compiler/rustc_ast_pretty/src/pprust/state/item.rs

   1 use crate::pp::Breaks::Inconsistent;
   2 use crate::pprust::state::delimited::IterDelimited;
   3 use crate::pprust::state::{AnnNode, PrintState, State, INDENT_UNIT};
   4
   5 use rustc_ast as ast;
   6 use rustc_ast::GenericBound;
   7 use rustc_ast::ModKind;
   8 use rustc_span::symbol::Ident;
   9
  10 fn visibility_qualified(vis: &ast::Visibility, s: &str) -> String {
  11     format!("{}{}", State::to_string(|s| s.print_visibility(vis)), s)
  12 }
  13
  14 impl<'a> State<'a> {
  15     fn print_foreign_mod(&mut self, nmod: &ast::ForeignMod, attrs: &[ast::Attribute]) {
  16         self.print_inner_attributes(attrs);
  17         for item in &nmod.items {
  18             self.print_foreign_item(item);
  19         }
  20     }
  21
  22     fn print_foreign_item(&mut self, item: &ast::ForeignItem) {
  23         let ast::Item { id, span, ident, ref attrs, ref kind, ref vis, tokens: _ } = *item;
  24         self.ann.pre(self, AnnNode::SubItem(id));
  25         self.hardbreak_if_not_bol();
  26         self.maybe_print_comment(span.lo());
  27         self.print_outer_attributes(attrs);
  28         match kind {
  29             ast::ForeignItemKind::Fn(box ast::Fn { defaultness, sig, generics, body }) => {
  30                 self.print_fn_full(sig, ident, generics, vis, *defaultness, body.as_deref(), attrs);
  31             }
  32             ast::ForeignItemKind::Static(ty, mutbl, body) => {
  33                 let def = ast::Defaultness::Final;
  34                 self.print_item_const(ident, Some(*mutbl), ty, body.as_deref(), vis, def);
  35             }
  36             ast::ForeignItemKind::TyAlias(box ast::TyAlias {
  37                 defaultness,
  38                 generics,
  39                 bounds,
  40                 ty,
  41             }) => {
  42                 self.print_associated_type(
  43                     ident,
  44                     generics,
  45                     bounds,
  46                     ty.as_deref(),
  47                     vis,
  48                     *defaultness,
  49                 );
  50             }
  51             ast::ForeignItemKind::MacCall(m) => {
  52                 self.print_mac(m);
  53                 if m.args.need_semicolon() {
  54                     self.word(";");
  55                 }
  56             }
  57         }
  58         self.ann.post(self, AnnNode::SubItem(id))
  59     }
  60
  61     fn print_item_const(
  62         &mut self,
  63         ident: Ident,
  64         mutbl: Option<ast::Mutability>,
  65         ty: &ast::Ty,
  66         body: Option<&ast::Expr>,
  67         vis: &ast::Visibility,
  68         defaultness: ast::Defaultness,
  69     ) {
  70         self.head("");
  71         self.print_visibility(vis);
  72         self.print_defaultness(defaultness);
  73         let leading = match mutbl {
  74             None => "const",
  75             Some(ast::Mutability::Not) => "static",
  76             Some(ast::Mutability::Mut) => "static mut",
  77         };
  78         self.word_space(leading);
  79         self.print_ident(ident);
  80         self.word_space(":");
  81         self.print_type(ty);
  82         if body.is_some() {
  83             self.space();
  84         }
  85         self.end(); // end the head-ibox
  86         if let Some(body) = body {
  87             self.word_space("=");
  88             self.print_expr(body);
  89         }
  90         self.word(";");
  91         self.end(); // end the outer cbox
  92     }
  93
  94     fn print_associated_type(
  95         &mut self,
  96         ident: Ident,
  97         generics: &ast::Generics,
  98         bounds: &ast::GenericBounds,
  99         ty: Option<&ast::Ty>,
 100         vis: &ast::Visibility,
 101         defaultness: ast::Defaultness,
 102     ) {
 103         self.head("");
 104         self.print_visibility(vis);
 105         self.print_defaultness(defaultness);
 106         self.word_space("type");
 107         self.print_ident(ident);
 108         self.print_generic_params(&generics.params);
 109         self.print_type_bounds(":", bounds);
 110         self.print_where_clause(&generics.where_clause);
 111         if let Some(ty) = ty {
 112             self.space();
 113             self.word_space("=");
 114             self.print_type(ty);
 115         }
 116         self.word(";");
 117         self.end(); // end inner head-block
 118         self.end(); // end outer head-block
 119     }
 120
 121     /// Pretty-prints an item.
