| //! A Folder represents an AST->AST fold; it accepts an AST piece, |
| //! and returns a piece of the same type. So, for instance, macro |
| //! expansion is a Folder that walks over an AST and produces another |
| //! AST. |
| //! |
| //! Note: using a Folder (other than the MacroExpander Folder) on |
| //! an AST before macro expansion is probably a bad idea. For instance, |
| //! a folder renaming item names in a module will miss all of those |
| //! that are created by the expansion of a macro. |
| |
| use ast::*; |
| use ast; |
| use syntax_pos::Span; |
| use source_map::{Spanned, respan}; |
| use parse::token::{self, Token}; |
| use ptr::P; |
| use smallvec::{Array, SmallVec}; |
| use symbol::keywords; |
| use ThinVec; |
| use tokenstream::*; |
| use util::move_map::MoveMap; |
| |
| use rustc_data_structures::sync::Lrc; |
| |
| pub trait ExpectOne<A: Array> { |
| fn expect_one(self, err: &'static str) -> A::Item; |
| } |
| |
| impl<A: Array> ExpectOne<A> for SmallVec<A> { |
| fn expect_one(self, err: &'static str) -> A::Item { |
| assert!(self.len() == 1, err); |
| self.into_iter().next().unwrap() |
| } |
| } |
| |
| pub trait Folder : Sized { |
| // Any additions to this trait should happen in form |
| // of a call to a public `noop_*` function that only calls |
| // out to the folder again, not other `noop_*` functions. |
| // |
| // This is a necessary API workaround to the problem of not |
| // being able to call out to the super default method |
| // in an overridden default method. |
| |
| fn fold_crate(&mut self, c: Crate) -> Crate { |
| noop_fold_crate(c, self) |
| } |
| |
| fn fold_meta_items(&mut self, meta_items: Vec<MetaItem>) -> Vec<MetaItem> { |
| noop_fold_meta_items(meta_items, self) |
| } |
| |
| fn fold_meta_list_item(&mut self, list_item: NestedMetaItem) -> NestedMetaItem { |
| noop_fold_meta_list_item(list_item, self) |
| } |
| |
| fn fold_meta_item(&mut self, meta_item: MetaItem) -> MetaItem { |
| noop_fold_meta_item(meta_item, self) |
| } |
| |
| fn fold_use_tree(&mut self, use_tree: UseTree) -> UseTree { |
| noop_fold_use_tree(use_tree, self) |
| } |
| |
| fn fold_foreign_item(&mut self, ni: ForeignItem) -> SmallVec<[ForeignItem; 1]> { |
| noop_fold_foreign_item(ni, self) |
| } |
| |
| fn fold_foreign_item_simple(&mut self, ni: ForeignItem) -> ForeignItem { |
| noop_fold_foreign_item_simple(ni, self) |
| } |
| |
| fn fold_item(&mut self, i: P<Item>) -> SmallVec<[P<Item>; 1]> { |
| noop_fold_item(i, self) |
| } |
| |
| fn fold_item_simple(&mut self, i: Item) -> Item { |
| noop_fold_item_simple(i, self) |
| } |
| |
| fn fold_fn_header(&mut self, header: FnHeader) -> FnHeader { |
| noop_fold_fn_header(header, self) |
| } |
| |
| fn fold_struct_field(&mut self, sf: StructField) -> StructField { |
| noop_fold_struct_field(sf, self) |
| } |
| |
| fn fold_item_kind(&mut self, i: ItemKind) -> ItemKind { |
| noop_fold_item_kind(i, self) |
| } |
| |
| fn fold_trait_item(&mut self, i: TraitItem) -> SmallVec<[TraitItem; 1]> { |
| noop_fold_trait_item(i, self) |
| } |
| |
| fn fold_impl_item(&mut self, i: ImplItem) -> SmallVec<[ImplItem; 1]> { |
| noop_fold_impl_item(i, self) |
| } |
| |
| fn fold_fn_decl(&mut self, d: P<FnDecl>) -> P<FnDecl> { |
| noop_fold_fn_decl(d, self) |
| } |
| |
| fn fold_asyncness(&mut self, a: IsAsync) -> IsAsync { |
| noop_fold_asyncness(a, self) |
| } |
| |
| fn fold_block(&mut self, b: P<Block>) -> P<Block> { |
| noop_fold_block(b, self) |
| } |
| |
| fn fold_stmt(&mut self, s: Stmt) -> SmallVec<[Stmt; 1]> { |
| noop_fold_stmt(s, self) |
| } |
| |
| fn fold_arm(&mut self, a: Arm) -> Arm { |
| noop_fold_arm(a, self) |
| } |
| |
| fn fold_guard(&mut self, g: Guard) -> Guard { |
| noop_fold_guard(g, self) |
| } |
| |
| fn fold_pat(&mut self, p: P<Pat>) -> P<Pat> { |
| noop_fold_pat(p, self) |
| } |
| |
| fn fold_anon_const(&mut self, c: AnonConst) -> AnonConst { |
| noop_fold_anon_const(c, self) |
| } |
| |
| fn fold_expr(&mut self, e: P<Expr>) -> P<Expr> { |
| e.map(|e| noop_fold_expr(e, self)) |
| } |
| |
| fn fold_range_end(&mut self, re: RangeEnd) -> RangeEnd { |
| noop_fold_range_end(re, self) |
| } |
| |
| fn fold_opt_expr(&mut self, e: P<Expr>) -> Option<P<Expr>> { |
| noop_fold_opt_expr(e, self) |
| } |
| |
| fn fold_exprs(&mut self, es: Vec<P<Expr>>) -> Vec<P<Expr>> { |
| noop_fold_exprs(es, self) |
| } |
| |
| fn fold_generic_arg(&mut self, arg: GenericArg) -> GenericArg { |
| match arg { |
| GenericArg::Lifetime(lt) => GenericArg::Lifetime(self.fold_lifetime(lt)), |
| GenericArg::Type(ty) => GenericArg::Type(self.fold_ty(ty)), |
| } |
| } |
| |
| fn fold_ty(&mut self, t: P<Ty>) -> P<Ty> { |
| noop_fold_ty(t, self) |
| } |
| |
| fn fold_lifetime(&mut self, l: Lifetime) -> Lifetime { |
| noop_fold_lifetime(l, self) |
| } |
| |
| fn fold_ty_binding(&mut self, t: TypeBinding) -> TypeBinding { |
| noop_fold_ty_binding(t, self) |
| } |
| |
| fn fold_mod(&mut self, m: Mod) -> Mod { |
| noop_fold_mod(m, self) |
| } |
| |
| fn fold_foreign_mod(&mut self, nm: ForeignMod) -> ForeignMod { |
| noop_fold_foreign_mod(nm, self) |
| } |
| |
| fn fold_global_asm(&mut self, ga: P<GlobalAsm>) -> P<GlobalAsm> { |
| noop_fold_global_asm(ga, self) |
| } |
| |
| fn fold_variant(&mut self, v: Variant) -> Variant { |
| noop_fold_variant(v, self) |
| } |
| |
| fn fold_ident(&mut self, i: Ident) -> Ident { |
| noop_fold_ident(i, self) |
| } |
| |
| fn fold_usize(&mut self, i: usize) -> usize { |
| noop_fold_usize(i, self) |
| } |
| |
| fn fold_path(&mut self, p: Path) -> Path { |
| noop_fold_path(p, self) |
| } |
| |
| fn fold_qpath(&mut self, qs: Option<QSelf>, p: Path) -> (Option<QSelf>, Path) { |
| noop_fold_qpath(qs, p, self) |
| } |
| |
| fn fold_generic_args(&mut self, p: GenericArgs) -> GenericArgs { |
| noop_fold_generic_args(p, self) |
| } |
| |
| fn fold_angle_bracketed_parameter_data(&mut self, p: AngleBracketedArgs) |
| -> AngleBracketedArgs |
| { |
| noop_fold_angle_bracketed_parameter_data(p, self) |
| } |
| |
| fn fold_parenthesized_parameter_data(&mut self, p: ParenthesisedArgs) |
