1 // Copyright 2012-2014 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 //! A Folder represents an AST->AST fold; it accepts an AST piece,
12 //! and returns a piece of the same type. So, for instance, macro
13 //! expansion is a Folder that walks over an AST and produces another
16 //! Note: using a Folder (other than the MacroExpander Folder) on
17 //! an AST before macro expansion is probably a bad idea. For instance,
18 //! a folder renaming item names in a module will miss all of those
19 //! that are created by the expansion of a macro.
24 use source_map::{Spanned, respan};
25 use parse::token::{self, Token};
27 use smallvec::{Array, SmallVec};
31 use util::move_map::MoveMap;
33 use rustc_data_structures::sync::Lrc;
35 pub trait ExpectOne<A: Array> {
36 fn expect_one(self, err: &'static str) -> A::Item;
39 impl<A: Array> ExpectOne<A> for SmallVec<A> {
40 fn expect_one(self, err: &'static str) -> A::Item {
41 assert!(self.len() == 1, err);
42 self.into_iter().next().unwrap()
46 pub trait Folder : Sized {
47 // Any additions to this trait should happen in form
48 // of a call to a public `noop_*` function that only calls
49 // out to the folder again, not other `noop_*` functions.
51 // This is a necessary API workaround to the problem of not
52 // being able to call out to the super default method
53 // in an overridden default method.
55 fn fold_crate(&mut self, c: Crate) -> Crate {
56 noop_fold_crate(c, self)
59 fn fold_meta_items(&mut self, meta_items: Vec<MetaItem>) -> Vec<MetaItem> {
60 noop_fold_meta_items(meta_items, self)
63 fn fold_meta_list_item(&mut self, list_item: NestedMetaItem) -> NestedMetaItem {
64 noop_fold_meta_list_item(list_item, self)
67 fn fold_meta_item(&mut self, meta_item: MetaItem) -> MetaItem {
68 noop_fold_meta_item(meta_item, self)
71 fn fold_use_tree(&mut self, use_tree: UseTree) -> UseTree {
72 noop_fold_use_tree(use_tree, self)
75 fn fold_foreign_item(&mut self, ni: ForeignItem) -> SmallVec<[ForeignItem; 1]> {
76 noop_fold_foreign_item(ni, self)
79 fn fold_foreign_item_simple(&mut self, ni: ForeignItem) -> ForeignItem {
80 noop_fold_foreign_item_simple(ni, self)
83 fn fold_item(&mut self, i: P<Item>) -> SmallVec<[P<Item>; 1]> {
84 noop_fold_item(i, self)
87 fn fold_item_simple(&mut self, i: Item) -> Item {
88 noop_fold_item_simple(i, self)
91 fn fold_fn_header(&mut self, header: FnHeader) -> FnHeader {
92 noop_fold_fn_header(header, self)
95 fn fold_struct_field(&mut self, sf: StructField) -> StructField {
96 noop_fold_struct_field(sf, self)
99 fn fold_item_kind(&mut self, i: ItemKind) -> ItemKind {
100 noop_fold_item_kind(i, self)
103 fn fold_trait_item(&mut self, i: TraitItem) -> SmallVec<[TraitItem; 1]> {
104 noop_fold_trait_item(i, self)
107 fn fold_impl_item(&mut self, i: ImplItem) -> SmallVec<[ImplItem; 1]> {
108 noop_fold_impl_item(i, self)
111 fn fold_fn_decl(&mut self, d: P<FnDecl>) -> P<FnDecl> {
112 noop_fold_fn_decl(d, self)
115 fn fold_asyncness(&mut self, a: IsAsync) -> IsAsync {
116 noop_fold_asyncness(a, self)
119 fn fold_block(&mut self, b: P<Block>) -> P<Block> {
120 noop_fold_block(b, self)
123 fn fold_stmt(&mut self, s: Stmt) -> SmallVec<[Stmt; 1]> {
124 noop_fold_stmt(s, self)
127 fn fold_arm(&mut self, a: Arm) -> Arm {
128 noop_fold_arm(a, self)
131 fn fold_guard(&mut self, g: Guard) -> Guard {
132 noop_fold_guard(g, self)
135 fn fold_pat(&mut self, p: P<Pat>) -> P<Pat> {
136 noop_fold_pat(p, self)
139 fn fold_anon_const(&mut self, c: AnonConst) -> AnonConst {
140 noop_fold_anon_const(c, self)
143 fn fold_expr(&mut self, e: P<Expr>) -> P<Expr> {
144 e.map(|e| noop_fold_expr(e, self))
147 fn fold_range_end(&mut self, re: RangeEnd) -> RangeEnd {
148 noop_fold_range_end(re, self)
151 fn fold_opt_expr(&mut self, e: P<Expr>) -> Option<P<Expr>> {
152 noop_fold_opt_expr(e, self)
155 fn fold_exprs(&mut self, es: Vec<P<Expr>>) -> Vec<P<Expr>> {
156 noop_fold_exprs(es, self)
159 fn fold_generic_arg(&mut self, arg: GenericArg) -> GenericArg {
161 GenericArg::Lifetime(lt) => GenericArg::Lifetime(self.fold_lifetime(lt)),
162 GenericArg::Type(ty) => GenericArg::Type(self.fold_ty(ty)),
166 fn fold_ty(&mut self, t: P<Ty>) -> P<Ty> {
167 noop_fold_ty(t, self)
170 fn fold_lifetime(&mut self, l: Lifetime) -> Lifetime {
171 noop_fold_lifetime(l, self)
174 fn fold_ty_binding(&mut self, t: TypeBinding) -> TypeBinding {
175 noop_fold_ty_binding(t, self)
178 fn fold_mod(&mut self, m: Mod) -> Mod {
179 noop_fold_mod(m, self)
182 fn fold_foreign_mod(&mut self, nm: ForeignMod) -> ForeignMod {
183 noop_fold_foreign_mod(nm, self)
186 fn fold_global_asm(&mut self, ga: P<GlobalAsm>) -> P<GlobalAsm> {
187 noop_fold_global_asm(ga, self)
190 fn fold_variant(&mut self, v: Variant) -> Variant {
191 noop_fold_variant(v, self)
194 fn fold_ident(&mut self, i: Ident) -> Ident {
195 noop_fold_ident(i, self)
198 fn fold_usize(&mut self, i: usize) -> usize {
199 noop_fold_usize(i, self)
202 fn fold_path(&mut self, p: Path) -> Path {
203 noop_fold_path(p, self)
206 fn fold_qpath(&mut self, qs: Option<QSelf>, p: Path) -> (Option<QSelf>, Path) {
207 noop_fold_qpath(qs, p, self)
210 fn fold_generic_args(&mut self, p: GenericArgs) -> GenericArgs {
211 noop_fold_generic_args(p, self)
214 fn fold_angle_bracketed_parameter_data(&mut self, p: AngleBracketedArgs)
215 -> AngleBracketedArgs
217 noop_fold_angle_bracketed_parameter_data(p, self)
220 fn fold_parenthesized_parameter_data(&mut self, p: ParenthesisedArgs)
223 noop_fold_parenthesized_parameter_data(p, self)
226 fn fold_local(&mut self, l: P<Local>) -> P<Local> {
227 noop_fold_local(l, self)
230 fn fold_mac(&mut self, _mac: Mac) -> Mac {
231 panic!("fold_mac disabled by default");
232 // N.B., see note about macros above.