 122     crate fn print_item(&mut self, item: &ast::Item) {
 123         self.hardbreak_if_not_bol();
 124         self.maybe_print_comment(item.span.lo());
 125         self.print_outer_attributes(&item.attrs);
 126         self.ann.pre(self, AnnNode::Item(item));
 127         match item.kind {
 128             ast::ItemKind::ExternCrate(orig_name) => {
 129                 self.head(visibility_qualified(&item.vis, "extern crate"));
 130                 if let Some(orig_name) = orig_name {
 131                     self.print_name(orig_name);
 132                     self.space();
 133                     self.word("as");
 134                     self.space();
 135                 }
 136                 self.print_ident(item.ident);
 137                 self.word(";");
 138                 self.end(); // end inner head-block
 139                 self.end(); // end outer head-block
 140             }
 141             ast::ItemKind::Use(ref tree) => {
 142                 self.print_visibility(&item.vis);
 143                 self.word_nbsp("use");
 144                 self.print_use_tree(tree);
 145                 self.word(";");
 146             }
 147             ast::ItemKind::Static(ref ty, mutbl, ref body) => {
 148                 let def = ast::Defaultness::Final;
 149                 self.print_item_const(item.ident, Some(mutbl), ty, body.as_deref(), &item.vis, def);
 150             }
 151             ast::ItemKind::Const(def, ref ty, ref body) => {
 152                 self.print_item_const(item.ident, None, ty, body.as_deref(), &item.vis, def);
 153             }
 154             ast::ItemKind::Fn(box ast::Fn { defaultness, ref sig, ref generics, ref body }) => {
 155                 let body = body.as_deref();
 156                 self.print_fn_full(
 157                     sig,
 158                     item.ident,
 159                     generics,
 160                     &item.vis,
 161                     defaultness,
 162                     body,
 163                     &item.attrs,
 164                 );
 165             }
 166             ast::ItemKind::Mod(unsafety, ref mod_kind) => {
 167                 self.head(Self::to_string(|s| {
 168                     s.print_visibility(&item.vis);
 169                     s.print_unsafety(unsafety);
 170                     s.word("mod");
 171                 }));
 172                 self.print_ident(item.ident);
 173
 174                 match mod_kind {
 175                     ModKind::Loaded(items, ..) => {
 176                         self.nbsp();
 177                         self.bopen();
 178                         self.print_inner_attributes(&item.attrs);
 179                         for item in items {
 180                             self.print_item(item);
 181                         }
 182                         let empty = item.attrs.is_empty() && items.is_empty();
 183                         self.bclose(item.span, empty);
 184                     }
 185                     ModKind::Unloaded => {
 186                         self.word(";");
 187                         self.end(); // end inner head-block
 188                         self.end(); // end outer head-block
 189                     }
 190                 }
 191             }
 192             ast::ItemKind::ForeignMod(ref nmod) => {
 193                 self.head(Self::to_string(|s| {
 194                     s.print_unsafety(nmod.unsafety);
 195                     s.word("extern");
 196                 }));
 197                 if let Some(abi) = nmod.abi {
 198                     self.print_literal(&abi.as_lit());
 199                     self.nbsp();
 200                 }
 201                 self.bopen();
 202                 self.print_foreign_mod(nmod, &item.attrs);
 203                 let empty = item.attrs.is_empty() && nmod.items.is_empty();
 204                 self.bclose(item.span, empty);
 205             }
 206             ast::ItemKind::GlobalAsm(ref asm) => {
 207                 self.head(visibility_qualified(&item.vis, "global_asm!"));
 208                 self.print_inline_asm(asm);
 209                 self.end();
 210             }
 211             ast::ItemKind::TyAlias(box ast::TyAlias {
 212                 defaultness,
 213                 ref generics,
 214                 ref bounds,
 215                 ref ty,
 216             }) => {
 217                 let ty = ty.as_deref();
 218                 self.print_associated_type(
 219                     item.ident,
 220                     generics,
 221                     bounds,
 222                     ty,
 223                     &item.vis,
 224                     defaultness,
 225                 );
 226             }
 227             ast::ItemKind::Enum(ref enum_definition, ref params) => {
 228                 self.print_enum_def(enum_definition, params, item.ident, item.span, &item.vis);
 229             }
 230             ast::ItemKind::Struct(ref struct_def, ref generics) => {
 231                 self.head(visibility_qualified(&item.vis, "struct"));
