From 698f8c2f01ea549d77d7dc3338a12e04c11057b9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:02:58 +0200 Subject: Adding upstream version 1.64.0+dfsg1. Signed-off-by: Daniel Baumann --- compiler/rustc_ast/src/mut_visit.rs | 1601 +++++++++++++++++++++++++++++++++++ 1 file changed, 1601 insertions(+) create mode 100644 compiler/rustc_ast/src/mut_visit.rs (limited to 'compiler/rustc_ast/src/mut_visit.rs') diff --git a/compiler/rustc_ast/src/mut_visit.rs b/compiler/rustc_ast/src/mut_visit.rs new file mode 100644 index 000000000..01bd498b3 --- /dev/null +++ b/compiler/rustc_ast/src/mut_visit.rs @@ -0,0 +1,1601 @@ +//! A `MutVisitor` represents an AST modification; it accepts an AST piece 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::ptr::P; +use crate::token::{self, Token}; +use crate::tokenstream::*; + +use rustc_data_structures::map_in_place::MapInPlace; +use rustc_data_structures::sync::Lrc; +use rustc_data_structures::thin_vec::ThinVec; +use rustc_span::source_map::Spanned; +use rustc_span::symbol::Ident; +use rustc_span::Span; + +use smallvec::{smallvec, Array, SmallVec}; +use std::ops::DerefMut; +use std::{panic, ptr}; + +pub trait ExpectOne { + fn expect_one(self, err: &'static str) -> A::Item; +} + +impl ExpectOne for SmallVec { + fn expect_one(self, err: &'static str) -> A::Item { + assert!(self.len() == 1, "{}", err); + self.into_iter().next().unwrap() + } +} + +pub trait MutVisitor: Sized { + /// Mutable token visiting only exists for the `macro_rules` token marker and should not be + /// used otherwise. Token visitor would be entirely separate from the regular visitor if + /// the marker didn't have to visit AST fragments in nonterminal tokens. + const VISIT_TOKENS: bool = false; + + // 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; // 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: P) -> SmallVec<[P; 1]> { + noop_flat_map_foreign_item(ni, self) + } + + fn flat_map_item(&mut self, i: P) -> SmallVec<[P; 1]> { + noop_flat_map_item(i, self) + } + + fn visit_fn_header(&mut self, header: &mut FnHeader) { + noop_visit_fn_header(header, self); + } + + fn flat_map_field_def(&mut self, fd: FieldDef) -> SmallVec<[FieldDef; 1]> { + noop_flat_map_field_def(fd, self) + } + + fn visit_item_kind(&mut self, i: &mut ItemKind) { + noop_visit_item_kind(i, self); + } + + fn flat_map_trait_item(&mut self, i: P) -> SmallVec<[P; 1]> { + noop_flat_map_assoc_item(i, self) + } + + fn flat_map_impl_item(&mut self, i: P) -> SmallVec<[P; 1]> { + noop_flat_map_assoc_item(i, self) + } + + fn visit_fn_decl(&mut self, d: &mut P) { + noop_visit_fn_decl(d, self); + } + + fn visit_asyncness(&mut self, a: &mut Async) { + noop_visit_asyncness(a, self); + } + + fn visit_closure_binder(&mut self, b: &mut ClosureBinder) { + noop_visit_closure_binder(b, self); + } + + fn visit_block(&mut self, b: &mut P) { + noop_visit_block(b, self); + } + + fn flat_map_stmt(&mut self, s: Stmt) -> SmallVec<[Stmt; 1]> { + noop_flat_map_stmt(s, self) + } + + fn flat_map_arm(&mut self, arm: Arm) -> SmallVec<[Arm; 1]> { + noop_flat_map_arm(arm, self) + } + + fn visit_pat(&mut self, p: &mut P) { + 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) { + noop_visit_expr(e, self); + } + + fn filter_map_expr(&mut self, e: P) -> Option> { + 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) { + noop_visit_ty(t, self); + } + + fn visit_lifetime(&mut self, l: &mut Lifetime) { + noop_visit_lifetime(l, self); + } + + fn visit_constraint(&mut self, t: &mut AssocConstraint) { + noop_visit_constraint(t, self); + } + + fn visit_foreign_mod(&mut self, nm: &mut ForeignMod) { + noop_visit_foreign_mod(nm, self); + } + + fn flat_map_variant(&mut self, v: Variant) -> SmallVec<[Variant; 1]> { + noop_flat_map_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) { + 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) { + noop_visit_local(l, self); + } + + fn visit_mac_call(&mut self, mac: &mut MacCall) { + 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 flat_map_param(&mut self, param: Param) -> SmallVec<[Param; 1]> { + noop_flat_map_param(param, 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 flat_map_generic_param(&mut