1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // Lowers the AST to the HIR
17 use syntax::codemap::{respan, Spanned, Span};
18 use syntax::owned_slice::OwnedSlice;
19 use syntax::parse::token::{self, str_to_ident};
20 use syntax::std_inject;
22 pub struct LoweringContext<'a, 'hir> {
25 id_assigner: &'a NodeIdAssigner,
26 crate_root: Option<&'static str>,
29 impl<'a, 'hir> LoweringContext<'a, 'hir> {
30 pub fn new(foo: &'hir i32, id_assigner: &'a NodeIdAssigner, c: &Crate) -> LoweringContext<'a, 'hir> {
31 let crate_root = if std_inject::no_core(c) {
33 } else if std_inject::no_std(c) {
41 id_assigner: id_assigner,
42 crate_root: crate_root,
46 fn next_id(&self) -> NodeId {
47 self.id_assigner.next_node_id()
51 pub fn lower_view_path(_lctx: &LoweringContext, view_path: &ViewPath) -> P<hir::ViewPath> {
53 node: match view_path.node {
54 ViewPathSimple(ident, ref path) => {
55 hir::ViewPathSimple(ident.name, lower_path(_lctx, path))
57 ViewPathGlob(ref path) => {
58 hir::ViewPathGlob(lower_path(_lctx, path))
60 ViewPathList(ref path, ref path_list_idents) => {
61 hir::ViewPathList(lower_path(_lctx, path),
62 path_list_idents.iter().map(|path_list_ident| {
64 node: match path_list_ident.node {
65 PathListIdent { id, name, rename } =>
69 rename: rename.map(|x| x.name),
71 PathListMod { id, rename } =>
74 rename: rename.map(|x| x.name)
77 span: path_list_ident.span
86 pub fn lower_arm(_lctx: &LoweringContext, arm: &Arm) -> hir::Arm {
88 attrs: arm.attrs.clone(),
89 pats: arm.pats.iter().map(|x| lower_pat(_lctx, x)).collect(),
90 guard: arm.guard.as_ref().map(|ref x| lower_expr(_lctx, x)),
91 body: lower_expr(_lctx, &arm.body),
95 pub fn lower_decl(_lctx: &LoweringContext, d: &Decl) -> P<hir::Decl> {
97 DeclLocal(ref l) => P(Spanned {
98 node: hir::DeclLocal(lower_local(_lctx, l)),
101 DeclItem(ref it) => P(Spanned {
102 node: hir::DeclItem(lower_item(_lctx, it)),
108 pub fn lower_ty_binding(_lctx: &LoweringContext, b: &TypeBinding) -> P<hir::TypeBinding> {
109 P(hir::TypeBinding { id: b.id, name: b.ident.name, ty: lower_ty(_lctx, &b.ty), span: b.span })
112 pub fn lower_ty(_lctx: &LoweringContext, t: &Ty) -> P<hir::Ty> {
116 TyInfer => hir::TyInfer,
117 TyVec(ref ty) => hir::TyVec(lower_ty(_lctx, ty)),
118 TyPtr(ref mt) => hir::TyPtr(lower_mt(_lctx, mt)),
119 TyRptr(ref region, ref mt) => {
120 hir::TyRptr(lower_opt_lifetime(_lctx, region), lower_mt(_lctx, mt))
123 hir::TyBareFn(P(hir::BareFnTy {
124 lifetimes: lower_lifetime_defs(_lctx, &f.lifetimes),
125 unsafety: lower_unsafety(_lctx, f.unsafety),
127 decl: lower_fn_decl(_lctx, &f.decl),
130 TyTup(ref tys) => hir::TyTup(tys.iter().map(|ty| lower_ty(_lctx, ty)).collect()),
131 TyParen(ref ty) => hir::TyParen(lower_ty(_lctx, ty)),
132 TyPath(ref qself, ref path) => {
133 let qself = qself.as_ref().map(|&QSelf { ref ty, position }| {
135 ty: lower_ty(_lctx, ty),
139 hir::TyPath(qself, lower_path(_lctx, path))
141 TyObjectSum(ref ty, ref bounds) => {
142 hir::TyObjectSum(lower_ty(_lctx, ty),
143 lower_bounds(_lctx, bounds))
145 TyFixedLengthVec(ref ty, ref e) => {
146 hir::TyFixedLengthVec(lower_ty(_lctx, ty), lower_expr(_lctx, e))
148 TyTypeof(ref expr) => {
149 hir::TyTypeof(lower_expr(_lctx, expr))
151 TyPolyTraitRef(ref bounds) => {
152 hir::TyPolyTraitRef(bounds.iter().map(|b| lower_ty_param_bound(_lctx, b)).collect())
154 TyMac(_) => panic!("TyMac should have been expanded by now."),
160 pub fn lower_foreign_mod(_lctx: &LoweringContext, fm: &ForeignMod) -> hir::ForeignMod {
163 items: fm.items.iter().map(|x| lower_foreign_item(_lctx, x)).collect(),
167 pub fn lower_variant(_lctx: &LoweringContext, v: &Variant) -> P<hir::Variant> {
169 node: hir::Variant_ {
171 name: v.node.name.name,
172 attrs: v.node.attrs.clone(),
173 kind: match v.node.kind {
174 TupleVariantKind(ref variant_args) => {
175 hir::TupleVariantKind(variant_args.iter().map(|ref x|
176 lower_variant_arg(_lctx, x)).collect())
178 StructVariantKind(ref struct_def) => {
179 hir::StructVariantKind(lower_struct_def(_lctx, struct_def))
182 disr_expr: v.node.disr_expr.as_ref().map(|e| lower_expr(_lctx, e)),
188 pub fn lower_path(_lctx: &LoweringContext, p: &Path) -> hir::Path {
191 segments: p.segments.iter().map(|&PathSegment {identifier, ref parameters}|
193 identifier: identifier,
194 parameters: lower_path_parameters(_lctx, parameters),
200 pub fn lower_path_parameters(_lctx: &LoweringContext,
