)? { - _serde::__private::Some(__wrap) => { - self.place.#member = __wrap.value; - } - _serde::__private::None => { - #value_if_none; - } - } - }) - } - }; - index_in_seq += 1; - write - } - }); - - let this_type = ¶ms.this_type; - let (_, ty_generics, _) = params.generics.split_for_impl(); - let let_default = match cattrs.default() { - attr::Default::Default => Some(quote!( - let __default: #this_type #ty_generics = _serde::__private::Default::default(); - )), - attr::Default::Path(path) => Some(quote!( - let __default: #this_type #ty_generics = #path(); - )), - attr::Default::None => { - // We don't need the default value, to prevent an unused variable warning - // we'll leave the line empty. - None - } - }; - - quote_block! { - #let_default - #(#write_values)* - _serde::__private::Ok(()) - } -} - -fn deserialize_newtype_struct( - type_path: &TokenStream, - params: &Parameters, - field: &Field, -) -> TokenStream { - let delife = params.borrowed.de_lifetime(); - let field_ty = field.ty; - - let value = match field.attrs.deserialize_with() { - None => { - let span = field.original.span(); - let func = quote_spanned!(span=> <#field_ty as _serde::Deserialize>::deserialize); - quote! { - #func(__e)? - } - } - Some(path) => { - quote! { - #path(__e)? - } - } - }; - - let mut result = quote!(#type_path(__field0)); - if params.has_getter { - let this_type = ¶ms.this_type; - let (_, ty_generics, _) = params.generics.split_for_impl(); - result = quote! { - _serde::__private::Into::<#this_type #ty_generics>::into(#result) - }; - } - - quote! { - #[inline] - fn visit_newtype_struct<__E>(self, __e: __E) -> _serde::__private::Result<Self::Value, __E::Error> - where - __E: _serde::Deserializer<#delife>, - { - let __field0: #field_ty = #value; - _serde::__private::Ok(#result) - } - } -} - -enum StructForm<'a> { - Struct, - /// Contains a variant name - ExternallyTagged(&'a syn::Ident), - /// Contains a variant name and an intermediate deserializer from which actual - /// deserialization will be performed - InternallyTagged(&'a syn::Ident, TokenStream), - /// Contains a variant name and an intermediate deserializer from which actual - /// deserialization will be performed - Untagged(&'a syn::Ident, TokenStream), -} - -fn deserialize_struct( - params: &Parameters, - fields: &[Field], - cattrs: &attr::Container, - form: StructForm, -) -> Fragment { - let this_type = ¶ms.this_type; - let this_value = ¶ms.this_value; - let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = - split_with_de_lifetime(params); - let delife = params.borrowed.de_lifetime(); - - // If there are getters (implying private fields), construct the local type - // and use an `Into` conversion to get the remote type. If there are no - // getters then construct the target type directly. - let construct = if params.has_getter { - let local = ¶ms.local; - quote!(#local) - } else { - quote!(#this_value) - }; - - let type_path = match form { - StructForm::Struct => construct, - StructForm::ExternallyTagged(variant_ident) - | StructForm::InternallyTagged(variant_ident, _) - | StructForm::Untagged(variant_ident, _) => quote!(#construct::#variant_ident), - }; - let expecting = match form { - StructForm::Struct => format!("struct {}", params.type_name()), - StructForm::ExternallyTagged(variant_ident) - | StructForm::InternallyTagged(variant_ident, _) - | StructForm::Untagged(variant_ident, _) => { - format!("struct variant {}::{}", params.type_name(), variant_ident) - } - }; - let expecting = cattrs.expecting().unwrap_or(&expecting); - - let field_names_idents: Vec<_> = fields - .iter() - .enumerate() - // Skip fields that shouldn't be deserialized or that were flattened, - // so they don't appear in the storage in their literal form - .filter(|&(_, field)| !field.attrs.skip_deserializing() && !field.attrs.flatten()) - .map(|(i, field)| { - ( - field.attrs.name().deserialize_name(), - field_i(i), - field.attrs.aliases(), - ) - }) - .collect(); - let field_visitor = deserialize_field_identifier(&field_names_idents, cattrs); - - // untagged struct variants do not get a visit_seq method. The same applies to - // structs that only have a map representation. - let visit_seq = match form { - StructForm::Untagged(..) => None, - _ if cattrs.has_flatten() => None, - _ => { - let mut_seq = if field_names_idents.is_empty() { - quote!(_) - } else { - quote!(mut __seq) - }; - - let visit_seq = Stmts(deserialize_seq( - &type_path, params, fields, true, cattrs, expecting, - )); - - Some(quote! { - #[inline] - fn visit_seq<__A>(self, #mut_seq: __A) -> _serde::__private::Result<Self::Value, __A::Error> - where - __A: _serde::de::SeqAccess<#delife>, - { - #visit_seq - } - }) - } - }; - let visit_map = Stmts(deserialize_map(&type_path, params, fields, cattrs)); - - let visitor_seed = match form { - StructForm::ExternallyTagged(..) if cattrs.has_flatten() => Some(quote! { - impl #de_impl_generics _serde::de::DeserializeSeed<#delife> for __Visitor #de_ty_generics #where_clause { - type Value = #this_type #ty_generics; - - fn deserialize<__D>(self, __deserializer: __D) -> _serde::__private::Result<Self::Value, __D::Error> - where - __D: _serde::Deserializer<#delife>, - { - _serde::Deserializer::deserialize_map(__deserializer, self) - } - } - }), - _ => None, - }; - - let fields_stmt = if cattrs.has_flatten() { - None - } else { - let field_names = field_names_idents - .iter() - .flat_map(|&(_, _, aliases)| aliases); - - Some(quote! { - #[doc(hidden)] - const FIELDS: &'static [&'static str] = &[ #(#field_names),* ]; - }) - }; - - let visitor_expr = quote! { - __Visitor { - marker: _serde::__private::PhantomData::<#this_type #ty_generics>, - lifetime: _serde::__private::PhantomData, - } - }; - let dispatch = match form { - StructForm::Struct if cattrs.has_flatten() => quote! { - _serde::Deserializer::deserialize_map(__deserializer, #visitor_expr) - }, - StructForm::Struct => { - let type_name = cattrs.name().deserialize_name(); - quote! { - _serde::Deserializer::deserialize_struct(__deserializer, #type_name, FIELDS, #visitor_expr) - } - } - StructForm::ExternallyTagged(_) if cattrs.has_flatten() => quote! { - _serde::de::VariantAccess::newtype_variant_seed(__variant, #visitor_expr) - }, - StructForm::ExternallyTagged(_) => quote! { - _serde::de::VariantAccess::struct_variant(__variant, FIELDS, #visitor_expr) - }, - StructForm::InternallyTagged(_, deserializer) => quote! { - _serde::Deserializer::deserialize_any(#deserializer, #visitor_expr) - }, - StructForm::Untagged(_, deserializer) => quote! { - _serde::Deserializer::deserialize_any(#deserializer, #visitor_expr) - }, - }; - - quote_block! { - #field_visitor - - #[doc(hidden)] - struct __Visitor #de_impl_generics #where_clause { - marker: _serde::__private::PhantomData<#this_type #ty_generics>, - lifetime: _serde::__private::PhantomData<&#delife ()>, - } - - impl #de_impl_generics _serde::de::Visitor<#delife> for __Visitor #de_ty_generics #where_clause { - type Value = #this_type #ty_generics; - - fn expecting(&self, __formatter: &mut _serde::__private::Formatter) -> _serde::__private::fmt::Result { - _serde::__private::Formatter::write_str(__formatter, #expecting) - } - - #visit_seq - - #[inline] - fn visit_map<__A>(self, mut __map: __A) -> _serde::__private::Result<Self::Value, __A::Error> - where - __A: _serde::de::MapAccess<#delife>, - { - #visit_map - } - } - - #visitor_seed - - #fields_stmt - - #dispatch - } -} - -#[cfg(feature = "deserialize_in_place")] -fn deserialize_struct_in_place( - params: &Parameters, - fields: &[Field], - cattrs: &attr::Container, -) -> Option<Fragment> { - // for now we do not support in_place deserialization for structs that - // are represented as map. - if cattrs.has_flatten() { - return None; - } - - let this_type = ¶ms.this_type; - let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = - split_with_de_lifetime(params); - let delife = params.borrowed.de_lifetime(); - - let expecting = format!