self, param: GenericParam) -> SmallVec<[GenericParam; 1]> { + noop_flat_map_generic_param(param, 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 flat_map_expr_field(&mut self, f: ExprField) -> SmallVec<[ExprField; 1]> { + noop_flat_map_expr_field(f, 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. + } + + fn flat_map_pat_field(&mut self, fp: PatField) -> SmallVec<[PatField; 1]> { + noop_flat_map_pat_field(fp, self) + } + + fn visit_inline_asm(&mut self, asm: &mut InlineAsm) { + noop_visit_inline_asm(asm, self) + } + + fn visit_inline_asm_sym(&mut self, sym: &mut InlineAsmSym) { + noop_visit_inline_asm_sym(sym, self) + } +} + +/// 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. +// +// No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. +pub fn visit_clobber(t: &mut T, f: impl 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(|err| { + // Set `t` to some valid but possible meaningless value, + // and pass the fatal error further. + ptr::write(t, T::dummy()); + panic::resume_unwind(err); + }); + ptr::write(t, new_t); + } +} + +// No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. +#[inline] +pub fn visit_vec(elems: &mut Vec, 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(opt: &mut Option, 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(attrs: &mut Vec, 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(attrs: &mut AttrVec, 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(exprs: &mut Vec>, 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(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_fn_sig(FnSig { header, decl, span }: &mut FnSig, vis: &mut T) { + vis.visit_fn_header(header); + vis.visit_fn_decl(decl); + vis.visit_span(span); +} + +// No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. +pub fn visit_mac_args(args: &mut MacArgs, vis: &mut T) { + match args { + MacArgs::Empty => {} + MacArgs::Delimited(dspan, _delim, tokens) => { + visit_delim_span(dspan, vis); + visit_tts(tokens, vis); + } + MacArgs::Eq(eq_span, MacArgsEq::Ast(expr)) => { + vis.visit_span(eq_span); + vis.visit_expr(expr); + } + MacArgs::Eq(_, MacArgsEq::Hir(lit)) => { + unreachable!("in literal form when visiting mac args eq: {:?}", lit) + } + } +} + +pub fn visit_delim_span(dspan: &mut DelimSpan, vis: &mut T) { + vis.visit_span(&mut dspan.open); + vis.visit_span(&mut dspan.close); +} + +pub fn noop_flat_map_pat_field( + mut fp: PatField, + vis: &mut T, +) -> SmallVec<[PatField; 1]> { + let PatField { attrs, id, ident, is_placeholder: _, is_shorthand: _, pat, span } = &mut fp; + vis.visit_id(id); + vis.visit_ident(ident); + vis.visit_pat(pat); + vis.visit_span(span); + visit_thin_attrs(attrs, vis); + smallvec![fp] +} + +pub fn noop_visit_use_tree(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_flat_map_arm(mut arm: Arm, vis: &mut T) -> SmallVec<[Arm; 1]> { + let Arm { attrs, pat, guard, body, span, id, is_placeholder: _ } = &mut arm; + visit_thin_attrs(attrs, vis); + vis.visit_id(id); + vis.visit_pat(pat); + visit_opt(guard, |guard| vis.visit_expr(guard)); + vis.visit_expr(body); + vis.visit_span(span); + smallvec![arm] +} + +pub fn noop_visit_constraint( + AssocConstraint { id, ident, gen_args, kind, span }: &mut AssocConstraint, + vis: &mut T, +) { + vis.visit_id(id); + vis.visit_ident(ident); + if let Some(ref mut gen_args) = gen_args { + vis.visit_generic_args(gen_args); + } + match kind { + AssocConstraintKind::Equality { ref mut term } => match term { + Term::Ty(ty) => vis.visit_ty(ty), + Term::Const(c) => vis.visit_anon_const(c), + }, + AssocConstraintKind::Bound { ref mut bounds } => visit_bounds(bounds, vis), + } + vis.visit_span(span); +} + +pub fn noop_visit_ty(ty: &mut P, vis: &mut T) { + let Ty { id, kind, span, tokens } = ty.deref_mut(); + vis.visit_id(id); + match kind { + 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, ext: _, generic_params, decl, decl_span } = bft.deref_mut(); + visit_unsafety(unsafety, vis); + generic_params.flat_map_in_place(|param| vis.flat_map_generic_param(param)); + vis.visit_fn_decl(decl); + vis.visit_span(decl_span); + } + 