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 stmt_expr(&self, expr: P<ast::Expr>) -> ast::Stmt {
 143         ast::Stmt { id: ast::DUMMY_NODE_ID, span: expr.span, kind: ast::StmtKind::Expr(expr) }
 144     }
 145
 146     pub fn stmt_let(&self, sp: Span, mutbl: bool, ident: Ident, ex: P<ast::Expr>) -> ast::Stmt {
 147         let pat = if mutbl {
 148             let binding_mode = ast::BindingMode::ByValue(ast::Mutability::Mut);
 149             self.pat_ident_binding_mode(sp, ident, binding_mode)
 150         } else {
 151             self.pat_ident(sp, ident)
 152         };
 153         let local = P(ast::Local {
 154             pat,
 155             ty: None,
 156             init: Some(ex),
 157             id: ast::DUMMY_NODE_ID,
 158             span: sp,
 159             attrs: AttrVec::new(),
 160             tokens: None,
 161         });
 162         ast::Stmt { id: ast::DUMMY_NODE_ID, kind: ast::StmtKind::Local(local), span: sp }
 163     }
 164
 165     // Generates `let _: Type;`, which is usually used for type assertions.
 166     pub fn stmt_let_type_only(&self, span: Span, ty: P<ast::Ty>) -> ast::Stmt {
 167         let local = P(ast::Local {
 168             pat: self.pat_wild(span),
 169             ty: Some(ty),
 170             init: None,
 171             id: ast::DUMMY_NODE_ID,
 172             span,
 173             attrs: AttrVec::new(),
 174             tokens: None,
 175         });
 176         ast::Stmt { id: ast::DUMMY_NODE_ID, kind: ast::StmtKind::Local(local), span }
 177     }
 178
 179     pub fn stmt_item(&self, sp: Span, item: P<ast::Item>) -> ast::Stmt {
 180         ast::Stmt { id: ast::DUMMY_NODE_ID, kind: ast::StmtKind::Item(item), span: sp }
 181     }
 182
 183     pub fn block_expr(&self, expr: P<ast::Expr>) -> P<ast::Block> {
 184         self.block(
 185             expr.span,
 186             vec![ast::Stmt {
 187                 id: ast::DUMMY_NODE_ID,
 188                 span: expr.span,
 189                 kind: ast::StmtKind::Expr(expr),
 190             }],
 191         )
 192     }
 193     pub fn block(&self, span: Span, stmts: Vec<ast::Stmt>) -> P<ast::Block> {
 194         P(ast::Block {
 195             stmts,
 196             id: ast::DUMMY_NODE_ID,
 197             rules: BlockCheckMode::Default,
 198             span,
 199             tokens: None,
 200         })
 201     }
 202
 203     pub fn expr(&self, span: Span, kind: ast::ExprKind) -> P<ast::Expr> {
 204         P(ast::Expr { id: ast::DUMMY_NODE_ID, kind, span, attrs: AttrVec::new(), tokens: None })
 205     }
 206
 207     pub fn expr_path(&self, path: ast::Path) -> P<ast::Expr> {
 208         self.expr(path.span, ast::ExprKind::Path(None, path))
 209     }
 210
 211     pub fn expr_ident(&self, span: Span, id: Ident) -> P<ast::Expr> {
 212         self.expr_path(self.path_ident(span, id))
 213     }
 214     pub fn expr_self(&self, span: Span) -> P<ast::Expr> {
 215         self.expr_ident(span, Ident::with_dummy_span(kw::SelfLower))
 216     }
 217
 218     pub fn expr_binary(
 219         &self,
 220         sp: Span,
 221         op: ast::BinOpKind,
 222         lhs: P<ast::Expr>,
 223         rhs: P<ast::Expr>,
 224     ) -> P<ast::Expr> {
 225         self.expr(sp, ast::ExprKind::Binary(Spanned { node: op, span: sp }, lhs, rhs))
 226     }
 227