("struct {}", params.type_name()); - let expecting = cattrs.expecting().unwrap_or(&expecting); - - let field_names_idents: Vec<_> = fields - .iter() - .enumerate() - .filter(|&(_, field)| !field.attrs.skip_deserializing()) - .map(|(i, field)| { - ( - field.attrs.name().deserialize_name(), - field_i(i), - field.attrs.aliases(), - ) - }) - .collect(); - - let field_visitor = deserialize_field_identifier(&field_names_idents, cattrs); - - let mut_seq = if field_names_idents.is_empty() { - quote!(_) - } else { - quote!(mut __seq) - }; - let visit_seq = Stmts(deserialize_seq_in_place(params, fields, cattrs, expecting)); - let visit_map = Stmts(deserialize_map_in_place(params, fields, cattrs)); - let field_names = field_names_idents - .iter() - .flat_map(|&(_, _, aliases)| aliases); - let type_name = cattrs.name().deserialize_name(); - - let in_place_impl_generics = de_impl_generics.in_place(); - let in_place_ty_generics = de_ty_generics.in_place(); - let place_life = place_lifetime(); - - Some(quote_block! { - #field_visitor - - #[doc(hidden)] - struct __Visitor #in_place_impl_generics #where_clause { - place: &#place_life mut #this_type #ty_generics, - lifetime: _serde::__private::PhantomData<&#delife ()>, - } - - impl #in_place_impl_generics _serde::de::Visitor<#delife> for __Visitor #in_place_ty_generics #where_clause { - type Value = (); - - fn expecting(&self, __formatter: &mut _serde::__private::Formatter) -> _serde::__private::fmt::Result { - _serde::__private::Formatter::write_str(__formatter, #expecting) - } - - #[inline] - fn visit_seq<__A>(self, #mut_seq: __A) -> _serde::__private::Result<Self::Value, __A::Error> - where - __A: _serde::de::SeqAccess<#delife>, - { - #visit_seq - } - - #[inline] - fn visit_map<__A>(self, mut __map: __A) -> _serde::__private::Result<Self::Value, __A::Error> - where - __A: _serde::de::MapAccess<#delife>, - { - #visit_map - } - } - - #[doc(hidden)] - const FIELDS: &'static [&'static str] = &[ #(#field_names),* ]; - - _serde::Deserializer::deserialize_struct(__deserializer, #type_name, FIELDS, __Visitor { - place: __place, - lifetime: _serde::__private::PhantomData, - }) - }) -} - -fn deserialize_enum( - params: &Parameters, - variants: &[Variant], - cattrs: &attr::Container, -) -> Fragment { - // The variants have already been checked (in ast.rs) that all untagged variants appear at the end - match variants.iter().position(|var| var.attrs.untagged()) { - Some(variant_idx) => { - let (tagged, untagged) = variants.split_at(variant_idx); - let tagged_frag = Expr(deserialize_homogeneous_enum(params, tagged, cattrs)); - deserialize_untagged_enum_after(params, untagged, cattrs, Some(tagged_frag)) - } - None => deserialize_homogeneous_enum(params, variants, cattrs), - } -} - -fn deserialize_homogeneous_enum( - params: &Parameters, - variants: &[Variant], - cattrs: &attr::Container, -) -> Fragment { - match cattrs.tag() { - attr::TagType::External => deserialize_externally_tagged_enum(params, variants, cattrs), - attr::TagType::Internal { tag } => { - deserialize_internally_tagged_enum(params, variants, cattrs, tag) - } - attr::TagType::Adjacent { tag, content } => { - deserialize_adjacently_tagged_enum(params, variants, cattrs, tag, content) - } - attr::TagType::None => deserialize_untagged_enum(params, variants, cattrs), - } -} - -fn prepare_enum_variant_enum( - variants: &[Variant], - cattrs: &attr::Container, -) -> (TokenStream, Stmts) { - let mut deserialized_variants = variants - .iter() - .enumerate() - .filter(|&(_, variant)| !variant.attrs.skip_deserializing()); - - let variant_names_idents: Vec<_> = deserialized_variants - .clone() - .map(|(i, variant)| { - ( - variant.attrs.name().deserialize_name(), - field_i(i), - variant.attrs.aliases(), - ) - }) - .collect(); - - let fallthrough = deserialized_variants - .position(|(_, variant)| variant.attrs.other()) - .map(|other_idx| { - let ignore_variant = variant_names_idents[other_idx].1.clone(); - quote!(_serde::__private::Ok(__Field::#ignore_variant)) - }); - - let variants_stmt = { - let variant_names = variant_names_idents.iter().map(|(name, _, _)| name); - quote! { - #[doc(hidden)] - const VARIANTS: &'static [&'static str] = &[ #(#variant_names),* ]; - } - }; - - let variant_visitor = Stmts(deserialize_generated_identifier( - &variant_names_idents, - cattrs, - true, - None, - fallthrough, - )); - - (variants_stmt, variant_visitor) -} - -fn deserialize_externally_tagged_enum( - params: &Parameters, - variants: &[Variant], - cattrs: &attr::Container, -) -> Fragment { - let this_type = ¶ms.this_type; - let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = - split_with_de_lifetime(params); - let delife = params.borrowed.de_lifetime(); - - let type_name = cattrs.name().deserialize_name(); - let expecting = format!("enum {}", params.type_name()); - let expecting = cattrs.expecting().unwrap_or(&expecting); - - let (variants_stmt, variant_visitor) = prepare_enum_variant_enum(variants, cattrs); - - // Match arms to extract a variant from a string - let variant_arms = variants - .iter() - .enumerate() - .filter(|&(_, variant)| !variant.attrs.skip_deserializing()) - .map(|(i, variant)| { - let variant_name = field_i(i); - - let block = Match(deserialize_externally_tagged_variant( - params, variant, cattrs, - )); - - quote! { - (__Field::#variant_name, __variant) => #block - } - }); - - let all_skipped = variants - .iter() - .all(|variant| variant.attrs.skip_deserializing()); - let match_variant = if all_skipped { - // This is an empty enum like `enum Impossible {}` or an enum in which - // all variants have `#[serde(skip_deserializing)]`. - quote! { - // FIXME: Once feature(exhaustive_patterns) is stable: - // let _serde::__private::Err(__err) = _serde::de::EnumAccess::variant::<__Field>(__data); - // _serde::__private::Err(__err) - _serde::__private::Result::map( - _serde::de::EnumAccess::variant::<__Field>(__data), - |(__impossible, _)| match __impossible {}) - } - } else { - quote! { - match _serde::de::EnumAccess::variant(__data)? { - #(#variant_arms)* - } - } - }; - - quote_block! { - #variant_visitor - - #[doc(hidden)] - struct __Visitor #de_impl_generics #where_clause { - marker: _serde::__private::PhantomData<#this_type #ty_generics>, - lifetime: _serde::__private::PhantomData<&#delife ()>, - } - - impl #de_impl_generics _serde::de::Visitor<#delife> for __Visitor #de_ty_generics #where_clause { - type Value = #this_type #ty_generics; - - fn expecting(&self, __formatter: &mut _serde::__private::Formatter) -> _serde::__private::fmt::Result { - _serde::__private::Formatter::write_str(__formatter, #expecting) - } - - fn visit_enum<__A>(self, __data: __A) -> _serde::__private::Result<Self::Value, __A::Error> - where - __A: _serde::de::EnumAccess<#delife>, - { - #match_variant - } - } - - #variants_stmt - - _serde::Deserializer::deserialize_enum( - __deserializer, - #type_name, - VARIANTS, - __Visitor { - marker: _serde::__private::PhantomData::<#this_type #ty_generics>, - lifetime: _serde::__private::PhantomData, - }, - ) - } -} - -fn deserialize_internally_tagged_enum( - params: &Parameters, - variants: &[Variant], - cattrs: &attr::Container, - tag: &str, -) -> Fragment { - let (variants_stmt, variant_visitor) = prepare_enum_variant_enum(variants, cattrs); - - // Match arms to extract a variant from a string - let variant_arms = variants - .iter() - .enumerate() - .filter(|&(_, variant)| !variant.attrs.skip_deserializing()) - .map(|(i, variant)| { - let variant_name = field_i(i); - - let block = Match(deserialize_internally_tagged_variant( - params, - variant, - cattrs, - quote!(__deserializer), - )); - - quote! { - __Field::#variant_name => #block - } - }); - - let expecting = format!