233 // if you really want a folder that
234 // works on macros, use this
235 // definition in your trait impl:
236 // fold::noop_fold_mac(_mac, self)
239 fn fold_macro_def(&mut self, def: MacroDef) -> MacroDef {
240 noop_fold_macro_def(def, self)
243 fn fold_label(&mut self, label: Label) -> Label {
244 noop_fold_label(label, self)
247 fn fold_attribute(&mut self, at: Attribute) -> Option<Attribute> {
248 noop_fold_attribute(at, self)
251 fn fold_arg(&mut self, a: Arg) -> Arg {
252 noop_fold_arg(a, self)
255 fn fold_generics(&mut self, generics: Generics) -> Generics {
256 noop_fold_generics(generics, self)
259 fn fold_trait_ref(&mut self, p: TraitRef) -> TraitRef {
260 noop_fold_trait_ref(p, self)
263 fn fold_poly_trait_ref(&mut self, p: PolyTraitRef) -> PolyTraitRef {
264 noop_fold_poly_trait_ref(p, self)
267 fn fold_variant_data(&mut self, vdata: VariantData) -> VariantData {
268 noop_fold_variant_data(vdata, self)
271 fn fold_generic_param(&mut self, param: GenericParam) -> GenericParam {
272 noop_fold_generic_param(param, self)
275 fn fold_generic_params(&mut self, params: Vec<GenericParam>) -> Vec<GenericParam> {
276 noop_fold_generic_params(params, self)
279 fn fold_tt(&mut self, tt: TokenTree) -> TokenTree {
280 noop_fold_tt(tt, self)
283 fn fold_tts(&mut self, tts: TokenStream) -> TokenStream {
284 noop_fold_tts(tts, self)
287 fn fold_token(&mut self, t: token::Token) -> token::Token {
288 noop_fold_token(t, self)
291 fn fold_interpolated(&mut self, nt: token::Nonterminal) -> token::Nonterminal {
292 noop_fold_interpolated(nt, self)
295 fn fold_opt_bounds(&mut self, b: Option<GenericBounds>) -> Option<GenericBounds> {
296 noop_fold_opt_bounds(b, self)
299 fn fold_bounds(&mut self, b: GenericBounds) -> GenericBounds {
300 noop_fold_bounds(b, self)
303 fn fold_param_bound(&mut self, tpb: GenericBound) -> GenericBound {
304 noop_fold_param_bound(tpb, self)
307 fn fold_mt(&mut self, mt: MutTy) -> MutTy {
308 noop_fold_mt(mt, self)
311 fn fold_field(&mut self, field: Field) -> Field {
312 noop_fold_field(field, self)
315 fn fold_where_clause(&mut self, where_clause: WhereClause)
317 noop_fold_where_clause(where_clause, self)
320 fn fold_where_predicate(&mut self, where_predicate: WherePredicate)
322 noop_fold_where_predicate(where_predicate, self)
325 fn fold_vis(&mut self, vis: Visibility) -> Visibility {
326 noop_fold_vis(vis, self)
329 fn new_id(&mut self, i: NodeId) -> NodeId {
333 fn new_span(&mut self, sp: Span) -> Span {
338 pub fn noop_fold_meta_items<T: Folder>(meta_items: Vec<MetaItem>, fld: &mut T) -> Vec<MetaItem> {
339 meta_items.move_map(|x| fld.fold_meta_item(x))
342 pub fn noop_fold_use_tree<T: Folder>(use_tree: UseTree, fld: &mut T) -> UseTree {
344 span: fld.new_span(use_tree.span),
345 prefix: fld.fold_path(use_tree.prefix),
346 kind: match use_tree.kind {
347 UseTreeKind::Simple(rename, id1, id2) =>
348 UseTreeKind::Simple(rename.map(|ident| fld.fold_ident(ident)),
349 fld.new_id(id1), fld.new_id(id2)),
350 UseTreeKind::Glob => UseTreeKind::Glob,
351 UseTreeKind::Nested(items) => UseTreeKind::Nested(items.move_map(|(tree, id)| {
352 (fld.fold_use_tree(tree), fld.new_id(id))
358 pub fn fold_attrs<T: Folder>(attrs: Vec<Attribute>, fld: &mut T) -> Vec<Attribute> {
359 attrs.move_flat_map(|x| fld.fold_attribute(x))
362 pub fn fold_thin_attrs<T: Folder>(attrs: ThinVec<Attribute>, fld: &mut T) -> ThinVec<Attribute> {
363 fold_attrs(attrs.into(), fld).into()
366 pub fn noop_fold_arm<T: Folder>(Arm {attrs, pats, guard, body}: Arm,
367 fld: &mut T) -> Arm {
369 attrs: fold_attrs(attrs, fld),
370 pats: pats.move_map(|x| fld.fold_pat(x)),
371 guard: guard.map(|x| fld.fold_guard(x)),
372 body: fld.fold_expr(body),
376 pub fn noop_fold_guard<T: Folder>(g: Guard, fld: &mut T) -> Guard {
378 Guard::If(e) => Guard::If(fld.fold_expr(e)),
382 pub fn noop_fold_ty_binding<T: Folder>(b: TypeBinding, fld: &mut T) -> TypeBinding {
384 id: fld.new_id(b.id),
385 ident: fld.fold_ident(b.ident),
386 ty: fld.fold_ty(b.ty),
387 span: fld.new_span(b.span),
391 pub fn noop_fold_ty<T: Folder>(t: P<Ty>, fld: &mut T) -> P<Ty> {
392 t.map(|Ty {id, node, span}| Ty {
395 TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err => node,
396 TyKind::Slice(ty) => TyKind::Slice(fld.fold_ty(ty)),
397 TyKind::Ptr(mt) => TyKind::Ptr(fld.fold_mt(mt)),
398 TyKind::Rptr(region, mt) => {
399 TyKind::Rptr(region.map(|lt| noop_fold_lifetime(lt, fld)), fld.fold_mt(mt))
401 TyKind::BareFn(f) => {
402 TyKind::BareFn(f.map(|BareFnTy {generic_params, unsafety, abi, decl}| BareFnTy {
403 generic_params: fld.fold_generic_params(generic_params),
406 decl: fld.fold_fn_decl(decl)
409 TyKind::Never => node,
410 TyKind::Tup(tys) => TyKind::Tup(tys.move_map(|ty| fld.fold_ty(ty))),
411 TyKind::Paren(ty) => TyKind::Paren(fld.fold_ty(ty)),
412 TyKind::Path(qself, path) => {
413 let (qself, path) = fld.fold_qpath(qself, path);
414 TyKind::Path(qself, path)
416 TyKind::Array(ty, length) => {
417 TyKind::Array(fld.fold_ty(ty), fld.fold_anon_const(length))
419 TyKind::Typeof(expr) => {
420 TyKind::Typeof(fld.fold_anon_const(expr))
422 TyKind::TraitObject(bounds, syntax) => {
423 TyKind::TraitObject(bounds.move_map(|b| fld.fold_param_bound(b)), syntax)
425 TyKind::ImplTrait(id, bounds) => {
426 TyKind::ImplTrait(fld.new_id(id), bounds.move_map(|b| fld.fold_param_bound(b)))