 232                 self.print_struct(struct_def, generics, item.ident, item.span, true);
 233             }
 234             ast::ItemKind::Union(ref struct_def, ref generics) => {
 235                 self.head(visibility_qualified(&item.vis, "union"));
 236                 self.print_struct(struct_def, generics, item.ident, item.span, true);
 237             }
 238             ast::ItemKind::Impl(box ast::Impl {
 239                 unsafety,
 240                 polarity,
 241                 defaultness,
 242                 constness,
 243                 ref generics,
 244                 ref of_trait,
 245                 ref self_ty,
 246                 ref items,
 247             }) => {
 248                 self.head("");
 249                 self.print_visibility(&item.vis);
 250                 self.print_defaultness(defaultness);
 251                 self.print_unsafety(unsafety);
 252                 self.word("impl");
 253
 254                 if generics.params.is_empty() {
 255                     self.nbsp();
 256                 } else {
 257                     self.print_generic_params(&generics.params);
 258                     self.space();
 259                 }
 260
 261                 self.print_constness(constness);
 262
 263                 if let ast::ImplPolarity::Negative(_) = polarity {
 264                     self.word("!");
 265                 }
 266
 267                 if let Some(ref t) = *of_trait {
 268                     self.print_trait_ref(t);
 269                     self.space();
 270                     self.word_space("for");
 271                 }
 272
 273                 self.print_type(self_ty);
 274                 self.print_where_clause(&generics.where_clause);
 275
 276                 self.space();
 277                 self.bopen();
 278                 self.print_inner_attributes(&item.attrs);
 279                 for impl_item in items {
 280                     self.print_assoc_item(impl_item);
 281                 }
 282                 let empty = item.attrs.is_empty() && items.is_empty();
 283                 self.bclose(item.span, empty);
 284             }
 285             ast::ItemKind::Trait(box ast::Trait {
 286                 is_auto,
 287                 unsafety,
 288                 ref generics,
 289                 ref bounds,
 290                 ref items,
 291                 ..
 292             }) => {
 293                 self.head("");
 294                 self.print_visibility(&item.vis);
 295                 self.print_unsafety(unsafety);
 296                 self.print_is_auto(is_auto);
 297                 self.word_nbsp("trait");
 298                 self.print_ident(item.ident);
 299                 self.print_generic_params(&generics.params);
 300                 let mut real_bounds = Vec::with_capacity(bounds.len());
 301                 for b in bounds.iter() {
 302                     if let GenericBound::Trait(ref ptr, ast::TraitBoundModifier::Maybe) = *b {
 303                         self.space();
 304                         self.word_space("for ?");
 305                         self.print_trait_ref(&ptr.trait_ref);
 306                     } else {
 307                         real_bounds.push(b.clone());
 308                     }
 309                 }
 310                 self.print_type_bounds(":", &real_bounds);
 311                 self.print_where_clause(&generics.where_clause);
 312                 self.word(" ");
 313                 self.bopen();
 314                 self.print_inner_attributes(&item.attrs);
 315                 for trait_item in items {
 316                     self.print_assoc_item(trait_item);
 317                 }
 318                 let empty = item.attrs.is_empty() && items.is_empty();
 319                 self.bclose(item.span, empty);
 320             }
 321             ast::ItemKind::TraitAlias(ref generics, ref bounds) => {
 322                 self.head(visibility_qualified(&item.vis, "trait"));
 323                 self.print_ident(item.ident);
 324                 self.print_generic_params(&generics.params);
 325                 let mut real_bounds = Vec::with_capacity(bounds.len());
 326                 // FIXME(durka) this seems to be some quite outdated syntax
 327                 for b in bounds.iter() {
 328                     if let GenericBound::Trait(ref ptr, ast::TraitBoundModifier::Maybe) = *b {
 329                         self.space();
 330                         self.word_space("for ?");
 331                         self.print_trait_ref(&ptr.trait_ref);
 332                     } else {
 333                         real_bounds.push(b.clone());
 334                     }
 335                 }
 336                 self.nbsp();
 337                 self.print_type_bounds("=", &real_bounds);
 338                 self.print_where_clause(&generics.where_clause);
 339                 self.word(";");
 340                 self.end(); // end inner head-block