("internally tagged enum {}", params.type_name()); - let expecting = cattrs.expecting().unwrap_or(&expecting); - - quote_block! { - #variant_visitor - - #variants_stmt - - let (__tag, __content) = _serde::Deserializer::deserialize_any( - __deserializer, - _serde::__private::de::TaggedContentVisitor::<__Field>::new(#tag, #expecting))?; - let __deserializer = _serde::__private::de::ContentDeserializer::<__D::Error>::new(__content); - - match __tag { - #(#variant_arms)* - } - } -} - -fn deserialize_adjacently_tagged_enum( - params: &Parameters, - variants: &[Variant], - cattrs: &attr::Container, - tag: &str, - content: &str, -) -> Fragment { - let this_type = ¶ms.this_type; - let this_value = ¶ms.this_value; - let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = - split_with_de_lifetime(params); - let delife = params.borrowed.de_lifetime(); - - let (variants_stmt, variant_visitor) = prepare_enum_variant_enum(variants, cattrs); - - let variant_arms: &Vec<_> = &variants - .iter() - .enumerate() - .filter(|&(_, variant)| !variant.attrs.skip_deserializing()) - .map(|(i, variant)| { - let variant_index = field_i(i); - - let block = Match(deserialize_untagged_variant( - params, - variant, - cattrs, - quote!(__deserializer), - )); - - quote! { - __Field::#variant_index => #block - } - }) - .collect(); - - let rust_name = params.type_name(); - let expecting = format!("adjacently tagged enum {}", rust_name); - let expecting = cattrs.expecting().unwrap_or(&expecting); - let type_name = cattrs.name().deserialize_name(); - let deny_unknown_fields = cattrs.deny_unknown_fields(); - - // If unknown fields are allowed, we pick the visitor that can step over - // those. Otherwise we pick the visitor that fails on unknown keys. - let field_visitor_ty = if deny_unknown_fields { - quote! { _serde::__private::de::TagOrContentFieldVisitor } - } else { - quote! { _serde::__private::de::TagContentOtherFieldVisitor } - }; - - let tag_or_content = quote! { - #field_visitor_ty { - tag: #tag, - content: #content, - } - }; - - let variant_seed = quote! { - _serde::__private::de::AdjacentlyTaggedEnumVariantSeed::<__Field> { - enum_name: #rust_name, - variants: VARIANTS, - fields_enum: _serde::__private::PhantomData - } - }; - - let mut missing_content = quote! { - _serde::__private::Err(<__A::Error as _serde::de::Error>::missing_field(#content)) - }; - let mut missing_content_fallthrough = quote!(); - let missing_content_arms = variants - .iter() - .enumerate() - .filter(|&(_, variant)| !variant.attrs.skip_deserializing()) - .filter_map(|(i, variant)| { - let variant_index = field_i(i); - let variant_ident = &variant.ident; - - let arm = match variant.style { - Style::Unit => quote! { - _serde::__private::Ok(#this_value::#variant_ident) - }, - Style::Newtype if variant.attrs.deserialize_with().is_none() => { - let span = variant.original.span(); - let func = quote_spanned!(span=> _serde::__private::de::missing_field); - quote! { - #func(#content).map(#this_value::#variant_ident) - } - } - _ => { - missing_content_fallthrough = quote!(_ => #missing_content); - return None; - } - }; - Some(quote! { - __Field::#variant_index => #arm, - }) - }) - .collect::<Vec<_>>(); - if !missing_content_arms.is_empty() { - missing_content = quote! { - match __field { - #(#missing_content_arms)* - #missing_content_fallthrough - } - }; - } - - // Advance the map by one key, returning early in case of error. - let next_key = quote! { - _serde::de::MapAccess::next_key_seed(&mut __map, #tag_or_content)? - }; - - let variant_from_map = quote! { - _serde::de::MapAccess::next_value_seed(&mut __map, #variant_seed)? - }; - - // When allowing unknown fields, we want to transparently step through keys - // we don't care about until we find `tag`, `content`, or run out of keys. - let next_relevant_key = if deny_unknown_fields { - next_key - } else { - quote!({ - let mut __rk : _serde::__private::Option<_serde::__private::de::TagOrContentField> = _serde::__private::None; - while let _serde::__private::Some(__k) = #next_key { - match __k { - _serde::__private::de::TagContentOtherField::Other => { - let _ = _serde::de::MapAccess::next_value::<_serde::de::IgnoredAny>(&mut __map)?; - continue; - }, - _serde::__private::de::TagContentOtherField::Tag => { - __rk = _serde::__private::Some(_serde::__private::de::TagOrContentField::Tag); - break; - } - _serde::__private::de::TagContentOtherField::Content => { - __rk = _serde::__private::Some(_serde::__private::de::TagOrContentField::Content); - break; - } - } - } - - __rk - }) - }; - - // Step through remaining keys, looking for duplicates of previously-seen - // keys. When unknown fields are denied, any key that isn't a duplicate will - // at this point immediately produce an error. - let visit_remaining_keys = quote! { - match #next_relevant_key { - _serde::__private::Some(_serde::__private::de::TagOrContentField::Tag) => { - _serde::__private::Err(<__A::Error as _serde::de::Error>::duplicate_field(#tag)) - } - _serde::__private::Some(_serde::__private::de::TagOrContentField::Content) => { - _serde::__private::Err(<__A::Error as _serde::de::Error>::duplicate_field(#content)) - } - _serde::__private::None => _serde::__private::Ok(__ret), - } - }; - - let finish_content_then_tag = if variant_arms.is_empty() { - quote! { - match #variant_from_map {} - } - } else { - quote! { - let __ret = match #variant_from_map { - // Deserialize the buffered content now that we know the variant. - #(#variant_arms)* - }?; - // Visit remaining keys, looking for duplicates. - #visit_remaining_keys - } - }; - - quote_block! { - #variant_visitor - - #variants_stmt - - #[doc(hidden)] - struct __Seed #de_impl_generics #where_clause { - field: __Field, - marker: _serde::__private::PhantomData<#this_type #ty_generics>, - lifetime: _serde::__private::PhantomData<&#delife ()>, - } - - impl #de_impl_generics _serde::de::DeserializeSeed<#delife> for __Seed #de_ty_generics #where_clause { - type Value = #this_type #ty_generics; - - fn deserialize<__D>(self, __deserializer: __D) -> _serde::__private::Result<Self::Value, __D::Error> - where - __D: _serde::Deserializer<#delife>, - { - match self.field { - #(#variant_arms)* - } - } - } - - #[doc(hidden)] - struct __Visitor #de_impl_generics #where_clause { - marker: _serde::__private::PhantomData<#this_type #ty_generics>, - lifetime: _serde::__private::PhantomData<&#delife ()>, - } - - impl #de_impl_generics _serde::de::Visitor<#delife> for __Visitor #de_ty_generics #where_clause { - type Value = #this_type #ty_generics; - - fn expecting(&self, __formatter: &mut _serde::__private::Formatter) -> _serde::__private::fmt::Result { - _serde::__private::Formatter::write_str(__formatter, #expecting) - } - - fn visit_map<__A>(self, mut __map: __A) -> _serde::__private::Result<Self::Value, __A::Error> - where - __A: _serde::de::MapAccess<#delife>, - { - // Visit the first relevant key. - match #next_relevant_key { - // First key is the tag. - _serde::__private::Some(_serde::__private::de::TagOrContentField::Tag) => { - // Parse the tag. - let __field = #variant_from_map; - // Visit the second key. - match #next_relevant_key { - // Second key is a duplicate of the tag. - _serde::__private::Some(_serde::__private::de::TagOrContentField::Tag) => { - _serde::__private::Err(<__A::Error as _serde::de::Error>::duplicate_field(#tag)) - } - // Second key is the content. - _serde::__private::Some(_serde::__private::de::TagOrContentField::Content) => { - let __ret = _serde::de::MapAccess::next_value_seed(&mut __map, - __Seed { - field: __field, - marker: _serde::__private::PhantomData, - lifetime: _serde::__private::PhantomData, - })?; - // Visit remaining keys, looking for duplicates. - #visit_remaining_keys - } - // There is no second key; might be okay if the we have a unit variant. - _serde::__private::None => #missing_content - } - } - // First key is the content. - _serde::__private::Some(_serde::__private::de::TagOrContentField::Content) => { - // Buffer up the content. - let __content = _serde::de::MapAccess::next_value::<_serde::__private::de::Content>(&mut __map)?; - // Visit the second key. - match #next_relevant_key { - // Second key is the tag. - _serde::__private::Some(_serde::__private::de::TagOrContentField::Tag) => { - let __deserializer = _serde::__private::de::ContentDeserializer::<__A::Error>::new(__content); - #finish_content_then_tag - } - // Second key is a duplicate of the content. - _serde::__private::Some(_serde::__private::de::TagOrContentField::Content) => { - _serde::__private::Err(<__A::Error as _serde::de::Error>::duplicate_field(#content)) - } - // There is no second key. - _serde::__private::None => { - _serde::__private::Err(<__A::Error as _serde::de::Error>::missing_field(#tag)) - } - } - } - // There is no first key. - _serde::__private::None => { - _serde::__private::Err(<__A::Error as _serde::de::Error>::missing_field(#tag)) - } - } - } - - fn visit_seq<__A>(self, mut __seq: __A) -> _serde::__private::Result<Self::Value, __A::Error> - where - __A: _serde::de::SeqAccess<#delife>, - { - // Visit the first element - the tag. - match _serde::de::SeqAccess::next_element(&mut __seq)? { - _serde::__private::Some(__field) => { - // Visit the second element - the content. - match _serde::de::SeqAccess::next_element_seed( - &mut __seq, - __Seed { - field: __field, - marker: _serde::__private::PhantomData, - lifetime: _serde::__private::PhantomData, - }, - )? { - _serde::__private::Some(__ret) => _serde::__private::Ok(__ret), - // There is no second element. - _serde::__private::None => { - _serde::__private::Err(_serde::de::Error::invalid_length(1, &self)) - } - } - } - // There is no first element. - _serde::__private::None => { - _serde::__private::Err(_serde::de::Error::invalid_length(0, &self)) - } - } - } - } - - #[doc(hidden)] - const FIELDS: &'static [&'static str] = &[#tag, #content]; - _serde::Deserializer::deserialize_struct( - __deserializer, - #type_name, - FIELDS, - __Visitor { - marker: _serde::__private::PhantomData::<#this_type #ty_generics>, - lifetime: _serde::__private::PhantomData, - }, - ) - } -} - -fn deserialize_untagged_enum( - params: &Parameters, - variants: &[Variant], - cattrs: &attr::Container, -) -> Fragment { - let first_attempt = None; - deserialize_untagged_enum_after(params, variants, cattrs, first_attempt) -} - -fn deserialize_untagged_enum_after( - params: &Parameters, - variants: &[Variant], - cattrs: &attr::Container, - first_attempt: Option<Expr>, -) -> Fragment { - let attempts = variants - .iter() - .filter(|variant| !variant.attrs.skip_deserializing()) - .map(|variant| { - Expr(deserialize_untagged_variant( - params, - variant, - cattrs, - quote!(__deserializer), - )) - }); - // 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 - // largest number of fields. I'm not sure I like that. Maybe it would be - // better to save all the errors and combine them into one message that - // explains why none of the variants matched. - let fallthrough_msg = format!( - "data did not match any variant of untagged enum {}", - params.type_name() - ); - let fallthrough_msg = cattrs.expecting().unwrap_or(&fallthrough_msg); - - // 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 first_attempt = first_attempt.map(|expr| { - quote! { - if let _serde::__private::Result::<_, __D::Error>::Ok(__ok) = (|| #expr)() { - return _serde::__private::Ok(__ok); - } - } - }); - - quote_block! { - let __content = <_serde::__private::de::Content as _serde::Deserialize>::deserialize(__deserializer)?; - let __deserializer = _serde::__private::de::ContentRefDeserializer::<__D::Error>::new(&__content); - - #first_attempt - - #( - if let _serde::__private::Ok(__ok) = #attempts { - return _serde::__private::Ok(__ok); - } - )* - - _serde::__private::Err(_serde::de::Error::custom(#fallthrough_msg)) - } -} - -fn deserialize_externally_tagged_variant( - params: &Parameters, - variant: &Variant, - cattrs: &attr::Container, -) -> Fragment { - if let Some(path) = variant.attrs.deserialize_with() { - let (wrapper, wrapper_ty, unwrap_fn) = wrap_deserialize_variant_with(params, variant, path); - return quote_block! { - #wrapper - _serde::__private::Result::map( - _serde::de::VariantAccess::newtype_variant::<#wrapper_ty>(__variant), #unwrap_fn) - }; - } - - let variant_ident = &variant.ident; - - match variant.style { - Style::Unit => { - let this_value = ¶ms.this_value; - quote_block! { - _serde::de::VariantAccess::unit_variant(__variant)?; - _serde::__private::Ok(#this_value::#variant_ident) - } - } - Style::Newtype => deserialize_externally_tagged_newtype_variant( - variant_ident, - params, - &variant.fields[0], - cattrs, - ), - Style::Tuple => deserialize_tuple( - params, - &variant.fields, - cattrs, - TupleForm::ExternallyTagged(variant_ident), - ), - Style::Struct => deserialize_struct( - params, - &variant.fields, - cattrs, - StructForm::ExternallyTagged(variant_ident), - ), - } -} - -// Generates significant part of the visit_seq and visit_map bodies of visitors -// for the variants of internally tagged enum. -fn deserialize_internally_tagged_variant( - params: &Parameters, - variant: &Variant, - cattrs: &attr::Container, - deserializer: TokenStream, -) -> Fragment { - if variant.attrs.deserialize_with().is_some() { - return deserialize_untagged_variant(params, variant, cattrs, deserializer); - } - - let variant_ident = &variant.ident; - - match effective_style(variant) { - Style::Unit => { - let this_value = ¶ms.this_value; - let type_name = params.type_name(); - let variant_name = variant.ident.to_string(); - let default = variant.fields.first().map(|field| { - let default = Expr(expr_is_missing(field, cattrs)); - quote!((#default)) - }); - quote_block! { - _serde::Deserializer::deserialize_any(#deserializer, _serde::__private::de::InternallyTaggedUnitVisitor::new(#type_name, #variant_name))?; - _serde::__private::Ok(#this_value::#variant_ident #default) - } - } - Style::Newtype => deserialize_untagged_newtype_variant( - variant_ident, - params, - &variant.fields[0], - &deserializer, - ), - Style::Struct => deserialize_struct( - params, - &variant.fields, - cattrs, - StructForm::InternallyTagged(variant_ident, deserializer), - ), - Style::Tuple => unreachable!("checked in serde_derive_internals"), - } -} - -fn deserialize_untagged_variant( - params: &Parameters, - variant: &Variant, - cattrs: &attr::Container, - deserializer: TokenStream, -) -> Fragment { - if let Some(path) = variant.attrs.deserialize_with() { - let unwrap_fn = unwrap_to_variant_closure(params, variant, false); - return quote_block! { - _serde::__private::Result::map(#path(#deserializer), #unwrap_fn) - }; - } - - let variant_ident = &variant.ident; - - match effective_style(variant) { - Style::Unit => { - let this_value = ¶ms.this_value; - let type_name = params.type_name(); - let variant_name = variant.ident.to_string(); - let default = variant.fields.first().map(|field| { - let default = Expr(expr_is_missing(field, cattrs)); - quote!((#default)) - }); - quote_expr! { - match _serde::Deserializer::deserialize_any( - #deserializer, - _serde::__private::de::UntaggedUnitVisitor::new(#type_name, #variant_name) - ) { - _serde::__private::Ok(()) => _serde::__private::Ok(#this_value::#variant_ident #default), - _serde::__private::Err(__err) => _serde::__private::Err(__err), - } - } - } - Style::Newtype => deserialize_untagged_newtype_variant( - variant_ident, - params, - &variant.fields[0], - &deserializer, - ), - Style::Tuple => deserialize_tuple( - params, - &variant.fields, - cattrs, - TupleForm::Untagged(variant_ident, deserializer), - ), - Style::Struct => deserialize_struct( - params, - &variant.fields, - cattrs, - StructForm::Untagged(variant_ident, deserializer), - ), - } -} - -fn deserialize_externally_tagged_newtype_variant( - variant_ident: &syn::Ident, - params: &Parameters, - field: &Field, - cattrs: &attr::Container, -) -> Fragment { - let this_value = ¶ms.this_value; - - if field.attrs.skip_deserializing() { - let default = Expr(expr_is_missing(field, cattrs)); - return quote_block! { - _serde::de::VariantAccess::unit_variant(__variant)?; - _serde::__private::Ok(#this_value::#variant_ident(#default)) - }; - } - - match field.attrs.deserialize_with() { - None => { - let field_ty = field.ty; - let span = field.original.span(); - let func = - quote_spanned!