compiler/rustc_expand/src/build.rs

   1 use crate::base::ExtCtxt;
   2
   3 use rustc_ast::attr;
   4 use rustc_ast::ptr::P;
   5 use rustc_ast::{self as ast, AttrVec, BlockCheckMode, Expr, PatKind, UnOp};
   6 use rustc_span::source_map::Spanned;
   7 use rustc_span::symbol::{kw, sym, Ident, Symbol};
   8
   9 use rustc_span::Span;
  10
  11 impl<'a> ExtCtxt<'a> {
  12     pub fn path(&self, span: Span, strs: Vec<Ident>) -> ast::Path {
  13         self.path_all(span, false, strs, vec![])
  14     }
  15     pub fn path_ident(&self, span: Span, id: Ident) -> ast::Path {
  16         self.path(span, vec![id])
  17     }
  18     pub fn path_global(&self, span: Span, strs: Vec<Ident>) -> ast::Path {
  19         self.path_all(span, true, strs, vec![])
  20     }
  21     pub fn path_all(
  22         &self,
  23         span: Span,
  24         global: bool,
  25         mut idents: Vec<Ident>,
  26         args: Vec<ast::GenericArg>,
  27     ) -> ast::Path {
  28         assert!(!idents.is_empty());
  29         let add_root = global && !idents[0].is_path_segment_keyword();
  30         let mut segments = Vec::with_capacity(idents.len() + add_root as usize);
  31         if add_root {
  32             segments.push(ast::PathSegment::path_root(span));
  33         }
  34         let last_ident = idents.pop().unwrap();
  35         segments.extend(
  36             idents.into_iter().map(|ident| ast::PathSegment::from_ident(ident.with_span_pos(span))),
  37         );
  38         let args = if !args.is_empty() {
  39             let args = args.into_iter().map(ast::AngleBracketedArg::Arg).collect();
  40             ast::AngleBracketedArgs { args, span }.into()
  41         } else {
  42             None
  43         };
  44         segments.push(ast::PathSegment {
  45             ident: last_ident.with_span_pos(span),
  46             id: ast::DUMMY_NODE_ID,
  47             args,
  48         });
  49         ast::Path { span, segments, tokens: None }
  50     }
  51
  52     pub fn ty_mt(&self, ty: P<ast::Ty>, mutbl: ast::Mutability) -> ast::MutTy {
  53         ast::MutTy { ty, mutbl }
  54     }
  55
  56     pub fn ty(&self, span: Span, kind: ast::TyKind) -> P<ast::Ty> {
  57         P(ast::Ty { id: ast::DUMMY_NODE_ID, span, kind, tokens: None })
  58     }
  59
  60     pub fn ty_path(&self, path: ast::Path) -> P<ast::Ty> {
  61         self.ty(path.span, ast::TyKind::Path(None, path))
  62     }
  63
  64     // Might need to take bounds as an argument in the future, if you ever want
  65     // to generate a bounded existential trait type.
  66     pub fn ty_ident(&self, span: Span, ident: Ident) -> P<ast::Ty> {
  67         self.ty_path(self.path_ident(span, ident))
  68     }
  69
  70     pub fn anon_const(&self, span: Span, kind: ast::ExprKind) -> ast::AnonConst {
  71         ast::AnonConst {
  72             id: ast::DUMMY_NODE_ID,
  73             value: P(ast::Expr {
  74                 id: ast::DUMMY_NODE_ID,
  75                 kind,
  76                 span,
  77                 attrs: AttrVec::new(),
  78                 tokens: None,
  79             }),
  80         }
  81     }
  82
  83     pub fn const_ident(&self, span: Span, ident: Ident) -> ast::AnonConst {
  84         self.anon_const(span, ast::ExprKind::Path(None, self.path_ident(span, ident)))
  85     }
  86
  87     pub fn ty_rptr(
  88         &self,
  89         span: Span,
  90         ty: P<ast::Ty>,
  91         lifetime: Option<ast::Lifetime>,