| -> ParenthesisedArgs |
| { |
| noop_fold_parenthesized_parameter_data(p, self) |
| } |
| |
| fn fold_local(&mut self, l: P<Local>) -> P<Local> { |
| noop_fold_local(l, self) |
| } |
| |
| fn fold_mac(&mut self, _mac: Mac) -> Mac { |
| panic!("fold_mac disabled by default"); |
| // N.B., see note about macros above. |
| // if you really want a folder that |
| // works on macros, use this |
| // definition in your trait impl: |
| // fold::noop_fold_mac(_mac, self) |
| } |
| |
| fn fold_macro_def(&mut self, def: MacroDef) -> MacroDef { |
| noop_fold_macro_def(def, self) |
| } |
| |
| fn fold_label(&mut self, label: Label) -> Label { |
| noop_fold_label(label, self) |
| } |
| |
| fn fold_attribute(&mut self, at: Attribute) -> Option<Attribute> { |
| noop_fold_attribute(at, self) |
| } |
| |
| fn fold_arg(&mut self, a: Arg) -> Arg { |
| noop_fold_arg(a, self) |
| } |
| |
| fn fold_generics(&mut self, generics: Generics) -> Generics { |
| noop_fold_generics(generics, self) |
| } |
| |
| fn fold_trait_ref(&mut self, p: TraitRef) -> TraitRef { |
| noop_fold_trait_ref(p, self) |
| } |
| |
| fn fold_poly_trait_ref(&mut self, p: PolyTraitRef) -> PolyTraitRef { |
| noop_fold_poly_trait_ref(p, self) |
| } |
| |
| fn fold_variant_data(&mut self, vdata: VariantData) -> VariantData { |
| noop_fold_variant_data(vdata, self) |
| } |
| |
| fn fold_generic_param(&mut self, param: GenericParam) -> GenericParam { |
| noop_fold_generic_param(param, self) |
| } |
| |
| fn fold_generic_params(&mut self, params: Vec<GenericParam>) -> Vec<GenericParam> { |
| noop_fold_generic_params(params, self) |
| } |
| |
| fn fold_tt(&mut self, tt: TokenTree) -> TokenTree { |
| noop_fold_tt(tt, self) |
| } |
| |
| fn fold_tts(&mut self, tts: TokenStream) -> TokenStream { |
| noop_fold_tts(tts, self) |
| } |
| |
| fn fold_token(&mut self, t: token::Token) -> token::Token { |
| noop_fold_token(t, self) |
| } |
| |
| fn fold_interpolated(&mut self, nt: token::Nonterminal) -> token::Nonterminal { |
| noop_fold_interpolated(nt, self) |
| } |
| |
| fn fold_opt_bounds(&mut self, b: Option<GenericBounds>) -> Option<GenericBounds> { |
| noop_fold_opt_bounds(b, self) |
| } |
| |
| fn fold_bounds(&mut self, b: GenericBounds) -> GenericBounds { |
| noop_fold_bounds(b, self) |
| } |
| |
| fn fold_param_bound(&mut self, tpb: GenericBound) -> GenericBound { |
| noop_fold_param_bound(tpb, self) |
| } |
| |
| fn fold_mt(&mut self, mt: MutTy) -> MutTy { |
| noop_fold_mt(mt, self) |
| } |
| |
| fn fold_field(&mut self, field: Field) -> Field { |
| noop_fold_field(field, self) |
| } |
| |
| fn fold_where_clause(&mut self, where_clause: WhereClause) |
| -> WhereClause { |
| noop_fold_where_clause(where_clause, self) |
| } |
| |
| fn fold_where_predicate(&mut self, where_predicate: WherePredicate) |
| -> WherePredicate { |
| noop_fold_where_predicate(where_predicate, self) |
| } |
| |
| fn fold_vis(&mut self, vis: Visibility) -> Visibility { |
| noop_fold_vis(vis, self) |
| } |
| |
| fn new_id(&mut self, i: NodeId) -> NodeId { |
| i |
| } |
| |
| fn new_span(&mut self, sp: Span) -> Span { |
| sp |
| } |
| } |
| |
| pub fn noop_fold_meta_items<T: Folder>(meta_items: Vec<MetaItem>, fld: &mut T) -> Vec<MetaItem> { |
| meta_items.move_map(|x| fld.fold_meta_item(x)) |
| } |
| |
| pub fn noop_fold_use_tree<T: Folder>(use_tree: UseTree, fld: &mut T) -> UseTree { |
| UseTree { |
| span: fld.new_span(use_tree.span), |
| prefix: fld.fold_path(use_tree.prefix), |
| kind: match use_tree.kind { |
| UseTreeKind::Simple(rename, id1, id2) => |
| UseTreeKind::Simple(rename.map(|ident| fld.fold_ident(ident)), |
| fld.new_id(id1), fld.new_id(id2)), |
| UseTreeKind::Glob => UseTreeKind::Glob, |
| UseTreeKind::Nested(items) => UseTreeKind::Nested(items.move_map(|(tree, id)| { |
| (fld.fold_use_tree(tree), fld.new_id(id)) |
| })), |
| }, |
| } |
| } |
| |
| pub fn fold_attrs<T: Folder>(attrs: Vec<Attribute>, fld: &mut T) -> Vec<Attribute> { |
| attrs.move_flat_map(|x| fld.fold_attribute(x)) |
| } |
| |
| pub fn fold_thin_attrs<T: Folder>(attrs: ThinVec<Attribute>, fld: &mut T) -> ThinVec<Attribute> { |
| fold_attrs(attrs.into(), fld).into() |
| } |
| |
| pub fn noop_fold_arm<T: Folder>(Arm {attrs, pats, guard, body}: Arm, |
| fld: &mut T) -> Arm { |
| Arm { |
| attrs: fold_attrs(attrs, fld), |
| pats: pats.move_map(|x| fld.fold_pat(x)), |
| guard: guard.map(|x| fld.fold_guard(x)), |
| body: fld.fold_expr(body), |
| } |
| } |
| |
| pub fn noop_fold_guard<T: Folder>(g: Guard, fld: &mut T) -> Guard { |
| match g { |
| Guard::If(e) => Guard::If(fld.fold_expr(e)), |
| } |
| } |
| |
| pub fn noop_fold_ty_binding<T: Folder>(b: TypeBinding, fld: &mut T) -> TypeBinding { |
| TypeBinding { |
| id: fld.new_id(b.id), |
| ident: fld.fold_ident(b.ident), |
| ty: fld.fold_ty(b.ty), |
| span: fld.new_span(b.span), |
| } |
| } |
| |
| pub fn noop_fold_ty<T: Folder>(t: P<Ty>, fld: &mut T) -> P<Ty> { |
| t.map(|Ty {id, node, span}| Ty { |
| id: fld.new_id(id), |
| node: match node { |
| TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err => node, |
| TyKind::Slice(ty) => TyKind::Slice(fld.fold_ty(ty)), |
| TyKind::Ptr(mt) => TyKind::Ptr(fld.fold_mt(mt)), |
| TyKind::Rptr(region, mt) => { |
| TyKind::Rptr(region.map(|lt| noop_fold_lifetime(lt, fld)), fld.fold_mt(mt)) |
| } |
| TyKind::BareFn(f) => { |
| TyKind::BareFn(f.map(|BareFnTy {generic_params, unsafety, abi, decl}| BareFnTy { |
| generic_params: fld.fold_generic_params(generic_params), |
| unsafety, |
| abi, |
| decl: fld.fold_fn_decl(decl) |
| })) |
| } |
| TyKind::Never => node, |
| TyKind::Tup(tys) => TyKind::Tup(tys.move_map(|ty| fld.fold_ty(ty))), |
| TyKind::Paren(ty) => TyKind::Paren(fld.fold_ty(ty)), |
| TyKind::Path(qself, path) => { |
| let (qself, path) = fld.fold_qpath(qself, path); |
| TyKind::Path(qself, path) |
| } |
| TyKind::Array(ty, length) => { |
| TyKind::Array(fld.fold_ty(ty), fld.fold_anon_const(length)) |
| } |
| TyKind::Typeof(expr) => { |
| TyKind::Typeof(fld.fold_anon_const(expr)) |
| } |