(span=> _serde::de::VariantAccess::newtype_variant::<#field_ty>); - quote_expr! { - _serde::__private::Result::map(#func(__variant), #this_value::#variant_ident) - } - } - Some(path) => { - let (wrapper, wrapper_ty) = wrap_deserialize_field_with(params, field.ty, path); - quote_block! { - #wrapper - _serde::__private::Result::map( - _serde::de::VariantAccess::newtype_variant::<#wrapper_ty>(__variant), - |__wrapper| #this_value::#variant_ident(__wrapper.value)) - } - } - } -} - -fn deserialize_untagged_newtype_variant( - variant_ident: &syn::Ident, - params: &Parameters, - field: &Field, - deserializer: &TokenStream, -) -> Fragment { - let this_value = ¶ms.this_value; - let field_ty = field.ty; - match field.attrs.deserialize_with() { - None => { - let span = field.original.span(); - let func = quote_spanned!(span=> <#field_ty as _serde::Deserialize>::deserialize); - quote_expr! { - _serde::__private::Result::map(#func(#deserializer), #this_value::#variant_ident) - } - } - Some(path) => { - quote_block! { - let __value: _serde::__private::Result<#field_ty, _> = #path(#deserializer); - _serde::__private::Result::map(__value, #this_value::#variant_ident) - } - } - } -} - -fn deserialize_generated_identifier( - fields: &[(&str, Ident, &BTreeSet<String>)], - cattrs: &attr::Container, - is_variant: bool, - ignore_variant: Option<TokenStream>, - fallthrough: Option<TokenStream>, -) -> Fragment { - let this_value = quote!(__Field); - let field_idents: &Vec<_> = &fields.iter().map(|(_, ident, _)| ident).collect(); - - let visitor_impl = Stmts(deserialize_identifier( - &this_value, - fields, - is_variant, - fallthrough, - None, - !is_variant && cattrs.has_flatten(), - None, - )); - - let lifetime = if !is_variant && cattrs.has_flatten() { - Some(quote!(<'de>)) - } else { - None - }; - - quote_block! { - #[allow(non_camel_case_types)] - #[doc(hidden)] - enum __Field #lifetime { - #(#field_idents,)* - #ignore_variant - } - - #[doc(hidden)] - struct __FieldVisitor; - - impl<'de> _serde::de::Visitor<'de> for __FieldVisitor { - type Value = __Field #lifetime; - - #visitor_impl - } - - impl<'de> _serde::Deserialize<'de> for __Field #lifetime { - #[inline] - fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error> - where - __D: _serde::Deserializer<'de>, - { - _serde::Deserializer::deserialize_identifier(__deserializer, __FieldVisitor) - } - } - } -} - -/// Generates enum and its `Deserialize` implementation that represents each -/// non-skipped field of the struct -fn deserialize_field_identifier( - fields: &[(&str, Ident, &BTreeSet<String>)], - cattrs: &attr::Container, -) -> Stmts { - let (ignore_variant, fallthrough) = if cattrs.has_flatten() { - let ignore_variant = quote!(__other(_serde::__private::de::Content<'de>),); - let fallthrough = quote!(_serde::__private::Ok(__Field::__other(__value))); - (Some(ignore_variant), Some(fallthrough)) - } else if cattrs.deny_unknown_fields() { - (None, None) - } else { - let ignore_variant = quote!(__ignore,); - let fallthrough = quote!(_serde::__private::Ok(__Field::__ignore)); - (Some(ignore_variant), Some(fallthrough)) - }; - - Stmts(deserialize_generated_identifier( - fields, - cattrs, - false, - ignore_variant, - fallthrough, - )) -} - -// Generates `Deserialize::deserialize` body for an enum with -// `serde(field_identifier)` or `serde(variant_identifier)` attribute. -fn deserialize_custom_identifier( - params: &Parameters, - variants: &[Variant], - cattrs: &attr::Container, -) -> Fragment { - let is_variant = match cattrs.identifier() { - attr::Identifier::Variant => true, - attr::Identifier::Field => false, - attr::Identifier::No => unreachable!(), - }; - - let this_type = params.this_type.to_token_stream(); - let this_value = params.this_value.to_token_stream(); - - let (ordinary, fallthrough, fallthrough_borrowed) = if let Some(last) = variants.last() { - let last_ident = &last.ident; - if last.attrs.other() { - // Process `serde(other)` attribute. It would always be found on the - // last variant (checked in `check_identifier`), so all preceding - // are ordinary variants. - let ordinary = &variants[..variants.len() - 1]; - let fallthrough = quote!(_serde::__private::Ok(#this_value::#last_ident)); - (ordinary, Some(fallthrough), None) - } else if let Style::Newtype = last.style { - let ordinary = &variants[..variants.len() - 1]; - let fallthrough = |value| { - quote! { - _serde::__private::Result::map( - _serde::Deserialize::deserialize( - _serde::__private::de::IdentifierDeserializer::from(#value) - ), - #this_value::#last_ident) - } - }; - ( - ordinary, - Some(fallthrough(quote!(__value))), - Some(fallthrough(quote!(_serde::__private::de::Borrowed( - __value - )))), - ) - } else { - (variants, None, None) - } - } else { - (variants, None, None) - }; - - let names_idents: Vec<_> = ordinary - .iter() - .map(|variant| { - ( - variant.attrs.name().deserialize_name(), - variant.ident.clone(), - variant.attrs.aliases(), - ) - }) - .collect(); - - let names = names_idents.iter().flat_map(|&(_, _, aliases)| aliases); - - let names_const = if fallthrough.is_some() { - None - } else if is_variant { - let variants = quote! { - #[doc(hidden)] - const VARIANTS: &'static [&'static str] = &[ #(#names),* ]; - }; - Some(variants) - } else { - let fields = quote! { - #[doc(hidden)] - const FIELDS: &'static [&'static str] = &[ #(#names),* ]; - }; - Some(fields) - }; - - let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = - split_with_de_lifetime(params); - let delife = params.borrowed.de_lifetime(); - let visitor_impl = Stmts(deserialize_identifier( - &this_value, - &names_idents, - is_variant, - fallthrough, - fallthrough_borrowed, - false, - cattrs.expecting(), - )); - - quote_block! { - #names_const - - #[doc(hidden)] - struct __FieldVisitor #de_impl_generics #where_clause { - marker: _serde::__private::PhantomData<#this_type #ty_generics>, - lifetime: _serde::__private::PhantomData<&#delife ()>, - } - - impl #de_impl_generics _serde::de::Visitor<#delife> for __FieldVisitor #de_ty_generics #where_clause { - type Value = #this_type #ty_generics; - - #visitor_impl - } - - let __visitor = __FieldVisitor { - marker: _serde::__private::PhantomData::<#this_type #ty_generics>, - lifetime: _serde::__private::PhantomData, - }; - _serde::Deserializer::deserialize_identifier(__deserializer, __visitor) - } -} - -fn deserialize_identifier( - this_value: &TokenStream, - fields: &[(&str, Ident, &BTreeSet<String>)], - is_variant: bool, - fallthrough: Option<TokenStream>, - fallthrough_borrowed: Option<TokenStream>, - collect_other_fields: bool, - expecting: Option<&str>, -) -> Fragment { - let str_mapping = fields.iter().map(|(_, ident, aliases)| { - // `aliases` also contains a main name - quote!(#(#aliases)|* => _serde::__private::Ok(#this_value::#ident)) - }); - let bytes_mapping = fields.iter().map(|(_, ident, aliases)| { - // `aliases` also contains a main name - let aliases = aliases - .iter() - .map(|alias| Literal::byte_string(alias.as_bytes())); - quote!