| //! A MutVisitor represents an AST modification; it accepts an AST piece and |
| //! and mutates it in place. So, for instance, macro expansion is a MutVisitor |
| //! that walks over an AST and modifies it. |
| //! |
| //! Note: using a MutVisitor (other than the MacroExpander MutVisitor) on |
| //! an AST before macro expansion is probably a bad idea. For instance, |
| //! a MutVisitor renaming item names in a module will miss all of those |
| //! that are created by the expansion of a macro. |
| |
| use crate::ast::*; |
| use crate::source_map::{Spanned, respan}; |
| use crate::parse::token::{self, Token}; |
| use crate::ptr::P; |
| use crate::symbol::keywords; |
| use crate::ThinVec; |
| use crate::tokenstream::*; |
| use crate::util::map_in_place::MapInPlace; |
| |
| use smallvec::{smallvec, Array, SmallVec}; |
| use syntax_pos::Span; |
| |
| use rustc_data_structures::sync::Lrc; |
| use std::ops::DerefMut; |
| use std::{panic, process, ptr}; |
| |
| 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 MutVisitor: Sized { |
| // Methods in this trait have one of three forms: |
| // |
| // fn visit_t(&mut self, t: &mut T); // common |
| // fn flat_map_t(&mut self, t: T) -> SmallVec<[T; 1]>; // rare |
| // fn filter_map_t(&mut self, t: T) -> Option<T>; // rarest |
| // |
| // Any additions to this trait should happen in form of a call to a public |
| // `noop_*` function that only calls out to the visitor 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. |
| // |
| // When writing these methods, it is better to use destructuring like this: |
| // |
| // fn visit_abc(&mut self, ABC { a, b, c: _ }: &mut ABC) { |
| // visit_a(a); |
| // visit_b(b); |
| // } |
| // |
| // than to use field access like this: |
| // |
| // fn visit_abc(&mut self, abc: &mut ABC) { |
| // visit_a(&mut abc.a); |
| // visit_b(&mut abc.b); |
| // // ignore abc.c |
| // } |
| // |
| // As well as being more concise, the former is explicit about which fields |
| // are skipped. Furthermore, if a new field is added, the destructuring |
| // version will cause a compile error, which is good. In comparison, the |
| // field access version will continue working and it would be easy to |
| // forget to add handling for it. |
| |
| fn visit_crate(&mut self, c: &mut Crate) { |
| noop_visit_crate(c, self) |
| } |
| |
| fn visit_meta_list_item(&mut self, list_item: &mut NestedMetaItem) { |
| noop_visit_meta_list_item(list_item, self); |
| } |
| |
| fn visit_meta_item(&mut self, meta_item: &mut MetaItem) { |
| noop_visit_meta_item(meta_item, self); |
| } |
| |
| fn visit_use_tree(&mut self, use_tree: &mut UseTree) { |
| noop_visit_use_tree(use_tree, self); |
| } |
| |
| fn flat_map_foreign_item(&mut self, ni: ForeignItem) -> SmallVec<[ForeignItem; 1]> { |
| noop_flat_map_foreign_item(ni, self) |
| } |
| |
| fn flat_map_item(&mut self, i: P<Item>) -> SmallVec<[P<Item>; 1]> { |
| noop_flat_map_item(i, self) |
| } |
| |
| fn visit_fn_header(&mut self, header: &mut FnHeader) { |
| noop_visit_fn_header(header, self); |
| } |
| |
| fn visit_struct_field(&mut self, sf: &mut StructField) { |
| noop_visit_struct_field(sf, self); |
| } |
| |
| fn visit_item_kind(&mut self, i: &mut ItemKind) { |
| noop_visit_item_kind(i, self); |
| } |
| |
| fn flat_map_trait_item(&mut self, i: TraitItem) -> SmallVec<[TraitItem; 1]> { |
| noop_flat_map_trait_item(i, self) |
| } |
| |
| fn flat_map_impl_item(&mut self, i: ImplItem) -> SmallVec<[ImplItem; 1]> { |
| noop_flat_map_impl_item(i, self) |
| } |
| |
| fn visit_fn_decl(&mut self, d: &mut P<FnDecl>) { |
| noop_visit_fn_decl(d, self); |
| } |
| |
| fn visit_asyncness(&mut self, a: &mut IsAsync) { |
| noop_visit_asyncness(a, self); |
| } |
| |
| fn visit_block(&mut self, b: &mut P<Block>) { |
| noop_visit_block(b, self); |
| } |
| |
| fn flat_map_stmt(&mut self, s: Stmt) -> SmallVec<[Stmt; 1]> { |
| noop_flat_map_stmt(s, self) |
| } |
| |
| fn visit_arm(&mut self, a: &mut Arm) { |
| noop_visit_arm(a, self); |
| } |
| |
| fn visit_guard(&mut self, g: &mut Guard) { |
| noop_visit_guard(g, self); |
| } |
| |
| fn visit_pat(&mut self, p: &mut P<Pat>) { |
| noop_visit_pat(p, self); |
| } |
| |
| fn visit_anon_const(&mut self, c: &mut AnonConst) { |
| noop_visit_anon_const(c, self); |
| } |
| |
| fn visit_expr(&mut self, e: &mut P<Expr>) { |
| noop_visit_expr(e, self); |
| } |
| |
| fn filter_map_expr(&mut self, e: P<Expr>) -> Option<P<Expr>> { |
| noop_filter_map_expr(e, self) |
| } |
| |
| fn visit_generic_arg(&mut self, arg: &mut GenericArg) { |
| noop_visit_generic_arg(arg, self); |
| } |
| |
| fn visit_ty(&mut self, t: &mut P<Ty>) { |
| noop_visit_ty(t, self); |
| } |
| |
| fn visit_lifetime(&mut self, l: &mut Lifetime) { |
| noop_visit_lifetime(l, self); |
| } |
| |
| fn visit_ty_binding(&mut self, t: &mut TypeBinding) { |
| noop_visit_ty_binding(t, self); |
| } |
| |
| fn visit_mod(&mut self, m: &mut Mod) { |
| noop_visit_mod(m, self); |
| } |
| |
| fn visit_foreign_mod(&mut self, nm: &mut ForeignMod) { |
| noop_visit_foreign_mod(nm, self); |
| } |
| |
| fn visit_variant(&mut self, v: &mut Variant) { |
| noop_visit_variant(v, self); |
| } |
| |
| fn visit_ident(&mut self, i: &mut Ident) { |
| noop_visit_ident(i, self); |
| } |
| |