| TyKind::TraitObject(bounds, syntax) => { |
| TyKind::TraitObject(bounds.move_map(|b| fld.fold_param_bound(b)), syntax) |
| } |
| TyKind::ImplTrait(id, bounds) => { |
| TyKind::ImplTrait(fld.new_id(id), bounds.move_map(|b| fld.fold_param_bound(b))) |
| } |
| TyKind::Mac(mac) => { |
| TyKind::Mac(fld.fold_mac(mac)) |
| } |
| }, |
| span: fld.new_span(span) |
| }) |
| } |
| |
| pub fn noop_fold_foreign_mod<T: Folder>(ForeignMod {abi, items}: ForeignMod, |
| fld: &mut T) -> ForeignMod { |
| ForeignMod { |
| abi, |
| items: items.move_flat_map(|x| fld.fold_foreign_item(x)), |
| } |
| } |
| |
| pub fn noop_fold_global_asm<T: Folder>(ga: P<GlobalAsm>, |
| _: &mut T) -> P<GlobalAsm> { |
| ga |
| } |
| |
| pub fn noop_fold_variant<T: Folder>(v: Variant, fld: &mut T) -> Variant { |
| Spanned { |
| node: Variant_ { |
| ident: fld.fold_ident(v.node.ident), |
| attrs: fold_attrs(v.node.attrs, fld), |
| data: fld.fold_variant_data(v.node.data), |
| disr_expr: v.node.disr_expr.map(|e| fld.fold_anon_const(e)), |
| }, |
| span: fld.new_span(v.span), |
| } |
| } |
| |
| pub fn noop_fold_ident<T: Folder>(ident: Ident, fld: &mut T) -> Ident { |
| Ident::new(ident.name, fld.new_span(ident.span)) |
| } |
| |
| pub fn noop_fold_usize<T: Folder>(i: usize, _: &mut T) -> usize { |
| i |
| } |
| |
| pub fn noop_fold_path<T: Folder>(Path { segments, span }: Path, fld: &mut T) -> Path { |
| Path { |
| segments: segments.move_map(|PathSegment { ident, id, args }| PathSegment { |
| ident: fld.fold_ident(ident), |
| id: fld.new_id(id), |
| args: args.map(|args| args.map(|args| fld.fold_generic_args(args))), |
| }), |
| span: fld.new_span(span) |
| } |
| } |
| |
| pub fn noop_fold_qpath<T: Folder>(qself: Option<QSelf>, |
| path: Path, |
| fld: &mut T) -> (Option<QSelf>, Path) { |
| let qself = qself.map(|QSelf { ty, path_span, position }| { |
| QSelf { |
| ty: fld.fold_ty(ty), |
| path_span: fld.new_span(path_span), |
| position, |
| } |
| }); |
| (qself, fld.fold_path(path)) |
| } |
| |
| pub fn noop_fold_generic_args<T: Folder>(generic_args: GenericArgs, fld: &mut T) -> GenericArgs |
| { |
| match generic_args { |
| GenericArgs::AngleBracketed(data) => { |
| GenericArgs::AngleBracketed(fld.fold_angle_bracketed_parameter_data(data)) |
| } |
| GenericArgs::Parenthesized(data) => { |
| GenericArgs::Parenthesized(fld.fold_parenthesized_parameter_data(data)) |
| } |
| } |
| } |
| |
| pub fn noop_fold_angle_bracketed_parameter_data<T: Folder>(data: AngleBracketedArgs, |
| fld: &mut T) |
| -> AngleBracketedArgs |
| { |
| let AngleBracketedArgs { args, bindings, span } = data; |
| AngleBracketedArgs { |
| args: args.move_map(|arg| fld.fold_generic_arg(arg)), |
| bindings: bindings.move_map(|b| fld.fold_ty_binding(b)), |
| span: fld.new_span(span) |
| } |
| } |
| |
| pub fn noop_fold_parenthesized_parameter_data<T: Folder>(data: ParenthesisedArgs, |
| fld: &mut T) |
| -> ParenthesisedArgs |
| { |
| let ParenthesisedArgs { inputs, output, span } = data; |
| ParenthesisedArgs { |
| inputs: inputs.move_map(|ty| fld.fold_ty(ty)), |
| output: output.map(|ty| fld.fold_ty(ty)), |
| span: fld.new_span(span) |
| } |
| } |
| |
| pub fn noop_fold_local<T: Folder>(l: P<Local>, fld: &mut T) -> P<Local> { |
| l.map(|Local {id, pat, ty, init, span, attrs}| Local { |
| id: fld.new_id(id), |
| pat: fld.fold_pat(pat), |
| ty: ty.map(|t| fld.fold_ty(t)), |
| init: init.map(|e| fld.fold_expr(e)), |
| span: fld.new_span(span), |
| attrs: fold_attrs(attrs.into(), fld).into(), |
| }) |
| } |
| |
| pub fn noop_fold_attribute<T: Folder>(attr: Attribute, fld: &mut T) -> Option<Attribute> { |
| Some(Attribute { |
| id: attr.id, |
| style: attr.style, |
| path: fld.fold_path(attr.path), |
| tokens: fld.fold_tts(attr.tokens), |
| is_sugared_doc: attr.is_sugared_doc, |
| span: fld.new_span(attr.span), |
| }) |
| } |
| |
| pub fn noop_fold_mac<T: Folder>(Spanned {node, span}: Mac, fld: &mut T) -> Mac { |
| Spanned { |
| node: Mac_ { |
| tts: fld.fold_tts(node.stream()).into(), |
| path: fld.fold_path(node.path), |
| delim: node.delim, |
| }, |
| span: fld.new_span(span) |
| } |
| } |
| |
| pub fn noop_fold_macro_def<T: Folder>(def: MacroDef, fld: &mut T) -> MacroDef { |
| MacroDef { |
| tokens: fld.fold_tts(def.tokens.into()).into(), |
| legacy: def.legacy, |
| } |
| } |
| |
| pub fn noop_fold_meta_list_item<T: Folder>(li: NestedMetaItem, fld: &mut T) |
| -> NestedMetaItem { |
| Spanned { |
| node: match li.node { |
| NestedMetaItemKind::MetaItem(mi) => { |
| NestedMetaItemKind::MetaItem(fld.fold_meta_item(mi)) |
| }, |
| NestedMetaItemKind::Literal(lit) => NestedMetaItemKind::Literal(lit) |
| }, |
| span: fld.new_span(li.span) |
| } |
| } |
| |
| pub fn noop_fold_meta_item<T: Folder>(mi: MetaItem, fld: &mut T) -> MetaItem { |
| MetaItem { |
| ident: mi.ident, |
| node: match mi.node { |
| MetaItemKind::Word => MetaItemKind::Word, |
| MetaItemKind::List(mis) => { |
| MetaItemKind::List(mis.move_map(|e| fld.fold_meta_list_item(e))) |
| }, |
| MetaItemKind::NameValue(s) => MetaItemKind::NameValue(s), |
| }, |
| span: fld.new_span(mi.span) |
| } |
| } |
| |
| pub fn noop_fold_arg<T: Folder>(Arg {id, pat, ty}: Arg, fld: &mut T) -> Arg { |
| Arg { |
| id: fld.new_id(id), |
| pat: fld.fold_pat(pat), |
| ty: fld.fold_ty(ty) |
| } |
| } |
| |
| pub fn noop_fold_tt<T: Folder>(tt: TokenTree, fld: &mut T) -> TokenTree { |
| match tt { |
| TokenTree::Token(span, tok) => |
| TokenTree::Token(fld.new_span(span), fld.fold_token(tok)), |
| TokenTree::Delimited(span, delim, tts) => TokenTree::Delimited( |
| DelimSpan::from_pair(fld.new_span(span.open), fld.new_span(span.close)), |
| delim, |
| fld.fold_tts(tts.stream()).into(), |
| ), |
| } |
| } |
| |
| pub fn noop_fold_tts<T: Folder>(tts: TokenStream, fld: &mut T) -> TokenStream { |
| tts.map(|tt| fld.fold_tt(tt)) |
| } |
| |
| // apply ident folder if it's an ident, apply other folds to interpolated nodes |
| pub fn noop_fold_token<T: Folder>(t: token::Token, fld: &mut T) -> token::Token { |
| match t { |
| token::Ident(id, is_raw) => token::Ident(fld.fold_ident(id), is_raw), |