  92         mutbl: ast::Mutability,
  93     ) -> P<ast::Ty> {
  94         self.ty(span, ast::TyKind::Rptr(lifetime, self.ty_mt(ty, mutbl)))
  95     }
  96
  97     pub fn ty_ptr(&self, span: Span, ty: P<ast::Ty>, mutbl: ast::Mutability) -> P<ast::Ty> {
  98         self.ty(span, ast::TyKind::Ptr(self.ty_mt(ty, mutbl)))
  99     }
 100
 101     pub fn typaram(
 102         &self,
 103         span: Span,
 104         ident: Ident,
 105         attrs: Vec<ast::Attribute>,
 106         bounds: ast::GenericBounds,
 107         default: Option<P<ast::Ty>>,
 108     ) -> ast::GenericParam {
 109         ast::GenericParam {
 110             ident: ident.with_span_pos(span),
 111             id: ast::DUMMY_NODE_ID,
 112             attrs: attrs.into(),
 113             bounds,
 114             kind: ast::GenericParamKind::Type { default },
 115             is_placeholder: false,
 116         }
 117     }
 118
 119     pub fn trait_ref(&self, path: ast::Path) -> ast::TraitRef {
 120         ast::TraitRef { path, ref_id: ast::DUMMY_NODE_ID }
 121     }
 122
 123     pub fn poly_trait_ref(&self, span: Span, path: ast::Path) -> ast::PolyTraitRef {
 124         ast::PolyTraitRef {
 125             bound_generic_params: Vec::new(),
 126             trait_ref: self.trait_ref(path),
 127             span,
 128         }
 129     }
 130
 131     pub fn trait_bound(&self, path: ast::Path) -> ast::GenericBound {
 132         ast::GenericBound::Trait(
 133             self.poly_trait_ref(path.span, path),
 134             ast::TraitBoundModifier::None,
 135         )
 136     }
 137
 138     pub fn lifetime(&self, span: Span, ident: Ident) -> ast::Lifetime {
 139         ast::Lifetime { id: ast::DUMMY_NODE_ID, ident: ident.with_span_pos(span) }
 140     }
 141
 142     pub fn lifetime_def(
 143         &self,
 144         span: Span,
 145         ident: Ident,
 146         attrs: Vec<ast::Attribute>,
 147         bounds: ast::GenericBounds,
 148     ) -> ast::GenericParam {
 149         let lifetime = self.lifetime(span, ident);
 150         ast::GenericParam {
 151             ident: lifetime.ident,
 152             id: lifetime.id,
 153             attrs: attrs.into(),
 154             bounds,
 155             kind: ast::GenericParamKind::Lifetime,
 156             is_placeholder: false,
 157         }
 158     }
 159
 160     pub fn stmt_expr(&self, expr: P<ast::Expr>) -> ast::Stmt {
 161         ast::Stmt {
 162             id: ast::DUMMY_NODE_ID,
 163             span: expr.span,
 164             kind: ast::StmtKind::Expr(expr),
 165             tokens: None,
 166         }
 167     }
 168
 169     pub fn stmt_let(&self, sp: Span, mutbl: bool, ident: Ident, ex: P<ast::Expr>) -> ast::Stmt {
 170         let pat = if mutbl {
 171             let binding_mode = ast::BindingMode::ByValue(ast::Mutability::Mut);
 172             self.pat_ident_binding_mode(sp, ident, binding_mode)
 173         } else {
 174             self.pat_ident(sp, ident)
 175         };
 176         let local = P(ast::Local {
 177             pat,
 178             ty: None,
 179             init: Some(ex),
 180             id: ast::DUMMY_NODE_ID,
 181             span: sp,
 182             attrs: AttrVec::new(),
 183         });
 184         ast::Stmt {
 185             id: ast::DUMMY_NODE_ID,
 186             kind: ast::StmtKind::Local(local),
 187             span: sp,
 188             tokens: None,
 189         }
 190     }
 191
 192     // Generates `let _: Type;`, which is usually used for type assertions.