 228     pub fn expr_deref(&self, sp: Span, e: P<ast::Expr>) -> P<ast::Expr> {
 229         self.expr(sp, ast::ExprKind::Unary(UnOp::Deref, e))
 230     }
 231
 232     pub fn expr_addr_of(&self, sp: Span, e: P<ast::Expr>) -> P<ast::Expr> {
 233         self.expr(sp, ast::ExprKind::AddrOf(ast::BorrowKind::Ref, ast::Mutability::Not, e))
 234     }
 235
 236     pub fn expr_call(
 237         &self,
 238         span: Span,
 239         expr: P<ast::Expr>,
 240         args: Vec<P<ast::Expr>>,
 241     ) -> P<ast::Expr> {
 242         self.expr(span, ast::ExprKind::Call(expr, args))
 243     }
 244     pub fn expr_call_ident(&self, span: Span, id: Ident, args: Vec<P<ast::Expr>>) -> P<ast::Expr> {
 245         self.expr(span, ast::ExprKind::Call(self.expr_ident(span, id), args))
 246     }
 247     pub fn expr_call_global(
 248         &self,
 249         sp: Span,
 250         fn_path: Vec<Ident>,
 251         args: Vec<P<ast::Expr>>,
 252     ) -> P<ast::Expr> {
 253         let pathexpr = self.expr_path(self.path_global(sp, fn_path));
 254         self.expr_call(sp, pathexpr, args)
 255     }
 256     pub fn expr_block(&self, b: P<ast::Block>) -> P<ast::Expr> {
 257         self.expr(b.span, ast::ExprKind::Block(b, None))
 258     }
 259     pub fn field_imm(&self, span: Span, ident: Ident, e: P<ast::Expr>) -> ast::ExprField {
 260         ast::ExprField {
 261             ident: ident.with_span_pos(span),
 262             expr: e,
 263             span,
 264             is_shorthand: false,
 265             attrs: AttrVec::new(),
 266             id: ast::DUMMY_NODE_ID,
 267             is_placeholder: false,
 268         }
 269     }
 270     pub fn expr_struct(
 271         &self,
 272         span: Span,
 273         path: ast::Path,
 274         fields: Vec<ast::ExprField>,
 275     ) -> P<ast::Expr> {
 276         self.expr(
 277             span,
 278             ast::ExprKind::Struct(P(ast::StructExpr {
 279                 qself: None,
 280                 path,
 281                 fields,
 282                 rest: ast::StructRest::None,
 283             })),
 284         )
 285     }
 286     pub fn expr_struct_ident(
 287         &self,
 288         span: Span,
 289         id: Ident,
 290         fields: Vec<ast::ExprField>,
 291     ) -> P<ast::Expr> {
 292         self.expr_struct(span, self.path_ident(span, id), fields)
 293     }
 294
 295     pub fn expr_lit(&self, span: Span, lit_kind: ast::LitKind) -> P<ast::Expr> {
 296         let lit = ast::Lit::from_lit_kind(lit_kind, span);
 297         self.expr(span, ast::ExprKind::Lit(lit))
 298     }
 299     pub fn expr_usize(&self, span: Span, i: usize) -> P<ast::Expr> {
 300         self.expr_lit(
 301             span,
 302             ast::LitKind::Int(i as u128, ast::LitIntType::Unsigned(ast::UintTy::Usize)),
 303         )
 304     }
 305     pub fn expr_u32(&self, sp: Span, u: u32) -> P<ast::Expr> {
 306         self.expr_lit(sp, ast::LitKind::Int(u as u128, ast::LitIntType::Unsigned(ast::UintTy::U32)))
 307     }
 308     pub fn expr_bool(&self, sp: Span, value: bool) -> P<ast::Expr> {
 309         self.expr_lit(sp, ast::LitKind::Bool(value))
 310     }
 311
 312     pub fn expr_vec(&self, sp: Span, exprs: Vec<P<ast::Expr>>) -> P<ast::Expr> {
 313         self.expr(sp, ast::ExprKind::Array(exprs))
 314     }
 315     pub fn expr_vec_slice(&self, sp: Span, exprs: Vec<P<ast::Expr>>) -> P<ast::Expr> {