(#(#aliases)|* => _serde::__private::Ok(#this_value::#ident)) - }); - - let expecting = expecting.unwrap_or(if is_variant { - "variant identifier" - } else { - "field identifier" - }); - - let bytes_to_str = if fallthrough.is_some() || collect_other_fields { - None - } else { - Some(quote! { - let __value = &_serde::__private::from_utf8_lossy(__value); - }) - }; - - let ( - value_as_str_content, - value_as_borrowed_str_content, - value_as_bytes_content, - value_as_borrowed_bytes_content, - ) = if collect_other_fields { - ( - Some(quote! { - let __value = _serde::__private::de::Content::String(_serde::__private::ToString::to_string(__value)); - }), - Some(quote! { - let __value = _serde::__private::de::Content::Str(__value); - }), - Some(quote! { - let __value = _serde::__private::de::Content::ByteBuf(__value.to_vec()); - }), - Some(quote! { - let __value = _serde::__private::de::Content::Bytes(__value); - }), - ) - } else { - (None, None, None, None) - }; - - let fallthrough_arm_tokens; - let fallthrough_arm = if let Some(fallthrough) = &fallthrough { - fallthrough - } else if is_variant { - fallthrough_arm_tokens = quote! { - _serde::__private::Err(_serde::de::Error::unknown_variant(__value, VARIANTS)) - }; - &fallthrough_arm_tokens - } else { - fallthrough_arm_tokens = quote! { - _serde::__private::Err(_serde::de::Error::unknown_field(__value, FIELDS)) - }; - &fallthrough_arm_tokens - }; - - let visit_other = if collect_other_fields { - quote! { - fn visit_bool<__E>(self, __value: bool) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - _serde::__private::Ok(__Field::__other(_serde::__private::de::Content::Bool(__value))) - } - - fn visit_i8<__E>(self, __value: i8) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - _serde::__private::Ok(__Field::__other(_serde::__private::de::Content::I8(__value))) - } - - fn visit_i16<__E>(self, __value: i16) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - _serde::__private::Ok(__Field::__other(_serde::__private::de::Content::I16(__value))) - } - - fn visit_i32<__E>(self, __value: i32) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - _serde::__private::Ok(__Field::__other(_serde::__private::de::Content::I32(__value))) - } - - fn visit_i64<__E>(self, __value: i64) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - _serde::__private::Ok(__Field::__other(_serde::__private::de::Content::I64(__value))) - } - - fn visit_u8<__E>(self, __value: u8) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - _serde::__private::Ok(__Field::__other(_serde::__private::de::Content::U8(__value))) - } - - fn visit_u16<__E>(self, __value: u16) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - _serde::__private::Ok(__Field::__other(_serde::__private::de::Content::U16(__value))) - } - - fn visit_u32<__E>(self, __value: u32) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - _serde::__private::Ok(__Field::__other(_serde::__private::de::Content::U32(__value))) - } - - fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - _serde::__private::Ok(__Field::__other(_serde::__private::de::Content::U64(__value))) - } - - fn visit_f32<__E>(self, __value: f32) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - _serde::__private::Ok(__Field::__other(_serde::__private::de::Content::F32(__value))) - } - - fn visit_f64<__E>(self, __value: f64) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - _serde::__private::Ok(__Field::__other(_serde::__private::de::Content::F64(__value))) - } - - fn visit_char<__E>(self, __value: char) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - _serde::__private::Ok(__Field::__other(_serde::__private::de::Content::Char(__value))) - } - - fn visit_unit<__E>(self) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - _serde::__private::Ok(__Field::__other(_serde::__private::de::Content::Unit)) - } - } - } else { - let u64_mapping = fields.iter().enumerate().map(|(i, (_, ident, _))| { - let i = i as u64; - quote!(#i => _serde::__private::Ok(#this_value::#ident)) - }); - - let u64_fallthrough_arm_tokens; - let u64_fallthrough_arm = if let Some(fallthrough) = &fallthrough { - fallthrough - } else { - let index_expecting = if is_variant { "variant" } else { "field" }; - let fallthrough_msg = format!("{} index 0 <= i < {}", index_expecting, fields.len()); - u64_fallthrough_arm_tokens = quote! { - _serde::__private::Err(_serde::de::Error::invalid_value( - _serde::de::Unexpected::Unsigned(__value), - &#fallthrough_msg, - )) - }; - &u64_fallthrough_arm_tokens - }; - - quote! { - fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - match __value { - #(#u64_mapping,)* - _ => #u64_fallthrough_arm, - } - } - } - }; - - let visit_borrowed = if fallthrough_borrowed.is_some() || collect_other_fields { - let str_mapping = str_mapping.clone(); - let bytes_mapping = bytes_mapping.clone(); - let fallthrough_borrowed_arm = fallthrough_borrowed.as_ref().unwrap_or(fallthrough_arm); - Some(quote! { - fn visit_borrowed_str<__E>(self, __value: &'de str) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - match __value { - #(#str_mapping,)* - _ => { - #value_as_borrowed_str_content - #fallthrough_borrowed_arm - } - } - } - - fn visit_borrowed_bytes<__E>(self, __value: &'de [u8]) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - match __value { - #(#bytes_mapping,)* - _ => { - #bytes_to_str - #value_as_borrowed_bytes_content - #fallthrough_borrowed_arm - } - } - } - }) - } else { - None - }; - - quote_block! { - fn expecting(&self, __formatter: &mut _serde::__private::Formatter) -> _serde::__private::fmt::Result { - _serde::__private::Formatter::write_str(__formatter, #expecting) - } - - #visit_other - - fn visit_str<__E>(self, __value: &str) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - match __value { - #(#str_mapping,)* - _ => { - #value_as_str_content - #fallthrough_arm - } - } - } - - fn visit_bytes<__E>(self, __value: &[u8]) -> _serde::__private::Result<Self::Value, __E> - where - __E: _serde::de::Error, - { - match __value { - #(#bytes_mapping,)* - _ => { - #bytes_to_str - #value_as_bytes_content - #fallthrough_arm - } - } - } - - #visit_borrowed - } -} - -fn deserialize_map( - struct_path: &TokenStream, - params: &Parameters, - fields: &[Field], - cattrs: &attr::Container, -) -> Fragment { - // Create the field names for the fields. - let fields_names: Vec<_> = fields - .iter() - .enumerate() - .map(|(i, field)| (field, field_i(i))) - .collect(); - - // Declare each field that will be deserialized. - let let_values = fields_names - .iter() - .filter(|&&(field, _)| !field.attrs.skip_deserializing() && !field.attrs.flatten()) - .map(|(field, name)| { - let field_ty = field.ty; - quote! { - let mut #name: _serde::__private::Option<#field_ty> = _serde::__private::None; - } - }); - - // Collect contents for flatten fields into a buffer - let let_collect = if cattrs.has_flatten() { - Some(quote! { - let mut __collect = _serde::__private::Vec::<_serde::__private::Option<( - _serde::__private::de::Content, - _serde::__private::de::Content - )>>::new(); - }) - } else { - None - }; - - // Match arms to extract a value for a field. - let value_arms = fields_names - .iter() - .filter(|&&(field, _)| !field.attrs.skip_deserializing() && !field.attrs.flatten()) - .map(|(field, name)| { - let deser_name = field.attrs.name().deserialize_name(); - - let visit = match field.attrs.deserialize_with() { - None => { - let field_ty = field.ty; - let span = field.original.span(); - let func = - quote_spanned!(span=> _serde::de::MapAccess::next_value::<#field_ty>); - quote! { - #func(&mut __map)? - } - } - Some(path) => { - let (wrapper, wrapper_ty) = wrap_deserialize_field_with(params, field.ty, path); - quote!({ - #wrapper - match _serde::de::MapAccess::next_value::<#wrapper_ty>(&mut __map) { - _serde::__private::Ok(__wrapper) => __wrapper.value, - _serde::__private::Err(__err) => { - return _serde::__private::Err(__err); - } - } - }) - } - }; - quote! { - __Field::#name => { - if _serde::__private::Option::is_some(&#name) { - return _serde::__private::Err(<__A::Error as _serde::de::Error>::duplicate_field(#deser_name)); - } - #name = _serde::__private::Some(#visit); - } - } - }); - - // Visit ignored values to consume them - let ignored_arm = if cattrs.has_flatten() { - Some(quote! { - __Field::__other(__name) => { - __collect.push(_serde::__private::Some(( - __name, - _serde::de::MapAccess::next_value(&mut __map)?))); - } - }) - } else if cattrs.deny_unknown_fields() { - None - } else { - Some(quote! { - _ => { let _ = _serde::de::MapAccess::next_value::<_serde::de::IgnoredAny>(&mut __map)?; } - }) - }; - - let all_skipped = fields.iter().all(|field| field.attrs.skip_deserializing()); - let match_keys = if cattrs.deny_unknown_fields() && all_skipped { - quote! { - // FIXME: Once feature(exhaustive_patterns) is stable: - // let _serde::__private::None::<__Field> = _serde::de::MapAccess::next_key(&mut __map)?; - _serde::__private::Option::map( - _serde::de::MapAccess::next_key::<__Field>(&mut __map)?, - |__impossible| match __impossible {}); - } - } else { - quote! { - while let _serde::__private::Some(__key) = _serde::de::MapAccess::next_key::<__Field>(&mut __map)? { - match __key { - #(#value_arms)* - #ignored_arm - } - } - } - }; - - let extract_values = fields_names - .iter() - .filter(|&&(field, _)| !field.attrs.skip_deserializing() && !field.attrs.flatten()) - .map(|(field, name)| { - let missing_expr = Match(expr_is_missing(field, cattrs)); - - quote! { - let #name = match #name { - _serde::__private::Some(#name) => #name, - _serde::__private::None => #missing_expr - }; - } - }); - - let extract_collected = fields_names - .iter() - .filter(|&&(field, _)| field.attrs.flatten() && !field.attrs.skip_deserializing()) - .map(|(field, name)| { - let field_ty = field.ty; - let func = match field.attrs.deserialize_with() { - None => { - let span = field.original.span(); - quote_spanned!