1 use proc_macro2::TokenStream;
5 pub fn type_decodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
6 let decoder_ty = quote! { __D };
7 if !s.ast().generics.lifetimes().any(|lt| lt.lifetime.ident == "tcx") {
8 s.add_impl_generic(parse_quote! { 'tcx });
10 s.add_impl_generic(parse_quote! {#decoder_ty: ::rustc_middle::ty::codec::TyDecoder<'tcx>});
11 s.add_bounds(synstructure::AddBounds::Generics);
13 decodable_body(s, decoder_ty)
16 pub fn meta_decodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
17 if !s.ast().generics.lifetimes().any(|lt| lt.lifetime.ident == "tcx") {
18 s.add_impl_generic(parse_quote! { 'tcx });
20 s.add_impl_generic(parse_quote! { '__a });
21 let decoder_ty = quote! { DecodeContext<'__a, 'tcx> };
22 s.add_bounds(synstructure::AddBounds::Generics);
24 decodable_body(s, decoder_ty)
27 pub fn decodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
28 let decoder_ty = quote! { __D };
29 s.add_impl_generic(parse_quote! {#decoder_ty: ::rustc_serialize::Decoder});
30 s.add_bounds(synstructure::AddBounds::Generics);
32 decodable_body(s, decoder_ty)
36 s: synstructure::Structure<'_>,
37 decoder_ty: TokenStream,
38 ) -> proc_macro2::TokenStream {
39 if let syn::Data::Union(_) = s.ast().data {
40 panic!("cannot derive on union")
42 let ty_name = s.ast().ident.to_string();
43 let decode_body = match s.variants() {
45 let construct = vi.construct(|field, index| decode_field(field, index, true));
47 ::rustc_serialize::Decoder::read_struct(
49 |__decoder| { ::std::result::Result::Ok(#construct) },
54 let match_inner: TokenStream = variants
58 let construct = vi.construct(|field, index| decode_field(field, index, false));
59 quote! { #idx => { ::std::result::Result::Ok(#construct) } }
62 let names: TokenStream = variants
65 let variant_name = vi.ast().ident.to_string();
66 quote!(#variant_name,)
69 let message = format!(
70 "invalid enum variant tag while decoding `{}`, expected 0..{}",
75 ::rustc_serialize::Decoder::read_enum(
78 ::rustc_serialize::Decoder::read_enum_variant(
81 |__decoder, __variant_idx| {
84 _ => return ::std::result::Result::Err(
85 ::rustc_serialize::Decoder::error(__decoder, #message)),
95 quote!(::rustc_serialize::Decodable<#decoder_ty>),
98 __decoder: &mut #decoder_ty,
99 ) -> ::std::result::Result<Self, <#decoder_ty as ::rustc_serialize::Decoder>::Error> {
106 fn decode_field(field: &syn::Field, index: usize, is_struct: bool) -> proc_macro2::TokenStream {
107 let decode_inner_method = if let syn::Type::Reference(_) = field.ty {
108 quote! { ::rustc_middle::ty::codec::RefDecodable::decode }
110 quote! { ::rustc_serialize::Decodable::decode }
112 let (decode_method, opt_field_name) = if is_struct {
113 let field_name = field.ident.as_ref().map_or_else(|| index.to_string(), |i| i.to_string());
115 proc_macro2::Ident::new("read_struct_field", proc_macro2::Span::call_site()),
116 quote! { #field_name, },
120 proc_macro2::Ident::new("read_enum_variant_arg", proc_macro2::Span::call_site()),
126 match ::rustc_serialize::Decoder::#decode_method(
127 __decoder, #opt_field_name #decode_inner_method) {
128 ::std::result::Result::Ok(__res) => __res,
129 ::std::result::Result::Err(__err) => return ::std::result::Result::Err(__err),
134 pub fn type_encodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