| token::Lifetime(id) => token::Lifetime(fld.fold_ident(id)), |
| token::Interpolated(nt) => { |
| let nt = match Lrc::try_unwrap(nt) { |
| Ok(nt) => nt, |
| Err(nt) => (*nt).clone(), |
| }; |
| Token::interpolated(fld.fold_interpolated(nt.0)) |
| } |
| _ => t |
| } |
| } |
| |
| /// apply folder to elements of interpolated nodes |
| // |
| // N.B., this can occur only when applying a fold to partially expanded code, where |
| // parsed pieces have gotten implanted ito *other* macro invocations. This is relevant |
| // for macro hygiene, but possibly not elsewhere. |
| // |
| // One problem here occurs because the types for fold_item, fold_stmt, etc. allow the |
| // folder to return *multiple* items; this is a problem for the nodes here, because |
| // they insist on having exactly one piece. One solution would be to mangle the fold |
| // trait to include one-to-many and one-to-one versions of these entry points, but that |
| // would probably confuse a lot of people and help very few. Instead, I'm just going |
| // to put in dynamic checks. I think the performance impact of this will be pretty much |
| // nonexistent. The danger is that someone will apply a fold to a partially expanded |
| // node, and will be confused by the fact that their "fold_item" or "fold_stmt" isn't |
| // getting called on NtItem or NtStmt nodes. Hopefully they'll wind up reading this |
| // comment, and doing something appropriate. |
| // |
| // BTW, design choice: I considered just changing the type of, e.g., NtItem to contain |
| // multiple items, but decided against it when I looked at parse_item_or_view_item and |
| // tried to figure out what I would do with multiple items there.... |
| pub fn noop_fold_interpolated<T: Folder>(nt: token::Nonterminal, fld: &mut T) |
| -> token::Nonterminal { |
| match nt { |
| token::NtItem(item) => |
| token::NtItem(fld.fold_item(item) |
| // this is probably okay, because the only folds likely |
| // to peek inside interpolated nodes will be renamings/markings, |
| // which map single items to single items |
| .expect_one("expected fold to produce exactly one item")), |
| token::NtBlock(block) => token::NtBlock(fld.fold_block(block)), |
| token::NtStmt(stmt) => |
| token::NtStmt(fld.fold_stmt(stmt) |
| // this is probably okay, because the only folds likely |
| // to peek inside interpolated nodes will be renamings/markings, |
| // which map single items to single items |
| .expect_one("expected fold to produce exactly one statement")), |
| token::NtPat(pat) => token::NtPat(fld.fold_pat(pat)), |
| token::NtExpr(expr) => token::NtExpr(fld.fold_expr(expr)), |
| token::NtTy(ty) => token::NtTy(fld.fold_ty(ty)), |
| token::NtIdent(ident, is_raw) => token::NtIdent(fld.fold_ident(ident), is_raw), |
| token::NtLifetime(ident) => token::NtLifetime(fld.fold_ident(ident)), |
| token::NtLiteral(expr) => token::NtLiteral(fld.fold_expr(expr)), |
| token::NtMeta(meta) => token::NtMeta(fld.fold_meta_item(meta)), |
| token::NtPath(path) => token::NtPath(fld.fold_path(path)), |
| token::NtTT(tt) => token::NtTT(fld.fold_tt(tt)), |
| token::NtArm(arm) => token::NtArm(fld.fold_arm(arm)), |
| token::NtImplItem(item) => |
| token::NtImplItem(fld.fold_impl_item(item) |
| .expect_one("expected fold to produce exactly one item")), |
| token::NtTraitItem(item) => |
| token::NtTraitItem(fld.fold_trait_item(item) |
| .expect_one("expected fold to produce exactly one item")), |
| token::NtGenerics(generics) => token::NtGenerics(fld.fold_generics(generics)), |
| token::NtWhereClause(where_clause) => |
| token::NtWhereClause(fld.fold_where_clause(where_clause)), |
| token::NtArg(arg) => token::NtArg(fld.fold_arg(arg)), |
| token::NtVis(vis) => token::NtVis(fld.fold_vis(vis)), |
| token::NtForeignItem(ni) => |
| token::NtForeignItem(fld.fold_foreign_item(ni) |
| // see reasoning above |
| .expect_one("expected fold to produce exactly one item")), |
| } |
| } |
| |
| pub fn noop_fold_asyncness<T: Folder>(asyncness: IsAsync, fld: &mut T) -> IsAsync { |
| match asyncness { |
| IsAsync::Async { closure_id, return_impl_trait_id } => IsAsync::Async { |
| closure_id: fld.new_id(closure_id), |
| return_impl_trait_id: fld.new_id(return_impl_trait_id), |
| }, |
| IsAsync::NotAsync => IsAsync::NotAsync, |
| } |
| } |
| |
| pub fn noop_fold_fn_decl<T: Folder>(decl: P<FnDecl>, fld: &mut T) -> P<FnDecl> { |
| decl.map(|FnDecl {inputs, output, variadic}| FnDecl { |
| inputs: inputs.move_map(|x| fld.fold_arg(x)), |
| output: match output { |
| FunctionRetTy::Ty(ty) => FunctionRetTy::Ty(fld.fold_ty(ty)), |
| FunctionRetTy::Default(span) => FunctionRetTy::Default(fld.new_span(span)), |
| }, |
| variadic, |
| }) |
| } |
| |
| pub fn noop_fold_param_bound<T>(pb: GenericBound, fld: &mut T) -> GenericBound where T: Folder { |
| match pb { |
| GenericBound::Trait(ty, modifier) => { |
| GenericBound::Trait(fld.fold_poly_trait_ref(ty), modifier) |
| } |
| GenericBound::Outlives(lifetime) => { |
| GenericBound::Outlives(noop_fold_lifetime(lifetime, fld)) |
| } |
| } |
| } |
| |
| pub fn noop_fold_generic_param<T: Folder>(param: GenericParam, fld: &mut T) -> GenericParam { |
| let attrs: Vec<_> = param.attrs.into(); |
| GenericParam { |
| ident: fld.fold_ident(param.ident), |
| id: fld.new_id(param.id), |
| attrs: attrs.into_iter() |
| .flat_map(|x| fld.fold_attribute(x).into_iter()) |
| .collect::<Vec<_>>() |
| .into(), |
| bounds: param.bounds.move_map(|l| noop_fold_param_bound(l, fld)), |
| kind: match param.kind { |
| GenericParamKind::Lifetime => GenericParamKind::Lifetime, |
| GenericParamKind::Type { default } => GenericParamKind::Type { |
| default: default.map(|ty| fld.fold_ty(ty)) |
| } |
| } |
| } |
| } |
| |
| pub fn noop_fold_generic_params<T: Folder>( |
| params: Vec<GenericParam>, |
| fld: &mut T |
| ) -> Vec<GenericParam> { |
| params.move_map(|p| fld.fold_generic_param(p)) |
| } |
| |
| pub fn noop_fold_label<T: Folder>(label: Label, fld: &mut T) -> Label { |
| Label { |
| ident: fld.fold_ident(label.ident), |
| } |
| } |