428 TyKind::Mac(mac) => {
429 TyKind::Mac(fld.fold_mac(mac))
432 span: fld.new_span(span)
436 pub fn noop_fold_foreign_mod<T: Folder>(ForeignMod {abi, items}: ForeignMod,
437 fld: &mut T) -> ForeignMod {
440 items: items.move_flat_map(|x| fld.fold_foreign_item(x)),
444 pub fn noop_fold_global_asm<T: Folder>(ga: P<GlobalAsm>,
445 _: &mut T) -> P<GlobalAsm> {
449 pub fn noop_fold_variant<T: Folder>(v: Variant, fld: &mut T) -> Variant {
452 ident: fld.fold_ident(v.node.ident),
453 attrs: fold_attrs(v.node.attrs, fld),
454 data: fld.fold_variant_data(v.node.data),
455 disr_expr: v.node.disr_expr.map(|e| fld.fold_anon_const(e)),
457 span: fld.new_span(v.span),
461 pub fn noop_fold_ident<T: Folder>(ident: Ident, fld: &mut T) -> Ident {
462 Ident::new(ident.name, fld.new_span(ident.span))
465 pub fn noop_fold_usize<T: Folder>(i: usize, _: &mut T) -> usize {
469 pub fn noop_fold_path<T: Folder>(Path { segments, span }: Path, fld: &mut T) -> Path {
471 segments: segments.move_map(|PathSegment { ident, id, args }| PathSegment {
472 ident: fld.fold_ident(ident),
474 args: args.map(|args| args.map(|args| fld.fold_generic_args(args))),
476 span: fld.new_span(span)
480 pub fn noop_fold_qpath<T: Folder>(qself: Option<QSelf>,
482 fld: &mut T) -> (Option<QSelf>, Path) {
483 let qself = qself.map(|QSelf { ty, path_span, position }| {
486 path_span: fld.new_span(path_span),
490 (qself, fld.fold_path(path))
493 pub fn noop_fold_generic_args<T: Folder>(generic_args: GenericArgs, fld: &mut T) -> GenericArgs
496 GenericArgs::AngleBracketed(data) => {
497 GenericArgs::AngleBracketed(fld.fold_angle_bracketed_parameter_data(data))
499 GenericArgs::Parenthesized(data) => {
500 GenericArgs::Parenthesized(fld.fold_parenthesized_parameter_data(data))
505 pub fn noop_fold_angle_bracketed_parameter_data<T: Folder>(data: AngleBracketedArgs,
507 -> AngleBracketedArgs
509 let AngleBracketedArgs { args, bindings, span } = data;
511 args: args.move_map(|arg| fld.fold_generic_arg(arg)),
512 bindings: bindings.move_map(|b| fld.fold_ty_binding(b)),
513 span: fld.new_span(span)
517 pub fn noop_fold_parenthesized_parameter_data<T: Folder>(data: ParenthesisedArgs,
521 let ParenthesisedArgs { inputs, output, span } = data;
523 inputs: inputs.move_map(|ty| fld.fold_ty(ty)),
524 output: output.map(|ty| fld.fold_ty(ty)),
525 span: fld.new_span(span)
529 pub fn noop_fold_local<T: Folder>(l: P<Local>, fld: &mut T) -> P<Local> {
530 l.map(|Local {id, pat, ty, init, span, attrs}| Local {
532 pat: fld.fold_pat(pat),
533 ty: ty.map(|t| fld.fold_ty(t)),
534 init: init.map(|e| fld.fold_expr(e)),
535 span: fld.new_span(span),
536 attrs: fold_attrs(attrs.into(), fld).into(),
540 pub fn noop_fold_attribute<T: Folder>(attr: Attribute, fld: &mut T) -> Option<Attribute> {
544 path: fld.fold_path(attr.path),
545 tokens: fld.fold_tts(attr.tokens),
546 is_sugared_doc: attr.is_sugared_doc,
547 span: fld.new_span(attr.span),
551 pub fn noop_fold_mac<T: Folder>(Spanned {node, span}: Mac, fld: &mut T) -> Mac {
554 tts: fld.fold_tts(node.stream()).into(),
555 path: fld.fold_path(node.path),
558 span: fld.new_span(span)
562 pub fn noop_fold_macro_def<T: Folder>(def: MacroDef, fld: &mut T) -> MacroDef {
564 tokens: fld.fold_tts(def.tokens.into()).into(),
569 pub fn noop_fold_meta_list_item<T: Folder>(li: NestedMetaItem, fld: &mut T)
572 node: match li.node {
573 NestedMetaItemKind::MetaItem(mi) => {
574 NestedMetaItemKind::MetaItem(fld.fold_meta_item(mi))
576 NestedMetaItemKind::Literal(lit) => NestedMetaItemKind::Literal(lit)
578 span: fld.new_span(li.span)
582 pub fn noop_fold_meta_item<T: Folder>(mi: MetaItem, fld: &mut T) -> MetaItem {
585 node: match mi.node {
586 MetaItemKind::Word => MetaItemKind::Word,
587 MetaItemKind::List(mis) => {
588 MetaItemKind::List(mis.move_map(|e| fld.fold_meta_list_item(e)))
590 MetaItemKind::NameValue(s) => MetaItemKind::NameValue(s),
592 span: fld.new_span(mi.span)
596 pub fn noop_fold_arg<T: Folder>(Arg {id, pat, ty}: Arg, fld: &mut T) -> Arg {
599 pat: fld.fold_pat(pat),
604 pub fn noop_fold_tt<T: Folder>(tt: TokenTree, fld: &mut T) -> TokenTree {
606 TokenTree::Token(span, tok) =>
607 TokenTree::Token(fld.new_span(span), fld.fold_token(tok)),
608 TokenTree::Delimited(span, delimed) => TokenTree::Delimited(
609 DelimSpan::from_pair(fld.new_span(span.open), fld.new_span(span.close)),
611 tts: fld.fold_tts(delimed.stream()).into(),
612 delim: delimed.delim,
618 pub fn noop_fold_tts<T: Folder>(tts: TokenStream, fld: &mut T) -> TokenStream {
619 tts.map(|tt| fld.fold_tt(tt))
622 // apply ident folder if it's an ident, apply other folds to interpolated nodes
623 pub fn noop_fold_token<T: Folder>(t: token::Token, fld: &mut T) -> token::Token {
625 token::Ident(id, is_raw) => token::Ident(fld.fold_ident(id), is_raw),
626 token::Lifetime(id) => token::Lifetime(fld.fold_ident(id)),
627 token::Interpolated(nt) => {
628 let nt = match Lrc::try_unwrap(nt) {
630 Err(nt) => (*nt).clone(),
632 Token::interpolated(fld.fold_interpolated(nt.0))
638 /// apply folder to elements of interpolated nodes
640 // N.B., this can occur only when applying a fold to partially expanded code, where
641 // parsed pieces have gotten implanted ito *other* macro invocations. This is relevant
642 // for macro hygiene, but possibly not elsewhere.