| fn visit_path(&mut self, p: &mut Path) { |
| noop_visit_path(p, self); |
| } |
| |
| fn visit_qself(&mut self, qs: &mut Option<QSelf>) { |
| noop_visit_qself(qs, self); |
| } |
| |
| fn visit_generic_args(&mut self, p: &mut GenericArgs) { |
| noop_visit_generic_args(p, self); |
| } |
| |
| fn visit_angle_bracketed_parameter_data(&mut self, p: &mut AngleBracketedArgs) { |
| noop_visit_angle_bracketed_parameter_data(p, self); |
| } |
| |
| fn visit_parenthesized_parameter_data(&mut self, p: &mut ParenthesizedArgs) { |
| noop_visit_parenthesized_parameter_data(p, self); |
| } |
| |
| fn visit_local(&mut self, l: &mut P<Local>) { |
| noop_visit_local(l, self); |
| } |
| |
| fn visit_mac(&mut self, _mac: &mut Mac) { |
| panic!("visit_mac disabled by default"); |
| // N.B., see note about macros above. If you really want a visitor that |
| // works on macros, use this definition in your trait impl: |
| // mut_visit::noop_visit_mac(_mac, self); |
| } |
| |
| fn visit_macro_def(&mut self, def: &mut MacroDef) { |
| noop_visit_macro_def(def, self); |
| } |
| |
| fn visit_label(&mut self, label: &mut Label) { |
| noop_visit_label(label, self); |
| } |
| |
| fn visit_attribute(&mut self, at: &mut Attribute) { |
| noop_visit_attribute(at, self); |
| } |
| |
| fn visit_arg(&mut self, a: &mut Arg) { |
| noop_visit_arg(a, self); |
| } |
| |
| fn visit_generics(&mut self, generics: &mut Generics) { |
| noop_visit_generics(generics, self); |
| } |
| |
| fn visit_trait_ref(&mut self, tr: &mut TraitRef) { |
| noop_visit_trait_ref(tr, self); |
| } |
| |
| fn visit_poly_trait_ref(&mut self, p: &mut PolyTraitRef) { |
| noop_visit_poly_trait_ref(p, self); |
| } |
| |
| fn visit_variant_data(&mut self, vdata: &mut VariantData) { |
| noop_visit_variant_data(vdata, self); |
| } |
| |
| fn visit_generic_param(&mut self, param: &mut GenericParam) { |
| noop_visit_generic_param(param, self); |
| } |
| |
| fn visit_generic_params(&mut self, params: &mut Vec<GenericParam>) { |
| noop_visit_generic_params(params, self); |
| } |
| |
| fn visit_tt(&mut self, tt: &mut TokenTree) { |
| noop_visit_tt(tt, self); |
| } |
| |
| fn visit_tts(&mut self, tts: &mut TokenStream) { |
| noop_visit_tts(tts, self); |
| } |
| |
| fn visit_token(&mut self, t: &mut Token) { |
| noop_visit_token(t, self); |
| } |
| |
| fn visit_interpolated(&mut self, nt: &mut token::Nonterminal) { |
| noop_visit_interpolated(nt, self); |
| } |
| |
| fn visit_param_bound(&mut self, tpb: &mut GenericBound) { |
| noop_visit_param_bound(tpb, self); |
| } |
| |
| fn visit_mt(&mut self, mt: &mut MutTy) { |
| noop_visit_mt(mt, self); |
| } |
| |
| fn visit_field(&mut self, field: &mut Field) { |
| noop_visit_field(field, self); |
| } |
| |
| fn visit_where_clause(&mut self, where_clause: &mut WhereClause) { |
| noop_visit_where_clause(where_clause, self); |
| } |
| |
| fn visit_where_predicate(&mut self, where_predicate: &mut WherePredicate) { |
| noop_visit_where_predicate(where_predicate, self); |
| } |
| |
| fn visit_vis(&mut self, vis: &mut Visibility) { |
| noop_visit_vis(vis, self); |
| } |
| |
| fn visit_id(&mut self, _id: &mut NodeId) { |
| // Do nothing. |
| } |
| |
| fn visit_span(&mut self, _sp: &mut Span) { |
| // Do nothing. |
| } |
| } |
| |
| /// Use a map-style function (`FnOnce(T) -> T`) to overwrite a `&mut T`. Useful |
| /// when using a `flat_map_*` or `filter_map_*` method within a `visit_` |
| /// method. Abort the program if the closure panics. |
| // |
| // No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. |
| pub fn visit_clobber<T, F>(t: &mut T, f: F) where F: FnOnce(T) -> T { |
| unsafe { |
| // Safe because `t` is used in a read-only fashion by `read()` before |
| // being overwritten by `write()`. |
| let old_t = ptr::read(t); |
| let new_t = panic::catch_unwind(panic::AssertUnwindSafe(|| f(old_t))) |
| .unwrap_or_else(|_| process::abort()); |
| ptr::write(t, new_t); |
| } |
| } |
| |
| // No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. |
| #[inline] |
| pub fn visit_vec<T, F>(elems: &mut Vec<T>, mut visit_elem: F) where F: FnMut(&mut T) { |
| for elem in elems { |
| visit_elem(elem); |
| } |
| } |
| |
| // No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. |
| #[inline] |
| pub fn visit_opt<T, F>(opt: &mut Option<T>, mut visit_elem: F) where F: FnMut(&mut T) { |
| if let Some(elem) = opt { |
| visit_elem(elem); |
| } |
| } |
| |
| // No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. |
| pub fn visit_attrs<T: MutVisitor>(attrs: &mut Vec<Attribute>, vis: &mut T) { |
| visit_vec(attrs, |attr| vis.visit_attribute(attr)); |
| } |
| |
| // No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. |
| pub fn visit_thin_attrs<T: MutVisitor>(attrs: &mut ThinVec<Attribute>, vis: &mut T) { |
| for attr in attrs.iter_mut() { |
| vis.visit_attribute(attr); |
| } |
| } |
| |
| // No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. |
| pub fn visit_exprs<T: MutVisitor>(exprs: &mut Vec<P<Expr>>, vis: &mut T) { |
| exprs.flat_map_in_place(|expr| vis.filter_map_expr(expr)) |
| } |
| |
| // No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. |
| pub fn visit_bounds<T: MutVisitor>(bounds: &mut GenericBounds, vis: &mut T) { |
| visit_vec(bounds, |bound| vis.visit_param_bound(bound)); |
| } |
| |
