src/librustc_expand/build.rs

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