201 path_parameters: &PathParameters)
202 -> hir::PathParameters {
203 match *path_parameters {
204 AngleBracketedParameters(ref data) =>
205 hir::AngleBracketedParameters(lower_angle_bracketed_parameter_data(_lctx, data)),
206 ParenthesizedParameters(ref data) =>
207 hir::ParenthesizedParameters(lower_parenthesized_parameter_data(_lctx, data)),
211 pub fn lower_angle_bracketed_parameter_data(_lctx: &LoweringContext,
212 data: &AngleBracketedParameterData)
213 -> hir::AngleBracketedParameterData {
214 let &AngleBracketedParameterData { ref lifetimes, ref types, ref bindings } = data;
215 hir::AngleBracketedParameterData {
216 lifetimes: lower_lifetimes(_lctx, lifetimes),
217 types: types.iter().map(|ty| lower_ty(_lctx, ty)).collect(),
218 bindings: bindings.iter().map(|b| lower_ty_binding(_lctx, b)).collect(),
222 pub fn lower_parenthesized_parameter_data(_lctx: &LoweringContext,
223 data: &ParenthesizedParameterData)
224 -> hir::ParenthesizedParameterData {
225 let &ParenthesizedParameterData { ref inputs, ref output, span } = data;
226 hir::ParenthesizedParameterData {
227 inputs: inputs.iter().map(|ty| lower_ty(_lctx, ty)).collect(),
228 output: output.as_ref().map(|ty| lower_ty(_lctx, ty)),
233 pub fn lower_local(_lctx: &LoweringContext, l: &Local) -> P<hir::Local> {
236 ty: l.ty.as_ref().map(|t| lower_ty(_lctx, t)),
237 pat: lower_pat(_lctx, &l.pat),
238 init: l.init.as_ref().map(|e| lower_expr(_lctx, e)),
243 pub fn lower_explicit_self_underscore(_lctx: &LoweringContext,
245 -> hir::ExplicitSelf_ {
247 SelfStatic => hir::SelfStatic,
248 SelfValue(v) => hir::SelfValue(v.name),
249 SelfRegion(ref lifetime, m, ident) => {
250 hir::SelfRegion(lower_opt_lifetime(_lctx, lifetime),
251 lower_mutability(_lctx, m),
254 SelfExplicit(ref typ, ident) => {
255 hir::SelfExplicit(lower_ty(_lctx, typ), ident.name)
260 pub fn lower_mutability(_lctx: &LoweringContext, m: Mutability) -> hir::Mutability {
262 MutMutable => hir::MutMutable,
263 MutImmutable => hir::MutImmutable,
267 pub fn lower_explicit_self(_lctx: &LoweringContext, s: &ExplicitSelf) -> hir::ExplicitSelf {
268 Spanned { node: lower_explicit_self_underscore(_lctx, &s.node), span: s.span }
271 pub fn lower_arg(_lctx: &LoweringContext, arg: &Arg) -> hir::Arg {
272 hir::Arg { id: arg.id, pat: lower_pat(_lctx, &arg.pat), ty: lower_ty(_lctx, &arg.ty) }
275 pub fn lower_fn_decl(_lctx: &LoweringContext, decl: &FnDecl) -> P<hir::FnDecl> {
277 inputs: decl.inputs.iter().map(|x| lower_arg(_lctx, x)).collect(),
278 output: match decl.output {
279 Return(ref ty) => hir::Return(lower_ty(_lctx, ty)),
280 DefaultReturn(span) => hir::DefaultReturn(span),
281 NoReturn(span) => hir::NoReturn(span),
283 variadic: decl.variadic,
287 pub fn lower_ty_param_bound(_lctx: &LoweringContext, tpb: &TyParamBound) -> hir::TyParamBound {
289 TraitTyParamBound(ref ty, modifier) => {
290 hir::TraitTyParamBound(lower_poly_trait_ref(_lctx, ty),
291 lower_trait_bound_modifier(_lctx, modifier))
293 RegionTyParamBound(ref lifetime) => {
294 hir::RegionTyParamBound(lower_lifetime(_lctx, lifetime))
299 pub fn lower_ty_param(_lctx: &LoweringContext, tp: &TyParam) -> hir::TyParam {
303 bounds: lower_bounds(_lctx, &tp.bounds),
304 default: tp.default.as_ref().map(|x| lower_ty(_lctx, x)),
309 pub fn lower_ty_params(_lctx: &LoweringContext,
310 tps: &OwnedSlice<TyParam>)
311 -> OwnedSlice<hir::TyParam> {
312 tps.iter().map(|tp| lower_ty_param(_lctx, tp)).collect()
315 pub fn lower_lifetime(_lctx: &LoweringContext, l: &Lifetime) -> hir::Lifetime {
316 hir::Lifetime { id: l.id, name: l.name, span: l.span }
319 pub fn lower_lifetime_def(_lctx: &LoweringContext, l: &LifetimeDef) -> hir::LifetimeDef {
321 lifetime: lower_lifetime(_lctx, &l.lifetime),
322 bounds: lower_lifetimes(_lctx, &l.bounds)
326 pub fn lower_lifetimes(_lctx: &LoweringContext, lts: &Vec<Lifetime>) -> Vec<hir::Lifetime> {
327 lts.iter().map(|l| lower_lifetime(_lctx, l)).collect()
330 pub fn lower_lifetime_defs(_lctx: &LoweringContext,
331 lts: &Vec<LifetimeDef>)
332 -> Vec<hir::LifetimeDef> {
333 lts.iter().map(|l| lower_lifetime_def(_lctx, l)).collect()
336 pub fn lower_opt_lifetime(_lctx: &LoweringContext,
337 o_lt: &Option<Lifetime>)
338 -> Option<hir::Lifetime> {
339 o_lt.as_ref().map(|lt| lower_lifetime(_lctx, lt))
342 pub fn lower_generics(_lctx: &LoweringContext, g: &Generics) -> hir::Generics {
344 ty_params: lower_ty_params(_lctx, &g.ty_params),