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::MacCall(mac) => vis.visit_mac_call(mac), + } + vis.visit_span(span); + visit_lazy_tts(tokens, vis); +} + +pub fn noop_visit_foreign_mod(foreign_mod: &mut ForeignMod, vis: &mut T) { + let ForeignMod { unsafety, abi: _, items } = foreign_mod; + visit_unsafety(unsafety, vis); + items.flat_map_in_place(|item| vis.flat_map_foreign_item(item)); +} + +pub fn noop_flat_map_variant( + mut variant: Variant, + visitor: &mut T, +) -> SmallVec<[Variant; 1]> { + let Variant { ident, vis, attrs, id, data, disr_expr, span, is_placeholder: _ } = &mut variant; + visitor.visit_ident(ident); + visitor.visit_vis(vis); + visit_thin_attrs(attrs, visitor); + visitor.visit_id(id); + visitor.visit_variant_data(data); + visit_opt(disr_expr, |disr_expr| visitor.visit_anon_const(disr_expr)); + visitor.visit_span(span); + smallvec![variant] +} + +pub fn noop_visit_ident(Ident { name: _, span }: &mut Ident, vis: &mut T) { + vis.visit_span(span); +} + +pub fn noop_visit_path(Path { segments, span, tokens }: &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)); + } + visit_lazy_tts(tokens, vis); +} + +pub fn noop_visit_qself(qself: &mut Option, 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(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(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( + data: &mut AngleBracketedArgs, + vis: &mut T, +) { + let AngleBracketedArgs { args, span } = data; + visit_vec(args, |arg| match arg { + AngleBracketedArg::Arg(arg) => vis.visit_generic_arg(arg), + AngleBracketedArg::Constraint(constraint) => vis.visit_constraint(constraint), + }); + vis.visit_span(span); +} + +pub fn noop_visit_parenthesized_parameter_data( + args: &mut ParenthesizedArgs, + vis: &mut T, +) { + let ParenthesizedArgs { inputs, output, span, .. } = args; + visit_vec(inputs, |input| vis.visit_ty(input)); + noop_visit_fn_ret_ty(output, vis); + vis.visit_span(span); +} + +pub fn noop_visit_local(local: &mut P, vis: &mut T) { + let Local { id, pat, ty, kind, span, attrs, tokens } = local.deref_mut(); + vis.visit_id(id); + vis.visit_pat(pat); + visit_opt(ty, |ty| vis.visit_ty(ty)); + match kind { + LocalKind::Decl => {} + LocalKind::Init(init) => { + vis.visit_expr(init); + } + LocalKind::InitElse(init, els) => { + vis.visit_expr(init); + vis.visit_block(els); + } + } + vis.visit_span(span); + visit_thin_attrs(attrs, vis); + visit_lazy_tts(tokens, vis); +} + +pub fn noop_visit_attribute(attr: &mut Attribute, vis: &mut T) { + let Attribute { kind, id: _, style: _, span } = attr; + match kind { + AttrKind::Normal(AttrItem { path, args, tokens }, attr_tokens) => { + vis.visit_path(path); + visit_mac_args(args, vis); + visit_lazy_tts(tokens, vis); + visit_lazy_tts(attr_tokens, vis); + } + AttrKind::DocComment(..) => {} + } + vis.visit_span(span); +} + +pub fn noop_visit_mac(mac: &mut MacCall, vis: &mut T) { + let MacCall { path, args, prior_type_ascription: _ } = mac; + vis.visit_path(path); + visit_mac_args(args, vis); +} + +pub fn noop_visit_macro_def(macro_def: &mut MacroDef, vis: &mut T) { + let MacroDef { body, macro_rules: _ } = macro_def; + visit_mac_args(body, vis); +} + +pub fn noop_visit_meta_list_item(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(mi: &mut MetaItem, vis: &mut T) { + let MetaItem { path: _, kind, span } = mi; + match kind { + 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_flat_map_param(mut param: Param, vis: &mut T) -> SmallVec<[Param; 1]> { + let Param { attrs, id, pat, span, ty, is_placeholder: _ } = &mut param; + vis.visit_id(id); + visit_thin_attrs(attrs, vis); + vis.visit_pat(pat); + vis.visit_span(span); + vis.visit_ty(ty); + smallvec![param] +} + +// No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. +pub fn visit_attr_annotated_tt(tt: &mut AttrAnnotatedTokenTree, vis: &mut T) { + match tt { + AttrAnnotatedTokenTree::Token(token) => { + visit_token(token, vis); + } + AttrAnnotatedTokenTree::Delimited(DelimSpan { open, close }, _delim, tts) => { + vis.visit_span(open); + vis.visit_span(close); + visit_attr_annotated_tts(tts, vis); + } + AttrAnnotatedTokenTree::Attributes(data) => { + for attr in &mut *data.attrs { + match &mut attr.kind { + AttrKind::Normal(_, attr_tokens) => { + visit_lazy_tts(attr_tokens, vis); + } + AttrKind::DocComment(..) => { + vis.visit_span(&mut attr.span); + } + } + } + visit_lazy_tts_opt_mut(Some(&mut data.tokens), vis); + } + } +} + +// No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. +pub fn visit_tt(tt: &mut TokenTree, vis: &mut T) { + match tt { + TokenTree::Token(token, _) => { + visit_token(token, vis); + } + TokenTree::Delimited(DelimSpan { open, close }, _delim, tts) => { + vis.visit_span(open); + vis.visit_span(close); + visit_tts(tts, vis); + } + } +} + +// No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. +pub fn visit_tts(TokenStream(tts): &mut TokenStream, vis: &mut T) { + if T::VISIT_TOKENS && !tts.is_empty() { + let tts = Lrc::make_mut(tts); + visit_vec(tts, |tree| visit_tt(tree, vis)); + } +} + +pub fn visit_attr_annotated_tts( + AttrAnnotatedTokenStream(tts): &mut AttrAnnotatedTokenStream, + vis: &mut T, +) { + if T::VISIT_TOKENS && !tts.is_empty() { + let tts = Lrc::make_mut(tts); + visit_vec(tts, |(tree, _is_joint)| visit_attr_annotated_tt(tree, vis)); + } +} + +pub fn visit_lazy_tts_opt_mut(lazy_tts: Option<&mut LazyTokenStream>, vis: &mut T) { + if T::VISIT_TOKENS { + if let Some(lazy_tts) = lazy_tts { + let mut tts = lazy_tts.create_token_stream(); + visit_attr_annotated_tts(&mut tts, vis); + *lazy_tts = LazyTokenStream::new(tts); + } + } +} + +pub fn visit_lazy_tts(lazy_tts: &mut Option, vis: &mut T) { + visit_lazy_tts_opt_mut(lazy_tts.as_mut(), vis); +} + +// No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. +// Applies ident visitor if it's an ident; applies other visits to interpolated nodes. +// In practice the ident part is not actually used by specific visitors right now, +// but there's a test below checking that it works. +pub fn visit_token(t: &mut Token, vis: &mut T) { + let Token { kind, span } = t; + match kind { + token::Ident(name, _) | token::Lifetime(name) => { + let mut ident = Ident::new(*name, *span); + vis.visit_ident(&mut ident); + *name = ident.name; + *span = ident.span; + return; // Avoid visiting the span for the second time. + } + token::Interpolated(nt) => { + let mut nt = Lrc::make_mut(nt); + visit_nonterminal(&mut nt, vis); + } + _ => {} + } + vis.visit_span(span); +} + +// No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. +/// Applies the 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 visit_nonterminal(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. + stmt.map(|stmt| { + 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(item) => { + let AttrItem { path, args, tokens } = item.deref_mut(); + vis.visit_path(path); + visit_mac_args(args, vis); + visit_lazy_tts(tokens, vis); + } + token::NtPath(path) => vis.visit_path(path), + token::NtVis(visib) => vis.visit_vis(visib), + } +} + +// No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. +pub fn visit_defaultness(defaultness: &mut Defaultness, vis: &mut T) { + match defaultness { + Defaultness::Default(span) => vis.visit_span(span), + Defaultness::Final => {} + } +} + +// No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. +pub fn visit_unsafety(unsafety: &mut Unsafe, vis: &mut T) { + match unsafety { + Unsafe::Yes(span) => vis.visit_span(span), + Unsafe::No => {} + } +} + +// No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. +pub fn visit_polarity(polarity: &mut ImplPolarity, vis: &mut T) { + match polarity { + ImplPolarity::Positive => {} + ImplPolarity::Negative(span) => vis.visit_span(span), + } +} + +// No `noop_` prefix because there isn't a corresponding method in `MutVisitor`. +pub fn visit_constness(constness: &mut Const, vis: &mut T) { + match constness { + Const::Yes(span) => vis.visit_span(span), + Const::No => {} + } +} + +pub fn noop_visit_closure_binder(binder: &mut ClosureBinder, vis: &mut T) { + match binder { + ClosureBinder::NotPresent => {} + ClosureBinder::For { span: _, generic_params } => { + let mut vec = std::mem::take(generic_params).into_vec(); + vec.flat_map_in_place(|param| vis.flat_map_generic_param(param)); + *generic_params = P::from_vec(vec); + } + } +} + +pub fn noop_visit_asyncness(asyncness: &mut Async, vis: &mut T) { + match asyncness { + Async::Yes { span: _, closure_id, return_impl_trait_id } => { + vis.visit_id(closure_id); + vis.visit_id(return_impl_trait_id); + } + Async::No => {} + } +} + +pub fn noop_visit_fn_decl(decl: &mut P, vis: &mut T) { + let FnDecl { inputs, output } = decl.deref_mut(); + inputs.flat_map_in_place(|param| vis.flat_map_param(param)); + noop_visit_fn_ret_ty(output, vis); +} + +pub fn noop_visit_fn_ret_ty(fn_ret_ty: &mut FnRetTy, vis: &mut T) { + match fn_ret_ty { + FnRetTy::Default(span) => vis.visit_span(span), + FnRetTy::Ty(ty) => vis.visit_ty(ty), + } +} + +pub fn noop_visit_param_bound(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_flat_map_generic_param( + mut param: GenericParam, + vis: &mut T, +) -> SmallVec<[GenericParam; 1]> { + let GenericParam { id, ident, attrs, bounds, kind, colon_span, is_placeholder: _ } = &mut param; + vis.visit_id(id); + vis.visit_ident(ident); + if let Some(ref mut colon_span) = colon_span { + vis.visit_span(colon_span); + } + 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, kw_span: _, default } => { + vis.visit_ty(ty); + visit_opt(default, |default| vis.visit_anon_const(default)); + } + } + smallvec![param] +} + +pub fn noop_visit_label(Label { ident }: &mut Label, vis: &mut T) { + vis.visit_ident(ident); +} + +fn noop_visit_lifetime(Lifetime { id, ident }: &mut Lifetime, vis: &mut T) { + vis.visit_id(id); + vis.visit_ident(ident); +} + +pub fn noop_visit_generics(generics: &mut Generics, vis: &mut T) { + let Generics { params, where_clause, span } = generics; + params.flat_map_in_place(|param| vis.flat_map_generic_param(param)); + vis.visit_where_clause(where_clause); + vis.visit_span(span); +} + +pub fn noop_visit_where_clause(wc: &mut WhereClause, vis: &mut T) { + let WhereClause { has_where_token: _, predicates, span } = wc; + visit_vec(predicates, |predicate| vis.visit_where_predicate(predicate)); + vis.visit_span(span); +} + +pub fn noop_visit_where_predicate(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); + bound_generic_params.flat_map_in_place(|param| vis.flat_map_generic_param(param)); + 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(vdata: &mut VariantData, vis: &mut T) { + match vdata { + VariantData::Struct(fields, ..) => { + fields.flat_map_in_place(|field| vis.flat_map_field_def(field)); + } + VariantData::Tuple(fields, id) => { + fields.flat_map_in_place(|field| vis.flat_map_field_def(field)); + vis.visit_id(id); + } + VariantData::Unit(id) => vis.visit_id(id), + } +} + +pub fn noop_visit_trait_ref(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(p: &mut PolyTraitRef, vis: &mut T) { + let PolyTraitRef { bound_generic_params, trait_ref, span } = p; + bound_generic_params.flat_map_in_place(|param| vis.flat_map_generic_param(param)); + vis.visit_trait_ref(trait_ref); + vis.visit_span(span); +} + +pub fn noop_flat_map_field_def( + mut fd: FieldDef, + visitor: &mut T, +) -> SmallVec<[FieldDef; 1]> { + let FieldDef { span, ident, vis, id, ty, attrs, is_placeholder: _ } = &mut fd; + 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_thin_attrs(attrs, visitor); + smallvec![fd] +} + +pub fn noop_flat_map_expr_field( + mut f: ExprField, + vis: &mut T, +) -> SmallVec<[ExprField; 1]> { + let ExprField { ident, expr, span, is_shorthand: _, attrs, id, is_placeholder: _ } = &mut f; + vis.visit_ident(ident); + vis.visit_expr(expr); + vis.visit_id(id); + vis.visit_span(span); + visit_thin_attrs(attrs, vis); + smallvec![f] +} + +pub fn noop_visit_mt(MutTy { ty, mutbl: _ }: &mut MutTy, vis: &mut T) { + vis.visit_ty(ty); +} + +pub fn noop_visit_block(block: &mut P, vis: &mut T) { + let Block { id, stmts, rules: _, span, tokens, could_be_bare_literal: _ } = block.deref_mut(); + vis.visit_id(id); + stmts.flat_map_in_place(|stmt| vis.flat_map_stmt(stmt)); + vis.visit_span(span); + visit_lazy_tts(tokens, vis); +} + +pub fn noop_visit_item_kind(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, _, expr) => { + vis.visit_ty(ty); + visit_opt(expr, |expr| vis.visit_expr(expr)); + } + ItemKind::Const(defaultness, ty, expr) => { + visit_defaultness(defaultness, vis); + vis.visit_ty(ty); + visit_opt(expr, |expr| vis.visit_expr(expr)); + } + ItemKind::Fn(box