| // No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. |
| pub fn visit_method_sig<T: MutVisitor>(MethodSig { header, decl }: &mut MethodSig, vis: &mut T) { |
| vis.visit_fn_header(header); |
| vis.visit_fn_decl(decl); |
| } |
| |
| pub fn noop_visit_use_tree<T: MutVisitor>(use_tree: &mut UseTree, vis: &mut T) { |
| let UseTree { prefix, kind, span } = use_tree; |
| vis.visit_path(prefix); |
| match kind { |
| UseTreeKind::Simple(rename, id1, id2) => { |
| visit_opt(rename, |rename| vis.visit_ident(rename)); |
| vis.visit_id(id1); |
| vis.visit_id(id2); |
| } |
| UseTreeKind::Nested(items) => { |
| for (tree, id) in items { |
| vis.visit_use_tree(tree); |
| vis.visit_id(id); |
| } |
| } |
| UseTreeKind::Glob => {} |
| } |
| vis.visit_span(span); |
| } |
| |
| pub fn noop_visit_arm<T: MutVisitor>(Arm { attrs, pats, guard, body }: &mut Arm, vis: &mut T) { |
| visit_attrs(attrs, vis); |
| visit_vec(pats, |pat| vis.visit_pat(pat)); |
| visit_opt(guard, |guard| vis.visit_guard(guard)); |
| vis.visit_expr(body); |
| } |
| |
| pub fn noop_visit_guard<T: MutVisitor>(g: &mut Guard, vis: &mut T) { |
| match g { |
| Guard::If(e) => vis.visit_expr(e), |
| } |
| } |
| |
| pub fn noop_visit_ty_binding<T: MutVisitor>(TypeBinding { id, ident, ty, span }: &mut TypeBinding, |
| vis: &mut T) { |
| vis.visit_id(id); |
| vis.visit_ident(ident); |
| vis.visit_ty(ty); |
| vis.visit_span(span); |
| } |
| |
| pub fn noop_visit_ty<T: MutVisitor>(ty: &mut P<Ty>, vis: &mut T) { |
| let Ty { id, node, span } = ty.deref_mut(); |
| vis.visit_id(id); |
| match node { |
| TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err | |
| TyKind::Never | TyKind::CVarArgs => {} |
| TyKind::Slice(ty) => vis.visit_ty(ty), |
| TyKind::Ptr(mt) => vis.visit_mt(mt), |
| TyKind::Rptr(lt, mt) => { |
| visit_opt(lt, |lt| noop_visit_lifetime(lt, vis)); |
| vis.visit_mt(mt); |
| } |
| TyKind::BareFn(bft) => { |
| let BareFnTy { unsafety: _, abi: _, generic_params, decl } = bft.deref_mut(); |
| vis.visit_generic_params(generic_params); |
| vis.visit_fn_decl(decl); |
| } |
| TyKind::Tup(tys) => visit_vec(tys, |ty| vis.visit_ty(ty)), |
| TyKind::Paren(ty) => vis.visit_ty(ty), |
| TyKind::Path(qself, path) => { |
| vis.visit_qself(qself); |
| vis.visit_path(path); |
| } |
| TyKind::Array(ty, length) => { |
| vis.visit_ty(ty); |
| vis.visit_anon_const(length); |
| } |
| TyKind::Typeof(expr) => vis.visit_anon_const(expr), |
| TyKind::TraitObject(bounds, _syntax) => |
| visit_vec(bounds, |bound| vis.visit_param_bound(bound)), |
| TyKind::ImplTrait(id, bounds) => { |
| vis.visit_id(id); |
| visit_vec(bounds, |bound| vis.visit_param_bound(bound)); |
| } |
| TyKind::Mac(mac) => vis.visit_mac(mac), |
| } |
| vis.visit_span(span); |
| } |
| |
| pub fn noop_visit_foreign_mod<T: MutVisitor>(foreign_mod: &mut ForeignMod, vis: &mut T) { |
| let ForeignMod { abi: _, items} = foreign_mod; |
| items.flat_map_in_place(|item| vis.flat_map_foreign_item(item)); |
| } |
| |
| pub fn noop_visit_variant<T: MutVisitor>(variant: &mut Variant, vis: &mut T) { |
| let Spanned { node: Variant_ { ident, attrs, id, data, disr_expr }, span } = variant; |
| vis.visit_ident(ident); |
| visit_attrs(attrs, vis); |
| vis.visit_id(id); |
| vis.visit_variant_data(data); |
| visit_opt(disr_expr, |disr_expr| vis.visit_anon_const(disr_expr)); |
| vis.visit_span(span); |
| } |
| |
| pub fn noop_visit_ident<T: MutVisitor>(Ident { name: _, span }: &mut Ident, vis: &mut T) { |
| vis.visit_span(span); |
| } |
| |
| pub fn noop_visit_path<T: MutVisitor>(Path { segments, span }: &mut Path, vis: &mut T) { |
| vis.visit_span(span); |
| for PathSegment { ident, id, args } in segments { |
| vis.visit_ident(ident); |
| vis.visit_id(id); |
| visit_opt(args, |args| vis.visit_generic_args(args)); |
| } |
| } |
| |
| pub fn noop_visit_qself<T: MutVisitor>(qself: &mut Option<QSelf>, vis: &mut T) { |
| visit_opt(qself, |QSelf { ty, path_span, position: _ }| { |
| vis.visit_ty(ty); |
| vis.visit_span(path_span); |
| }) |
| } |
| |
| pub fn noop_visit_generic_args<T: MutVisitor>(generic_args: &mut GenericArgs, vis: &mut T) { |
| match generic_args { |
| GenericArgs::AngleBracketed(data) => vis.visit_angle_bracketed_parameter_data(data), |
| GenericArgs::Parenthesized(data) => vis.visit_parenthesized_parameter_data(data), |
| } |
| } |
| |
| pub fn noop_visit_generic_arg<T: MutVisitor>(arg: &mut GenericArg, vis: &mut T) { |
| match arg { |
| GenericArg::Lifetime(lt) => vis.visit_lifetime(lt), |
| GenericArg::Type(ty) => vis.visit_ty(ty), |
| GenericArg::Const(ct) => vis.visit_anon_const(ct), |
| } |
| } |
| |
| pub fn noop_visit_angle_bracketed_parameter_data<T: MutVisitor>(data: &mut AngleBracketedArgs, |
| vis: &mut T) { |
| let AngleBracketedArgs { args, bindings, span } = data; |
| visit_vec(args, |arg| vis.visit_generic_arg(arg)); |
| visit_vec(bindings, |binding| vis.visit_ty_binding(binding)); |
| vis.visit_span(span); |
| } |
| |
| pub fn noop_visit_parenthesized_parameter_data<T: MutVisitor>(args: &mut ParenthesizedArgs, |
| vis: &mut T) { |
| let ParenthesizedArgs { inputs, output, span } = args; |
| visit_vec(inputs, |input| vis.visit_ty(input)); |
| visit_opt(output, |output| vis.visit_ty(output)); |
| vis.visit_span(span); |
| } |
| |