345 lifetimes: lower_lifetime_defs(_lctx, &g.lifetimes),
346 where_clause: lower_where_clause(_lctx, &g.where_clause),
350 pub fn lower_where_clause(_lctx: &LoweringContext, wc: &WhereClause) -> hir::WhereClause {
353 predicates: wc.predicates.iter().map(|predicate|
354 lower_where_predicate(_lctx, predicate)).collect(),
358 pub fn lower_where_predicate(_lctx: &LoweringContext,
359 pred: &WherePredicate)
360 -> hir::WherePredicate {
362 WherePredicate::BoundPredicate(WhereBoundPredicate{ ref bound_lifetimes,
366 hir::WherePredicate::BoundPredicate(hir::WhereBoundPredicate {
367 bound_lifetimes: lower_lifetime_defs(_lctx, bound_lifetimes),
368 bounded_ty: lower_ty(_lctx, bounded_ty),
369 bounds: bounds.iter().map(|x| lower_ty_param_bound(_lctx, x)).collect(),
373 WherePredicate::RegionPredicate(WhereRegionPredicate{ ref lifetime,
376 hir::WherePredicate::RegionPredicate(hir::WhereRegionPredicate {
378 lifetime: lower_lifetime(_lctx, lifetime),
379 bounds: bounds.iter().map(|bound| lower_lifetime(_lctx, bound)).collect()
382 WherePredicate::EqPredicate(WhereEqPredicate{ id,
386 hir::WherePredicate::EqPredicate(hir::WhereEqPredicate {
388 path: lower_path(_lctx, path),
389 ty:lower_ty(_lctx, ty),
396 pub fn lower_struct_def(_lctx: &LoweringContext, sd: &StructDef) -> P<hir::StructDef> {
398 fields: sd.fields.iter().map(|f| lower_struct_field(_lctx, f)).collect(),
403 pub fn lower_trait_ref(_lctx: &LoweringContext, p: &TraitRef) -> hir::TraitRef {
404 hir::TraitRef { path: lower_path(_lctx, &p.path), ref_id: p.ref_id }
407 pub fn lower_poly_trait_ref(_lctx: &LoweringContext, p: &PolyTraitRef) -> hir::PolyTraitRef {
409 bound_lifetimes: lower_lifetime_defs(_lctx, &p.bound_lifetimes),
410 trait_ref: lower_trait_ref(_lctx, &p.trait_ref),
415 pub fn lower_struct_field(_lctx: &LoweringContext, f: &StructField) -> hir::StructField {
417 node: hir::StructField_ {
419 kind: lower_struct_field_kind(_lctx, &f.node.kind),
420 ty: lower_ty(_lctx, &f.node.ty),
421 attrs: f.node.attrs.clone(),
427 pub fn lower_field(_lctx: &LoweringContext, f: &Field) -> hir::Field {
429 name: respan(f.ident.span, f.ident.node.name),
430 expr: lower_expr(_lctx, &f.expr), span: f.span
434 pub fn lower_mt(_lctx: &LoweringContext, mt: &MutTy) -> hir::MutTy {
435 hir::MutTy { ty: lower_ty(_lctx, &mt.ty), mutbl: lower_mutability(_lctx, mt.mutbl) }
438 pub fn lower_opt_bounds(_lctx: &LoweringContext, b: &Option<OwnedSlice<TyParamBound>>)
439 -> Option<OwnedSlice<hir::TyParamBound>> {
440 b.as_ref().map(|ref bounds| lower_bounds(_lctx, bounds))
443 fn lower_bounds(_lctx: &LoweringContext, bounds: &TyParamBounds) -> hir::TyParamBounds {
444 bounds.iter().map(|bound| lower_ty_param_bound(_lctx, bound)).collect()
447 fn lower_variant_arg(_lctx: &LoweringContext, va: &VariantArg) -> hir::VariantArg {
448 hir::VariantArg { id: va.id, ty: lower_ty(_lctx, &va.ty) }
451 pub fn lower_block(_lctx: &LoweringContext, b: &Block) -> P<hir::Block> {
454 stmts: b.stmts.iter().map(|s| lower_stmt(_lctx, s)).collect(),
455 expr: b.expr.as_ref().map(|ref x| lower_expr(_lctx, x)),
456 rules: lower_block_check_mode(_lctx, &b.rules),
461 pub fn lower_item_underscore(_lctx: &LoweringContext, i: &Item_) -> hir::Item_ {
463 ItemExternCrate(string) => hir::ItemExternCrate(string),
464 ItemUse(ref view_path) => {
465 hir::ItemUse(lower_view_path(_lctx, view_path))
467 ItemStatic(ref t, m, ref e) => {
468 hir::ItemStatic(lower_ty(_lctx, t), lower_mutability(_lctx, m), lower_expr(_lctx, e))
470 ItemConst(ref t, ref e) => {
471 hir::ItemConst(lower_ty(_lctx, t), lower_expr(_lctx, e))
473 ItemFn(ref decl, unsafety, constness, abi, ref generics, ref body) => {
475 lower_fn_decl(_lctx, decl),
476 lower_unsafety(_lctx, unsafety),
477 lower_constness(_lctx, constness),
479 lower_generics(_lctx, generics),
480 lower_block(_lctx, body)
483 ItemMod(ref m) => hir::ItemMod(lower_mod(_lctx, m)),
484 ItemForeignMod(ref nm) => hir::ItemForeignMod(lower_foreign_mod(_lctx, nm)),
485 ItemTy(ref t, ref generics) => {
486 hir::ItemTy(lower_ty(_lctx, t), lower_generics(_lctx, generics))
488 ItemEnum(ref enum_definition, ref generics) => {
491 variants: enum_definition.variants.iter().map(|x| {
492 lower_variant(_lctx, x)
495 lower_generics(_lctx, generics))
497 ItemStruct(ref struct_def, ref generics) => {
498 let struct_def = lower_struct_def(_lctx, struct_def);
499 hir::ItemStruct(struct_def, lower_generics(_lctx, generics))