| |
| fn noop_fold_lifetime<T: Folder>(l: Lifetime, fld: &mut T) -> Lifetime { |
| Lifetime { |
| id: fld.new_id(l.id), |
| ident: fld.fold_ident(l.ident), |
| } |
| } |
| |
| pub fn noop_fold_generics<T: Folder>(Generics { params, where_clause, span }: Generics, |
| fld: &mut T) -> Generics { |
| Generics { |
| params: fld.fold_generic_params(params), |
| where_clause: fld.fold_where_clause(where_clause), |
| span: fld.new_span(span), |
| } |
| } |
| |
| pub fn noop_fold_where_clause<T: Folder>( |
| WhereClause {id, predicates, span}: WhereClause, |
| fld: &mut T) |
| -> WhereClause { |
| WhereClause { |
| id: fld.new_id(id), |
| predicates: predicates.move_map(|predicate| { |
| fld.fold_where_predicate(predicate) |
| }), |
| span, |
| } |
| } |
| |
| pub fn noop_fold_where_predicate<T: Folder>( |
| pred: WherePredicate, |
| fld: &mut T) |
| -> WherePredicate { |
| match pred { |
| ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate{bound_generic_params, |
| bounded_ty, |
| bounds, |
| span}) => { |
| ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate { |
| bound_generic_params: fld.fold_generic_params(bound_generic_params), |
| bounded_ty: fld.fold_ty(bounded_ty), |
| bounds: bounds.move_map(|x| fld.fold_param_bound(x)), |
| span: fld.new_span(span) |
| }) |
| } |
| ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate{lifetime, |
| bounds, |
| span}) => { |
| ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate { |
| span: fld.new_span(span), |
| lifetime: noop_fold_lifetime(lifetime, fld), |
| bounds: bounds.move_map(|bound| noop_fold_param_bound(bound, fld)) |
| }) |
| } |
| ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{id, |
| lhs_ty, |
| rhs_ty, |
| span}) => { |
| ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{ |
| id: fld.new_id(id), |
| lhs_ty: fld.fold_ty(lhs_ty), |
| rhs_ty: fld.fold_ty(rhs_ty), |
| span: fld.new_span(span) |
| }) |
| } |
| } |
| } |
| |
| pub fn noop_fold_variant_data<T: Folder>(vdata: VariantData, fld: &mut T) -> VariantData { |
| match vdata { |
| ast::VariantData::Struct(fields, id) => { |
| ast::VariantData::Struct(fields.move_map(|f| fld.fold_struct_field(f)), |
| fld.new_id(id)) |
| } |
| ast::VariantData::Tuple(fields, id) => { |
| ast::VariantData::Tuple(fields.move_map(|f| fld.fold_struct_field(f)), |
| fld.new_id(id)) |
| } |
| ast::VariantData::Unit(id) => ast::VariantData::Unit(fld.new_id(id)) |
| } |
| } |
| |
| pub fn noop_fold_trait_ref<T: Folder>(p: TraitRef, fld: &mut T) -> TraitRef { |
| let id = fld.new_id(p.ref_id); |
| let TraitRef { |
| path, |
| ref_id: _, |
| } = p; |
| ast::TraitRef { |
| path: fld.fold_path(path), |
| ref_id: id, |
| } |
| } |
| |
| pub fn noop_fold_poly_trait_ref<T: Folder>(p: PolyTraitRef, fld: &mut T) -> PolyTraitRef { |
| ast::PolyTraitRef { |
| bound_generic_params: fld.fold_generic_params(p.bound_generic_params), |
| trait_ref: fld.fold_trait_ref(p.trait_ref), |
| span: fld.new_span(p.span), |
| } |
| } |
| |
| pub fn noop_fold_struct_field<T: Folder>(f: StructField, fld: &mut T) -> StructField { |
| StructField { |
| span: fld.new_span(f.span), |
| id: fld.new_id(f.id), |
| ident: f.ident.map(|ident| fld.fold_ident(ident)), |
| vis: fld.fold_vis(f.vis), |
| ty: fld.fold_ty(f.ty), |
| attrs: fold_attrs(f.attrs, fld), |
| } |
| } |
| |
| pub fn noop_fold_field<T: Folder>(f: Field, folder: &mut T) -> Field { |
| Field { |
| ident: folder.fold_ident(f.ident), |
| expr: folder.fold_expr(f.expr), |
| span: folder.new_span(f.span), |
| is_shorthand: f.is_shorthand, |
| attrs: fold_thin_attrs(f.attrs, folder), |
| } |
| } |
| |
| pub fn noop_fold_mt<T: Folder>(MutTy {ty, mutbl}: MutTy, folder: &mut T) -> MutTy { |
| MutTy { |
| ty: folder.fold_ty(ty), |
| mutbl, |
| } |
| } |
| |
| pub fn noop_fold_opt_bounds<T: Folder>(b: Option<GenericBounds>, folder: &mut T) |
| -> Option<GenericBounds> { |
| b.map(|bounds| folder.fold_bounds(bounds)) |
| } |
| |
| fn noop_fold_bounds<T: Folder>(bounds: GenericBounds, folder: &mut T) |
| -> GenericBounds { |
| bounds.move_map(|bound| folder.fold_param_bound(bound)) |
| } |
| |
| pub fn noop_fold_block<T: Folder>(b: P<Block>, folder: &mut T) -> P<Block> { |
| b.map(|Block {id, stmts, rules, span}| Block { |
| id: folder.new_id(id), |
| stmts: stmts.move_flat_map(|s| folder.fold_stmt(s).into_iter()), |
| rules, |
| span: folder.new_span(span), |
| }) |
| } |
| |
| pub fn noop_fold_item_kind<T: Folder>(i: ItemKind, folder: &mut T) -> ItemKind { |
| match i { |
| ItemKind::ExternCrate(orig_name) => ItemKind::ExternCrate(orig_name), |
| ItemKind::Use(use_tree) => { |
| ItemKind::Use(use_tree.map(|tree| folder.fold_use_tree(tree))) |
| } |
| ItemKind::Static(t, m, e) => { |
| ItemKind::Static(folder.fold_ty(t), m, folder.fold_expr(e)) |
| } |
| ItemKind::Const(t, e) => { |
| ItemKind::Const(folder.fold_ty(t), folder.fold_expr(e)) |
| } |
| ItemKind::Fn(decl, header, generics, body) => { |
| let generics = folder.fold_generics(generics); |
| let header = folder.fold_fn_header(header); |
| let decl = folder.fold_fn_decl(decl); |
| let body = folder.fold_block(body); |
| ItemKind::Fn(decl, header, generics, body) |
| } |
| ItemKind::Mod(m) => ItemKind::Mod(folder.fold_mod(m)), |
| ItemKind::ForeignMod(nm) => ItemKind::ForeignMod(folder.fold_foreign_mod(nm)), |
| ItemKind::GlobalAsm(ga) => ItemKind::GlobalAsm(folder.fold_global_asm(ga)), |
| ItemKind::Ty(t, generics) => { |
| ItemKind::Ty(folder.fold_ty(t), folder.fold_generics(generics)) |
| } |
| ItemKind::Existential(bounds, generics) => ItemKind::Existential( |
| folder.fold_bounds(bounds), |
| folder.fold_generics(generics), |
| ), |
| ItemKind::Enum(enum_definition, generics) => { |
| let generics = folder.fold_generics(generics); |
| let variants = enum_definition.variants.move_map(|x| folder.fold_variant(x)); |
| ItemKind::Enum(ast::EnumDef { variants }, generics) |
| } |
| ItemKind::Struct(struct_def, generics) => { |
| let generics = folder.fold_generics(generics); |
| ItemKind::Struct(folder.fold_variant_data(struct_def), generics) |