| pub fn noop_visit_local<T: MutVisitor>(local: &mut P<Local>, vis: &mut T) { |
| let Local { id, pat, ty, init, span, attrs } = local.deref_mut(); |
| vis.visit_id(id); |
| vis.visit_pat(pat); |
| visit_opt(ty, |ty| vis.visit_ty(ty)); |
| visit_opt(init, |init| vis.visit_expr(init)); |
| vis.visit_span(span); |
| visit_thin_attrs(attrs, vis); |
| } |
| |
| pub fn noop_visit_attribute<T: MutVisitor>(attr: &mut Attribute, vis: &mut T) { |
| let Attribute { id: _, style: _, path, tokens, is_sugared_doc: _, span } = attr; |
| vis.visit_path(path); |
| vis.visit_tts(tokens); |
| vis.visit_span(span); |
| } |
| |
| pub fn noop_visit_mac<T: MutVisitor>(Spanned { node, span }: &mut Mac, vis: &mut T) { |
| let Mac_ { path, delim: _, tts } = node; |
| vis.visit_path(path); |
| vis.visit_tts(tts); |
| vis.visit_span(span); |
| } |
| |
| pub fn noop_visit_macro_def<T: MutVisitor>(macro_def: &mut MacroDef, vis: &mut T) { |
| let MacroDef { tokens, legacy: _ } = macro_def; |
| vis.visit_tts(tokens); |
| } |
| |
| pub fn noop_visit_meta_list_item<T: MutVisitor>(li: &mut NestedMetaItem, vis: &mut T) { |
| match li { |
| NestedMetaItem::MetaItem(mi) => vis.visit_meta_item(mi), |
| NestedMetaItem::Literal(_lit) => {} |
| } |
| } |
| |
| pub fn noop_visit_meta_item<T: MutVisitor>(mi: &mut MetaItem, vis: &mut T) { |
| let MetaItem { path: _, node, span } = mi; |
| match node { |
| MetaItemKind::Word => {} |
| MetaItemKind::List(mis) => visit_vec(mis, |mi| vis.visit_meta_list_item(mi)), |
| MetaItemKind::NameValue(_s) => {} |
| } |
| vis.visit_span(span); |
| } |
| |
| pub fn noop_visit_arg<T: MutVisitor>(Arg { id, pat, ty }: &mut Arg, vis: &mut T) { |
| vis.visit_id(id); |
| vis.visit_pat(pat); |
| vis.visit_ty(ty); |
| } |
| |
| pub fn noop_visit_tt<T: MutVisitor>(tt: &mut TokenTree, vis: &mut T) { |
| match tt { |
| TokenTree::Token(span, tok) => { |
| vis.visit_span(span); |
| vis.visit_token(tok); |
| } |
| TokenTree::Delimited(DelimSpan { open, close }, _delim, tts) => { |
| vis.visit_span(open); |
| vis.visit_span(close); |
| vis.visit_tts(tts); |
| } |
| } |
| } |
| |
| pub fn noop_visit_tts<T: MutVisitor>(TokenStream(tts): &mut TokenStream, vis: &mut T) { |
| visit_opt(tts, |tts| { |
| let tts = Lrc::make_mut(tts); |
| visit_vec(tts, |(tree, _is_joint)| vis.visit_tt(tree)); |
| }) |
| } |
| |
| // apply ident visitor if it's an ident, apply other visits to interpolated nodes |
| pub fn noop_visit_token<T: MutVisitor>(t: &mut Token, vis: &mut T) { |
| match t { |
| token::Ident(id, _is_raw) => vis.visit_ident(id), |
| token::Lifetime(id) => vis.visit_ident(id), |
| token::Interpolated(nt) => { |
| let mut nt = Lrc::make_mut(nt); |
| vis.visit_interpolated(&mut nt); |
| } |
| _ => {} |
| } |
| } |
| |
| /// Apply visitor to elements of interpolated nodes. |
| // |
| // N.B., this can occur only when applying a visitor 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 flat_map_item, flat_map_stmt, |
| // etc. allow the visitor 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 MutVisitor 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 MutVisitor to a |
| // partially expanded node, and will be confused by the fact that their |
| // "flat_map_item" or "flat_map_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_visit_interpolated<T: MutVisitor>(nt: &mut token::Nonterminal, vis: &mut T) { |
| match nt { |
| token::NtItem(item) => |
| visit_clobber(item, |item| { |
| // This is probably okay, because the only visitors likely to |
| // peek inside interpolated nodes will be renamings/markings, |
| // which map single items to single items. |
| vis.flat_map_item(item).expect_one("expected visitor to produce exactly one item") |
| }), |
| token::NtBlock(block) => vis.visit_block(block), |
| token::NtStmt(stmt) => |
| visit_clobber(stmt, |stmt| { |
| // See reasoning above. |
| vis.flat_map_stmt(stmt).expect_one("expected visitor to produce exactly one item") |
| }), |
| token::NtPat(pat) => vis.visit_pat(pat), |
| token::NtExpr(expr) => vis.visit_expr(expr), |
| token::NtTy(ty) => vis.visit_ty(ty), |
| token::NtIdent(ident, _is_raw) => vis.visit_ident(ident), |
| token::NtLifetime(ident) => vis.visit_ident(ident), |
| token::NtLiteral(expr) => vis.visit_expr(expr), |
| token::NtMeta(meta) => vis.visit_meta_item(meta), |
| token::NtPath(path) => vis.visit_path(path), |
| token::NtTT(tt) => vis.visit_tt(tt), |
| token::NtArm(arm) => vis.visit_arm(arm), |
| token::NtImplItem(item) => |
| visit_clobber(item, |item| { |
| // See reasoning above. |
| vis.flat_map_impl_item(item) |
| .expect_one("expected visitor to produce exactly one item") |
| }), |
| token::NtTraitItem(item) => |
| visit_clobber(item, |item| { |
| // See reasoning above. |
| vis.flat_map_trait_item(item) |
| .expect_one("expected visitor to produce exactly one item") |
| }), |
| token::NtGenerics(generics) => vis.visit_generics(generics), |
| token::NtWhereClause(where_clause) => vis.visit_where_clause(where_clause), |
| token::NtArg(arg) => vis.visit_arg(arg), |
| token::NtVis(visib) => vis.visit_vis(visib), |
| token::NtForeignItem(item) => |
| visit_clobber(item, |item| { |
| // See reasoning above. |
| vis.flat_map_foreign_item(item) |
| .expect_one("expected visitor to produce exactly one item") |
| }), |