644 // One problem here occurs because the types for fold_item, fold_stmt, etc. allow the
645 // folder to return *multiple* items; this is a problem for the nodes here, because
646 // they insist on having exactly one piece. One solution would be to mangle the fold
647 // trait to include one-to-many and one-to-one versions of these entry points, but that
648 // would probably confuse a lot of people and help very few. Instead, I'm just going
649 // to put in dynamic checks. I think the performance impact of this will be pretty much
650 // nonexistent. The danger is that someone will apply a fold to a partially expanded
651 // node, and will be confused by the fact that their "fold_item" or "fold_stmt" isn't
652 // getting called on NtItem or NtStmt nodes. Hopefully they'll wind up reading this
653 // comment, and doing something appropriate.
655 // BTW, design choice: I considered just changing the type of, e.g., NtItem to contain
656 // multiple items, but decided against it when I looked at parse_item_or_view_item and
657 // tried to figure out what I would do with multiple items there....
658 pub fn noop_fold_interpolated<T: Folder>(nt: token::Nonterminal, fld: &mut T)
659 -> token::Nonterminal {
661 token::NtItem(item) =>
662 token::NtItem(fld.fold_item(item)
663 // this is probably okay, because the only folds likely
664 // to peek inside interpolated nodes will be renamings/markings,
665 // which map single items to single items
666 .expect_one("expected fold to produce exactly one item")),
667 token::NtBlock(block) => token::NtBlock(fld.fold_block(block)),
668 token::NtStmt(stmt) =>
669 token::NtStmt(fld.fold_stmt(stmt)
670 // this is probably okay, because the only folds likely
671 // to peek inside interpolated nodes will be renamings/markings,
672 // which map single items to single items
673 .expect_one("expected fold to produce exactly one statement")),
674 token::NtPat(pat) => token::NtPat(fld.fold_pat(pat)),
675 token::NtExpr(expr) => token::NtExpr(fld.fold_expr(expr)),
676 token::NtTy(ty) => token::NtTy(fld.fold_ty(ty)),
677 token::NtIdent(ident, is_raw) => token::NtIdent(fld.fold_ident(ident), is_raw),
678 token::NtLifetime(ident) => token::NtLifetime(fld.fold_ident(ident)),
679 token::NtLiteral(expr) => token::NtLiteral(fld.fold_expr(expr)),
680 token::NtMeta(meta) => token::NtMeta(fld.fold_meta_item(meta)),
681 token::NtPath(path) => token::NtPath(fld.fold_path(path)),
682 token::NtTT(tt) => token::NtTT(fld.fold_tt(tt)),
683 token::NtArm(arm) => token::NtArm(fld.fold_arm(arm)),
684 token::NtImplItem(item) =>
685 token::NtImplItem(fld.fold_impl_item(item)
686 .expect_one("expected fold to produce exactly one item")),
687 token::NtTraitItem(item) =>
688 token::NtTraitItem(fld.fold_trait_item(item)
689 .expect_one("expected fold to produce exactly one item")),
690 token::NtGenerics(generics) => token::NtGenerics(fld.fold_generics(generics)),
691 token::NtWhereClause(where_clause) =>
692 token::NtWhereClause(fld.fold_where_clause(where_clause)),
693 token::NtArg(arg) => token::NtArg(fld.fold_arg(arg)),
694 token::NtVis(vis) => token::NtVis(fld.fold_vis(vis)),
695 token::NtForeignItem(ni) =>
696 token::NtForeignItem(fld.fold_foreign_item(ni)
697 // see reasoning above
698 .expect_one("expected fold to produce exactly one item")),
702 pub fn noop_fold_asyncness<T: Folder>(asyncness: IsAsync, fld: &mut T) -> IsAsync {
704 IsAsync::Async { closure_id, return_impl_trait_id } => IsAsync::Async {
705 closure_id: fld.new_id(closure_id),
706 return_impl_trait_id: fld.new_id(return_impl_trait_id),
708 IsAsync::NotAsync => IsAsync::NotAsync,
712 pub fn noop_fold_fn_decl<T: Folder>(decl: P<FnDecl>, fld: &mut T) -> P<FnDecl> {
713 decl.map(|FnDecl {inputs, output, variadic}| FnDecl {
714 inputs: inputs.move_map(|x| fld.fold_arg(x)),
715 output: match output {
716 FunctionRetTy::Ty(ty) => FunctionRetTy::Ty(fld.fold_ty(ty)),
717 FunctionRetTy::Default(span) => FunctionRetTy::Default(fld.new_span(span)),
723 pub fn noop_fold_param_bound<T>(pb: GenericBound, fld: &mut T) -> GenericBound where T: Folder {
725 GenericBound::Trait(ty, modifier) => {
726 GenericBound::Trait(fld.fold_poly_trait_ref(ty), modifier)
728 GenericBound::Outlives(lifetime) => {
729 GenericBound::Outlives(noop_fold_lifetime(lifetime, fld))
734 pub fn noop_fold_generic_param<T: Folder>(param: GenericParam, fld: &mut T) -> GenericParam {
735 let attrs: Vec<_> = param.attrs.into();
737 ident: fld.fold_ident(param.ident),
738 id: fld.new_id(param.id),
739 attrs: attrs.into_iter()
740 .flat_map(|x| fld.fold_attribute(x).into_iter())
743 bounds: param.bounds.move_map(|l| noop_fold_param_bound(l, fld)),
744 kind: match param.kind {
745 GenericParamKind::Lifetime => GenericParamKind::Lifetime,
746 GenericParamKind::Type { default } => GenericParamKind::Type {
747 default: default.map(|ty| fld.fold_ty(ty))
753 pub fn noop_fold_generic_params<T: Folder>(
754 params: Vec<GenericParam>,
756 ) -> Vec<GenericParam> {
757 params.move_map(|p| fld.fold_generic_param(p))
760 pub fn noop_fold_label<T: Folder>(label: Label, fld: &mut T) -> Label {
762 ident: fld.fold_ident(label.ident),
766 fn noop_fold_lifetime<T: Folder>(l: Lifetime, fld: &mut T) -> Lifetime {
768 id: fld.new_id(l.id),
769 ident: fld.fold_ident(l.ident),
773 pub fn noop_fold_generics<T: Folder>(Generics { params, where_clause, span }: Generics,
774 fld: &mut T) -> Generics {
776 params: fld.fold_generic_params(params),
777 where_clause: fld.fold_where_clause(where_clause),
778 span: fld.new_span(span),
782 pub fn noop_fold_where_clause<T: Folder>(
783 WhereClause {id, predicates, span}: WhereClause,
788 predicates: predicates.move_map(|predicate| {