 193     pub fn stmt_let_type_only(&self, span: Span, ty: P<ast::Ty>) -> ast::Stmt {
 194         let local = P(ast::Local {
 195             pat: self.pat_wild(span),
 196             ty: Some(ty),
 197             init: None,
 198             id: ast::DUMMY_NODE_ID,
 199             span,
 200             attrs: AttrVec::new(),
 201         });
 202         ast::Stmt { id: ast::DUMMY_NODE_ID, kind: ast::StmtKind::Local(local), span, tokens: None }
 203     }
 204
 205     pub fn stmt_item(&self, sp: Span, item: P<ast::Item>) -> ast::Stmt {
 206         ast::Stmt {
 207             id: ast::DUMMY_NODE_ID,
 208             kind: ast::StmtKind::Item(item),
 209             span: sp,
 210             tokens: None,
 211         }
 212     }
 213
 214     pub fn block_expr(&self, expr: P<ast::Expr>) -> P<ast::Block> {
 215         self.block(
 216             expr.span,
 217             vec![ast::Stmt {
 218                 id: ast::DUMMY_NODE_ID,
 219                 span: expr.span,
 220                 kind: ast::StmtKind::Expr(expr),
 221                 tokens: None,
 222             }],
 223         )
 224     }
 225     pub fn block(&self, span: Span, stmts: Vec<ast::Stmt>) -> P<ast::Block> {
 226         P(ast::Block {
 227             stmts,
 228             id: ast::DUMMY_NODE_ID,
 229             rules: BlockCheckMode::Default,
 230             span,
 231             tokens: None,
 232         })
 233     }
 234
 235     pub fn expr(&self, span: Span, kind: ast::ExprKind) -> P<ast::Expr> {
 236         P(ast::Expr { id: ast::DUMMY_NODE_ID, kind, span, attrs: AttrVec::new(), tokens: None })
 237     }
 238
 239     pub fn expr_path(&self, path: ast::Path) -> P<ast::Expr> {
 240         self.expr(path.span, ast::ExprKind::Path(None, path))
 241     }
 242
 243     pub fn expr_ident(&self, span: Span, id: Ident) -> P<ast::Expr> {
 244         self.expr_path(self.path_ident(span, id))
 245     }
 246     pub fn expr_self(&self, span: Span) -> P<ast::Expr> {
 247         self.expr_ident(span, Ident::with_dummy_span(kw::SelfLower))
 248     }
 249
 250     pub fn expr_binary(
 251         &self,
 252         sp: Span,
 253         op: ast::BinOpKind,
 254         lhs: P<ast::Expr>,
 255         rhs: P<ast::Expr>,
 256     ) -> P<ast::Expr> {
 257         self.expr(sp, ast::ExprKind::Binary(Spanned { node: op, span: sp }, lhs, rhs))
 258     }
 259
 260     pub fn expr_deref(&self, sp: Span, e: P<ast::Expr>) -> P<ast::Expr> {
 261         self.expr(sp, ast::ExprKind::Unary(UnOp::Deref, e))
 262     }
 263
 264     pub fn expr_addr_of(&self, sp: Span, e: P<ast::Expr>) -> P<ast::Expr> {
 265         self.expr(sp, ast::ExprKind::AddrOf(ast::BorrowKind::Ref, ast::Mutability::Not, e))
 266     }
 267
 268     pub fn expr_call(
 269         &self,
 270         span: Span,
 271         expr: P<ast::Expr>,
 272         args: Vec<P<ast::Expr>>,
 273     ) -> P<ast::Expr> {
 274         self.expr(span, ast::ExprKind::Call(expr, args))
 275     }
 276     pub fn expr_call_ident(&self, span: Span, id: Ident, args: Vec<P<ast::Expr>>) -> P<ast::Expr> {
 277         self.expr(span, ast::ExprKind::Call(self.expr_ident(span, id), args))
 278     }
 279     pub fn expr_call_global(
 280         &self,
 281         sp: Span,
 282         fn_path: Vec<Ident>,
 283         args: Vec<P<ast::Expr>>,
 284     ) -> P<ast::Expr> {
 285         let pathexpr = self.expr_path(self.path_global(sp, fn_path));
 286         self.expr_call(sp, pathexpr, args)
 287     }
 288     pub fn expr_method_call(