501 ItemDefaultImpl(unsafety, ref trait_ref) => {
502 hir::ItemDefaultImpl(lower_unsafety(_lctx, unsafety), lower_trait_ref(_lctx, trait_ref))
504 ItemImpl(unsafety, polarity, ref generics, ref ifce, ref ty, ref impl_items) => {
506 impl_items.iter().map(|item| lower_impl_item(_lctx, item)).collect();
507 let ifce = ifce.as_ref().map(|trait_ref| lower_trait_ref(_lctx, trait_ref));
508 hir::ItemImpl(lower_unsafety(_lctx, unsafety),
509 lower_impl_polarity(_lctx, polarity),
510 lower_generics(_lctx, generics),
515 ItemTrait(unsafety, ref generics, ref bounds, ref items) => {
516 let bounds = lower_bounds(_lctx, bounds);
517 let items = items.iter().map(|item| lower_trait_item(_lctx, item)).collect();
518 hir::ItemTrait(lower_unsafety(_lctx, unsafety),
519 lower_generics(_lctx, generics),
523 ItemMac(_) => panic!("Shouldn't still be around"),
527 pub fn lower_trait_item(_lctx: &LoweringContext, i: &TraitItem) -> P<hir::TraitItem> {
531 attrs: i.attrs.clone(),
533 ConstTraitItem(ref ty, ref default) => {
534 hir::ConstTraitItem(lower_ty(_lctx, ty),
535 default.as_ref().map(|x| lower_expr(_lctx, x)))
537 MethodTraitItem(ref sig, ref body) => {
538 hir::MethodTraitItem(lower_method_sig(_lctx, sig),
539 body.as_ref().map(|x| lower_block(_lctx, x)))
541 TypeTraitItem(ref bounds, ref default) => {
542 hir::TypeTraitItem(lower_bounds(_lctx, bounds),
543 default.as_ref().map(|x| lower_ty(_lctx, x)))
550 pub fn lower_impl_item(_lctx: &LoweringContext, i: &ImplItem) -> P<hir::ImplItem> {
554 attrs: i.attrs.clone(),
555 vis: lower_visibility(_lctx, i.vis),
557 ConstImplItem(ref ty, ref expr) => {
558 hir::ConstImplItem(lower_ty(_lctx, ty), lower_expr(_lctx, expr))
560 MethodImplItem(ref sig, ref body) => {
561 hir::MethodImplItem(lower_method_sig(_lctx, sig),
562 lower_block(_lctx, body))
564 TypeImplItem(ref ty) => hir::TypeImplItem(lower_ty(_lctx, ty)),
565 MacImplItem(..) => panic!("Shouldn't exist any more"),
571 pub fn lower_mod(_lctx: &LoweringContext, m: &Mod) -> hir::Mod {
572 hir::Mod { inner: m.inner, items: m.items.iter().map(|x| lower_item(_lctx, x)).collect() }
575 pub fn lower_crate(_lctx: &LoweringContext, c: &Crate) -> hir::Crate {
577 module: lower_mod(_lctx, &c.module),
578 attrs: c.attrs.clone(),
579 config: c.config.clone(),
581 exported_macros: c.exported_macros.iter().map(|m| lower_macro_def(_lctx, m)).collect(),
585 pub fn lower_macro_def(_lctx: &LoweringContext, m: &MacroDef) -> hir::MacroDef {
588 attrs: m.attrs.clone(),
591 imported_from: m.imported_from.map(|x| x.name),
593 use_locally: m.use_locally,
594 allow_internal_unstable: m.allow_internal_unstable,
595 body: m.body.clone(),
599 // fold one item into possibly many items
600 pub fn lower_item(_lctx: &LoweringContext, i: &Item) -> P<hir::Item> {
601 P(lower_item_simple(_lctx, i))
604 // fold one item into exactly one item
605 pub fn lower_item_simple(_lctx: &LoweringContext, i: &Item) -> hir::Item {
606 let node = lower_item_underscore(_lctx, &i.node);
611 attrs: i.attrs.clone(),
613 vis: lower_visibility(_lctx, i.vis),
618 pub fn lower_foreign_item(_lctx: &LoweringContext, i: &ForeignItem) -> P<hir::ForeignItem> {
622 attrs: i.attrs.clone(),
624 ForeignItemFn(ref fdec, ref generics) => {
625 hir::ForeignItemFn(lower_fn_decl(_lctx, fdec), lower_generics(_lctx, generics))
627 ForeignItemStatic(ref t, m) => {
628 hir::ForeignItemStatic(lower_ty(_lctx, t), m)
631 vis: lower_visibility(_lctx, i.vis),
636 pub fn lower_method_sig(_lctx: &LoweringContext, sig: &MethodSig) -> hir::MethodSig {
638 generics: lower_generics(_lctx, &sig.generics),
640 explicit_self: lower_explicit_self(_lctx, &sig.explicit_self),
641 unsafety: lower_unsafety(_lctx, sig.unsafety),
642 constness: lower_constness(_lctx, sig.constness),
643 decl: lower_fn_decl(_lctx, &sig.decl),
647 pub fn lower_unsafety(_lctx: &LoweringContext, u: Unsafety) -> hir::Unsafety {
649 Unsafety::Unsafe => hir::Unsafety::Unsafe,
650 Unsafety::Normal => hir::Unsafety::Normal,
654 pub fn lower_constness(_lctx: &LoweringContext, c: Constness) -> hir::Constness {
656 Constness::Const => hir::Constness::Const,
657 Constness::NotConst => hir::Constness::NotConst,
661 pub fn lower_unop(_lctx: &LoweringContext, u: UnOp) -> hir::UnOp {
663 UnDeref => hir::UnDeref,
669 pub fn lower_binop(_lctx: &LoweringContext, b: BinOp) -> hir::BinOp {
679 BiBitXor => hir::BiBitXor,