789 fld.fold_where_predicate(predicate)
795 pub fn noop_fold_where_predicate<T: Folder>(
796 pred: WherePredicate,
800 ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate{bound_generic_params,
804 ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate {
805 bound_generic_params: fld.fold_generic_params(bound_generic_params),
806 bounded_ty: fld.fold_ty(bounded_ty),
807 bounds: bounds.move_map(|x| fld.fold_param_bound(x)),
808 span: fld.new_span(span)
811 ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate{lifetime,
814 ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate {
815 span: fld.new_span(span),
816 lifetime: noop_fold_lifetime(lifetime, fld),
817 bounds: bounds.move_map(|bound| noop_fold_param_bound(bound, fld))
820 ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{id,
824 ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{
826 lhs_ty: fld.fold_ty(lhs_ty),
827 rhs_ty: fld.fold_ty(rhs_ty),
828 span: fld.new_span(span)
834 pub fn noop_fold_variant_data<T: Folder>(vdata: VariantData, fld: &mut T) -> VariantData {
836 ast::VariantData::Struct(fields, id) => {
837 ast::VariantData::Struct(fields.move_map(|f| fld.fold_struct_field(f)),
840 ast::VariantData::Tuple(fields, id) => {
841 ast::VariantData::Tuple(fields.move_map(|f| fld.fold_struct_field(f)),
844 ast::VariantData::Unit(id) => ast::VariantData::Unit(fld.new_id(id))
848 pub fn noop_fold_trait_ref<T: Folder>(p: TraitRef, fld: &mut T) -> TraitRef {
849 let id = fld.new_id(p.ref_id);
855 path: fld.fold_path(path),
860 pub fn noop_fold_poly_trait_ref<T: Folder>(p: PolyTraitRef, fld: &mut T) -> PolyTraitRef {
862 bound_generic_params: fld.fold_generic_params(p.bound_generic_params),
863 trait_ref: fld.fold_trait_ref(p.trait_ref),
864 span: fld.new_span(p.span),
868 pub fn noop_fold_struct_field<T: Folder>(f: StructField, fld: &mut T) -> StructField {
870 span: fld.new_span(f.span),
871 id: fld.new_id(f.id),
872 ident: f.ident.map(|ident| fld.fold_ident(ident)),
873 vis: fld.fold_vis(f.vis),
874 ty: fld.fold_ty(f.ty),
875 attrs: fold_attrs(f.attrs, fld),
879 pub fn noop_fold_field<T: Folder>(f: Field, folder: &mut T) -> Field {
881 ident: folder.fold_ident(f.ident),
882 expr: folder.fold_expr(f.expr),
883 span: folder.new_span(f.span),
884 is_shorthand: f.is_shorthand,
885 attrs: fold_thin_attrs(f.attrs, folder),
889 pub fn noop_fold_mt<T: Folder>(MutTy {ty, mutbl}: MutTy, folder: &mut T) -> MutTy {
891 ty: folder.fold_ty(ty),
896 pub fn noop_fold_opt_bounds<T: Folder>(b: Option<GenericBounds>, folder: &mut T)
897 -> Option<GenericBounds> {
898 b.map(|bounds| folder.fold_bounds(bounds))
901 fn noop_fold_bounds<T: Folder>(bounds: GenericBounds, folder: &mut T)
903 bounds.move_map(|bound| folder.fold_param_bound(bound))
906 pub fn noop_fold_block<T: Folder>(b: P<Block>, folder: &mut T) -> P<Block> {
907 b.map(|Block {id, stmts, rules, span, recovered}| Block {
908 id: folder.new_id(id),
909 stmts: stmts.move_flat_map(|s| folder.fold_stmt(s).into_iter()),
911 span: folder.new_span(span),
916 pub fn noop_fold_item_kind<T: Folder>(i: ItemKind, folder: &mut T) -> ItemKind {
918 ItemKind::ExternCrate(orig_name) => ItemKind::ExternCrate(orig_name),
919 ItemKind::Use(use_tree) => {
920 ItemKind::Use(use_tree.map(|tree| folder.fold_use_tree(tree)))
922 ItemKind::Static(t, m, e) => {
923 ItemKind::Static(folder.fold_ty(t), m, folder.fold_expr(e))
925 ItemKind::Const(t, e) => {
926 ItemKind::Const(folder.fold_ty(t), folder.fold_expr(e))
928 ItemKind::Fn(decl, header, generics, body) => {
929 let generics = folder.fold_generics(generics);
930 let header = folder.fold_fn_header(header);
931 let decl = folder.fold_fn_decl(decl);
932 let body = folder.fold_block(body);
933 ItemKind::Fn(decl, header, generics, body)
935 ItemKind::Mod(m) => ItemKind::Mod(folder.fold_mod(m)),
936 ItemKind::ForeignMod(nm) => ItemKind::ForeignMod(folder.fold_foreign_mod(nm)),
937 ItemKind::GlobalAsm(ga) => ItemKind::GlobalAsm(folder.fold_global_asm(ga)),
938 ItemKind::Ty(t, generics) => {
939 ItemKind::Ty(folder.fold_ty(t), folder.fold_generics(generics))
941 ItemKind::Existential(bounds, generics) => ItemKind::Existential(
942 folder.fold_bounds(bounds),
943 folder.fold_generics(generics),
945 ItemKind::Enum(enum_definition, generics) => {
946 let generics = folder.fold_generics(generics);
947 let variants = enum_definition.variants.move_map(|x| folder.fold_variant(x));
948 ItemKind::Enum(ast::EnumDef { variants }, generics)
950 ItemKind::Struct(struct_def, generics) => {
951 let generics = folder.fold_generics(generics);
952 ItemKind::Struct(folder.fold_variant_data(struct_def), generics)
954 ItemKind::Union(struct_def, generics) => {
955 let generics = folder.fold_generics(generics);
956 ItemKind::Union(folder.fold_variant_data(struct_def), generics)
958 ItemKind::Impl(unsafety,
964 impl_items) => ItemKind::Impl(
968 folder.fold_generics(generics),
969 ifce.map(|trait_ref| folder.fold_trait_ref(trait_ref)),
971 impl_items.move_flat_map(|item| folder.fold_impl_item(item)),
973 ItemKind::Trait(is_auto, unsafety, generics, bounds, items) => ItemKind::Trait(
976 folder.fold_generics(generics),
977 folder.fold_bounds(bounds),
978 items.move_flat_map(|item| folder.fold_trait_item(item)),
980 ItemKind::TraitAlias(generics, bounds) => ItemKind::TraitAlias(
981 folder.fold_generics(generics),
982 folder.fold_bounds(bounds)),
983 ItemKind::Mac(m) => ItemKind::Mac(folder.fold_mac(m)),
984 ItemKind::MacroDef(def) => ItemKind::MacroDef(folder.fold_macro_def(def)),
988 pub fn noop_fold_trait_item<T: Folder>(i: TraitItem, folder: &mut T) -> SmallVec<[TraitItem; 1]> {
989 smallvec![TraitItem {
990 id: folder.new_id(i.id),
991 ident: folder.fold_ident(i.ident),