 316         self.expr_addr_of(sp, self.expr_vec(sp, exprs))
 317     }
 318     pub fn expr_str(&self, sp: Span, s: Symbol) -> P<ast::Expr> {
 319         self.expr_lit(sp, ast::LitKind::Str(s, ast::StrStyle::Cooked))
 320     }
 321
 322     pub fn expr_cast(&self, sp: Span, expr: P<ast::Expr>, ty: P<ast::Ty>) -> P<ast::Expr> {
 323         self.expr(sp, ast::ExprKind::Cast(expr, ty))
 324     }
 325
 326     pub fn expr_some(&self, sp: Span, expr: P<ast::Expr>) -> P<ast::Expr> {
 327         let some = self.std_path(&[sym::option, sym::Option, sym::Some]);
 328         self.expr_call_global(sp, some, vec![expr])
 329     }
 330
 331     pub fn expr_tuple(&self, sp: Span, exprs: Vec<P<ast::Expr>>) -> P<ast::Expr> {
 332         self.expr(sp, ast::ExprKind::Tup(exprs))
 333     }
 334
 335     pub fn expr_fail(&self, span: Span, msg: Symbol) -> P<ast::Expr> {
 336         self.expr_call_global(
 337             span,
 338             [sym::std, sym::rt, sym::begin_panic].iter().map(|s| Ident::new(*s, span)).collect(),
 339             vec![self.expr_str(span, msg)],
 340         )
 341     }
 342
 343     pub fn expr_unreachable(&self, span: Span) -> P<ast::Expr> {
 344         self.expr_fail(span, Symbol::intern("internal error: entered unreachable code"))
 345     }
 346
 347     pub fn expr_ok(&self, sp: Span, expr: P<ast::Expr>) -> P<ast::Expr> {
 348         let ok = self.std_path(&[sym::result, sym::Result, sym::Ok]);
 349         self.expr_call_global(sp, ok, vec![expr])
 350     }
 351
 352     pub fn expr_try(&self, sp: Span, head: P<ast::Expr>) -> P<ast::Expr> {
 353         let ok = self.std_path(&[sym::result, sym::Result, sym::Ok]);
 354         let ok_path = self.path_global(sp, ok);
 355         let err = self.std_path(&[sym::result, sym::Result, sym::Err]);
 356         let err_path = self.path_global(sp, err);
 357
 358         let binding_variable = Ident::new(sym::__try_var, sp);
 359         let binding_pat = self.pat_ident(sp, binding_variable);
 360         let binding_expr = self.expr_ident(sp, binding_variable);
 361
 362         // `Ok(__try_var)` pattern
 363         let ok_pat = self.pat_tuple_struct(sp, ok_path, vec![binding_pat.clone()]);
 364
 365         // `Err(__try_var)` (pattern and expression respectively)
 366         let err_pat = self.pat_tuple_struct(sp, err_path.clone(), vec![binding_pat]);
 367         let err_inner_expr =
 368             self.expr_call(sp, self.expr_path(err_path), vec![binding_expr.clone()]);
 369         // `return Err(__try_var)`
 370         let err_expr = self.expr(sp, ast::ExprKind::Ret(Some(err_inner_expr)));
 371
 372         // `Ok(__try_var) => __try_var`
 373         let ok_arm = self.arm(sp, ok_pat, binding_expr);
 374         // `Err(__try_var) => return Err(__try_var)`
 375         let err_arm = self.arm(sp, err_pat, err_expr);
 376
 377         // `match head { Ok() => ..., Err() => ... }`
 378         self.expr_match(sp, head, vec![ok_arm, err_arm])
 379     }
 380
 381     pub fn pat(&self, span: Span, kind: PatKind) -> P<ast::Pat> {
 382         P(ast::Pat { id: ast::DUMMY_NODE_ID, kind, span, tokens: None })
 383     }
 384     pub fn pat_wild(&self, span: Span) -> P<ast::Pat> {
 385         self.pat(span, PatKind::Wild)
 386     }
 387     pub fn pat_lit(&self, span: Span, expr: P<ast::Expr>) -> P<ast::Pat> {