680 BiBitAnd => hir::BiBitAnd,
681 BiBitOr => hir::BiBitOr,
695 pub fn lower_pat(_lctx: &LoweringContext, p: &Pat) -> P<hir::Pat> {
699 PatWild(k) => hir::PatWild(lower_pat_wild_kind(_lctx, k)),
700 PatIdent(ref binding_mode, pth1, ref sub) => {
701 hir::PatIdent(lower_binding_mode(_lctx, binding_mode),
703 sub.as_ref().map(|x| lower_pat(_lctx, x)))
705 PatLit(ref e) => hir::PatLit(lower_expr(_lctx, e)),
706 PatEnum(ref pth, ref pats) => {
707 hir::PatEnum(lower_path(_lctx, pth),
709 .map(|pats| pats.iter().map(|x| lower_pat(_lctx, x)).collect()))
711 PatQPath(ref qself, ref pth) => {
712 let qself = hir::QSelf {
713 ty: lower_ty(_lctx, &qself.ty),
714 position: qself.position,
716 hir::PatQPath(qself, lower_path(_lctx, pth))
718 PatStruct(ref pth, ref fields, etc) => {
719 let pth = lower_path(_lctx, pth);
720 let fs = fields.iter().map(|f| {
721 Spanned { span: f.span,
722 node: hir::FieldPat {
723 name: f.node.ident.name,
724 pat: lower_pat(_lctx, &f.node.pat),
725 is_shorthand: f.node.is_shorthand,
728 hir::PatStruct(pth, fs, etc)
730 PatTup(ref elts) => hir::PatTup(elts.iter().map(|x| lower_pat(_lctx, x)).collect()),
731 PatBox(ref inner) => hir::PatBox(lower_pat(_lctx, inner)),
732 PatRegion(ref inner, mutbl) => hir::PatRegion(lower_pat(_lctx, inner),
733 lower_mutability(_lctx, mutbl)),
734 PatRange(ref e1, ref e2) => {
735 hir::PatRange(lower_expr(_lctx, e1), lower_expr(_lctx, e2))
737 PatVec(ref before, ref slice, ref after) => {
738 hir::PatVec(before.iter().map(|x| lower_pat(_lctx, x)).collect(),
739 slice.as_ref().map(|x| lower_pat(_lctx, x)),
740 after.iter().map(|x| lower_pat(_lctx, x)).collect())
742 PatMac(_) => panic!("Shouldn't exist here"),
748 pub fn lower_expr(lctx: &LoweringContext, e: &Expr) -> P<hir::Expr> {
753 hir::ExprBox(lower_expr(lctx, e))
755 ExprVec(ref exprs) => {
756 hir::ExprVec(exprs.iter().map(|x| lower_expr(lctx, x)).collect())
758 ExprRepeat(ref expr, ref count) => {
759 hir::ExprRepeat(lower_expr(lctx, expr), lower_expr(lctx, count))
761 ExprTup(ref elts) => {
762 hir::ExprTup(elts.iter().map(|x| lower_expr(lctx, x)).collect())
764 ExprCall(ref f, ref args) => {
765 hir::ExprCall(lower_expr(lctx, f),
766 args.iter().map(|x| lower_expr(lctx, x)).collect())
768 ExprMethodCall(i, ref tps, ref args) => {
770 respan(i.span, i.node.name),
771 tps.iter().map(|x| lower_ty(lctx, x)).collect(),
772 args.iter().map(|x| lower_expr(lctx, x)).collect())
774 ExprBinary(binop, ref lhs, ref rhs) => {
775 hir::ExprBinary(lower_binop(lctx, binop),
776 lower_expr(lctx, lhs),
777 lower_expr(lctx, rhs))
779 ExprUnary(op, ref ohs) => {
780 hir::ExprUnary(lower_unop(lctx, op), lower_expr(lctx, ohs))
782 ExprLit(ref l) => hir::ExprLit(P((**l).clone())),
783 ExprCast(ref expr, ref ty) => {
784 hir::ExprCast(lower_expr(lctx, expr), lower_ty(lctx, ty))
786 ExprAddrOf(m, ref ohs) => {
787 hir::ExprAddrOf(lower_mutability(lctx, m), lower_expr(lctx, ohs))
789 // More complicated than you might expect because the else branch
790 // might be `if let`.
791 ExprIf(ref cond, ref blk, ref else_opt) => {
792 let else_opt = else_opt.as_ref().map(|els| match els.node {
794 // wrap the if-let expr in a block
796 let blk = P(hir::Block {
798 expr: Some(lower_expr(lctx, els)),
800 rules: hir::DefaultBlock,
803 expr_block(lctx, blk)
805 _ => lower_expr(lctx, els)
808 hir::ExprIf(lower_expr(lctx, cond),
809 lower_block(lctx, blk),
812 ExprWhile(ref cond, ref body, opt_ident) => {
813 hir::ExprWhile(lower_expr(lctx, cond),
814 lower_block(lctx, body),
817 ExprLoop(ref body, opt_ident) => {
818 hir::ExprLoop(lower_block(lctx, body),
821 ExprMatch(ref expr, ref arms, ref source) => {
822 hir::ExprMatch(lower_expr(lctx, expr),
823 arms.iter().map(|x| lower_arm(lctx, x)).collect(),
824 lower_match_source(lctx, source))
826 ExprClosure(capture_clause, ref decl, ref body) => {
827 hir::ExprClosure(lower_capture_clause(lctx, capture_clause),
828 lower_fn_decl(lctx, decl),
829 lower_block(lctx, body))
831 ExprBlock(ref blk) => hir::ExprBlock(lower_block(lctx, blk)),
832 ExprAssign(ref el, ref er) => {
833 hir::ExprAssign(lower_expr(lctx, el), lower_expr(lctx, er))
835 ExprAssignOp(op, ref el, ref er) => {
836 hir::ExprAssignOp(lower_binop(lctx, op),
837 lower_expr(lctx, el),
838 lower_expr(lctx, er))
840 ExprField(ref el, ident) => {
841 hir::ExprField(lower_expr(lctx, el), respan(ident.span, ident.node.name))
843 ExprTupField(ref el, ident) => {