992 attrs: fold_attrs(i.attrs, folder),
993 generics: folder.fold_generics(i.generics),
995 TraitItemKind::Const(ty, default) => {
996 TraitItemKind::Const(folder.fold_ty(ty),
997 default.map(|x| folder.fold_expr(x)))
999 TraitItemKind::Method(sig, body) => {
1000 TraitItemKind::Method(noop_fold_method_sig(sig, folder),
1001 body.map(|x| folder.fold_block(x)))
1003 TraitItemKind::Type(bounds, default) => {
1004 TraitItemKind::Type(folder.fold_bounds(bounds),
1005 default.map(|x| folder.fold_ty(x)))
1007 ast::TraitItemKind::Macro(mac) => {
1008 TraitItemKind::Macro(folder.fold_mac(mac))
1011 span: folder.new_span(i.span),
1016 pub fn noop_fold_impl_item<T: Folder>(i: ImplItem, folder: &mut T)-> SmallVec<[ImplItem; 1]> {
1017 smallvec![ImplItem {
1018 id: folder.new_id(i.id),
1019 vis: folder.fold_vis(i.vis),
1020 ident: folder.fold_ident(i.ident),
1021 attrs: fold_attrs(i.attrs, folder),
1022 generics: folder.fold_generics(i.generics),
1023 defaultness: i.defaultness,
1024 node: match i.node {
1025 ast::ImplItemKind::Const(ty, expr) => {
1026 ast::ImplItemKind::Const(folder.fold_ty(ty), folder.fold_expr(expr))
1028 ast::ImplItemKind::Method(sig, body) => {
1029 ast::ImplItemKind::Method(noop_fold_method_sig(sig, folder),
1030 folder.fold_block(body))
1032 ast::ImplItemKind::Type(ty) => ast::ImplItemKind::Type(folder.fold_ty(ty)),
1033 ast::ImplItemKind::Existential(bounds) => {
1034 ast::ImplItemKind::Existential(folder.fold_bounds(bounds))
1036 ast::ImplItemKind::Macro(mac) => ast::ImplItemKind::Macro(folder.fold_mac(mac))
1038 span: folder.new_span(i.span),
1043 pub fn noop_fold_fn_header<T: Folder>(mut header: FnHeader, folder: &mut T) -> FnHeader {
1044 header.asyncness = folder.fold_asyncness(header.asyncness);
1048 pub fn noop_fold_mod<T: Folder>(Mod {inner, items, inline}: Mod, folder: &mut T) -> Mod {
1050 inner: folder.new_span(inner),
1051 items: items.move_flat_map(|x| folder.fold_item(x)),
1056 pub fn noop_fold_crate<T: Folder>(Crate {module, attrs, span}: Crate,
1057 folder: &mut T) -> Crate {
1058 let mut items = folder.fold_item(P(ast::Item {
1059 ident: keywords::Invalid.ident(),
1061 id: ast::DUMMY_NODE_ID,
1062 vis: respan(span.shrink_to_lo(), ast::VisibilityKind::Public),
1064 node: ast::ItemKind::Mod(module),
1068 let (module, attrs, span) = match items.next() {
1070 assert!(items.next().is_none(),
1071 "a crate cannot expand to more than one item");
1072 item.and_then(|ast::Item { attrs, span, node, .. }| {
1074 ast::ItemKind::Mod(m) => (m, attrs, span),
1075 _ => panic!("fold converted a module to not a module"),
1093 // fold one item into possibly many items
1094 pub fn noop_fold_item<T: Folder>(i: P<Item>, folder: &mut T) -> SmallVec<[P<Item>; 1]> {
1095 smallvec![i.map(|i| folder.fold_item_simple(i))]
1098 // fold one item into exactly one item
1099 pub fn noop_fold_item_simple<T: Folder>(Item {id, ident, attrs, node, vis, span, tokens}: Item,
1100 folder: &mut T) -> Item {
1102 id: folder.new_id(id),
1103 vis: folder.fold_vis(vis),
1104 ident: folder.fold_ident(ident),
1105 attrs: fold_attrs(attrs, folder),
1106 node: folder.fold_item_kind(node),
1107 span: folder.new_span(span),
1109 // FIXME: if this is replaced with a call to `folder.fold_tts` it causes
1110 // an ICE during resolve... odd!
1115 pub fn noop_fold_foreign_item<T: Folder>(ni: ForeignItem, folder: &mut T)
1116 -> SmallVec<[ForeignItem; 1]>
1118 smallvec![folder.fold_foreign_item_simple(ni)]
1121 pub fn noop_fold_foreign_item_simple<T: Folder>(ni: ForeignItem, folder: &mut T) -> ForeignItem {
1123 id: folder.new_id(ni.id),
1124 vis: folder.fold_vis(ni.vis),
1125 ident: folder.fold_ident(ni.ident),
1126 attrs: fold_attrs(ni.attrs, folder),
1127 node: match ni.node {
1128 ForeignItemKind::Fn(fdec, generics) => {
1129 ForeignItemKind::Fn(folder.fold_fn_decl(fdec), folder.fold_generics(generics))
1131 ForeignItemKind::Static(t, m) => {
1132 ForeignItemKind::Static(folder.fold_ty(t), m)
1134 ForeignItemKind::Ty => ForeignItemKind::Ty,
1135 ForeignItemKind::Macro(mac) => ForeignItemKind::Macro(folder.fold_mac(mac)),
1137 span: folder.new_span(ni.span)
1141 pub fn noop_fold_method_sig<T: Folder>(sig: MethodSig, folder: &mut T) -> MethodSig {
1143 header: folder.fold_fn_header(sig.header),
1144 decl: folder.fold_fn_decl(sig.decl)
1148 pub fn noop_fold_pat<T: Folder>(p: P<Pat>, folder: &mut T) -> P<Pat> {
1149 p.map(|Pat {id, node, span}| Pat {
1150 id: folder.new_id(id),
1152 PatKind::Wild => PatKind::Wild,
1153 PatKind::Ident(binding_mode, ident, sub) => {
1154 PatKind::Ident(binding_mode,
1155 folder.fold_ident(ident),
1156 sub.map(|x| folder.fold_pat(x)))
1158 PatKind::Lit(e) => PatKind::Lit(folder.fold_expr(e)),
1159 PatKind::TupleStruct(pth, pats, ddpos) => {
1160 PatKind::TupleStruct(folder.fold_path(pth),
1161 pats.move_map(|x| folder.fold_pat(x)), ddpos)
1163 PatKind::Path(qself, pth) => {
1164 let (qself, pth) = folder.fold_qpath(qself, pth);
1165 PatKind::Path(qself, pth)
1167 PatKind::Struct(pth, fields, etc) => {
1168 let pth = folder.fold_path(pth);
1169 let fs = fields.move_map(|f| {
1170 Spanned { span: folder.new_span(f.span),
1171 node: ast::FieldPat {
1172 ident: folder.fold_ident(f.node.ident),
1173 pat: folder.fold_pat(f.node.pat),
1174 is_shorthand: f.node.is_shorthand,
1175 attrs: fold_attrs(f.node.attrs.into(), folder).into()
1178 PatKind::Struct(pth, fs, etc)
1180 PatKind::Tuple(elts, ddpos) => {
1181 PatKind::Tuple(elts.move_map(|x| folder.fold_pat(x)), ddpos)
1183 PatKind::Box(inner) => PatKind::Box(folder.fold_pat(inner)),
1184 PatKind::Ref(inner, mutbl) => PatKind::Ref(folder.fold_pat(inner), mutbl),
1185 PatKind::Range(e1, e2, Spanned { span, node: end }) => {
1186 PatKind::Range(folder.fold_expr(e1),