Fn { defaultness, generics, sig, body }) => { + visit_defaultness(defaultness, vis); + visit_fn_sig(sig, vis); + vis.visit_generics(generics); + visit_opt(body, |body| vis.visit_block(body)); + } + ItemKind::Mod(unsafety, mod_kind) => { + visit_unsafety(unsafety, vis); + match mod_kind { + ModKind::Loaded(items, _inline, ModSpans { inner_span, inject_use_span }) => { + vis.visit_span(inner_span); + vis.visit_span(inject_use_span); + items.flat_map_in_place(|item| vis.flat_map_item(item)); + } + ModKind::Unloaded => {} + } + } + ItemKind::ForeignMod(nm) => vis.visit_foreign_mod(nm), + ItemKind::GlobalAsm(asm) => vis.visit_inline_asm(asm), + ItemKind::TyAlias(box TyAlias { + defaultness, generics, where_clauses, bounds, ty, .. + }) => { + visit_defaultness(defaultness, vis); + vis.visit_generics(generics); + vis.visit_span(&mut where_clauses.0.1); + vis.visit_span(&mut where_clauses.1.1); + visit_bounds(bounds, vis); + visit_opt(ty, |ty| vis.visit_ty(ty)); + } + ItemKind::Enum(EnumDef { variants }, generics) => { + variants.flat_map_in_place(|variant| vis.flat_map_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(box Impl { + defaultness, + unsafety, + generics, + constness, + polarity, + of_trait, + self_ty, + items, + }) => { + visit_defaultness(defaultness, vis); + visit_unsafety(unsafety, vis); + vis.visit_generics(generics); + visit_constness(constness, vis); + visit_polarity(polarity, vis); + visit_opt(of_trait, |trait_ref| vis.visit_trait_ref(trait_ref)); + vis.visit_ty(self_ty); + items.flat_map_in_place(|item| vis.flat_map_impl_item(item)); + } + ItemKind::Trait(box Trait { unsafety, is_auto: _, generics, bounds, items }) => { + visit_unsafety(unsafety, vis); + 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::MacCall(m) => vis.visit_mac_call(m), + ItemKind::MacroDef(def) => vis.visit_macro_def(def), + } +} + +pub fn noop_flat_map_assoc_item( + mut item: P, + visitor: &mut T, +) -> SmallVec<[P; 1]> { + let Item { id, ident, vis, attrs, kind, span, tokens } = item.deref_mut(); + visitor.visit_id(id); + visitor.visit_ident(ident); + visitor.visit_vis(vis); + visit_attrs(attrs, visitor); + match kind { + AssocItemKind::Const(defaultness, ty, expr) => { + visit_defaultness(defaultness, visitor); + visitor.visit_ty(ty); + visit_opt(expr, |expr| visitor.visit_expr(expr)); + } + AssocItemKind::Fn(box Fn { defaultness, generics, sig, body }) => { + visit_defaultness(defaultness, visitor); + visitor.visit_generics(generics); + visit_fn_sig(sig, visitor); + visit_opt(body, |body| visitor.visit_block(body)); + } + AssocItemKind::TyAlias(box TyAlias { + defaultness, + generics, + where_clauses, + bounds, + ty, + .. + }) => { + visit_defaultness(defaultness, visitor); + visitor.visit_generics(generics); + visitor.visit_span(&mut where_clauses.0.1); + visitor.visit_span(&mut where_clauses.1.1); + visit_bounds(bounds, visitor); + visit_opt(ty, |ty| visitor.visit_ty(ty)); + } + AssocItemKind::MacCall(mac) => visitor.visit_mac_call(mac), + } + visitor.visit_span(span); + visit_lazy_tts(tokens, visitor); + smallvec![item] +} + +pub fn noop_visit_fn_header(header: &mut FnHeader, vis: &mut T) { + let FnHeader { unsafety, asyncness, constness, ext: _ } = header; + visit_constness(constness, vis); + vis.visit_asyncness(asyncness); + visit_unsafety(unsafety, vis); +} + +pub fn noop_visit_crate(krate: &mut Crate, vis: &mut T) { + let Crate { attrs, items, spans, id, is_placeholder: _ } = krate; + vis.visit_id(id); + visit_attrs(attrs, vis); + items.flat_map_in_place(|item| vis.flat_map_item(item)); + let ModSpans { inner_span, inject_use_span } = spans; + vis.visit_span(inner_span); + vis.visit_span(inject_use_span); +} + +// Mutates one item into possibly many items. +pub fn noop_flat_map_item( + mut item: P, + visitor: &mut T, +) -> SmallVec<[P; 1]> { + let Item { ident, attrs, id, kind, vis, span, tokens } = item.deref_mut(); + visitor.visit_ident(ident); + visit_attrs(attrs, visitor); + visitor.visit_id(id); + visitor.visit_item_kind(kind); + visitor.visit_vis(vis); + visitor.visit_span(span); + visit_lazy_tts(tokens, visitor); + + smallvec![item] +} + +pub fn