| } |
| } |
| |
| pub fn noop_visit_asyncness<T: MutVisitor>(asyncness: &mut IsAsync, vis: &mut T) { |
| match asyncness { |
| IsAsync::Async { closure_id, return_impl_trait_id } => { |
| vis.visit_id(closure_id); |
| vis.visit_id(return_impl_trait_id); |
| } |
| IsAsync::NotAsync => {} |
| } |
| } |
| |
| pub fn noop_visit_fn_decl<T: MutVisitor>(decl: &mut P<FnDecl>, vis: &mut T) { |
| let FnDecl { inputs, output, c_variadic: _ } = decl.deref_mut(); |
| visit_vec(inputs, |input| vis.visit_arg(input)); |
| match output { |
| FunctionRetTy::Default(span) => vis.visit_span(span), |
| FunctionRetTy::Ty(ty) => vis.visit_ty(ty), |
| } |
| } |
| |
| pub fn noop_visit_param_bound<T: MutVisitor>(pb: &mut GenericBound, vis: &mut T) { |
| match pb { |
| GenericBound::Trait(ty, _modifier) => vis.visit_poly_trait_ref(ty), |
| GenericBound::Outlives(lifetime) => noop_visit_lifetime(lifetime, vis), |
| } |
| } |
| |
| pub fn noop_visit_generic_param<T: MutVisitor>(param: &mut GenericParam, vis: &mut T) { |
| let GenericParam { id, ident, attrs, bounds, kind } = param; |
| vis.visit_id(id); |
| vis.visit_ident(ident); |
| visit_thin_attrs(attrs, vis); |
| visit_vec(bounds, |bound| noop_visit_param_bound(bound, vis)); |
| match kind { |
| GenericParamKind::Lifetime => {} |
| GenericParamKind::Type { default } => { |
| visit_opt(default, |default| vis.visit_ty(default)); |
| } |
| GenericParamKind::Const { ty } => { |
| vis.visit_ty(ty); |
| } |
| } |
| } |
| |
| pub fn noop_visit_generic_params<T: MutVisitor>(params: &mut Vec<GenericParam>, vis: &mut T){ |
| visit_vec(params, |param| vis.visit_generic_param(param)); |
| } |
| |
| pub fn noop_visit_label<T: MutVisitor>(Label { ident }: &mut Label, vis: &mut T) { |
| vis.visit_ident(ident); |
| } |
| |
| fn noop_visit_lifetime<T: MutVisitor>(Lifetime { id, ident }: &mut Lifetime, vis: &mut T) { |
| vis.visit_id(id); |
| vis.visit_ident(ident); |
| } |
| |
| pub fn noop_visit_generics<T: MutVisitor>(generics: &mut Generics, vis: &mut T) { |
| let Generics { params, where_clause, span } = generics; |
| vis.visit_generic_params(params); |
| vis.visit_where_clause(where_clause); |
| vis.visit_span(span); |
| } |
| |
| pub fn noop_visit_where_clause<T: MutVisitor>(wc: &mut WhereClause, vis: &mut T) { |
| let WhereClause { id, predicates, span } = wc; |
| vis.visit_id(id); |
| visit_vec(predicates, |predicate| vis.visit_where_predicate(predicate)); |
| vis.visit_span(span); |
| } |
| |
| pub fn noop_visit_where_predicate<T: MutVisitor>(pred: &mut WherePredicate, vis: &mut T) { |
| match pred { |
| WherePredicate::BoundPredicate(bp) => { |
| let WhereBoundPredicate { span, bound_generic_params, bounded_ty, bounds } = bp; |
| vis.visit_span(span); |
| vis.visit_generic_params(bound_generic_params); |
| vis.visit_ty(bounded_ty); |
| visit_vec(bounds, |bound| vis.visit_param_bound(bound)); |
| } |
| WherePredicate::RegionPredicate(rp) => { |
| let WhereRegionPredicate { span, lifetime, bounds } = rp; |
| vis.visit_span(span); |
| noop_visit_lifetime(lifetime, vis); |
| visit_vec(bounds, |bound| noop_visit_param_bound(bound, vis)); |
| } |
| WherePredicate::EqPredicate(ep) => { |
| let WhereEqPredicate { id, span, lhs_ty, rhs_ty } = ep; |
| vis.visit_id(id); |
| vis.visit_span(span); |
| vis.visit_ty(lhs_ty); |
| vis.visit_ty(rhs_ty); |
| } |
| } |
| } |
| |
| pub fn noop_visit_variant_data<T: MutVisitor>(vdata: &mut VariantData, vis: &mut T) { |
| match vdata { |
| VariantData::Struct(fields, ..) => visit_vec(fields, |field| vis.visit_struct_field(field)), |
| VariantData::Tuple(fields, id) => { |
| visit_vec(fields, |field| vis.visit_struct_field(field)); |
| vis.visit_id(id); |
| }, |
| VariantData::Unit(id) => vis.visit_id(id), |
| } |
| } |
| |
| pub fn noop_visit_trait_ref<T: MutVisitor>(TraitRef { path, ref_id }: &mut TraitRef, vis: &mut T) { |
| vis.visit_path(path); |
| vis.visit_id(ref_id); |
| } |
| |
| pub fn noop_visit_poly_trait_ref<T: MutVisitor>(p: &mut PolyTraitRef, vis: &mut T) { |
| let PolyTraitRef { bound_generic_params, trait_ref, span } = p; |
| vis.visit_generic_params(bound_generic_params); |
| vis.visit_trait_ref(trait_ref); |
| vis.visit_span(span); |
| } |
| |
| pub fn noop_visit_struct_field<T: MutVisitor>(f: &mut StructField, visitor: &mut T) { |
| let StructField { span, ident, vis, id, ty, attrs } = f; |
| visitor.visit_span(span); |
| visit_opt(ident, |ident| visitor.visit_ident(ident)); |
| visitor.visit_vis(vis); |
| visitor.visit_id(id); |
| visitor.visit_ty(ty); |
| visit_attrs(attrs, visitor); |
| } |
| |
| pub fn noop_visit_field<T: MutVisitor>(f: &mut Field, vis: &mut T) { |
| let Field { ident, expr, span, is_shorthand: _, attrs } = f; |
| vis.visit_ident(ident); |
| vis.visit_expr(expr); |
| vis.visit_span(span); |
| visit_thin_attrs(attrs, vis); |
| } |
| |
| pub fn noop_visit_mt<T: MutVisitor>(MutTy { ty, mutbl: _ }: &mut MutTy, vis: &mut T) { |
| vis.visit_ty(ty); |
| } |
| |
| pub fn noop_visit_block<T: MutVisitor>(block: &mut P<Block>, vis: &mut T) { |
| let Block { id, stmts, rules: _, span } = block.deref_mut(); |
| vis.visit_id(id); |
| stmts.flat_map_in_place(|stmt| vis.flat_map_stmt(stmt)); |
| vis.visit_span(span); |
| } |
| |
| pub fn noop_visit_item_kind<T: MutVisitor>(kind: &mut ItemKind, vis: &mut T) { |
