1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306
#![recursion_limit="128"] extern crate proc_macro; use quote::{quote, quote_spanned}; use syn::{parse_macro_input, Fields, DeriveInput, Data}; use syn::spanned::Spanned; use deriving::{has_attribute, normalized_fields, is_fields_variant_unnamed, normalized_variant_match_cause}; use proc_macro::TokenStream; #[proc_macro_derive(IntoTree, attributes(bm))] pub fn into_tree_derive(input: TokenStream) -> TokenStream { let input = parse_macro_input!(input as DeriveInput); let name = &input.ident; let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl(); let build_fields = |fs, prefix| { let where_fields = normalized_fields(fs) .iter() .map(|f| { let ty = &f.1.ty; if has_attribute("bm", &f.1.attrs, "compact") { quote_spanned! { f.1.span() => for<'a> bm_le::CompactRef<'a, #ty>: bm_le::IntoTree } } else { quote_spanned! { f.1.span() => #ty: bm_le::IntoTree } } }).collect::<Vec<_>>(); let fields = normalized_fields(fs) .iter() .map(|f| { let ident = &f.0; if has_attribute("bm", &f.1.attrs, "compact") { quote_spanned! { f.1.span() => { vector.push(bm_le::IntoTree::into_tree(&bm_le::CompactRef(#prefix #ident), db)?); } } } else { quote_spanned! { f.1.span() => { vector.push(bm_le::IntoTree::into_tree(#prefix #ident, db)?); } } } }).collect::<Vec<_>>(); let inner = quote! { let mut vector = Vec::new(); #(#fields)* bm_le::utils::vector_tree(&vector, db, None) }; (where_fields, inner) }; let (where_fields, inner) = match input.data { Data::Struct(ref data) => { let (where_fields, inner) = build_fields(&data.fields, quote! { &self. }); (where_fields, inner) }, Data::Enum(ref data) => { let mut where_fields = Vec::new(); let variants = data.variants .iter() .enumerate() .map(|(i, variant)| { let (mut variant_where_fields, variant_inner) = build_fields( &variant.fields, if is_fields_variant_unnamed(variant) { quote! { variant. } } else { quote! {} } ); where_fields.append(&mut variant_where_fields); normalized_variant_match_cause(&input.ident, &variant, quote! { let vector_root = { #variant_inner }?; bm_le::utils::mix_in_type(&vector_root, db, #i) }) }).collect::<Vec<_>>(); (where_fields, quote! { match self { #(#variants)* } }) }, Data::Union(_) => panic!("Unsupported"), }; let expanded = quote! { impl #impl_generics bm_le::IntoTree for #name #ty_generics where #where_clause #(#where_fields),* { fn into_tree<DB: bm_le::WriteBackend>( &self, db: &mut DB ) -> Result<<DB::Construct as bm_le::Construct>::Value, bm_le::Error<DB::Error>> where DB::Construct: bm_le::CompatibleConstruct { #inner } } }; proc_macro::TokenStream::from(expanded) } #[proc_macro_derive(FromTree, attributes(bm))] pub fn from_tree_derive(input: TokenStream) -> TokenStream { let input = parse_macro_input!(input as DeriveInput); let name = input.ident; let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl(); let build_fields = |fs| { let where_fields = normalized_fields(fs) .iter() .map(|f| { let ty = &f.1.ty; if has_attribute("bm", &f.1.attrs, "compact") { quote_spanned! { f.1.span() => bm_le::Compact<#ty>: bm_le::FromTree } } else { quote_spanned! { f.1.span() => #ty: bm_le::FromTree } } }).collect::<Vec<_>>(); let fields = normalized_fields(fs) .iter() .enumerate() .map(|(i, f)| { let name = &f.0; let ty = &f.1.ty; (quote_spanned! { f.1.span() => #name }, if has_attribute("bm", &f.1.attrs, "compact") { quote_spanned! { f.1.span() => <bm_le::Compact<#ty> as bm_le::FromTree>::from_tree( &vector.get(db, #i)?, db, )?.0 } } else { quote_spanned! { f.1.span() => bm_le::FromTree::from_tree( &vector.get(db, #i)?, db, )? } }) }).collect::<Vec<_>>(); (where_fields, fields) }; let (where_fields, inner) = match input.data { Data::Struct(ref data) => { let (where_fields, fields) = build_fields(&data.fields); let fields_count = fields.iter().count(); let fields = fields.into_iter().map(|f| { let name = f.0; let value = f.1; quote! { #name: #value, } }); let inner = quote! { { use bm_le::Leak; let vector = bm_le::DanglingVector::<DB::Construct>::from_leaked( (root.clone(), #fields_count, None) ); Ok(Self { #(#fields)* }) } }; (where_fields, inner) }, Data::Enum(ref data) => { let mut where_fields = Vec::new(); let variants = data.variants .iter() .enumerate() .map(|(i, variant)| { let (mut variant_where_fields, variant_fields) = build_fields( &variant.fields, ); let ident = &variant.ident; where_fields.append(&mut variant_where_fields); let fields_count = variant_fields.iter().count(); match variant.fields { Fields::Named(_) => { let fields = variant_fields.into_iter().map(|f| { let name = f.0; let value = f.1; quote! { #name: #value, } }); quote! { #i => { use bm_le::Leak; let vector = bm_le::DanglingVector::<DB::Construct>::from_leaked( (vector_root.clone(), #fields_count, None) ); Ok(#name::#ident { #(#fields)* }) }, } }, Fields::Unnamed(_) => { let fields = variant_fields.into_iter().map(|f| { let value = f.1; quote! { #value, } }); quote! { #i => { use bm_le::Leak; let vector = bm_le::DanglingVector::<DB::Construct>::from_leaked( (vector_root.clone(), #fields_count, None) ); Ok(#name::#ident( #(#fields)* )) }, } }, Fields::Unit => { quote! { #i => { if vector_root != &Default::default() { return Err(bm_le::Error::CorruptedDatabase) } Ok(#name::#ident) }, } }, } }).collect::<Vec<_>>(); (where_fields, quote! { bm_le::utils::decode_with_type(root, db, |vector_root, db, ty| { match ty { #(#variants)* _ => return Err(bm_le::Error::CorruptedDatabase) } }) }) }, Data::Union(_) => panic!("Not supported"), }; let expanded = quote! { impl #impl_generics bm_le::FromTree for #name #ty_generics where #where_clause #(#where_fields),* { fn from_tree<DB: bm_le::ReadBackend>( root: &<DB::Construct as bm_le::Construct>::Value, db: &mut DB, ) -> Result<Self, bm_le::Error<DB::Error>> where DB::Construct: bm_le::CompatibleConstruct { #inner } } }; proc_macro::TokenStream::from(expanded) }