| } |
| ItemKind::Union(struct_def, generics) => { |
| let generics = folder.fold_generics(generics); |
| ItemKind::Union(folder.fold_variant_data(struct_def), generics) |
| } |
| ItemKind::Impl(unsafety, |
| polarity, |
| defaultness, |
| generics, |
| ifce, |
| ty, |
| impl_items) => ItemKind::Impl( |
| unsafety, |
| polarity, |
| defaultness, |
| folder.fold_generics(generics), |
| ifce.map(|trait_ref| folder.fold_trait_ref(trait_ref)), |
| folder.fold_ty(ty), |
| impl_items.move_flat_map(|item| folder.fold_impl_item(item)), |
| ), |
| ItemKind::Trait(is_auto, unsafety, generics, bounds, items) => ItemKind::Trait( |
| is_auto, |
| unsafety, |
| folder.fold_generics(generics), |
| folder.fold_bounds(bounds), |
| items.move_flat_map(|item| folder.fold_trait_item(item)), |
| ), |
| ItemKind::TraitAlias(generics, bounds) => ItemKind::TraitAlias( |
| folder.fold_generics(generics), |
| folder.fold_bounds(bounds)), |
| ItemKind::Mac(m) => ItemKind::Mac(folder.fold_mac(m)), |
| ItemKind::MacroDef(def) => ItemKind::MacroDef(folder.fold_macro_def(def)), |
| } |
| } |
| |
| pub fn noop_fold_trait_item<T: Folder>(i: TraitItem, folder: &mut T) -> SmallVec<[TraitItem; 1]> { |
| smallvec![TraitItem { |
| id: folder.new_id(i.id), |
| ident: folder.fold_ident(i.ident), |
| attrs: fold_attrs(i.attrs, folder), |
| generics: folder.fold_generics(i.generics), |
| node: match i.node { |
| TraitItemKind::Const(ty, default) => { |
| TraitItemKind::Const(folder.fold_ty(ty), |
| default.map(|x| folder.fold_expr(x))) |
| } |
| TraitItemKind::Method(sig, body) => { |
| TraitItemKind::Method(noop_fold_method_sig(sig, folder), |
| body.map(|x| folder.fold_block(x))) |
| } |
| TraitItemKind::Type(bounds, default) => { |
| TraitItemKind::Type(folder.fold_bounds(bounds), |
| default.map(|x| folder.fold_ty(x))) |
| } |
| ast::TraitItemKind::Macro(mac) => { |
| TraitItemKind::Macro(folder.fold_mac(mac)) |
| } |
| }, |
| span: folder.new_span(i.span), |
| tokens: i.tokens, |
| }] |
| } |
| |
| pub fn noop_fold_impl_item<T: Folder>(i: ImplItem, folder: &mut T)-> SmallVec<[ImplItem; 1]> { |
| smallvec![ImplItem { |
| id: folder.new_id(i.id), |
| vis: folder.fold_vis(i.vis), |
| ident: folder.fold_ident(i.ident), |
| attrs: fold_attrs(i.attrs, folder), |
| generics: folder.fold_generics(i.generics), |
| defaultness: i.defaultness, |
| node: match i.node { |
| ast::ImplItemKind::Const(ty, expr) => { |
| ast::ImplItemKind::Const(folder.fold_ty(ty), folder.fold_expr(expr)) |
| } |
| ast::ImplItemKind::Method(sig, body) => { |
| ast::ImplItemKind::Method(noop_fold_method_sig(sig, folder), |
| folder.fold_block(body)) |
| } |
| ast::ImplItemKind::Type(ty) => ast::ImplItemKind::Type(folder.fold_ty(ty)), |
| ast::ImplItemKind::Existential(bounds) => { |
| ast::ImplItemKind::Existential(folder.fold_bounds(bounds)) |
| }, |
| ast::ImplItemKind::Macro(mac) => ast::ImplItemKind::Macro(folder.fold_mac(mac)) |
| }, |
| span: folder.new_span(i.span), |
| tokens: i.tokens, |
| }] |
| } |
| |
| pub fn noop_fold_fn_header<T: Folder>(mut header: FnHeader, folder: &mut T) -> FnHeader { |
| header.asyncness = folder.fold_asyncness(header.asyncness); |
| header |
| } |
| |
| pub fn noop_fold_mod<T: Folder>(Mod {inner, items, inline}: Mod, folder: &mut T) -> Mod { |
| Mod { |
| inner: folder.new_span(inner), |
| items: items.move_flat_map(|x| folder.fold_item(x)), |
| inline: inline, |
| } |
| } |
| |
| pub fn noop_fold_crate<T: Folder>(Crate {module, attrs, span}: Crate, |
| folder: &mut T) -> Crate { |
| let mut items = folder.fold_item(P(ast::Item { |
| ident: keywords::Invalid.ident(), |
| attrs, |
| id: ast::DUMMY_NODE_ID, |
| vis: respan(span.shrink_to_lo(), ast::VisibilityKind::Public), |
| span, |
| node: ast::ItemKind::Mod(module), |
| tokens: None, |
| })).into_iter(); |
| |
| let (module, attrs, span) = match items.next() { |
| Some(item) => { |
| assert!(items.next().is_none(), |
| "a crate cannot expand to more than one item"); |
| item.and_then(|ast::Item { attrs, span, node, .. }| { |
| match node { |
| ast::ItemKind::Mod(m) => (m, attrs, span), |
| _ => panic!("fold converted a module to not a module"), |
| } |
| }) |
| } |
| None => (ast::Mod { |
| inner: span, |
| items: vec![], |
| inline: true, |
| }, vec![], span) |
| }; |
| |
| Crate { |
| module, |
| attrs, |
| span, |
| } |
| } |
| |
| // fold one item into possibly many items |
| pub fn noop_fold_item<T: Folder>(i: P<Item>, folder: &mut T) -> SmallVec<[P<Item>; 1]> { |
| smallvec![i.map(|i| folder.fold_item_simple(i))] |
| } |
| |
| // fold one item into exactly one item |
| pub fn noop_fold_item_simple<T: Folder>(Item {id, ident, attrs, node, vis, span, tokens}: Item, |
| folder: &mut T) -> Item { |
| Item { |
| id: folder.new_id(id), |
| vis: folder.fold_vis(vis), |
| ident: folder.fold_ident(ident), |
| attrs: fold_attrs(attrs, folder), |
| node: folder.fold_item_kind(node), |
| span: folder.new_span(span), |
| |
| // FIXME: if this is replaced with a call to `folder.fold_tts` it causes |
| // an ICE during resolve... odd! |
| tokens, |
| } |
| } |
| |
| pub fn noop_fold_foreign_item<T: Folder>(ni: ForeignItem, folder: &mut T) |
| -> SmallVec<[ForeignItem; 1]> |
| { |
| smallvec![folder.fold_foreign_item_simple(ni)] |
| } |
| |
| pub fn noop_fold_foreign_item_simple<T: Folder>(ni: ForeignItem, folder: &mut T) -> ForeignItem { |
| ForeignItem { |
| id: folder.new_id(ni.id), |
| vis: folder.fold_vis(ni.vis), |
| ident: folder.fold_ident(ni.ident), |
| attrs: fold_attrs(ni.attrs, folder), |
| node: match ni.node { |
| ForeignItemKind::Fn(fdec, generics) => { |
| ForeignItemKind::Fn(folder.fold_fn_decl(fdec), folder.fold_generics(generics)) |
| } |
| ForeignItemKind::Static(t, m) => { |
| ForeignItemKind::Static(folder.fold_ty(t), m) |
| } |
| ForeignItemKind::Ty => ForeignItemKind::Ty, |
| ForeignItemKind::Macro(mac) => ForeignItemKind::Macro(folder.fold_mac(mac)), |
| }, |
| span: folder.new_span(ni.span) |
| } |
| } |
| |
| pub fn noop_fold_method_sig<T: Folder>(sig: MethodSig, folder: &mut T) -> MethodSig { |