noop_flat_map_foreign_item( + mut item: P, + visitor: &mut T, +) -> SmallVec<[P; 1]> { + let Item { ident, attrs, id, kind, vis, span, tokens } = item.deref_mut(); + visitor.visit_id(id); + visitor.visit_ident(ident); + visitor.visit_vis(vis); + visit_attrs(attrs, visitor); + match kind { + ForeignItemKind::Static(ty, _, expr) => { + visitor.visit_ty(ty); + visit_opt(expr, |expr| visitor.visit_expr(expr)); + } + ForeignItemKind::Fn(box Fn { defaultness, generics, sig, body }) => { + visit_defaultness(defaultness, visitor); + visitor.visit_generics(generics); + visit_fn_sig(sig, visitor); + visit_opt(body, |body| visitor.visit_block(body)); + } + ForeignItemKind::TyAlias(box TyAlias { + defaultness, + generics, + where_clauses, + bounds, + ty, + .. + }) => { + visit_defaultness(defaultness, visitor); + visitor.visit_generics(generics); + visitor.visit_span(&mut where_clauses.0.1); + visitor.visit_span(&mut where_clauses.1.1); + visit_bounds(bounds, visitor); + visit_opt(ty, |ty| visitor.visit_ty(ty)); + } + ForeignItemKind::MacCall(mac) => visitor.visit_mac_call(mac), + } + visitor.visit_span(span); + visit_lazy_tts(tokens, visitor); + smallvec![item] +} + +pub fn noop_visit_pat(pat: &mut P, vis: &mut T) { + let Pat { id, kind, span, tokens } = pat.deref_mut(); + vis.visit_id(id); + match kind { + PatKind::Wild | PatKind::Rest => {} + 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(qself, path, elems) => { + vis.visit_qself(qself); + vis.visit_path(path); + visit_vec(elems, |elem| vis.visit_pat(elem)); + } + PatKind::Path(qself, path) => { + vis.visit_qself(qself); + vis.visit_path(path); + } + PatKind::Struct(qself, path, fields, _etc) => { + vis.visit_qself(qself); + vis.visit_path(path); + fields.flat_map_in_place(|field| vis.flat_map_pat_field(field)); + } + PatKind::Box(inner) => vis.visit_pat(inner), + PatKind::Ref(inner, _mutbl) => vis.visit_pat(inner), + PatKind::Range(e1, e2, Spanned { span: _, node: _ }) => { + visit_opt(e1, |e| vis.visit_expr(e)); + visit_opt(e2, |e| vis.visit_expr(e)); + vis.visit_span(span); + } + PatKind::Tuple(elems) | PatKind::Slice(elems) | PatKind::Or(elems) => { + visit_vec(elems, |elem| vis.visit_pat(elem)) + } + PatKind::Paren(inner) => vis.visit_pat(inner), + PatKind::MacCall(mac) => vis.visit_mac_call(mac), + } + vis.visit_span(span); + visit_lazy_tts(tokens, vis); +} + +pub fn noop_visit_anon_const(AnonConst { id, value }: &mut AnonConst, vis: &mut T) { + vis.visit_id(id); + vis.visit_expr(value); +} + +pub fn noop_visit_inline_asm(asm: &mut InlineAsm, vis: &mut T) { + for (op, _) in &mut asm.operands { + match op { + InlineAsmOperand::In { expr, .. } + | InlineAsmOperand::Out { expr: Some(expr), .. } + | InlineAsmOperand::InOut { expr, .. } => vis.visit_expr(expr), + InlineAsmOperand::Out { expr: None, .. } => {} + InlineAsmOperand::SplitInOut { in_expr, out_expr, .. } => { + vis.visit_expr(in_expr); + if let Some(out_expr) = out_expr { + vis.visit_expr(out_expr); + } + } + InlineAsmOperand::Const { anon_const } => vis.visit_anon_const(anon_const), + InlineAsmOperand::Sym { sym } => vis.visit_inline_asm_sym(sym), + } + } +} + +pub fn noop_visit_inline_asm_sym( + InlineAsmSym { id, qself, path }: &mut InlineAsmSym, + vis: &mut T, +) { + vis.visit_id(id); + vis.visit_qself(qself); + vis.visit_path(path); +} + +pub fn noop_visit_expr( + Expr { kind, id, span, attrs, tokens }: &mut Expr, + vis: &mut T, +) { + match kind { + ExprKind::Box(expr) => vis.visit_expr(expr), + ExprKind::Array(exprs) => visit_exprs(exprs, vis), + ExprKind::ConstBlock(anon_const) => { + vis.visit_anon_const(anon_const); + } + 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, span) => { + vis.visit_ident(ident); + vis.visit_id(id); + visit_opt(args, |args| vis.visit_generic_args(args)); + visit_exprs(exprs, vis); + vis.visit_span(span); + } + ExprKind::Binary(_binop, lhs, rhs) => { + vis.visit_expr(lhs); + vis.visit_expr(rhs); + } + ExprKind::Unary(_unop, ohs) => vis.visit_expr(ohs), + 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(_, _, ohs) => vis.visit_expr(ohs), + ExprKind::Let(pat, scrutinee, _) => { + vis.visit_pat(pat); + vis.visit_expr(scrutinee); + } + ExprKind::If(cond, tr, fl) => { + vis.visit_expr(cond); + 