1187 folder.fold_expr(e2),
1188 Spanned { span, node: folder.fold_range_end(end) })
1190 PatKind::Slice(before, slice, after) => {
1191 PatKind::Slice(before.move_map(|x| folder.fold_pat(x)),
1192 slice.map(|x| folder.fold_pat(x)),
1193 after.move_map(|x| folder.fold_pat(x)))
1195 PatKind::Paren(inner) => PatKind::Paren(folder.fold_pat(inner)),
1196 PatKind::Mac(mac) => PatKind::Mac(folder.fold_mac(mac))
1198 span: folder.new_span(span)
1202 pub fn noop_fold_range_end<T: Folder>(end: RangeEnd, _folder: &mut T) -> RangeEnd {
1206 pub fn noop_fold_anon_const<T: Folder>(constant: AnonConst, folder: &mut T) -> AnonConst {
1207 let AnonConst {id, value} = constant;
1209 id: folder.new_id(id),
1210 value: folder.fold_expr(value),
1214 pub fn noop_fold_expr<T: Folder>(Expr {id, node, span, attrs}: Expr, folder: &mut T) -> Expr {
1217 ExprKind::Box(e) => {
1218 ExprKind::Box(folder.fold_expr(e))
1220 ExprKind::ObsoleteInPlace(a, b) => {
1221 ExprKind::ObsoleteInPlace(folder.fold_expr(a), folder.fold_expr(b))
1223 ExprKind::Array(exprs) => {
1224 ExprKind::Array(folder.fold_exprs(exprs))
1226 ExprKind::Repeat(expr, count) => {
1227 ExprKind::Repeat(folder.fold_expr(expr), folder.fold_anon_const(count))
1229 ExprKind::Tup(exprs) => ExprKind::Tup(folder.fold_exprs(exprs)),
1230 ExprKind::Call(f, args) => {
1231 ExprKind::Call(folder.fold_expr(f),
1232 folder.fold_exprs(args))
1234 ExprKind::MethodCall(seg, args) => {
1235 ExprKind::MethodCall(
1237 ident: folder.fold_ident(seg.ident),
1238 id: folder.new_id(seg.id),
1239 args: seg.args.map(|args| {
1240 args.map(|args| folder.fold_generic_args(args))
1243 folder.fold_exprs(args))
1245 ExprKind::Binary(binop, lhs, rhs) => {
1246 ExprKind::Binary(binop,
1247 folder.fold_expr(lhs),
1248 folder.fold_expr(rhs))
1250 ExprKind::Unary(binop, ohs) => {
1251 ExprKind::Unary(binop, folder.fold_expr(ohs))
1253 ExprKind::Lit(l) => ExprKind::Lit(l),
1254 ExprKind::Cast(expr, ty) => {
1255 ExprKind::Cast(folder.fold_expr(expr), folder.fold_ty(ty))
1257 ExprKind::Type(expr, ty) => {
1258 ExprKind::Type(folder.fold_expr(expr), folder.fold_ty(ty))
1260 ExprKind::AddrOf(m, ohs) => ExprKind::AddrOf(m, folder.fold_expr(ohs)),
1261 ExprKind::If(cond, tr, fl) => {
1262 ExprKind::If(folder.fold_expr(cond),
1263 folder.fold_block(tr),
1264 fl.map(|x| folder.fold_expr(x)))
1266 ExprKind::IfLet(pats, expr, tr, fl) => {
1267 ExprKind::IfLet(pats.move_map(|pat| folder.fold_pat(pat)),
1268 folder.fold_expr(expr),
1269 folder.fold_block(tr),
1270 fl.map(|x| folder.fold_expr(x)))
1272 ExprKind::While(cond, body, opt_label) => {
1273 ExprKind::While(folder.fold_expr(cond),
1274 folder.fold_block(body),
1275 opt_label.map(|label| folder.fold_label(label)))
1277 ExprKind::WhileLet(pats, expr, body, opt_label) => {
1278 ExprKind::WhileLet(pats.move_map(|pat| folder.fold_pat(pat)),
1279 folder.fold_expr(expr),
1280 folder.fold_block(body),
1281 opt_label.map(|label| folder.fold_label(label)))
1283 ExprKind::ForLoop(pat, iter, body, opt_label) => {
1284 ExprKind::ForLoop(folder.fold_pat(pat),
1285 folder.fold_expr(iter),
1286 folder.fold_block(body),
1287 opt_label.map(|label| folder.fold_label(label)))
1289 ExprKind::Loop(body, opt_label) => {
1290 ExprKind::Loop(folder.fold_block(body),
1291 opt_label.map(|label| folder.fold_label(label)))
1293 ExprKind::Match(expr, arms) => {
1294 ExprKind::Match(folder.fold_expr(expr),
1295 arms.move_map(|x| folder.fold_arm(x)))
1297 ExprKind::Closure(capture_clause, asyncness, movability, decl, body, span) => {
1298 ExprKind::Closure(capture_clause,
1299 folder.fold_asyncness(asyncness),
1301 folder.fold_fn_decl(decl),
1302 folder.fold_expr(body),
1303 folder.new_span(span))
1305 ExprKind::Block(blk, opt_label) => {
1306 ExprKind::Block(folder.fold_block(blk),
1307 opt_label.map(|label| folder.fold_label(label)))
1309 ExprKind::Async(capture_clause, node_id, body) => {
1312 folder.new_id(node_id),
1313 folder.fold_block(body),
1316 ExprKind::Assign(el, er) => {
1317 ExprKind::Assign(folder.fold_expr(el), folder.fold_expr(er))
1319 ExprKind::AssignOp(op, el, er) => {
1320 ExprKind::AssignOp(op,
1321 folder.fold_expr(el),
1322 folder.fold_expr(er))
1324 ExprKind::Field(el, ident) => {
1325 ExprKind::Field(folder.fold_expr(el), folder.fold_ident(ident))
1327 ExprKind::Index(el, er) => {
1328 ExprKind::Index(folder.fold_expr(el), folder.fold_expr(er))
1330 ExprKind::Range(e1, e2, lim) => {
1331 ExprKind::Range(e1.map(|x| folder.fold_expr(x)),
1332 e2.map(|x| folder.fold_expr(x)),
1335 ExprKind::Path(qself, path) => {
1336 let (qself, path) = folder.fold_qpath(qself, path);
1337 ExprKind::Path(qself, path)
1339 ExprKind::Break(opt_label, opt_expr) => {
1340 ExprKind::Break(opt_label.map(|label| folder.fold_label(label)),
1341 opt_expr.map(|e| folder.fold_expr(e)))
1343 ExprKind::Continue(opt_label) => {
1344 ExprKind::Continue(opt_label.map(|label| folder.fold_label(label)))
1346 ExprKind::Ret(e) => ExprKind::Ret(e.map(|x| folder.fold_expr(x))),
1347 ExprKind::InlineAsm(asm) => ExprKind::InlineAsm(asm.map(|asm| {
1349 inputs: asm.inputs.move_map(|(c, input)| {
1350 (c, folder.fold_expr(input))
1352 outputs: asm.outputs.move_map(|out| {
1354 constraint: out.constraint,
1355 expr: folder.fold_expr(out.expr),
1357 is_indirect: out.is_indirect,
1363 ExprKind::Mac(mac) => ExprKind::Mac(folder.fold_mac(mac)),
1364 ExprKind::Struct(path, fields, maybe_expr) => {
1365 ExprKind::Struct(folder.fold_path(path),
1366 fields.move_map(|x| folder.fold_field(x)),
1367 maybe_expr.map(|x| folder.fold_expr(x)))
1369 ExprKind::Paren(ex) => {
1370 let sub_expr = folder.fold_expr(ex);
1372 // Nodes that are equal modulo `Paren` sugar no-ops should have the same ids.