 289         &self,
 290         span: Span,
 291         expr: P<ast::Expr>,
 292         ident: Ident,
 293         mut args: Vec<P<ast::Expr>>,
 294     ) -> P<ast::Expr> {
 295         args.insert(0, expr);
 296         let segment = ast::PathSegment::from_ident(ident.with_span_pos(span));
 297         self.expr(span, ast::ExprKind::MethodCall(segment, args, span))
 298     }
 299     pub fn expr_block(&self, b: P<ast::Block>) -> P<ast::Expr> {
 300         self.expr(b.span, ast::ExprKind::Block(b, None))
 301     }
 302     pub fn field_imm(&self, span: Span, ident: Ident, e: P<ast::Expr>) -> ast::Field {
 303         ast::Field {
 304             ident: ident.with_span_pos(span),
 305             expr: e,
 306             span,
 307             is_shorthand: false,
 308             attrs: AttrVec::new(),
 309             id: ast::DUMMY_NODE_ID,
 310             is_placeholder: false,
 311         }
 312     }
 313     pub fn expr_struct(
 314         &self,
 315         span: Span,
 316         path: ast::Path,
 317         fields: Vec<ast::Field>,
 318     ) -> P<ast::Expr> {
 319         self.expr(span, ast::ExprKind::Struct(path, fields, None))
 320     }
 321     pub fn expr_struct_ident(
 322         &self,
 323         span: Span,
 324         id: Ident,
 325         fields: Vec<ast::Field>,
 326     ) -> P<ast::Expr> {
 327         self.expr_struct(span, self.path_ident(span, id), fields)
 328     }
 329
 330     pub fn expr_lit(&self, span: Span, lit_kind: ast::LitKind) -> P<ast::Expr> {
 331         let lit = ast::Lit::from_lit_kind(lit_kind, span);
 332         self.expr(span, ast::ExprKind::Lit(lit))
 333     }
 334     pub fn expr_usize(&self, span: Span, i: usize) -> P<ast::Expr> {
 335         self.expr_lit(
 336             span,
 337             ast::LitKind::Int(i as u128, ast::LitIntType::Unsigned(ast::UintTy::Usize)),
 338         )
 339     }
 340     pub fn expr_u32(&self, sp: Span, u: u32) -> P<ast::Expr> {
 341         self.expr_lit(sp, ast::LitKind::Int(u as u128, ast::LitIntType::Unsigned(ast::UintTy::U32)))
 342     }
 343     pub fn expr_bool(&self, sp: Span, value: bool) -> P<ast::Expr> {
 344         self.expr_lit(sp, ast::LitKind::Bool(value))
 345     }
 346
 347     pub fn expr_vec(&self, sp: Span, exprs: Vec<P<ast::Expr>>) -> P<ast::Expr> {
 348         self.expr(sp, ast::ExprKind::Array(exprs))
 349     }
 350     pub fn expr_vec_slice(&self, sp: Span, exprs: Vec<P<ast::Expr>>) -> P<ast::Expr> {
 351         self.expr_addr_of(sp, self.expr_vec(sp, exprs))
 352     }
 353     pub fn expr_str(&self, sp: Span, s: Symbol) -> P<ast::Expr> {
 354         self.expr_lit(sp, ast::LitKind::Str(s, ast::StrStyle::Cooked))
 355     }
 356
 357     pub fn expr_cast(&self, sp: Span, expr: P<ast::Expr>, ty: P<ast::Ty>) -> P<ast::Expr> {
 358         self.expr(sp, ast::ExprKind::Cast(expr, ty))
 359     }
 360
 361     pub fn expr_some(&self, sp: Span, expr: P<ast::Expr>) -> P<ast::Expr> {
 362         let some = self.std_path(&[sym::option, sym::Option, sym::Some]);
 363         self.expr_call_global(sp, some, vec![expr])
 364     }
 365
 366     pub fn expr_tuple(&self, sp: Span, exprs: Vec<P<ast::Expr>>) -> P<ast::Expr> {
 367         self.expr(sp, ast::ExprKind::Tup(exprs))
 368     }
 369
 370     pub fn expr_fail(&self, span: Span, msg: Symbol) -> P<ast::Expr> {
 371         self.expr_call_global(
 372             span,
 373             [sym::std, sym::rt, sym::begin_panic].iter().map(|s| Ident::new(*s, span)).collect(),
