frame_support_procedural/no_bound/
debug.rs
1use syn::spanned::Spanned;
19
20pub fn derive_debug_no_bound(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
22 let input = syn::parse_macro_input!(input as syn::DeriveInput);
23
24 let input_ident = &input.ident;
25 let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
26
27 let impl_ = match input.data {
28 syn::Data::Struct(struct_) => match struct_.fields {
29 syn::Fields::Named(named) => {
30 let fields =
31 named.named.iter().map(|i| &i.ident).map(
32 |i| quote::quote_spanned!(i.span() => .field(stringify!(#i), &self.#i) ),
33 );
34
35 quote::quote!(
36 fmt.debug_struct(stringify!(#input_ident))
37 #( #fields )*
38 .finish()
39 )
40 },
41 syn::Fields::Unnamed(unnamed) => {
42 let fields = unnamed
43 .unnamed
44 .iter()
45 .enumerate()
46 .map(|(i, _)| syn::Index::from(i))
47 .map(|i| quote::quote_spanned!(i.span() => .field(&self.#i) ));
48
49 quote::quote!(
50 fmt.debug_tuple(stringify!(#input_ident))
51 #( #fields )*
52 .finish()
53 )
54 },
55 syn::Fields::Unit => quote::quote!(fmt.write_str(stringify!(#input_ident))),
56 },
57 syn::Data::Enum(enum_) => {
58 let variants = enum_.variants.iter().map(|variant| {
59 let ident = &variant.ident;
60 let full_variant_str = format!("{}::{}", input_ident, ident);
61 match &variant.fields {
62 syn::Fields::Named(named) => {
63 let captured = named.named.iter().map(|i| &i.ident);
64 let debugged = captured.clone().map(|i| {
65 quote::quote_spanned!(i.span() =>
66 .field(stringify!(#i), &#i)
67 )
68 });
69 quote::quote!(
70 Self::#ident { #( ref #captured, )* } => {
71 fmt.debug_struct(#full_variant_str)
72 #( #debugged )*
73 .finish()
74 }
75 )
76 },
77 syn::Fields::Unnamed(unnamed) => {
78 let captured = unnamed
79 .unnamed
80 .iter()
81 .enumerate()
82 .map(|(i, f)| syn::Ident::new(&format!("_{}", i), f.span()));
83 let debugged = captured
84 .clone()
85 .map(|i| quote::quote_spanned!(i.span() => .field(&#i)));
86 quote::quote!(
87 Self::#ident ( #( ref #captured, )* ) => {
88 fmt.debug_tuple(#full_variant_str)
89 #( #debugged )*
90 .finish()
91 }
92 )
93 },
94 syn::Fields::Unit => quote::quote!(
95 Self::#ident => fmt.write_str(#full_variant_str)
96 ),
97 }
98 });
99
100 quote::quote!(match *self {
101 #( #variants, )*
102 })
103 },
104 syn::Data::Union(_) => {
105 let msg = "Union type not supported by `derive(DebugNoBound)`";
106 return syn::Error::new(input.span(), msg).to_compile_error().into()
107 },
108 };
109
110 quote::quote!(
111 const _: () = {
112 #[automatically_derived]
113 #[allow(deprecated)]
114 impl #impl_generics ::core::fmt::Debug for #input_ident #ty_generics #where_clause {
115 fn fmt(&self, fmt: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
116 #impl_
117 }
118 }
119 };
120 )
121 .into()
122}