| match kind { |
| ItemKind::ExternCrate(_orig_name) => {} |
| ItemKind::Use(use_tree) => vis.visit_use_tree(use_tree), |
| ItemKind::Static(ty, _mut, expr) => { |
| vis.visit_ty(ty); |
| vis.visit_expr(expr); |
| } |
| ItemKind::Const(ty, expr) => { |
| vis.visit_ty(ty); |
| vis.visit_expr(expr); |
| } |
| ItemKind::Fn(decl, header, generics, body) => { |
| vis.visit_fn_decl(decl); |
| vis.visit_fn_header(header); |
| vis.visit_generics(generics); |
| vis.visit_block(body); |
| } |
| ItemKind::Mod(m) => vis.visit_mod(m), |
| ItemKind::ForeignMod(nm) => vis.visit_foreign_mod(nm), |
| ItemKind::GlobalAsm(_ga) => {} |
| ItemKind::Ty(ty, generics) => { |
| vis.visit_ty(ty); |
| vis.visit_generics(generics); |
| } |
| ItemKind::Existential(bounds, generics) => { |
| visit_bounds(bounds, vis); |
| vis.visit_generics(generics); |
| } |
| ItemKind::Enum(EnumDef { variants }, generics) => { |
| visit_vec(variants, |variant| vis.visit_variant(variant)); |
| vis.visit_generics(generics); |
| } |
| ItemKind::Struct(variant_data, generics) | |
| ItemKind::Union(variant_data, generics) => { |
| vis.visit_variant_data(variant_data); |
| vis.visit_generics(generics); |
| } |
| ItemKind::Impl(_unsafety, _polarity, _defaultness, generics, trait_ref, ty, items) => { |
| vis.visit_generics(generics); |
| visit_opt(trait_ref, |trait_ref| vis.visit_trait_ref(trait_ref)); |
| vis.visit_ty(ty); |
| items.flat_map_in_place(|item| vis.flat_map_impl_item(item)); |
| } |
| ItemKind::Trait(_is_auto, _unsafety, generics, bounds, items) => { |
| vis.visit_generics(generics); |
| visit_bounds(bounds, vis); |
| items.flat_map_in_place(|item| vis.flat_map_trait_item(item)); |
| } |
| ItemKind::TraitAlias(generics, bounds) => { |
| vis.visit_generics(generics); |
| visit_bounds(bounds, vis); |
| } |
| ItemKind::Mac(m) => vis.visit_mac(m), |
| ItemKind::MacroDef(def) => vis.visit_macro_def(def), |
| } |
| } |
| |
| pub fn noop_flat_map_trait_item<T: MutVisitor>(mut item: TraitItem, vis: &mut T) |
| -> SmallVec<[TraitItem; 1]> |
| { |
| let TraitItem { id, ident, attrs, generics, node, span, tokens: _ } = &mut item; |
| vis.visit_id(id); |
| vis.visit_ident(ident); |
| visit_attrs(attrs, vis); |
| vis.visit_generics(generics); |
| match node { |
| TraitItemKind::Const(ty, default) => { |
| vis.visit_ty(ty); |
| visit_opt(default, |default| vis.visit_expr(default)); |
| } |
| TraitItemKind::Method(sig, body) => { |
| visit_method_sig(sig, vis); |
| visit_opt(body, |body| vis.visit_block(body)); |
| } |
| TraitItemKind::Type(bounds, default) => { |
| visit_bounds(bounds, vis); |
| visit_opt(default, |default| vis.visit_ty(default)); |
| } |
| TraitItemKind::Macro(mac) => { |
| vis.visit_mac(mac); |
| } |
| } |
| vis.visit_span(span); |
| |
| smallvec![item] |
| } |
| |
| pub fn noop_flat_map_impl_item<T: MutVisitor>(mut item: ImplItem, visitor: &mut T) |
| -> SmallVec<[ImplItem; 1]> |
| { |
| let ImplItem { id, ident, vis, defaultness: _, attrs, generics, node, span, tokens: _ } = |
| &mut item; |
| visitor.visit_id(id); |
| visitor.visit_ident(ident); |
| visitor.visit_vis(vis); |
| visit_attrs(attrs, visitor); |
| visitor.visit_generics(generics); |
| match node { |
| ImplItemKind::Const(ty, expr) => { |
| visitor.visit_ty(ty); |
| visitor.visit_expr(expr); |
| } |
| ImplItemKind::Method(sig, body) => { |
| visit_method_sig(sig, visitor); |
| visitor.visit_block(body); |
| } |
| ImplItemKind::Type(ty) => visitor.visit_ty(ty), |
| ImplItemKind::Existential(bounds) => visit_bounds(bounds, visitor), |
| ImplItemKind::Macro(mac) => visitor.visit_mac(mac), |
| } |
| visitor.visit_span(span); |
| |
| smallvec![item] |
| } |
| |
| pub fn noop_visit_fn_header<T: MutVisitor>(header: &mut FnHeader, vis: &mut T) { |
| let FnHeader { unsafety: _, asyncness, constness: _, abi: _ } = header; |
| vis.visit_asyncness(&mut asyncness.node); |
| } |
| |
| pub fn noop_visit_mod<T: MutVisitor>(Mod { inner, items, inline: _ }: &mut Mod, vis: &mut T) { |
| vis.visit_span(inner); |
| items.flat_map_in_place(|item| vis.flat_map_item(item)); |
| } |
| |
| pub fn noop_visit_crate<T: MutVisitor>(krate: &mut Crate, vis: &mut T) { |
| visit_clobber(krate, |Crate { module, attrs, span }| { |
| let item = P(Item { |
| ident: keywords::Invalid.ident(), |
| attrs, |
| id: DUMMY_NODE_ID, |
| vis: respan(span.shrink_to_lo(), VisibilityKind::Public), |
| span, |
| node: ItemKind::Mod(module), |
| tokens: None, |
| }); |
| let items = vis.flat_map_item(item); |
| |
| let len = items.len(); |
| if len == 0 { |
| let module = Mod { inner: span, items: vec![], inline: true }; |
| Crate { module, attrs: vec![], span } |
| } else if len == 1 { |
| let Item { attrs, span, node, .. } = items.into_iter().next().unwrap().into_inner(); |
| match node { |
| ItemKind::Mod(module) => Crate { module, attrs, span }, |
| _ => panic!("visitor converted a module to not a module"), |
| } |
| } else { |
| panic!("a crate cannot expand to more than one item"); |
| } |
| }); |
| } |
| |
| // Mutate one item into possibly many items. |
| pub fn noop_flat_map_item<T: MutVisitor>(mut item: P<Item>, visitor: &mut T) |
| -> SmallVec<[P<Item>; 1]> { |
| let Item { ident, attrs, id, node, vis, span, tokens: _ } = item.deref_mut(); |