 374             vec![self.expr_str(span, msg)],
 375         )
 376     }
 377
 378     pub fn expr_unreachable(&self, span: Span) -> P<ast::Expr> {
 379         self.expr_fail(span, Symbol::intern("internal error: entered unreachable code"))
 380     }
 381
 382     pub fn expr_ok(&self, sp: Span, expr: P<ast::Expr>) -> P<ast::Expr> {
 383         let ok = self.std_path(&[sym::result, sym::Result, sym::Ok]);
 384         self.expr_call_global(sp, ok, vec![expr])
 385     }
 386
 387     pub fn expr_try(&self, sp: Span, head: P<ast::Expr>) -> P<ast::Expr> {
 388         let ok = self.std_path(&[sym::result, sym::Result, sym::Ok]);
 389         let ok_path = self.path_global(sp, ok);
 390         let err = self.std_path(&[sym::result, sym::Result, sym::Err]);
 391         let err_path = self.path_global(sp, err);
 392
 393         let binding_variable = Ident::new(sym::__try_var, sp);
 394         let binding_pat = self.pat_ident(sp, binding_variable);
 395         let binding_expr = self.expr_ident(sp, binding_variable);
 396
 397         // `Ok(__try_var)` pattern
 398         let ok_pat = self.pat_tuple_struct(sp, ok_path, vec![binding_pat.clone()]);
 399
 400         // `Err(__try_var)` (pattern and expression respectively)
 401         let err_pat = self.pat_tuple_struct(sp, err_path.clone(), vec![binding_pat]);
 402         let err_inner_expr =
 403             self.expr_call(sp, self.expr_path(err_path), vec![binding_expr.clone()]);
 404         // `return Err(__try_var)`
 405         let err_expr = self.expr(sp, ast::ExprKind::Ret(Some(err_inner_expr)));
 406
 407         // `Ok(__try_var) => __try_var`
 408         let ok_arm = self.arm(sp, ok_pat, binding_expr);
 409         // `Err(__try_var) => return Err(__try_var)`
 410         let err_arm = self.arm(sp, err_pat, err_expr);
 411
 412         // `match head { Ok() => ..., Err() => ... }`
 413         self.expr_match(sp, head, vec![ok_arm, err_arm])
 414     }
 415
 416     pub fn pat(&self, span: Span, kind: PatKind) -> P<ast::Pat> {
 417         P(ast::Pat { id: ast::DUMMY_NODE_ID, kind, span, tokens: None })
 418     }
 419     pub fn pat_wild(&self, span: Span) -> P<ast::Pat> {
 420         self.pat(span, PatKind::Wild)
 421     }
 422     pub fn pat_lit(&self, span: Span, expr: P<ast::Expr>) -> P<ast::Pat> {
 423         self.pat(span, PatKind::Lit(expr))
 424     }
 425     pub fn pat_ident(&self, span: Span, ident: Ident) -> P<ast::Pat> {
 426         let binding_mode = ast::BindingMode::ByValue(ast::Mutability::Not);
 427         self.pat_ident_binding_mode(span, ident, binding_mode)
 428     }
 429
 430     pub fn pat_ident_binding_mode(
 431         &self,
 432         span: Span,
 433         ident: Ident,
 434         bm: ast::BindingMode,
 435     ) -> P<ast::Pat> {
 436         let pat = PatKind::Ident(bm, ident.with_span_pos(span), None);
 437         self.pat(span, pat)
 438     }
 439     pub fn pat_path(&self, span: Span, path: ast::Path) -> P<ast::Pat> {
 440         self.pat(span, PatKind::Path(None, path))
 441     }
 442     pub fn pat_tuple_struct(
 443         &self,
 444         span: Span,
 445         path: ast::Path,
 446         subpats: Vec<P<ast::Pat>>,
 447     ) -> P<ast::Pat> {
 448         self.pat(span, PatKind::TupleStruct(path, subpats))
 449     }
 450     pub fn pat_struct(
 451         &self,
 452         span: Span,
 453         path: ast::Path,
 454         field_pats: Vec<ast::FieldPat>,
 455     ) -> P<ast::Pat> {
 456         self.pat(span, PatKind::Struct(path, field_pats, false))