844 hir::ExprTupField(lower_expr(lctx, el), ident)
846 ExprIndex(ref el, ref er) => {
847 hir::ExprIndex(lower_expr(lctx, el), lower_expr(lctx, er))
849 ExprRange(ref e1, ref e2) => {
850 hir::ExprRange(e1.as_ref().map(|x| lower_expr(lctx, x)),
851 e2.as_ref().map(|x| lower_expr(lctx, x)))
853 ExprPath(ref qself, ref path) => {
854 let qself = qself.as_ref().map(|&QSelf { ref ty, position }| {
856 ty: lower_ty(lctx, ty),
860 hir::ExprPath(qself, lower_path(lctx, path))
862 ExprBreak(opt_ident) => hir::ExprBreak(opt_ident),
863 ExprAgain(opt_ident) => hir::ExprAgain(opt_ident),
864 ExprRet(ref e) => hir::ExprRet(e.as_ref().map(|x| lower_expr(lctx, x))),
865 ExprInlineAsm(InlineAsm {
875 }) => hir::ExprInlineAsm(hir::InlineAsm {
876 inputs: inputs.iter().map(|&(ref c, ref input)| {
877 (c.clone(), lower_expr(lctx, input))
879 outputs: outputs.iter().map(|&(ref c, ref out, ref is_rw)| {
880 (c.clone(), lower_expr(lctx, out), *is_rw)
883 asm_str_style: asm_str_style,
884 clobbers: clobbers.clone(),
886 alignstack: alignstack,
890 ExprStruct(ref path, ref fields, ref maybe_expr) => {
891 hir::ExprStruct(lower_path(lctx, path),
892 fields.iter().map(|x| lower_field(lctx, x)).collect(),
893 maybe_expr.as_ref().map(|x| lower_expr(lctx, x)))
895 ExprParen(ref ex) => {
896 return lower_expr(lctx, ex);
903 // From: `if let <pat> = <sub_expr> <body> [<else_opt>]`
904 ExprIfLet(ref pat, ref sub_expr, ref body, ref else_opt) => {
907 // match <sub_expr> {
909 // [_ if <else_opt_if_cond> => <else_opt_if_body>,]
910 // _ => [<else_opt> | ()]
915 let body_expr = expr_block(lctx, lower_block(lctx, body));
916 arm(vec![lower_pat(lctx, pat)], body_expr)
919 // `[_ if <else_opt_if_cond> => <else_opt_if_body>,]`
920 let mut else_opt = else_opt.as_ref().map(|e| lower_expr(lctx, e));
922 let mut arms = vec![];
924 let else_opt_continue = else_opt
925 .and_then(|els| els.and_then(|els| match els.node {
927 hir::ExprIf(cond, then, else_opt) => {
928 let pat_under = pat_wild(lctx, e.span);
931 pats: vec![pat_under],
933 body: expr_block(lctx, then)
935 else_opt.map(|else_opt| (else_opt, true))
937 _ => Some((P(els), false))
939 match else_opt_continue {
943 Some((e, false)) => {
956 let contains_else_clause = else_opt.is_some();
958 // `_ => [<else_opt> | ()]`
960 let pat_under = pat_wild(lctx, e.span);
961 let else_expr = else_opt.unwrap_or_else(|| expr_tuple(lctx, e.span, vec![]));
962 arm(vec![pat_under], else_expr)
965 let mut arms = Vec::with_capacity(else_if_arms.len() + 2);
967 arms.extend(else_if_arms);
970 let match_expr = expr(lctx,
972 hir::ExprMatch(lower_expr(lctx, sub_expr), arms,
973 hir::MatchSource::IfLetDesugar {
974 contains_else_clause: contains_else_clause,
979 // Desugar ExprWhileLet
980 // From: `[opt_ident]: while let <pat> = <sub_expr> <body>`
981 ExprWhileLet(ref pat, ref sub_expr, ref body, opt_ident) => {
984 // [opt_ident]: loop {
985 // match <sub_expr> {
993 let body_expr = expr_block(lctx, lower_block(lctx, body));
994 arm(vec![lower_pat(lctx, pat)], body_expr)
999 let pat_under = pat_wild(lctx, e.span);
1000 let break_expr = expr_break(lctx, e.span);
1001 arm(vec![pat_under], break_expr)
1004 // // `match <sub_expr> { ... }`
1005 let arms = vec![pat_arm, break_arm];
1006 let match_expr = expr(lctx,
1008 hir::ExprMatch(lower_expr(lctx, sub_expr), arms, hir::MatchSource::WhileLetDesugar));
1010 // `[opt_ident]: loop { ... }`
1011 let loop_block = block_expr(lctx, match_expr);
1012 return expr(lctx, e.span, hir::ExprLoop(loop_block, opt_ident));
1015 // Desugar ExprForLoop
1016 // From: `[opt_ident]: for <pat> in <head> <body>`
1017 ExprForLoop(ref pat, ref head, ref body, opt_ident) => {
1021 // let result = match ::std::iter::IntoIterator::into_iter(<head>) {
1023 // [opt_ident]: loop {
1024 // match ::std::iter::Iterator::next(&mut iter) {
1025 // ::std::option::Option::Some(<pat>) => <body>,
1026 // ::std::option::Option::None => break
1035 let head = lower_expr(lctx, head);
1037 let iter = token::gensym_ident("iter");
1039 // `::std::option::Option::Some(<pat>) => <body>`
1041 let body_block = lower_block(lctx, body);
1042 let body_span = body_block.span;
1043 let body_expr = P(hir::Expr {
1045 node: hir::ExprBlock(body_block),
1048 let pat = lower_pat(lctx, pat);
1049 let some_pat = pat_some(lctx, e.span, pat);
1051 arm(vec![some_pat], body_expr)
1054 // `::std::option::Option::None => break`