| visitor.visit_ident(ident); |
| visit_attrs(attrs, visitor); |
| visitor.visit_id(id); |
| visitor.visit_item_kind(node); |
| visitor.visit_vis(vis); |
| visitor.visit_span(span); |
| |
| // FIXME: if `tokens` is modified with a call to `vis.visit_tts` it causes |
| // an ICE during resolve... odd! |
| |
| smallvec![item] |
| } |
| |
| pub fn noop_flat_map_foreign_item<T: MutVisitor>(mut item: ForeignItem, visitor: &mut T) |
| -> SmallVec<[ForeignItem; 1]> |
| { |
| let ForeignItem { ident, attrs, node, id, span, vis } = &mut item; |
| visitor.visit_ident(ident); |
| visit_attrs(attrs, visitor); |
| match node { |
| ForeignItemKind::Fn(fdec, generics) => { |
| visitor.visit_fn_decl(fdec); |
| visitor.visit_generics(generics); |
| } |
| ForeignItemKind::Static(t, _m) => visitor.visit_ty(t), |
| ForeignItemKind::Ty => {} |
| ForeignItemKind::Macro(mac) => visitor.visit_mac(mac), |
| } |
| visitor.visit_id(id); |
| visitor.visit_span(span); |
| visitor.visit_vis(vis); |
| |
| smallvec![item] |
| } |
| |
| pub fn noop_visit_pat<T: MutVisitor>(pat: &mut P<Pat>, vis: &mut T) { |
| let Pat { id, node, span } = pat.deref_mut(); |
| vis.visit_id(id); |
| match node { |
| PatKind::Wild => {} |
| PatKind::Ident(_binding_mode, ident, sub) => { |
| vis.visit_ident(ident); |
| visit_opt(sub, |sub| vis.visit_pat(sub)); |
| } |
| PatKind::Lit(e) => vis.visit_expr(e), |
| PatKind::TupleStruct(path, pats, _ddpos) => { |
| vis.visit_path(path); |
| visit_vec(pats, |pat| vis.visit_pat(pat)); |
| } |
| PatKind::Path(qself, path) => { |
| vis.visit_qself(qself); |
| vis.visit_path(path); |
| } |
| PatKind::Struct(path, fields, _etc) => { |
| vis.visit_path(path); |
| for Spanned { node: FieldPat { ident, pat, is_shorthand: _, attrs }, span } in fields { |
| vis.visit_ident(ident); |
| vis.visit_pat(pat); |
| visit_thin_attrs(attrs, vis); |
| vis.visit_span(span); |
| }; |
| } |
| PatKind::Tuple(elts, _ddpos) => visit_vec(elts, |elt| vis.visit_pat(elt)), |
| PatKind::Box(inner) => vis.visit_pat(inner), |
| PatKind::Ref(inner, _mutbl) => vis.visit_pat(inner), |
| PatKind::Range(e1, e2, Spanned { span: _, node: _ }) => { |
| vis.visit_expr(e1); |
| vis.visit_expr(e2); |
| vis.visit_span(span); |
| } |
| PatKind::Slice(before, slice, after) => { |
| visit_vec(before, |pat| vis.visit_pat(pat)); |
| visit_opt(slice, |slice| vis.visit_pat(slice)); |
| visit_vec(after, |pat| vis.visit_pat(pat)); |
| } |
| PatKind::Paren(inner) => vis.visit_pat(inner), |
| PatKind::Mac(mac) => vis.visit_mac(mac), |
| } |
| vis.visit_span(span); |
| } |
| |
| pub fn noop_visit_anon_const<T: MutVisitor>(AnonConst { id, value }: &mut AnonConst, vis: &mut T) { |
| vis.visit_id(id); |
| vis.visit_expr(value); |
| } |
| |
| pub fn noop_visit_expr<T: MutVisitor>(Expr { node, id, span, attrs }: &mut Expr, vis: &mut T) { |
| match node { |
| ExprKind::Box(expr) => vis.visit_expr(expr), |
| ExprKind::ObsoleteInPlace(a, b) => { |
| vis.visit_expr(a); |
| vis.visit_expr(b); |
| } |
| ExprKind::Array(exprs) => visit_exprs(exprs, vis), |
| ExprKind::Repeat(expr, count) => { |
| vis.visit_expr(expr); |
| vis.visit_anon_const(count); |
| } |
| ExprKind::Tup(exprs) => visit_exprs(exprs, vis), |
| ExprKind::Call(f, args) => { |
| vis.visit_expr(f); |
| visit_exprs(args, vis); |
| } |
| ExprKind::MethodCall(PathSegment { ident, id, args }, exprs) => { |
| vis.visit_ident(ident); |
| vis.visit_id(id); |
| visit_opt(args, |args| vis.visit_generic_args(args)); |
| visit_exprs(exprs, vis); |
| } |
| ExprKind::Binary(_binop, lhs, rhs) => { |
| vis.visit_expr(lhs); |
| vis.visit_expr(rhs); |
| } |
| ExprKind::Unary(_unop, ohs) => vis.visit_expr(ohs), |
| ExprKind::Lit(_lit) => {} |
| ExprKind::Cast(expr, ty) => { |
| vis.visit_expr(expr); |
| vis.visit_ty(ty); |
| } |
| ExprKind::Type(expr, ty) => { |
| vis.visit_expr(expr); |
| vis.visit_ty(ty); |
| } |
| ExprKind::AddrOf(_m, ohs) => vis.visit_expr(ohs), |
| ExprKind::If(cond, tr, fl) => { |
| vis.visit_expr(cond); |
| vis.visit_block(tr); |
| visit_opt(fl, |fl| vis.visit_expr(fl)); |
| } |
| ExprKind::IfLet(pats, expr, tr, fl) => { |
| visit_vec(pats, |pat| vis.visit_pat(pat)); |
| vis.visit_expr(expr); |
| vis.visit_block(tr); |
| visit_opt(fl, |fl| vis.visit_expr(fl)); |
| } |
| ExprKind::While(cond, body, label) => { |
| vis.visit_expr(cond); |
| vis.visit_block(body); |
| visit_opt(label, |label| vis.visit_label(label)); |
| } |
| ExprKind::WhileLet(pats, expr, body, label) => { |
| visit_vec(pats, |pat| vis.visit_pat(pat)); |
| vis.visit_expr(expr); |
| vis.visit_block(body); |
| visit_opt(label, |label| vis.visit_label(label)); |
| } |
| ExprKind::ForLoop(pat, iter, body, label) => { |
| vis.visit_pat(pat); |
| vis.visit_expr(iter); |
| vis.visit_block(body); |
| visit_opt(label, |label| vis.visit_label(label)); |
| } |
| ExprKind::Loop(body, label) => { |
| vis.visit_block(body); |
| visit_opt(label, |label| vis.visit_label(label)); |
| } |
| ExprKind::Match(expr, arms) => { |
| vis.visit_expr(expr); |
| visit_vec(arms, |arm| vis.visit_arm(arm)); |
| } |
| ExprKind::Closure(_capture_by, asyncness, _movability, decl, body, span) => { |
| vis.visit_asyncness(asyncness); |
| vis.visit_fn_decl(decl); |
| vis.visit_expr(body); |
| vis.visit_span(span); |