(span=> _serde::de::Deserialize::deserialize) - } - Some(path) => quote!(#path), - }; - quote! { - let #name: #field_ty = #func( - _serde::__private::de::FlatMapDeserializer( - &mut __collect, - _serde::__private::PhantomData))?; - } - }); - - let collected_deny_unknown_fields = if cattrs.has_flatten() && cattrs.deny_unknown_fields() { - Some(quote! { - if let _serde::__private::Some(_serde::__private::Some((__key, _))) = - __collect.into_iter().filter(_serde::__private::Option::is_some).next() - { - if let _serde::__private::Some(__key) = __key.as_str() { - return _serde::__private::Err( - _serde::de::Error::custom(format_args!("unknown field `{}`", &__key))); - } else { - return _serde::__private::Err( - _serde::de::Error::custom(format_args!("unexpected map key"))); - } - } - }) - } else { - None - }; - - let result = fields_names.iter().map(|(field, name)| { - let member = &field.member; - if field.attrs.skip_deserializing() { - let value = Expr(expr_is_missing(field, cattrs)); - quote!(#member: #value) - } else { - quote!(#member: #name) - } - }); - - let let_default = match cattrs.default() { - attr::Default::Default => Some(quote!( - let __default: Self::Value = _serde::__private::Default::default(); - )), - attr::Default::Path(path) => Some(quote!( - let __default: Self::Value = #path(); - )), - attr::Default::None => { - // We don't need the default value, to prevent an unused variable warning - // we'll leave the line empty. - None - } - }; - - let mut result = quote!(#struct_path { #(#result),* }); - if params.has_getter { - let this_type = ¶ms.this_type; - let (_, ty_generics, _) = params.generics.split_for_impl(); - result = quote! { - _serde::__private::Into::<#this_type #ty_generics>::into(#result) - }; - } - - quote_block! { - #(#let_values)* - - #let_collect - - #match_keys - - #let_default - - #(#extract_values)* - - #(#extract_collected)* - - #collected_deny_unknown_fields - - _serde::__private::Ok(#result) - } -} - -#[cfg(feature = "deserialize_in_place")] -fn deserialize_map_in_place( - params: &Parameters, - fields: &[Field], - cattrs: &attr::Container, -) -> Fragment { - assert!(!cattrs.has_flatten()); - - // Create the field names for the fields. - let fields_names: Vec<_> = fields - .iter() - .enumerate() - .map(|(i, field)| (field, field_i(i))) - .collect(); - - // For deserialize_in_place, declare booleans for each field that will be - // deserialized. - let let_flags = fields_names - .iter() - .filter(|&&(field, _)| !field.attrs.skip_deserializing()) - .map(|(_, name)| { - quote! { - let mut #name: bool = false; - } - }); - - // Match arms to extract a value for a field. - let value_arms_from = fields_names - .iter() - .filter(|&&(field, _)| !field.attrs.skip_deserializing()) - .map(|(field, name)| { - let deser_name = field.attrs.name().deserialize_name(); - let member = &field.member; - - let visit = match field.attrs.deserialize_with() { - None => { - quote! { - _serde::de::MapAccess::next_value_seed(&mut __map, _serde::__private::de::InPlaceSeed(&mut self.place.#member))? - } - } - Some(path) => { - let (wrapper, wrapper_ty) = wrap_deserialize_field_with(params, field.ty, path); - quote!({ - #wrapper - self.place.#member = match _serde::de::MapAccess::next_value::<#wrapper_ty>(&mut __map) { - _serde::__private::Ok(__wrapper) => __wrapper.value, - _serde::__private::Err(__err) => { - return _serde::__private::Err(__err); - } - }; - }) - } - }; - quote! { - __Field::#name => { - if #name { - return _serde::__private::Err(<__A::Error as _serde::de::Error>::duplicate_field(#deser_name)); - } - #visit; - #name = true; - } - } - }); - - // Visit ignored values to consume them - let ignored_arm = if cattrs.deny_unknown_fields() { - None - } else { - Some(quote! { - _ => { let _ = _serde::de::MapAccess::next_value::<_serde::de::IgnoredAny>(&mut __map)?; } - }) - }; - - let all_skipped = fields.iter().all(|field| field.attrs.skip_deserializing()); - - let match_keys = if cattrs.deny_unknown_fields() && all_skipped { - quote! { - // FIXME: Once feature(exhaustive_patterns) is stable: - // let _serde::__private::None::<__Field> = _serde::de::MapAccess::next_key(&mut __map)?; - _serde::__private::Option::map( - _serde::de::MapAccess::next_key::<__Field>(&mut __map)?, - |__impossible| match __impossible {}); - } - } else { - quote! { - while let _serde::__private::Some(__key) = _serde::de::MapAccess::next_key::<__Field>(&mut __map)? { - match __key { - #(#value_arms_from)* - #ignored_arm - } - } - } - }; - - let check_flags = fields_names - .iter() - .filter(|&&(field, _)| !field.attrs.skip_deserializing()) - .map(|(field, name)| { - let missing_expr = expr_is_missing(field, cattrs); - // If missing_expr unconditionally returns an error, don't try - // to assign its value to self.place. - if field.attrs.default().is_none() - && cattrs.default().is_none() - && field.attrs.deserialize_with().is_some() - { - let missing_expr = Stmts(missing_expr); - quote! { - if !#name { - #missing_expr; - } - } - } else { - let member = &field.member; - let missing_expr = Expr(missing_expr); - quote! { - if !#name { - self.place.#member = #missing_expr; - }; - } - } - }); - - let this_type = ¶ms.this_type; - let (_, _, ty_generics, _) = split_with_de_lifetime(params); - - let let_default = match cattrs.default() { - attr::Default::Default => Some(quote!( - let __default: #this_type #ty_generics = _serde::__private::Default::default(); - )), - attr::Default::Path(path) => Some(quote!( - let __default: #this_type #ty_generics = #path(); - )), - attr::Default::None => { - // We don't need the default value, to prevent an unused variable warning - // we'll leave the line empty. - None - } - }; - - quote_block! { - #(#let_flags)* - - #match_keys - - #let_default - - #(#check_flags)* - - _serde::__private::Ok(()) - } -} - -fn field_i(i: usize) -> Ident { - Ident::new(&format!("__field{}", i), Span::call_site()) -} - -/// This function wraps the expression in `#[serde(deserialize_with = "...")]` -/// in a trait to prevent it from accessing the internal `Deserialize` state. -fn wrap_deserialize_with( - params: &Parameters, - value_ty: &TokenStream, - deserialize_with: &syn::ExprPath, -) -> (TokenStream, TokenStream) { - let this_type = ¶ms.this_type; - let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = - split_with_de_lifetime(params); - let delife = params.borrowed.de_lifetime(); - - let wrapper = quote! { - #[doc(hidden)] - struct __DeserializeWith #de_impl_generics #where_clause { - value: #value_ty, - phantom: _serde::__private::PhantomData<#this_type #ty_generics>, - lifetime: _serde::__private::PhantomData<&#delife ()>, - } - - impl #de_impl_generics _serde::Deserialize<#delife> for __DeserializeWith #de_ty_generics #where_clause { - fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error> - where - __D: _serde::Deserializer<#delife>, - { - _serde::__private::Ok(__DeserializeWith { - value: #deserialize_with(__deserializer)?, - phantom: _serde::__private::PhantomData, - lifetime: _serde::__private::PhantomData, - }) - } - } - }; - - let wrapper_ty = quote!