 388         self.pat(span, PatKind::Lit(expr))
 389     }
 390     pub fn pat_ident(&self, span: Span, ident: Ident) -> P<ast::Pat> {
 391         let binding_mode = ast::BindingMode::ByValue(ast::Mutability::Not);
 392         self.pat_ident_binding_mode(span, ident, binding_mode)
 393     }
 394
 395     pub fn pat_ident_binding_mode(
 396         &self,
 397         span: Span,
 398         ident: Ident,
 399         bm: ast::BindingMode,
 400     ) -> P<ast::Pat> {
 401         let pat = PatKind::Ident(bm, ident.with_span_pos(span), None);
 402         self.pat(span, pat)
 403     }
 404     pub fn pat_path(&self, span: Span, path: ast::Path) -> P<ast::Pat> {
 405         self.pat(span, PatKind::Path(None, path))
 406     }
 407     pub fn pat_tuple_struct(
 408         &self,
 409         span: Span,
 410         path: ast::Path,
 411         subpats: Vec<P<ast::Pat>>,
 412     ) -> P<ast::Pat> {
 413         self.pat(span, PatKind::TupleStruct(None, path, subpats))
 414     }
 415     pub fn pat_struct(
 416         &self,
 417         span: Span,
 418         path: ast::Path,
 419         field_pats: Vec<ast::PatField>,
 420     ) -> P<ast::Pat> {
 421         self.pat(span, PatKind::Struct(None, path, field_pats, false))
 422     }
 423     pub fn pat_tuple(&self, span: Span, pats: Vec<P<ast::Pat>>) -> P<ast::Pat> {
 424         self.pat(span, PatKind::Tuple(pats))
 425     }
 426
 427     pub fn pat_some(&self, span: Span, pat: P<ast::Pat>) -> P<ast::Pat> {
 428         let some = self.std_path(&[sym::option, sym::Option, sym::Some]);
 429         let path = self.path_global(span, some);
 430         self.pat_tuple_struct(span, path, vec![pat])
 431     }
 432
 433     pub fn arm(&self, span: Span, pat: P<ast::Pat>, expr: P<ast::Expr>) -> ast::Arm {
 434         ast::Arm {
 435             attrs: AttrVec::new(),
 436             pat,
 437             guard: None,
 438             body: expr,
 439             span,
 440             id: ast::DUMMY_NODE_ID,
 441             is_placeholder: false,
 442         }
 443     }
 444
 445     pub fn arm_unreachable(&self, span: Span) -> ast::Arm {
 446         self.arm(span, self.pat_wild(span), self.expr_unreachable(span))
 447     }
 448
 449     pub fn expr_match(&self, span: Span, arg: P<ast::Expr>, arms: Vec<ast::Arm>) -> P<Expr> {
 450         self.expr(span, ast::ExprKind::Match(arg, arms))
 451     }
 452
 453     pub fn expr_if(
 454         &self,
 455         span: Span,
 456         cond: P<ast::Expr>,
 457         then: P<ast::Expr>,
 458         els: Option<P<ast::Expr>>,
 459     ) -> P<ast::Expr> {
 460         let els = els.map(|x| self.expr_block(self.block_expr(x)));
 461         self.expr(span, ast::ExprKind::If(cond, self.block_expr(then), els))
 462     }
 463
 464     pub fn lambda(&self, span: Span, ids: Vec<Ident>, body: P<ast::Expr>) -> P<ast::Expr> {
 465         let fn_decl = self.fn_decl(
 466             ids.iter().map(|id| self.param(span, *id, self.ty(span, ast::TyKind::Infer))).collect(),
 467             ast::FnRetTy::Default(span),
 468         );
 469
 470         // FIXME -- We are using `span` as the span of the `|...|`
 471         // part of the lambda, but it probably (maybe?) corresponds to
 472         // the entire lambda body. Probably we should extend the API
 473         // here, but that's not entirely clear.