 341                 self.end(); // end outer head-block
 342             }
 343             ast::ItemKind::MacCall(ref mac) => {
 344                 self.print_mac(mac);
 345                 if mac.args.need_semicolon() {
 346                     self.word(";");
 347                 }
 348             }
 349             ast::ItemKind::MacroDef(ref macro_def) => {
 350                 self.print_mac_def(macro_def, &item.ident, item.span, |state| {
 351                     state.print_visibility(&item.vis)
 352                 });
 353             }
 354         }
 355         self.ann.post(self, AnnNode::Item(item))
 356     }
 357
 358     fn print_enum_def(
 359         &mut self,
 360         enum_definition: &ast::EnumDef,
 361         generics: &ast::Generics,
 362         ident: Ident,
 363         span: rustc_span::Span,
 364         visibility: &ast::Visibility,
 365     ) {
 366         self.head(visibility_qualified(visibility, "enum"));
 367         self.print_ident(ident);
 368         self.print_generic_params(&generics.params);
 369         self.print_where_clause(&generics.where_clause);
 370         self.space();
 371         self.print_variants(&enum_definition.variants, span)
 372     }
 373
 374     fn print_variants(&mut self, variants: &[ast::Variant], span: rustc_span::Span) {
 375         self.bopen();
 376         for v in variants {
 377             self.space_if_not_bol();
 378             self.maybe_print_comment(v.span.lo());
 379             self.print_outer_attributes(&v.attrs);
 380             self.ibox(0);
 381             self.print_variant(v);
 382             self.word(",");
 383             self.end();
 384             self.maybe_print_trailing_comment(v.span, None);
 385         }
 386         let empty = variants.is_empty();
 387         self.bclose(span, empty)
 388     }
 389
 390     crate fn print_visibility(&mut self, vis: &ast::Visibility) {
 391         match vis.kind {
 392             ast::VisibilityKind::Public => self.word_nbsp("pub"),
 393             ast::VisibilityKind::Crate(sugar) => match sugar {
 394                 ast::CrateSugar::PubCrate => self.word_nbsp("pub(crate)"),
 395                 ast::CrateSugar::JustCrate => self.word_nbsp("crate"),
 396             },
 397             ast::VisibilityKind::Restricted { ref path, .. } => {
 398                 let path = Self::to_string(|s| s.print_path(path, false, 0));
 399                 if path == "self" || path == "super" {
 400                     self.word_nbsp(format!("pub({})", path))
 401                 } else {
 402                     self.word_nbsp(format!("pub(in {})", path))
 403                 }
 404             }
 405             ast::VisibilityKind::Inherited => {}
 406         }
 407     }
 408
 409     fn print_defaultness(&mut self, defaultness: ast::Defaultness) {
 410         if let ast::Defaultness::Default(_) = defaultness {
 411             self.word_nbsp("default");
 412         }
 413     }
 414
 415     fn print_record_struct_body(&mut self, fields: &[ast::FieldDef], span: rustc_span::Span) {
 416         self.nbsp();
 417         self.bopen();
 418
 419         let empty = fields.is_empty();
 420         if !empty {
 421             self.hardbreak_if_not_bol();
 422
 423             for field in fields {
 424                 self.hardbreak_if_not_bol();
 425                 self.maybe_print_comment(field.span.lo());
 426                 self.print_outer_attributes(&field.attrs);
 427                 self.print_visibility(&field.vis);
 428                 self.print_ident(field.ident.unwrap());
 429                 self.word_nbsp(":");
 430                 self.print_type(&field.ty);
 431                 self.word(",");
 432             }
 433         }
 434
 435         self.bclose(span, empty);
 436     }
 437
 438     fn print_struct(
 439         &mut self,
 440         struct_def: &ast::VariantData,
 441         generics: &ast::Generics,
 442         ident: Ident,
 443         span: rustc_span::Span,
 444         print_finalizer: bool,
 445     ) {
 446         self.print_ident(ident);
 447         self.print_generic_params(&generics.params);
 448         match struct_def {
 449             ast::VariantData::Tuple(..) | ast::VariantData::Unit(..) => {
 450                 if let ast::VariantData::Tuple(..) = struct_def {
 451                     self.popen();
 452                     self.commasep(Inconsistent, struct_def.fields(), |s, field| {
 453                         s.maybe_print_comment(field.span.lo());
 454                         s.print_outer_attributes(&field.attrs);
 455                         s.print_visibility(&field.vis);
 456                         s.print_type(&field.ty)
 457                     });
 458                     self.pclose();
 459                 }
 460                 self.print_where_clause(&generics.where_clause);
 461                 if print_finalizer {
 462                     self.word(";");
 463                 }
 464                 self.end();
 465                 self.end(); // Close the outer-box.