 457     }
 458     pub fn pat_tuple(&self, span: Span, pats: Vec<P<ast::Pat>>) -> P<ast::Pat> {
 459         self.pat(span, PatKind::Tuple(pats))
 460     }
 461
 462     pub fn pat_some(&self, span: Span, pat: P<ast::Pat>) -> P<ast::Pat> {
 463         let some = self.std_path(&[sym::option, sym::Option, sym::Some]);
 464         let path = self.path_global(span, some);
 465         self.pat_tuple_struct(span, path, vec![pat])
 466     }
 467
 468     pub fn pat_none(&self, span: Span) -> P<ast::Pat> {
 469         let some = self.std_path(&[sym::option, sym::Option, sym::None]);
 470         let path = self.path_global(span, some);
 471         self.pat_path(span, path)
 472     }
 473
 474     pub fn pat_ok(&self, span: Span, pat: P<ast::Pat>) -> P<ast::Pat> {
 475         let some = self.std_path(&[sym::result, sym::Result, sym::Ok]);
 476         let path = self.path_global(span, some);
 477         self.pat_tuple_struct(span, path, vec![pat])
 478     }
 479
 480     pub fn pat_err(&self, span: Span, pat: P<ast::Pat>) -> P<ast::Pat> {
 481         let some = self.std_path(&[sym::result, sym::Result, sym::Err]);
 482         let path = self.path_global(span, some);
 483         self.pat_tuple_struct(span, path, vec![pat])
 484     }
 485
 486     pub fn arm(&self, span: Span, pat: P<ast::Pat>, expr: P<ast::Expr>) -> ast::Arm {
 487         ast::Arm {
 488             attrs: vec![],
 489             pat,
 490             guard: None,
 491             body: expr,
 492             span,
 493             id: ast::DUMMY_NODE_ID,
 494             is_placeholder: false,
 495         }
 496     }
 497
 498     pub fn arm_unreachable(&self, span: Span) -> ast::Arm {
 499         self.arm(span, self.pat_wild(span), self.expr_unreachable(span))
 500     }
 501
 502     pub fn expr_match(&self, span: Span, arg: P<ast::Expr>, arms: Vec<ast::Arm>) -> P<Expr> {
 503         self.expr(span, ast::ExprKind::Match(arg, arms))
 504     }
 505
 506     pub fn expr_if(
 507         &self,
 508         span: Span,
 509         cond: P<ast::Expr>,
 510         then: P<ast::Expr>,
 511         els: Option<P<ast::Expr>>,
 512     ) -> P<ast::Expr> {
 513         let els = els.map(|x| self.expr_block(self.block_expr(x)));
 514         self.expr(span, ast::ExprKind::If(cond, self.block_expr(then), els))
 515     }
 516
 517     pub fn lambda_fn_decl(
 518         &self,
 519         span: Span,
 520         fn_decl: P<ast::FnDecl>,
 521         body: P<ast::Expr>,
 522         fn_decl_span: Span,
 523     ) -> P<ast::Expr> {
 524         self.expr(
 525             span,
 526             ast::ExprKind::Closure(
 527                 ast::CaptureBy::Ref,
 528                 ast::Async::No,
 529                 ast::Movability::Movable,
 530                 fn_decl,
 531                 body,
 532                 fn_decl_span,
 533             ),
 534         )
 535     }
 536
 537     pub fn lambda(&self, span: Span, ids: Vec<Ident>, body: P<ast::Expr>) -> P<ast::Expr> {
 538         let fn_decl = self.fn_decl(
 539             ids.iter().map(|id| self.param(span, *id, self.ty(span, ast::TyKind::Infer))).collect(),
 540             ast::FnRetTy::Default(span),
 541         );
 542
 543         // FIXME -- We are using `span` as the span of the `|...|`
 544         // part of the lambda, but it probably (maybe?) corresponds to
 545         // the entire lambda body. Probably we should extend the API
 546         // here, but that's not entirely clear.