1056 let break_expr = expr_break(lctx, e.span);
1058 arm(vec![pat_none(lctx, e.span)], break_expr)
1061 // `match ::std::iter::Iterator::next(&mut iter) { ... }`
1064 let strs = std_path(lctx, &["iter", "Iterator", "next"]);
1066 path_global(e.span, strs)
1068 let ref_mut_iter = expr_mut_addr_of(lctx, e.span, expr_ident(lctx, e.span, iter));
1070 expr_call(lctx, e.span, expr_path(lctx, next_path), vec![ref_mut_iter]);
1071 let arms = vec![pat_arm, break_arm];
1075 hir::ExprMatch(next_expr, arms, hir::MatchSource::ForLoopDesugar))
1078 // `[opt_ident]: loop { ... }`
1079 let loop_block = block_expr(lctx, match_expr);
1080 let loop_expr = expr(lctx, e.span, hir::ExprLoop(loop_block, opt_ident));
1082 // `mut iter => { ... }`
1085 pat_ident_binding_mode(lctx, e.span, iter, hir::BindByValue(hir::MutMutable));
1086 arm(vec![iter_pat], loop_expr)
1089 // `match ::std::iter::IntoIterator::into_iter(<head>) { ... }`
1090 let into_iter_expr = {
1091 let into_iter_path = {
1092 let strs = std_path(lctx, &["iter", "IntoIterator", "into_iter"]);
1094 path_global(e.span, strs)
1097 expr_call(lctx, e.span, expr_path(lctx, into_iter_path), vec![head])
1100 let match_expr = expr_match(lctx, e.span, into_iter_expr, vec![iter_arm]);
1102 // `{ let result = ...; result }`
1103 let result_ident = token::gensym_ident("result");
1104 return expr_block(lctx,
1107 vec![stmt_let(lctx, e.span,
1111 Some(expr_ident(lctx, e.span, result_ident))))
1114 ExprMac(_) => panic!("Shouldn't exist here"),
1120 pub fn lower_stmt(_lctx: &LoweringContext, s: &Stmt) -> P<hir::Stmt> {
1122 StmtDecl(ref d, id) => {
1124 node: hir::StmtDecl(lower_decl(_lctx, d), id),
1128 StmtExpr(ref e, id) => {
1130 node: hir::StmtExpr(lower_expr(_lctx, e), id),
1134 StmtSemi(ref e, id) => {
1136 node: hir::StmtSemi(lower_expr(_lctx, e), id),
1140 StmtMac(..) => panic!("Shouldn't exist here"),
1144 pub fn lower_match_source(_lctx: &LoweringContext, m: &MatchSource) -> hir::MatchSource {
1146 MatchSource::Normal => hir::MatchSource::Normal,
1147 MatchSource::IfLetDesugar { contains_else_clause } => {
1148 hir::MatchSource::IfLetDesugar { contains_else_clause: contains_else_clause }
1150 MatchSource::WhileLetDesugar => hir::MatchSource::WhileLetDesugar,
1151 MatchSource::ForLoopDesugar => hir::MatchSource::ForLoopDesugar,
1155 pub fn lower_capture_clause(_lctx: &LoweringContext, c: CaptureClause) -> hir::CaptureClause {
1157 CaptureByValue => hir::CaptureByValue,
1158 CaptureByRef => hir::CaptureByRef,
1162 pub fn lower_visibility(_lctx: &LoweringContext, v: Visibility) -> hir::Visibility {
1164 Public => hir::Public,
1165 Inherited => hir::Inherited,
1169 pub fn lower_block_check_mode(_lctx: &LoweringContext, b: &BlockCheckMode) -> hir::BlockCheckMode {
1171 DefaultBlock => hir::DefaultBlock,
1172 UnsafeBlock(u) => hir::UnsafeBlock(lower_unsafe_source(_lctx, u)),
1173 PushUnsafeBlock(u) => hir::PushUnsafeBlock(lower_unsafe_source(_lctx, u)),
1174 PopUnsafeBlock(u) => hir::PopUnsafeBlock(lower_unsafe_source(_lctx, u)),
1178 pub fn lower_pat_wild_kind(_lctx: &LoweringContext, p: PatWildKind) -> hir::PatWildKind {
1180 PatWildSingle => hir::PatWildSingle,
1181 PatWildMulti => hir::PatWildMulti,
1185 pub fn lower_binding_mode(_lctx: &LoweringContext, b: &BindingMode) -> hir::BindingMode {
1187 BindByRef(m) => hir::BindByRef(lower_mutability(_lctx, m)),
1188 BindByValue(m) => hir::BindByValue(lower_mutability(_lctx, m)),
1192 pub fn lower_struct_field_kind(_lctx: &LoweringContext,
1193 s: &StructFieldKind)
1194 -> hir::StructFieldKind {
1196 NamedField(ident, vis) => hir::NamedField(ident.name, lower_visibility(_lctx, vis)),
1197 UnnamedField(vis) => hir::UnnamedField(lower_visibility(_lctx, vis)),
1201 pub fn lower_unsafe_source(_lctx: &LoweringContext, u: UnsafeSource) -> hir::UnsafeSource {
1203 CompilerGenerated => hir::CompilerGenerated,
1204 UserProvided => hir::UserProvided,
1208 pub fn lower_impl_polarity(_lctx: &LoweringContext, i: ImplPolarity) -> hir::ImplPolarity {
1210 ImplPolarity::Positive => hir::ImplPolarity::Positive,
1211 ImplPolarity::Negative => hir::ImplPolarity::Negative,
1215 pub fn lower_trait_bound_modifier(_lctx: &LoweringContext,
1216 f: TraitBoundModifier)
1217 -> hir::TraitBoundModifier {
1219 TraitBoundModifier::None => hir::TraitBoundModifier::None,
1220 TraitBoundModifier::Maybe => hir::TraitBoundModifier::Maybe,
1224 // Helper methods for building HIR.