| MethodSig { |
| header: folder.fold_fn_header(sig.header), |
| decl: folder.fold_fn_decl(sig.decl) |
| } |
| } |
| |
| pub fn noop_fold_pat<T: Folder>(p: P<Pat>, folder: &mut T) -> P<Pat> { |
| p.map(|Pat {id, node, span}| Pat { |
| id: folder.new_id(id), |
| node: match node { |
| PatKind::Wild => PatKind::Wild, |
| PatKind::Ident(binding_mode, ident, sub) => { |
| PatKind::Ident(binding_mode, |
| folder.fold_ident(ident), |
| sub.map(|x| folder.fold_pat(x))) |
| } |
| PatKind::Lit(e) => PatKind::Lit(folder.fold_expr(e)), |
| PatKind::TupleStruct(pth, pats, ddpos) => { |
| PatKind::TupleStruct(folder.fold_path(pth), |
| pats.move_map(|x| folder.fold_pat(x)), ddpos) |
| } |
| PatKind::Path(qself, pth) => { |
| let (qself, pth) = folder.fold_qpath(qself, pth); |
| PatKind::Path(qself, pth) |
| } |
| PatKind::Struct(pth, fields, etc) => { |
| let pth = folder.fold_path(pth); |
| let fs = fields.move_map(|f| { |
| Spanned { span: folder.new_span(f.span), |
| node: ast::FieldPat { |
| ident: folder.fold_ident(f.node.ident), |
| pat: folder.fold_pat(f.node.pat), |
| is_shorthand: f.node.is_shorthand, |
| attrs: fold_attrs(f.node.attrs.into(), folder).into() |
| }} |
| }); |
| PatKind::Struct(pth, fs, etc) |
| } |
| PatKind::Tuple(elts, ddpos) => { |
| PatKind::Tuple(elts.move_map(|x| folder.fold_pat(x)), ddpos) |
| } |
| PatKind::Box(inner) => PatKind::Box(folder.fold_pat(inner)), |
| PatKind::Ref(inner, mutbl) => PatKind::Ref(folder.fold_pat(inner), mutbl), |
| PatKind::Range(e1, e2, Spanned { span, node: end }) => { |
| PatKind::Range(folder.fold_expr(e1), |
| folder.fold_expr(e2), |
| Spanned { span, node: folder.fold_range_end(end) }) |
| }, |
| PatKind::Slice(before, slice, after) => { |
| PatKind::Slice(before.move_map(|x| folder.fold_pat(x)), |
| slice.map(|x| folder.fold_pat(x)), |
| after.move_map(|x| folder.fold_pat(x))) |
| } |
| PatKind::Paren(inner) => PatKind::Paren(folder.fold_pat(inner)), |
| PatKind::Mac(mac) => PatKind::Mac(folder.fold_mac(mac)) |
| }, |
| span: folder.new_span(span) |
| }) |
| } |
| |
| pub fn noop_fold_range_end<T: Folder>(end: RangeEnd, _folder: &mut T) -> RangeEnd { |
| end |
| } |
| |
| pub fn noop_fold_anon_const<T: Folder>(constant: AnonConst, folder: &mut T) -> AnonConst { |
| let AnonConst {id, value} = constant; |
| AnonConst { |
| id: folder.new_id(id), |
| value: folder.fold_expr(value), |
| } |
| } |
| |
| pub fn noop_fold_expr<T: Folder>(Expr {id, node, span, attrs}: Expr, folder: &mut T) -> Expr { |
| Expr { |
| node: match node { |
| ExprKind::Box(e) => { |
| ExprKind::Box(folder.fold_expr(e)) |
| } |
| ExprKind::ObsoleteInPlace(a, b) => { |
| ExprKind::ObsoleteInPlace(folder.fold_expr(a), folder.fold_expr(b)) |
| } |
| ExprKind::Array(exprs) => { |
| ExprKind::Array(folder.fold_exprs(exprs)) |
| } |
| ExprKind::Repeat(expr, count) => { |
| ExprKind::Repeat(folder.fold_expr(expr), folder.fold_anon_const(count)) |
| } |
| ExprKind::Tup(exprs) => ExprKind::Tup(folder.fold_exprs(exprs)), |
| ExprKind::Call(f, args) => { |
| ExprKind::Call(folder.fold_expr(f), |
| folder.fold_exprs(args)) |
| } |
| ExprKind::MethodCall(seg, args) => { |
| ExprKind::MethodCall( |
| PathSegment { |
| ident: folder.fold_ident(seg.ident), |
| id: folder.new_id(seg.id), |
| args: seg.args.map(|args| { |
| args.map(|args| folder.fold_generic_args(args)) |
| }), |
| }, |
| folder.fold_exprs(args)) |
| } |
| ExprKind::Binary(binop, lhs, rhs) => { |
| ExprKind::Binary(binop, |
| folder.fold_expr(lhs), |
| folder.fold_expr(rhs)) |
| } |
| ExprKind::Unary(binop, ohs) => { |
| ExprKind::Unary(binop, folder.fold_expr(ohs)) |
| } |
| ExprKind::Lit(l) => ExprKind::Lit(l), |
| ExprKind::Cast(expr, ty) => { |
| ExprKind::Cast(folder.fold_expr(expr), folder.fold_ty(ty)) |
| } |
| ExprKind::Type(expr, ty) => { |
| ExprKind::Type(folder.fold_expr(expr), folder.fold_ty(ty)) |
| } |
| ExprKind::AddrOf(m, ohs) => ExprKind::AddrOf(m, folder.fold_expr(ohs)), |
| ExprKind::If(cond, tr, fl) => { |
| ExprKind::If(folder.fold_expr(cond), |
| folder.fold_block(tr), |
| fl.map(|x| folder.fold_expr(x))) |
| } |
| ExprKind::IfLet(pats, expr, tr, fl) => { |
| ExprKind::IfLet(pats.move_map(|pat| folder.fold_pat(pat)), |
| folder.fold_expr(expr), |
| folder.fold_block(tr), |
| fl.map(|x| folder.fold_expr(x))) |
| } |
| ExprKind::While(cond, body, opt_label) => { |
| ExprKind::While(folder.fold_expr(cond), |
| folder.fold_block(body), |
| opt_label.map(|label| folder.fold_label(label))) |
| } |
| ExprKind::WhileLet(pats, expr, body, opt_label) => { |
| ExprKind::WhileLet(pats.move_map(|pat| folder.fold_pat(pat)), |
| folder.fold_expr(expr), |
| folder.fold_block(body), |
| opt_label.map(|label| folder.fold_label(label))) |
| } |
| ExprKind::ForLoop(pat, iter, body, opt_label) => { |
| ExprKind::ForLoop(folder.fold_pat(pat), |
| folder.fold_expr(iter), |
| folder.fold_block(body), |
| opt_label.map(|label| folder.fold_label(label))) |
| } |
| ExprKind::Loop(body, opt_label) => { |
| ExprKind::Loop(folder.fold_block(body), |
| opt_label.map(|label| folder.fold_label(label))) |
| } |
| ExprKind::Match(expr, arms) => { |
| ExprKind::Match(folder.fold_expr(expr), |
| arms.move_map(|x| folder.fold_arm(x))) |
| } |
| ExprKind::Closure(capture_clause, asyncness, movability, decl, body, span) => { |
| ExprKind::Closure(capture_clause, |
| folder.fold_asyncness(asyncness), |
| movability, |
| folder.fold_fn_decl(decl), |
| folder.fold_expr(body), |
| folder.new_span(span)) |
| } |
| ExprKind::Block(blk, opt_label) => { |
| ExprKind::Block(folder.fold_block(blk), |
| opt_label.map(|label| folder.fold_label(label))) |
| } |
| ExprKind::Async(capture_clause, node_id, body) => { |
| ExprKind::Async( |
| capture_clause, |
| folder.new_id(node_id), |
| folder.fold_block(body), |
| ) |
| } |
| ExprKind::Assign(el, er) => { |
| ExprKind::Assign(folder.fold_expr(el), folder.fold_expr(er)) |
| } |
| ExprKind::AssignOp(op, el, er) => { |
| ExprKind::AssignOp(op, |
| folder.fold_expr(el), |
| folder.fold_expr(er)) |