 547         self.expr(
 548             span,
 549             ast::ExprKind::Closure(
 550                 ast::CaptureBy::Ref,
 551                 ast::Async::No,
 552                 ast::Movability::Movable,
 553                 fn_decl,
 554                 body,
 555                 span,
 556             ),
 557         )
 558     }
 559
 560     pub fn lambda0(&self, span: Span, body: P<ast::Expr>) -> P<ast::Expr> {
 561         self.lambda(span, Vec::new(), body)
 562     }
 563
 564     pub fn lambda1(&self, span: Span, body: P<ast::Expr>, ident: Ident) -> P<ast::Expr> {
 565         self.lambda(span, vec![ident], body)
 566     }
 567
 568     pub fn lambda_stmts_1(&self, span: Span, stmts: Vec<ast::Stmt>, ident: Ident) -> P<ast::Expr> {
 569         self.lambda1(span, self.expr_block(self.block(span, stmts)), ident)
 570     }
 571
 572     pub fn param(&self, span: Span, ident: Ident, ty: P<ast::Ty>) -> ast::Param {
 573         let arg_pat = self.pat_ident(span, ident);
 574         ast::Param {
 575             attrs: AttrVec::default(),
 576             id: ast::DUMMY_NODE_ID,
 577             pat: arg_pat,
 578             span,
 579             ty,
 580             is_placeholder: false,
 581         }
 582     }
 583
 584     // FIXME: unused `self`
 585     pub fn fn_decl(&self, inputs: Vec<ast::Param>, output: ast::FnRetTy) -> P<ast::FnDecl> {
 586         P(ast::FnDecl { inputs, output })
 587     }
 588
 589     pub fn item(
 590         &self,
 591         span: Span,
 592         name: Ident,
 593         attrs: Vec<ast::Attribute>,
 594         kind: ast::ItemKind,
 595     ) -> P<ast::Item> {
 596         // FIXME: Would be nice if our generated code didn't violate
 597         // Rust coding conventions
 598         P(ast::Item {
 599             ident: name,
 600             attrs,
 601             id: ast::DUMMY_NODE_ID,
 602             kind,
 603             vis: ast::Visibility {
 604                 span: span.shrink_to_lo(),
 605                 kind: ast::VisibilityKind::Inherited,
 606                 tokens: None,
 607             },
 608             span,
 609             tokens: None,
 610         })
 611     }
 612
 613     pub fn variant(&self, span: Span, ident: Ident, tys: Vec<P<ast::Ty>>) -> ast::Variant {
 614         let vis_span = span.shrink_to_lo();
 615         let fields: Vec<_> = tys
 616             .into_iter()
 617             .map(|ty| ast::StructField {
 618                 span: ty.span,
 619                 ty,
 620                 ident: None,
 621                 vis: ast::Visibility {
 622                     span: vis_span,
 623                     kind: ast::VisibilityKind::Inherited,
 624                     tokens: None,
 625                 },
 626                 attrs: Vec::new(),
 627                 id: ast::DUMMY_NODE_ID,
 628                 is_placeholder: false,
 629             })
 630             .collect();
 631
 632         let vdata = if fields.is_empty() {
 633             ast::VariantData::Unit(ast::DUMMY_NODE_ID)
 634         } else {
 635             ast::VariantData::Tuple(fields, ast::DUMMY_NODE_ID)
 636         };
 637
 638         ast::Variant {
 639             attrs: Vec::new(),
 640             data: vdata,
 641             disr_expr: None,
 642             id: ast::DUMMY_NODE_ID,
 643             ident,
 644             vis: ast::Visibility {
 645                 span: vis_span,
 646                 kind: ast::VisibilityKind::Inherited,
 647                 tokens: None,
 648             },
 649             span,
 650             is_placeholder: false,
 651         }
 652     }
 653
 654     pub fn item_static(
 655         &self,
 656         span: Span,
 657         name: Ident,
 658         ty: P<ast::Ty>,
 659         mutbl: ast::Mutability,
 660         expr: P<ast::Expr>,
 661     ) -> P<ast::Item> {
 662         self.item(span, name, Vec::new(), ast::ItemKind::Static(ty, mutbl, Some(expr)))
 663     }
 664
 665     pub fn item_const(
 666         &self,
 667         span: Span,
 668         name: Ident,
 669         ty: P<ast::Ty>,
 670         expr: P<ast::Expr>,
 671     ) -> P<ast::Item> {
 672         let def = ast::Defaultness::Final;
 673         self.item(span, name, Vec::new(), ast::ItemKind::Const(def, ty, Some(expr)))
 674     }
 675
 676     pub fn attribute(&self, mi: ast::MetaItem) -> ast::Attribute {
 677         attr::mk_attr_outer(mi)
 678     }
 679
 680     pub fn meta_word(&self, sp: Span, w: Symbol) -> ast::MetaItem {
 681         attr::mk_word_item(Ident::new(w, sp))
 682     }
 683 }