| } |
| ExprKind::Block(blk, label) => { |
| vis.visit_block(blk); |
| visit_opt(label, |label| vis.visit_label(label)); |
| } |
| ExprKind::Async(_capture_by, node_id, body) => { |
| vis.visit_id(node_id); |
| vis.visit_block(body); |
| } |
| ExprKind::Assign(el, er) => { |
| vis.visit_expr(el); |
| vis.visit_expr(er); |
| } |
| ExprKind::AssignOp(_op, el, er) => { |
| vis.visit_expr(el); |
| vis.visit_expr(er); |
| } |
| ExprKind::Field(el, ident) => { |
| vis.visit_expr(el); |
| vis.visit_ident(ident); |
| } |
| ExprKind::Index(el, er) => { |
| vis.visit_expr(el); |
| vis.visit_expr(er); |
| } |
| ExprKind::Range(e1, e2, _lim) => { |
| visit_opt(e1, |e1| vis.visit_expr(e1)); |
| visit_opt(e2, |e2| vis.visit_expr(e2)); |
| } |
| ExprKind::Path(qself, path) => { |
| vis.visit_qself(qself); |
| vis.visit_path(path); |
| } |
| ExprKind::Break(label, expr) => { |
| visit_opt(label, |label| vis.visit_label(label)); |
| visit_opt(expr, |expr| vis.visit_expr(expr)); |
| } |
| ExprKind::Continue(label) => { |
| visit_opt(label, |label| vis.visit_label(label)); |
| } |
| ExprKind::Ret(expr) => { |
| visit_opt(expr, |expr| vis.visit_expr(expr)); |
| } |
| ExprKind::InlineAsm(asm) => { |
| let InlineAsm { asm: _, asm_str_style: _, outputs, inputs, clobbers: _, volatile: _, |
| alignstack: _, dialect: _, ctxt: _ } = asm.deref_mut(); |
| for out in outputs { |
| let InlineAsmOutput { constraint: _, expr, is_rw: _, is_indirect: _ } = out; |
| vis.visit_expr(expr); |
| } |
| visit_vec(inputs, |(_c, expr)| vis.visit_expr(expr)); |
| } |
| ExprKind::Mac(mac) => vis.visit_mac(mac), |
| ExprKind::Struct(path, fields, expr) => { |
| vis.visit_path(path); |
| visit_vec(fields, |field| vis.visit_field(field)); |
| visit_opt(expr, |expr| vis.visit_expr(expr)); |
| }, |
| ExprKind::Paren(expr) => { |
| vis.visit_expr(expr); |
| |
| // Nodes that are equal modulo `Paren` sugar no-ops should have the same ids. |
| *id = expr.id; |
| vis.visit_span(span); |
| visit_thin_attrs(attrs, vis); |
| return; |
| } |
| ExprKind::Yield(expr) => { |
| visit_opt(expr, |expr| vis.visit_expr(expr)); |
| } |
| ExprKind::Try(expr) => vis.visit_expr(expr), |
| ExprKind::TryBlock(body) => vis.visit_block(body), |
| ExprKind::Err => {} |
| } |
| vis.visit_id(id); |
| vis.visit_span(span); |
| visit_thin_attrs(attrs, vis); |
| } |
| |
| pub fn noop_filter_map_expr<T: MutVisitor>(mut e: P<Expr>, vis: &mut T) -> Option<P<Expr>> { |
| Some({ vis.visit_expr(&mut e); e }) |
| } |
| |
| pub fn noop_flat_map_stmt<T: MutVisitor>(Stmt { node, mut span, mut id }: Stmt, vis: &mut T) |
| -> SmallVec<[Stmt; 1]> |
| { |
| vis.visit_id(&mut id); |
| vis.visit_span(&mut span); |
| noop_flat_map_stmt_kind(node, vis).into_iter().map(|node| { |
| Stmt { id, node, span } |
| }).collect() |
| } |
| |
| pub fn noop_flat_map_stmt_kind<T: MutVisitor>(node: StmtKind, vis: &mut T) |
| -> SmallVec<[StmtKind; 1]> { |
| match node { |
| StmtKind::Local(mut local) => |
| smallvec![StmtKind::Local({ vis.visit_local(&mut local); local })], |
| StmtKind::Item(item) => vis.flat_map_item(item).into_iter().map(StmtKind::Item).collect(), |
| StmtKind::Expr(expr) => { |
| vis.filter_map_expr(expr).into_iter().map(StmtKind::Expr).collect() |
| } |
| StmtKind::Semi(expr) => { |
| vis.filter_map_expr(expr).into_iter().map(StmtKind::Semi).collect() |
| } |
| StmtKind::Mac(mut mac) => { |
| let (mac_, _semi, attrs) = mac.deref_mut(); |
| vis.visit_mac(mac_); |
| visit_thin_attrs(attrs, vis); |
| smallvec![StmtKind::Mac(mac)] |
| } |
| } |
| } |
| |
| pub fn noop_visit_vis<T: MutVisitor>(Spanned { node, span }: &mut Visibility, vis: &mut T) { |
| match node { |
| VisibilityKind::Public | VisibilityKind::Crate(_) | VisibilityKind::Inherited => {} |
| VisibilityKind::Restricted { path, id } => { |
| vis.visit_path(path); |
| vis.visit_id(id); |
| } |
| } |
| vis.visit_span(span); |
| } |
| |
| #[cfg(test)] |
| mod tests { |
| use std::io; |
| use crate::ast::{self, Ident}; |
| use crate::util::parser_testing::{string_to_crate, matches_codepattern}; |
| use crate::print::pprust; |
| use crate::mut_visit; |
| use crate::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 ToZzIdentMutVisitor; |
| |
| impl MutVisitor for ToZzIdentMutVisitor { |
| fn visit_ident(&mut self, ident: &mut ast::Ident) { |
| *ident = Ident::from_str("zz"); |
| } |
| fn visit_mac(&mut self, mac: &mut ast::Mac) { |
| mut_visit::noop_visit_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_visitor = ToZzIdentMutVisitor; |
| let mut krate = string_to_crate( |
| "#[a] mod b {fn c (d : e, f : g) {h!(i,j,k);l;m}}".to_string()); |
| zz_visitor.visit_crate(&mut krate); |
| assert_pred!( |
| matches_codepattern, |
| "matches_codepattern", |
| pprust::to_string(|s| fake_print_crate(s, &krate)), |
| "#[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_visitor = ToZzIdentMutVisitor; |
| let mut krate = string_to_crate( |
| "macro_rules! a {(b $c:expr $(d $e:token)f+ => \ |
| (g $(d $d $e)+))} ".to_string()); |
| zz_visitor.visit_crate(&mut krate); |
| assert_pred!( |
| matches_codepattern, |
| "matches_codepattern", |
| pprust::to_string(|s| fake_print_crate(s, &krate)), |
| "macro_rules! zz((zz$zz:zz$(zz $zz:zz)zz+=>(zz$(zz$zz$zz)+)));".to_string()); |
| }) |
| } |
| } |