 466             }
 467             ast::VariantData::Struct(ref fields, ..) => {
 468                 self.print_where_clause(&generics.where_clause);
 469                 self.print_record_struct_body(fields, span);
 470             }
 471         }
 472     }
 473
 474     crate fn print_variant(&mut self, v: &ast::Variant) {
 475         self.head("");
 476         self.print_visibility(&v.vis);
 477         let generics = ast::Generics::default();
 478         self.print_struct(&v.data, &generics, v.ident, v.span, false);
 479         if let Some(ref d) = v.disr_expr {
 480             self.space();
 481             self.word_space("=");
 482             self.print_expr(&d.value)
 483         }
 484     }
 485
 486     fn print_assoc_item(&mut self, item: &ast::AssocItem) {
 487         let ast::Item { id, span, ident, ref attrs, ref kind, ref vis, tokens: _ } = *item;
 488         self.ann.pre(self, AnnNode::SubItem(id));
 489         self.hardbreak_if_not_bol();
 490         self.maybe_print_comment(span.lo());
 491         self.print_outer_attributes(attrs);
 492         match kind {
 493             ast::AssocItemKind::Fn(box ast::Fn { defaultness, sig, generics, body }) => {
 494                 self.print_fn_full(sig, ident, generics, vis, *defaultness, body.as_deref(), attrs);
 495             }
 496             ast::AssocItemKind::Const(def, ty, body) => {
 497                 self.print_item_const(ident, None, ty, body.as_deref(), vis, *def);
 498             }
 499             ast::AssocItemKind::TyAlias(box ast::TyAlias { defaultness, generics, bounds, ty }) => {
 500                 self.print_associated_type(
 501                     ident,
 502                     generics,
 503                     bounds,
 504                     ty.as_deref(),
 505                     vis,
 506                     *defaultness,
 507                 );
 508             }
 509             ast::AssocItemKind::MacCall(m) => {
 510                 self.print_mac(m);
 511                 if m.args.need_semicolon() {
 512                     self.word(";");
 513                 }
 514             }
 515         }
 516         self.ann.post(self, AnnNode::SubItem(id))
 517     }
 518
 519     fn print_fn_full(
 520         &mut self,
 521         sig: &ast::FnSig,
 522         name: Ident,
 523         generics: &ast::Generics,
 524         vis: &ast::Visibility,
 525         defaultness: ast::Defaultness,
 526         body: Option<&ast::Block>,
 527         attrs: &[ast::Attribute],
 528     ) {
 529         if body.is_some() {
 530             self.head("");
 531         }
 532         self.print_visibility(vis);
 533         self.print_defaultness(defaultness);
 534         self.print_fn(&sig.decl, sig.header, Some(name), generics);
 535         if let Some(body) = body {
 536             self.nbsp();
 537             self.print_block_with_attrs(body, attrs);
 538         } else {
 539             self.word(";");
 540         }
 541     }
 542
 543     crate fn print_fn(
 544         &mut self,
 545         decl: &ast::FnDecl,
 546         header: ast::FnHeader,
 547         name: Option<Ident>,
 548         generics: &ast::Generics,
 549     ) {
 550         self.print_fn_header_info(header);
 551         if let Some(name) = name {
 552             self.nbsp();
 553             self.print_ident(name);
 554         }
 555         self.print_generic_params(&generics.params);
 556         self.print_fn_params_and_ret(decl, false);
 557         self.print_where_clause(&generics.where_clause)
 558     }
 559
 560     crate fn print_fn_params_and_ret(&mut self, decl: &ast::FnDecl, is_closure: bool) {
 561         let (open, close) = if is_closure { ("|", "|") } else { ("(", ")") };
 562         self.word(open);
 563         self.commasep(Inconsistent, &decl.inputs, |s, param| s.print_param(param, is_closure));
 564         self.word(close);
 565         self.print_fn_ret_ty(&decl.output)