1226 fn arm(pats: Vec<P<hir::Pat>>, expr: P<hir::Expr>) -> hir::Arm {
1235 fn expr_break(lctx: &LoweringContext, span: Span) -> P<hir::Expr> {
1236 expr(lctx, span, hir::ExprBreak(None))
1239 fn expr_call(lctx: &LoweringContext, span: Span, e: P<hir::Expr>, args: Vec<P<hir::Expr>>) -> P<hir::Expr> {
1240 expr(lctx, span, hir::ExprCall(e, args))
1243 fn expr_ident(lctx: &LoweringContext, span: Span, id: Ident) -> P<hir::Expr> {
1244 expr_path(lctx, path_ident(span, id))
1247 fn expr_mut_addr_of(lctx: &LoweringContext, span: Span, e: P<hir::Expr>) -> P<hir::Expr> {
1248 expr(lctx, span, hir::ExprAddrOf(hir::MutMutable, e))
1251 fn expr_path(lctx: &LoweringContext, path: hir::Path) -> P<hir::Expr> {
1252 expr(lctx, path.span, hir::ExprPath(None, path))
1255 fn expr_match(lctx: &LoweringContext, span: Span, arg: P<hir::Expr>, arms: Vec<hir::Arm>) -> P<hir::Expr> {
1256 expr(lctx, span, hir::ExprMatch(arg, arms, hir::MatchSource::Normal))
1259 fn expr_block(lctx: &LoweringContext, b: P<hir::Block>) -> P<hir::Expr> {
1260 expr(lctx, b.span, hir::ExprBlock(b))
1263 fn expr_tuple(lctx: &LoweringContext, sp: Span, exprs: Vec<P<hir::Expr>>) -> P<hir::Expr> {
1264 expr(lctx, sp, hir::ExprTup(exprs))
1267 fn expr(lctx: &LoweringContext, span: Span, node: hir::Expr_) -> P<hir::Expr> {
1275 fn stmt_let(lctx: &LoweringContext, sp: Span, mutbl: bool, ident: Ident, ex: P<hir::Expr>) -> P<hir::Stmt> {
1276 let pat = if mutbl {
1277 pat_ident_binding_mode(lctx, sp, ident, hir::BindByValue(hir::MutMutable))
1279 pat_ident(lctx, sp, ident)
1281 let local = P(hir::Local {
1288 let decl = respan(sp, hir::DeclLocal(local));
1289 P(respan(sp, hir::StmtDecl(P(decl), lctx.next_id())))
1292 fn block_expr(lctx: &LoweringContext, expr: P<hir::Expr>) -> P<hir::Block> {
1293 block_all(lctx, expr.span, Vec::new(), Some(expr))
1296 fn block_all(lctx: &LoweringContext,
1298 stmts: Vec<P<hir::Stmt>>,
1299 expr: Option<P<hir::Expr>>) -> P<hir::Block> {
1304 rules: hir::DefaultBlock,
1309 fn pat_some(lctx: &LoweringContext, span: Span, pat: P<hir::Pat>) -> P<hir::Pat> {
1310 let some = std_path(lctx, &["option", "Option", "Some"]);
1311 let path = path_global(span, some);
1312 pat_enum(lctx, span, path, vec!(pat))
1315 fn pat_none(lctx: &LoweringContext, span: Span) -> P<hir::Pat> {
1316 let none = std_path(lctx, &["option", "Option", "None"]);
1317 let path = path_global(span, none);
1318 pat_enum(lctx, span, path, vec![])
1321 fn pat_enum(lctx: &LoweringContext, span: Span, path: hir::Path, subpats: Vec<P<hir::Pat>>) -> P<hir::Pat> {
1322 let pt = hir::PatEnum(path, Some(subpats));
1326 fn pat_ident(lctx: &LoweringContext, span: Span, ident: Ident) -> P<hir::Pat> {
1327 pat_ident_binding_mode(lctx, span, ident, hir::BindByValue(hir::MutImmutable))
1330 fn pat_ident_binding_mode(lctx: &LoweringContext,
1333 bm: hir::BindingMode) -> P<hir::Pat> {
1334 let pat_ident = hir::PatIdent(bm, Spanned{span: span, node: ident}, None);
1335 pat(lctx, span, pat_ident)
1338 fn pat_wild(lctx: &LoweringContext, span: Span) -> P<hir::Pat> {
1339 pat(lctx, span, hir::PatWild(hir::PatWildSingle))
1342 fn pat(lctx: &LoweringContext, span: Span, pat: hir::Pat_) -> P<hir::Pat> {
1343 P(hir::Pat { id: lctx.next_id(), node: pat, span: span })
1346 fn path_ident(span: Span, id: Ident) -> hir::Path {
1347 path(span, vec!(id))
1350 fn path(span: Span, strs: Vec<Ident> ) -> hir::Path {
1351 path_all(span, false, strs, Vec::new(), Vec::new(), Vec::new())
1354 fn path_global(span: Span, strs: Vec<Ident> ) -> hir::Path {
1355 path_all(span, true, strs, Vec::new(), Vec::new(), Vec::new())
1358 fn path_all(sp: Span,
1360 mut idents: Vec<Ident> ,
1361 lifetimes: Vec<hir::Lifetime>,
1362 types: Vec<P<hir::Ty>>,
1363 bindings: Vec<P<hir::TypeBinding>> )
1365 let last_identifier = idents.pop().unwrap();
1366 let mut segments: Vec<hir::PathSegment> = idents.into_iter()
1370 parameters: hir::PathParameters::none(),
1373 segments.push(hir::PathSegment {
1374 identifier: last_identifier,
1375 parameters: hir::AngleBracketedParameters(hir::AngleBracketedParameterData {
1376 lifetimes: lifetimes,
1377 types: OwnedSlice::from_vec(types),
1378 bindings: OwnedSlice::from_vec(bindings),
1388 fn std_path(lctx: &LoweringContext, components: &[&str]) -> Vec<Ident> {
1389 let mut v = Vec::new();
1390 if let Some(s) = lctx.crate_root {
1391 v.push(str_to_ident(s));
1393 v.extend(components.iter().map(|s| str_to_ident(s)));