diff options
Diffstat (limited to 'compiler/rustc_macros/src/serialize.rs')
| -rw-r--r-- | compiler/rustc_macros/src/serialize.rs | 47 |
1 files changed, 30 insertions, 17 deletions
diff --git a/compiler/rustc_macros/src/serialize.rs b/compiler/rustc_macros/src/serialize.rs index 82e6972d0..8d017d149 100644 --- a/compiler/rustc_macros/src/serialize.rs +++ b/compiler/rustc_macros/src/serialize.rs @@ -42,6 +42,12 @@ fn decodable_body( } let ty_name = s.ast().ident.to_string(); let decode_body = match s.variants() { + [] => { + let message = format!("`{}` has no variants to decode", ty_name); + quote! { + panic!(#message) + } + } [vi] => vi.construct(|field, _index| decode_field(field)), variants => { let match_inner: TokenStream = variants @@ -139,6 +145,11 @@ fn encodable_body( }); let encode_body = match s.variants() { + [] => { + quote! { + match *self {} + } + } [_] => { let encode_inner = s.each_variant(|vi| { vi.bindings() @@ -160,6 +171,23 @@ fn encodable_body( } } _ => { + let disc = { + let mut variant_idx = 0usize; + let encode_inner = s.each_variant(|_| { + let result = quote! { + #variant_idx + }; + variant_idx += 1; + result + }); + quote! { + let disc = match *self { + #encode_inner + }; + ::rustc_serialize::Encoder::emit_usize(__encoder, disc); + } + }; + let mut variant_idx = 0usize; let encode_inner = s.each_variant(|vi| { let encode_fields: TokenStream = vi @@ -176,26 +204,11 @@ fn encodable_body( result }) .collect(); - - let result = if !vi.bindings().is_empty() { - quote! { - ::rustc_serialize::Encoder::emit_enum_variant( - __encoder, - #variant_idx, - |__encoder| { #encode_fields } - ) - } - } else { - quote! { - ::rustc_serialize::Encoder::emit_fieldless_enum_variant::<#variant_idx>( - __encoder, - ) - } - }; variant_idx += 1; - result + encode_fields }); quote! { + #disc match *self { #encode_inner } |