 566     }
 567
 568     fn print_where_clause(&mut self, where_clause: &ast::WhereClause) {
 569         if where_clause.predicates.is_empty() && !where_clause.has_where_token {
 570             return;
 571         }
 572
 573         self.space();
 574         self.word_space("where");
 575
 576         for (i, predicate) in where_clause.predicates.iter().enumerate() {
 577             if i != 0 {
 578                 self.word_space(",");
 579             }
 580
 581             self.print_where_predicate(predicate);
 582         }
 583     }
 584
 585     pub fn print_where_predicate(&mut self, predicate: &ast::WherePredicate) {
 586         match predicate {
 587             ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate {
 588                 bound_generic_params,
 589                 bounded_ty,
 590                 bounds,
 591                 ..
 592             }) => {
 593                 self.print_formal_generic_params(bound_generic_params);
 594                 self.print_type(bounded_ty);
 595                 self.print_type_bounds(":", bounds);
 596             }
 597             ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate {
 598                 lifetime,
 599                 bounds,
 600                 ..
 601             }) => {
 602                 self.print_lifetime_bounds(*lifetime, bounds);
 603             }
 604             ast::WherePredicate::EqPredicate(ast::WhereEqPredicate { lhs_ty, rhs_ty, .. }) => {
 605                 self.print_type(lhs_ty);
 606                 self.space();
 607                 self.word_space("=");
 608                 self.print_type(rhs_ty);
 609             }
 610         }
 611     }
 612
 613     fn print_use_tree(&mut self, tree: &ast::UseTree) {
 614         match tree.kind {
 615             ast::UseTreeKind::Simple(rename, ..) => {
 616                 self.print_path(&tree.prefix, false, 0);
 617                 if let Some(rename) = rename {
 618                     self.nbsp();
 619                     self.word_nbsp("as");
 620                     self.print_ident(rename);
 621                 }
 622             }
 623             ast::UseTreeKind::Glob => {
 624                 if !tree.prefix.segments.is_empty() {
 625                     self.print_path(&tree.prefix, false, 0);
 626                     self.word("::");
 627                 }
 628                 self.word("*");
 629             }
 630             ast::UseTreeKind::Nested(ref items) => {
 631                 if !tree.prefix.segments.is_empty() {
 632                     self.print_path(&tree.prefix, false, 0);
 633                     self.word("::");
 634                 }
 635                 if items.is_empty() {
 636                     self.word("{}");
 637                 } else if items.len() == 1 {
 638                     self.print_use_tree(&items[0].0);
 639                 } else {
 640                     self.cbox(INDENT_UNIT);
 641                     self.word("{");
 642                     self.zerobreak();
 643                     self.ibox(0);
 644                     for use_tree in items.iter().delimited() {
 645                         self.print_use_tree(&use_tree.0);
 646                         if !use_tree.is_last {
 647                             self.word(",");
 648                             if let ast::UseTreeKind::Nested(_) = use_tree.0.kind {
 649                                 self.hardbreak();
 650                             } else {
 651                                 self.space();
 652                             }
 653                         }
 654                     }
 655                     self.end();
 656                     self.trailing_comma();
 657                     self.offset(-INDENT_UNIT);
 658                     self.word("}");
 659                     self.end();
 660                 }
 661             }
 662         }
 663     }
 664 }