135 if !s.ast().generics.lifetimes().any(|lt| lt.lifetime.ident == "tcx") {
136 s.add_impl_generic(parse_quote! {'tcx});
138 let encoder_ty = quote! { __E };
139 s.add_impl_generic(parse_quote! {#encoder_ty: ::rustc_middle::ty::codec::TyEncoder<'tcx>});
140 s.add_bounds(synstructure::AddBounds::Generics);
142 encodable_body(s, encoder_ty, false)
145 pub fn meta_encodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
146 if !s.ast().generics.lifetimes().any(|lt| lt.lifetime.ident == "tcx") {
147 s.add_impl_generic(parse_quote! {'tcx});
149 s.add_impl_generic(parse_quote! { '__a });
150 let encoder_ty = quote! { EncodeContext<'__a, 'tcx> };
151 s.add_bounds(synstructure::AddBounds::Generics);
153 encodable_body(s, encoder_ty, true)
156 pub fn encodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
157 let encoder_ty = quote! { __E };
158 s.add_impl_generic(parse_quote! { #encoder_ty: ::rustc_serialize::Encoder});
159 s.add_bounds(synstructure::AddBounds::Generics);
161 encodable_body(s, encoder_ty, false)
165 mut s: synstructure::Structure<'_>,
166 encoder_ty: TokenStream,
167 allow_unreachable_code: bool,
168 ) -> proc_macro2::TokenStream {
169 if let syn::Data::Union(_) = s.ast().data {
170 panic!("cannot derive on union")
173 s.bind_with(|binding| {
174 // Handle the lack of a blanket reference impl.
175 if let syn::Type::Reference(_) = binding.ast().ty {
176 synstructure::BindStyle::Move
178 synstructure::BindStyle::Ref
182 let encode_body = match s.variants() {
184 let mut field_idx = 0usize;
185 let encode_inner = s.each_variant(|vi| {
189 let bind_ident = &binding.binding;
190 let field_name = binding
194 .map_or_else(|| field_idx.to_string(), |i| i.to_string());
195 let first = field_idx == 0;
196 let result = quote! {
197 match ::rustc_serialize::Encoder::emit_struct_field(
202 ::rustc_serialize::Encodable::<#encoder_ty>::encode(#bind_ident, __encoder),
204 ::std::result::Result::Ok(()) => (),
205 ::std::result::Result::Err(__err)
206 => return ::std::result::Result::Err(__err),
212 .collect::<TokenStream>()
214 let no_fields = field_idx == 0;
216 ::rustc_serialize::Encoder::emit_struct(__encoder, #no_fields, |__encoder| {
217 ::std::result::Result::Ok(match *self { #encode_inner })
222 let mut variant_idx = 0usize;
223 let encode_inner = s.each_variant(|vi| {
224 let variant_name = vi.ast().ident.to_string();
225 let mut field_idx = 0usize;
227 let encode_fields: TokenStream = vi
231 let bind_ident = &binding.binding;
232 let first = field_idx == 0;
233 let result = quote! {
234 match ::rustc_serialize::Encoder::emit_enum_variant_arg(
238 ::rustc_serialize::Encodable::<#encoder_ty>::encode(#bind_ident, __encoder),
240 ::std::result::Result::Ok(()) => (),
241 ::std::result::Result::Err(__err)
242 => return ::std::result::Result::Err(__err),
250 let result = quote! { ::rustc_serialize::Encoder::emit_enum_variant(
255 |__encoder| { ::std::result::Result::Ok({ #encode_fields }) }
261 ::rustc_serialize::Encoder::emit_enum(__encoder, |__encoder| {
270 let lints = if allow_unreachable_code {
271 quote! { #![allow(unreachable_code)] }
277 quote!(::rustc_serialize::Encodable<#encoder_ty>),
281 __encoder: &mut #encoder_ty,
282 ) -> ::std::result::Result<(), <#encoder_ty as ::rustc_serialize::Encoder>::Error> {