| } |
| ExprKind::Field(el, ident) => { |
| ExprKind::Field(folder.fold_expr(el), folder.fold_ident(ident)) |
| } |
| ExprKind::Index(el, er) => { |
| ExprKind::Index(folder.fold_expr(el), folder.fold_expr(er)) |
| } |
| ExprKind::Range(e1, e2, lim) => { |
| ExprKind::Range(e1.map(|x| folder.fold_expr(x)), |
| e2.map(|x| folder.fold_expr(x)), |
| lim) |
| } |
| ExprKind::Path(qself, path) => { |
| let (qself, path) = folder.fold_qpath(qself, path); |
| ExprKind::Path(qself, path) |
| } |
| ExprKind::Break(opt_label, opt_expr) => { |
| ExprKind::Break(opt_label.map(|label| folder.fold_label(label)), |
| opt_expr.map(|e| folder.fold_expr(e))) |
| } |
| ExprKind::Continue(opt_label) => { |
| ExprKind::Continue(opt_label.map(|label| folder.fold_label(label))) |
| } |
| ExprKind::Ret(e) => ExprKind::Ret(e.map(|x| folder.fold_expr(x))), |
| ExprKind::InlineAsm(asm) => ExprKind::InlineAsm(asm.map(|asm| { |
| InlineAsm { |
| inputs: asm.inputs.move_map(|(c, input)| { |
| (c, folder.fold_expr(input)) |
| }), |
| outputs: asm.outputs.move_map(|out| { |
| InlineAsmOutput { |
| constraint: out.constraint, |
| expr: folder.fold_expr(out.expr), |
| is_rw: out.is_rw, |
| is_indirect: out.is_indirect, |
| } |
| }), |
| ..asm |
| } |
| })), |
| ExprKind::Mac(mac) => ExprKind::Mac(folder.fold_mac(mac)), |
| ExprKind::Struct(path, fields, maybe_expr) => { |
| ExprKind::Struct(folder.fold_path(path), |
| fields.move_map(|x| folder.fold_field(x)), |
| maybe_expr.map(|x| folder.fold_expr(x))) |
| }, |
| ExprKind::Paren(ex) => { |
| let sub_expr = folder.fold_expr(ex); |
| return Expr { |
| // Nodes that are equal modulo `Paren` sugar no-ops should have the same ids. |
| id: sub_expr.id, |
| node: ExprKind::Paren(sub_expr), |
| span: folder.new_span(span), |
| attrs: fold_attrs(attrs.into(), folder).into(), |
| }; |
| } |
| ExprKind::Yield(ex) => ExprKind::Yield(ex.map(|x| folder.fold_expr(x))), |
| ExprKind::Try(ex) => ExprKind::Try(folder.fold_expr(ex)), |
| ExprKind::TryBlock(body) => ExprKind::TryBlock(folder.fold_block(body)), |
| ExprKind::Err => ExprKind::Err, |
| }, |
| id: folder.new_id(id), |
| span: folder.new_span(span), |
| attrs: fold_attrs(attrs.into(), folder).into(), |
| } |
| } |
| |
| pub fn noop_fold_opt_expr<T: Folder>(e: P<Expr>, folder: &mut T) -> Option<P<Expr>> { |
| Some(folder.fold_expr(e)) |
| } |
| |
| pub fn noop_fold_exprs<T: Folder>(es: Vec<P<Expr>>, folder: &mut T) -> Vec<P<Expr>> { |
| es.move_flat_map(|e| folder.fold_opt_expr(e)) |
| } |
| |
| pub fn noop_fold_stmt<T: Folder>(Stmt {node, span, id}: Stmt, folder: &mut T) -> SmallVec<[Stmt; 1]> |
| { |
| let id = folder.new_id(id); |
| let span = folder.new_span(span); |
| noop_fold_stmt_kind(node, folder).into_iter().map(|node| { |
| Stmt { id: id, node: node, span: span } |
| }).collect() |
| } |
| |
| pub fn noop_fold_stmt_kind<T: Folder>(node: StmtKind, folder: &mut T) -> SmallVec<[StmtKind; 1]> { |
| match node { |
| StmtKind::Local(local) => smallvec![StmtKind::Local(folder.fold_local(local))], |
| StmtKind::Item(item) => folder.fold_item(item).into_iter().map(StmtKind::Item).collect(), |
| StmtKind::Expr(expr) => { |
| folder.fold_opt_expr(expr).into_iter().map(StmtKind::Expr).collect() |
| } |
| StmtKind::Semi(expr) => { |
| folder.fold_opt_expr(expr).into_iter().map(StmtKind::Semi).collect() |
| } |
| StmtKind::Mac(mac) => smallvec![StmtKind::Mac(mac.map(|(mac, semi, attrs)| { |
| (folder.fold_mac(mac), semi, fold_attrs(attrs.into(), folder).into()) |
| }))], |
| } |
| } |
| |
| pub fn noop_fold_vis<T: Folder>(vis: Visibility, folder: &mut T) -> Visibility { |
| match vis.node { |
| VisibilityKind::Restricted { path, id } => { |
| respan(vis.span, VisibilityKind::Restricted { |
| path: path.map(|path| folder.fold_path(path)), |
| id: folder.new_id(id), |
| }) |
| } |
| _ => vis, |
| } |
| } |
| |
| #[cfg(test)] |
| mod tests { |
| use std::io; |
| use ast::{self, Ident}; |
| use util::parser_testing::{string_to_crate, matches_codepattern}; |
| use print::pprust; |
| use fold; |
| use with_globals; |
| use super::*; |
| |
| // this version doesn't care about getting comments or docstrings in. |
| fn fake_print_crate(s: &mut pprust::State, |
| krate: &ast::Crate) -> io::Result<()> { |
| s.print_mod(&krate.module, &krate.attrs) |
| } |
| |
| // change every identifier to "zz" |
| struct ToZzIdentFolder; |
| |
| impl Folder for ToZzIdentFolder { |
| fn fold_ident(&mut self, _: ast::Ident) -> ast::Ident { |
| Ident::from_str("zz") |
| } |
| fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac { |
| fold::noop_fold_mac(mac, self) |
| } |
| } |
| |
| // maybe add to expand.rs... |
| macro_rules! assert_pred { |
| ($pred:expr, $predname:expr, $a:expr , $b:expr) => ( |
| { |
| let pred_val = $pred; |
| let a_val = $a; |
| let b_val = $b; |
| if !(pred_val(&a_val, &b_val)) { |
| panic!("expected args satisfying {}, got {} and {}", |
| $predname, a_val, b_val); |
| } |
| } |
| ) |
| } |
| |
| // make sure idents get transformed everywhere |
| #[test] fn ident_transformation () { |
| with_globals(|| { |
| let mut zz_fold = ToZzIdentFolder; |
| let ast = string_to_crate( |
| "#[a] mod b {fn c (d : e, f : g) {h!(i,j,k);l;m}}".to_string()); |
| let folded_crate = zz_fold.fold_crate(ast); |
| assert_pred!( |
| matches_codepattern, |
| "matches_codepattern", |
| pprust::to_string(|s| fake_print_crate(s, &folded_crate)), |
| "#[zz]mod zz{fn zz(zz:zz,zz:zz){zz!(zz,zz,zz);zz;zz}}".to_string()); |
| }) |
| } |
| |
| // even inside macro defs.... |
| #[test] fn ident_transformation_in_defs () { |
| with_globals(|| { |
| let mut zz_fold = ToZzIdentFolder; |
| let ast = string_to_crate( |
| "macro_rules! a {(b $c:expr $(d $e:token)f+ => \ |
| (g $(d $d $e)+))} ".to_string()); |
| let folded_crate = zz_fold.fold_crate(ast); |
| assert_pred!( |
| matches_codepattern, |
| "matches_codepattern", |
| pprust::to_string(|s| fake_print_crate(s, &folded_crate)), |
| "macro_rules! zz((zz$zz:zz$(zz $zz:zz)zz+=>(zz$(zz$zz$zz)+)));".to_string()); |
| }) |
| } |
| } |