(__DeserializeWith #de_ty_generics); - - (wrapper, wrapper_ty) -} - -fn wrap_deserialize_field_with( - params: &Parameters, - field_ty: &syn::Type, - deserialize_with: &syn::ExprPath, -) -> (TokenStream, TokenStream) { - wrap_deserialize_with(params, "e!(#field_ty), deserialize_with) -} - -fn wrap_deserialize_variant_with( - params: &Parameters, - variant: &Variant, - deserialize_with: &syn::ExprPath, -) -> (TokenStream, TokenStream, TokenStream) { - let field_tys = variant.fields.iter().map(|field| field.ty); - let (wrapper, wrapper_ty) = - wrap_deserialize_with(params, "e!((#(#field_tys),*)), deserialize_with); - - let unwrap_fn = unwrap_to_variant_closure(params, variant, true); - - (wrapper, wrapper_ty, unwrap_fn) -} - -// Generates closure that converts single input parameter to the final value. -fn unwrap_to_variant_closure( - params: &Parameters, - variant: &Variant, - with_wrapper: bool, -) -> TokenStream { - let this_value = ¶ms.this_value; - let variant_ident = &variant.ident; - - let (arg, wrapper) = if with_wrapper { - (quote! { __wrap }, quote! { __wrap.value }) - } else { - let field_tys = variant.fields.iter().map(|field| field.ty); - (quote! { __wrap: (#(#field_tys),*) }, quote! { __wrap }) - }; - - let field_access = (0..variant.fields.len()).map(|n| { - Member::Unnamed(Index { - index: n as u32, - span: Span::call_site(), - }) - }); - - match variant.style { - Style::Struct if variant.fields.len() == 1 => { - let member = &variant.fields[0].member; - quote! { - |#arg| #this_value::#variant_ident { #member: #wrapper } - } - } - Style::Struct => { - let members = variant.fields.iter().map(|field| &field.member); - quote! { - |#arg| #this_value::#variant_ident { #(#members: #wrapper.#field_access),* } - } - } - Style::Tuple => quote! { - |#arg| #this_value::#variant_ident(#(#wrapper.#field_access),*) - }, - Style::Newtype => quote! { - |#arg| #this_value::#variant_ident(#wrapper) - }, - Style::Unit => quote! { - |#arg| #this_value::#variant_ident - }, - } -} - -fn expr_is_missing(field: &Field, cattrs: &attr::Container) -> Fragment { - match field.attrs.default() { - attr::Default::Default => { - let span = field.original.span(); - let func = quote_spanned!(span=> _serde::__private::Default::default); - return quote_expr!(#func()); - } - attr::Default::Path(path) => { - return quote_expr!(#path()); - } - attr::Default::None => { /* below */ } - } - - match *cattrs.default() { - attr::Default::Default | attr::Default::Path(_) => { - let member = &field.member; - return quote_expr!(__default.#member); - } - attr::Default::None => { /* below */ } - } - - let name = field.attrs.name().deserialize_name(); - match field.attrs.deserialize_with() { - None => { - let span = field.original.span(); - let func = quote_spanned!(span=> _serde::__private::de::missing_field); - quote_expr! { - #func(#name)? - } - } - Some(_) => { - quote_expr! { - return _serde::__private::Err(<__A::Error as _serde::de::Error>::missing_field(#name)) - } - } - } -} - -fn expr_is_missing_seq( - assign_to: Option<TokenStream>, - index: usize, - field: &Field, - cattrs: &attr::Container, - expecting: &str, -) -> TokenStream { - match field.attrs.default() { - attr::Default::Default => { - let span = field.original.span(); - return quote_spanned!(span=> #assign_to _serde::__private::Default::default()); - } - attr::Default::Path(path) => { - return quote_spanned!(path.span()=> #assign_to #path()); - } - attr::Default::None => { /* below */ } - } - - match *cattrs.default() { - attr::Default::Default | attr::Default::Path(_) => { - let member = &field.member; - quote!(#assign_to __default.#member) - } - attr::Default::None => quote!( - return _serde::__private::Err(_serde::de::Error::invalid_length(#index, &#expecting)) - ), - } -} - -fn effective_style(variant: &Variant) -> Style { - match variant.style { - Style::Newtype if variant.fields[0].attrs.skip_deserializing() => Style::Unit, - other => other, - } -} - -struct DeImplGenerics<'a>(&'a Parameters); -#[cfg(feature = "deserialize_in_place")] -struct InPlaceImplGenerics<'a>(&'a Parameters); - -impl<'a> ToTokens for DeImplGenerics<'a> { - fn to_tokens(&self, tokens: &mut TokenStream) { - let mut generics = self.0.generics.clone(); - if let Some(de_lifetime) = self.0.borrowed.de_lifetime_param() { - generics.params = Some(syn::GenericParam::Lifetime(de_lifetime)) - .into_iter() - .chain(generics.params) - .collect(); - } - let (impl_generics, _, _) = generics.split_for_impl(); - impl_generics.to_tokens(tokens); - } -} - -#[cfg(feature = "deserialize_in_place")] -impl<'a> ToTokens for InPlaceImplGenerics<'a> { - fn to_tokens(&self, tokens: &mut TokenStream) { - let place_lifetime = place_lifetime(); - let mut generics = self.0.generics.clone(); - - // Add lifetime for `&'place mut Self, and `'a: 'place` - for param in &mut generics.params { - match param { - syn::GenericParam::Lifetime(param) => { - param.bounds.push(place_lifetime.lifetime.clone()); - } - syn::GenericParam::Type(param) => { - param.bounds.push(syn::TypeParamBound::Lifetime( - place_lifetime.lifetime.clone(), - )); - } - syn::GenericParam::Const(_) => {} - } - } - generics.params = Some(syn::GenericParam::Lifetime(place_lifetime)) - .into_iter() - .chain(generics.params) - .collect(); - if let Some(de_lifetime) = self.0.borrowed.de_lifetime_param() { - generics.params = Some(syn::GenericParam::Lifetime(de_lifetime)) - .into_iter() - .chain(generics.params) - .collect(); - } - let (impl_generics, _, _) = generics.split_for_impl(); - impl_generics.to_tokens(tokens); - } -} - -#[cfg(feature = "deserialize_in_place")] -impl<'a> DeImplGenerics<'a> { - fn in_place(self) -> InPlaceImplGenerics<'a> { - InPlaceImplGenerics(self.0) - } -} - -struct DeTypeGenerics<'a>(&'a Parameters); -#[cfg(feature = "deserialize_in_place")] -struct InPlaceTypeGenerics<'a>(&'a Parameters); - -fn de_type_generics_to_tokens( - mut generics: syn::Generics, - borrowed: &BorrowedLifetimes, - tokens: &mut TokenStream, -) { - if borrowed.de_lifetime_param().is_some() { - let def = syn::LifetimeParam { - attrs: Vec::new(), - lifetime: syn::Lifetime::new("'de", Span::call_site()), - colon_token: None, - bounds: Punctuated::new(), - }; - // Prepend 'de lifetime to list of generics - generics.params = Some(syn::GenericParam::Lifetime(def)) - .into_iter() - .chain(generics.params) - .collect(); - } - let (_, ty_generics, _) = generics.split_for_impl(); - ty_generics.to_tokens(tokens); -} - -impl<'a> ToTokens for DeTypeGenerics<'a> { - fn to_tokens(&self, tokens: &mut TokenStream) { - de_type_generics_to_tokens(self.0.generics.clone(), &self.0.borrowed, tokens); - } -} - -#[cfg(feature = "deserialize_in_place")] -impl<'a> ToTokens for InPlaceTypeGenerics<'a> { - fn to_tokens(&self, tokens: &mut TokenStream) { - let mut generics = self.0.generics.clone(); - generics.params = Some(syn::GenericParam::Lifetime(place_lifetime())) - .into_iter() - .chain(generics.params) - .collect(); - - de_type_generics_to_tokens(generics, &self.0.borrowed, tokens); - } -} - -#[cfg(feature = "deserialize_in_place")] -impl<'a> DeTypeGenerics<'a> { - fn in_place(self) -> InPlaceTypeGenerics<'a> { - InPlaceTypeGenerics(self.0) - } -} - -#[cfg(feature = "deserialize_in_place")] -fn place_lifetime() -> syn::LifetimeParam { - syn::LifetimeParam { - attrs: Vec::new(), - lifetime: syn::Lifetime::new("'place", Span::call_site()), - colon_token: None, - bounds: Punctuated::new(), - } -} - -fn split_with_de_lifetime( - params: &Parameters, -) -> ( - DeImplGenerics, - DeTypeGenerics, - syn::TypeGenerics, - Option<&syn::WhereClause>, -) { - let de_impl_generics = DeImplGenerics(params); - let de_ty_generics = DeTypeGenerics(params); - let (_, ty_generics, where_clause) = params.generics.split_for_impl(); - (de_impl_generics, de_ty_generics, ty_generics, where_clause) -} |