1374 node: ExprKind::Paren(sub_expr),
1375 span: folder.new_span(span),
1376 attrs: fold_attrs(attrs.into(), folder).into(),
1379 ExprKind::Yield(ex) => ExprKind::Yield(ex.map(|x| folder.fold_expr(x))),
1380 ExprKind::Try(ex) => ExprKind::Try(folder.fold_expr(ex)),
1381 ExprKind::TryBlock(body) => ExprKind::TryBlock(folder.fold_block(body)),
1383 id: folder.new_id(id),
1384 span: folder.new_span(span),
1385 attrs: fold_attrs(attrs.into(), folder).into(),
1389 pub fn noop_fold_opt_expr<T: Folder>(e: P<Expr>, folder: &mut T) -> Option<P<Expr>> {
1390 Some(folder.fold_expr(e))
1393 pub fn noop_fold_exprs<T: Folder>(es: Vec<P<Expr>>, folder: &mut T) -> Vec<P<Expr>> {
1394 es.move_flat_map(|e| folder.fold_opt_expr(e))
1397 pub fn noop_fold_stmt<T: Folder>(Stmt {node, span, id}: Stmt, folder: &mut T) -> SmallVec<[Stmt; 1]>
1399 let id = folder.new_id(id);
1400 let span = folder.new_span(span);
1401 noop_fold_stmt_kind(node, folder).into_iter().map(|node| {
1402 Stmt { id: id, node: node, span: span }
1406 pub fn noop_fold_stmt_kind<T: Folder>(node: StmtKind, folder: &mut T) -> SmallVec<[StmtKind; 1]> {
1408 StmtKind::Local(local) => smallvec![StmtKind::Local(folder.fold_local(local))],
1409 StmtKind::Item(item) => folder.fold_item(item).into_iter().map(StmtKind::Item).collect(),
1410 StmtKind::Expr(expr) => {
1411 folder.fold_opt_expr(expr).into_iter().map(StmtKind::Expr).collect()
1413 StmtKind::Semi(expr) => {
1414 folder.fold_opt_expr(expr).into_iter().map(StmtKind::Semi).collect()
1416 StmtKind::Mac(mac) => smallvec![StmtKind::Mac(mac.map(|(mac, semi, attrs)| {
1417 (folder.fold_mac(mac), semi, fold_attrs(attrs.into(), folder).into())
1422 pub fn noop_fold_vis<T: Folder>(vis: Visibility, folder: &mut T) -> Visibility {
1424 VisibilityKind::Restricted { path, id } => {
1425 respan(vis.span, VisibilityKind::Restricted {
1426 path: path.map(|path| folder.fold_path(path)),
1427 id: folder.new_id(id),
1437 use ast::{self, Ident};
1438 use util::parser_testing::{string_to_crate, matches_codepattern};
1444 // this version doesn't care about getting comments or docstrings in.
1445 fn fake_print_crate(s: &mut pprust::State,
1446 krate: &ast::Crate) -> io::Result<()> {
1447 s.print_mod(&krate.module, &krate.attrs)
1450 // change every identifier to "zz"
1451 struct ToZzIdentFolder;
1453 impl Folder for ToZzIdentFolder {
1454 fn fold_ident(&mut self, _: ast::Ident) -> ast::Ident {
1455 Ident::from_str("zz")
1457 fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
1458 fold::noop_fold_mac(mac, self)
1462 // maybe add to expand.rs...
1463 macro_rules! assert_pred {
1464 ($pred:expr, $predname:expr, $a:expr , $b:expr) => (
1466 let pred_val = $pred;
1469 if !(pred_val(&a_val, &b_val)) {
1470 panic!("expected args satisfying {}, got {} and {}",
1471 $predname, a_val, b_val);
1477 // make sure idents get transformed everywhere
1478 #[test] fn ident_transformation () {
1480 let mut zz_fold = ToZzIdentFolder;
1481 let ast = string_to_crate(
1482 "#[a] mod b {fn c (d : e, f : g) {h!(i,j,k);l;m}}".to_string());
1483 let folded_crate = zz_fold.fold_crate(ast);
1485 matches_codepattern,
1486 "matches_codepattern",
1487 pprust::to_string(|s| fake_print_crate(s, &folded_crate)),
1488 "#[zz]mod zz{fn zz(zz:zz,zz:zz){zz!(zz,zz,zz);zz;zz}}".to_string());
1492 // even inside macro defs....
1493 #[test] fn ident_transformation_in_defs () {
1495 let mut zz_fold = ToZzIdentFolder;
1496 let ast = string_to_crate(
1497 "macro_rules! a {(b $c:expr $(d $e:token)f+ => \
1498 (g $(d $d $e)+))} ".to_string());
1499 let folded_crate = zz_fold.fold_crate(ast);
1501 matches_codepattern,
1502 "matches_codepattern",
1503 pprust::to_string(|s| fake_print_crate(s, &folded_crate)),
1504 "macro_rules! zz((zz$zz:zz$(zz $zz:zz)zz+=>(zz$(zz$zz$zz)+)));".to_string());