 474         self.expr(
 475             span,
 476             ast::ExprKind::Closure(
 477                 ast::CaptureBy::Ref,
 478                 ast::Async::No,
 479                 ast::Movability::Movable,
 480                 fn_decl,
 481                 body,
 482                 span,
 483             ),
 484         )
 485     }
 486
 487     pub fn lambda0(&self, span: Span, body: P<ast::Expr>) -> P<ast::Expr> {
 488         self.lambda(span, Vec::new(), body)
 489     }
 490
 491     pub fn lambda1(&self, span: Span, body: P<ast::Expr>, ident: Ident) -> P<ast::Expr> {
 492         self.lambda(span, vec![ident], body)
 493     }
 494
 495     pub fn lambda_stmts_1(&self, span: Span, stmts: Vec<ast::Stmt>, ident: Ident) -> P<ast::Expr> {
 496         self.lambda1(span, self.expr_block(self.block(span, stmts)), ident)
 497     }
 498
 499     pub fn param(&self, span: Span, ident: Ident, ty: P<ast::Ty>) -> ast::Param {
 500         let arg_pat = self.pat_ident(span, ident);
 501         ast::Param {
 502             attrs: AttrVec::default(),
 503             id: ast::DUMMY_NODE_ID,
 504             pat: arg_pat,
 505             span,
 506             ty,
 507             is_placeholder: false,
 508         }
 509     }
 510
 511     // FIXME: unused `self`
 512     pub fn fn_decl(&self, inputs: Vec<ast::Param>, output: ast::FnRetTy) -> P<ast::FnDecl> {
 513         P(ast::FnDecl { inputs, output })
 514     }
 515
 516     pub fn item(
 517         &self,
 518         span: Span,
 519         name: Ident,
 520         attrs: Vec<ast::Attribute>,
 521         kind: ast::ItemKind,
 522     ) -> P<ast::Item> {
 523         // FIXME: Would be nice if our generated code didn't violate
 524         // Rust coding conventions
 525         P(ast::Item {
 526             ident: name,
 527             attrs,
 528             id: ast::DUMMY_NODE_ID,
 529             kind,
 530             vis: ast::Visibility {
 531                 span: span.shrink_to_lo(),
 532                 kind: ast::VisibilityKind::Inherited,
 533                 tokens: None,
 534             },
 535             span,
 536             tokens: None,
 537         })
 538     }
 539
 540     pub fn item_static(
 541         &self,
 542         span: Span,
 543         name: Ident,
 544         ty: P<ast::Ty>,
 545         mutbl: ast::Mutability,
 546         expr: P<ast::Expr>,
 547     ) -> P<ast::Item> {
 548         self.item(span, name, Vec::new(), ast::ItemKind::Static(ty, mutbl, Some(expr)))
 549     }
 550
 551     pub fn item_const(
 552         &self,
 553         span: Span,
 554         name: Ident,
 555         ty: P<ast::Ty>,
 556         expr: P<ast::Expr>,
 557     ) -> P<ast::Item> {
 558         let def = ast::Defaultness::Final;
 559         self.item(span, name, Vec::new(), ast::ItemKind::Const(def, ty, Some(expr)))
 560     }
 561
 562     pub fn attribute(&self, mi: ast::MetaItem) -> ast::Attribute {
 563         attr::mk_attr_outer(mi)
 564     }
 565
 566     pub fn meta_word(&self, sp: Span, w: Symbol) -> ast::MetaItem {
 567         attr::mk_word_item(Ident::new(w, sp))
 568     }
 569 }