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::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); + arms.flat_map_in_place(|arm| vis.flat_map_arm(arm)); + } + ExprKind::Closure(binder, _capture_by, asyncness, _movability, decl, body, span) => { + vis.visit_closure_binder(binder); + 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::Await(expr) => vis.visit_expr(expr), + 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::Underscore => {} + 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::Yeet(expr) => { + visit_opt(expr, |expr| vis.visit_expr(expr)); + } + ExprKind::InlineAsm(asm) => vis.visit_inline_asm(asm), + ExprKind::MacCall(mac) => vis.visit_mac_call(mac), + ExprKind::Struct(se) => { + let StructExpr { qself, path, fields, rest } = se.deref_mut(); + vis.visit_qself(qself); + vis.visit_path(path); + fields.flat_map_in_place(|field| vis.flat_map_expr_field(field)); + match rest { + StructRest::Base(expr) => vis.visit_expr(expr), + StructRest::Rest(_span) => {} + StructRest::None => {} + } + } + ExprKind::Paren(expr) => { + vis.visit_expr(expr); + } + 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::Lit(_) | ExprKind::Err => {} + } + vis.visit_id(id); + vis.visit_span(span); + visit_thin_attrs(attrs, vis); + visit_lazy_tts(tokens, vis); +} + +pub fn noop_filter_map_expr(mut e: P, vis: &mut T) -> Option> { + Some({ + vis.visit_expr(&mut e); + e + }) +} + +pub fn noop_flat_map_stmt( + Stmt { kind, mut span, mut id }: Stmt, + vis: &mut T, +) -> SmallVec<[Stmt; 1]> { + vis.visit_id(&mut id); + vis.visit_span(&mut span); + let stmts: SmallVec<_> = noop_flat_map_stmt_kind(kind, vis) + .into_iter() + .map(|kind| Stmt { id, kind, span }) + .collect(); + if stmts.len() > 1 { + panic!( + "cloning statement `NodeId`s is prohibited by default, \ + the visitor should implement custom statement visiting" + ); + } + stmts +} + +pub fn noop_flat_map_stmt_kind( + kind: StmtKind, + vis: &mut T, +) -> SmallVec<[StmtKind; 1]> { + match kind { + 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::Empty => smallvec![StmtKind::Empty], + StmtKind::MacCall(mut mac) => { + let MacCallStmt { mac: mac_, style: _, attrs, tokens } = mac.deref_mut(); + vis.visit_mac_call(mac_); + visit_thin_attrs(attrs, vis); + visit_lazy_tts(tokens, vis); + smallvec![StmtKind::MacCall(mac)] + } + } +} + +pub fn noop_visit_vis(visibility: &mut Visibility, vis: &mut T) { + match &mut visibility.kind { + VisibilityKind::Public | VisibilityKind::Inherited => {} + VisibilityKind::Restricted { path, id } => { + vis.visit_path(path); + vis.visit_id(id); + } + } + vis.visit_span(&mut visibility.span); +} + +/// Some value for the AST node that is valid but possibly meaningless. +pub trait DummyAstNode { + fn dummy() -> Self; +} + +impl DummyAstNode for Option { + fn dummy() -> Self { + Default::default() + } +} + +impl DummyAstNode for P { + fn dummy() -> Self { + P(DummyAstNode::dummy()) + } +} + +impl DummyAstNode for ThinVec { + fn dummy() -> Self { + Default::default() + } +} + +impl DummyAstNode for Item { + fn dummy() -> Self { + Item { + attrs: Default::default(), + id: DUMMY_NODE_ID, + span: Default::default(), + vis: Visibility { + kind: VisibilityKind::Public, + span: Default::default(), + tokens: Default::default(), + }, + ident: Ident::empty(), + kind: ItemKind::ExternCrate(None), + tokens: Default::default(), + } + } +} + +impl DummyAstNode for Expr { + fn dummy() -> Self { + Expr { + id: DUMMY_NODE_ID, + kind: ExprKind::Err, + span: Default::default(), + attrs: Default::default(), + tokens: Default::default(), + } + } +} + +impl DummyAstNode for Ty { + fn dummy() -> Self { + Ty { + id: DUMMY_NODE_ID, + kind: TyKind::Err, + span: Default::default(), + tokens: Default::default(), + } + } +} + +impl DummyAstNode for Pat { + fn dummy() -> Self { + Pat { + id: DUMMY_NODE_ID, + kind: PatKind::Wild, + span: Default::default(), + tokens: Default::default(), + } + } +} + +impl DummyAstNode for Stmt { + fn dummy() -> Self { + Stmt { id: DUMMY_NODE_ID, kind: StmtKind::Empty, span: Default::default() } + } +} + +impl DummyAstNode for Block { + fn dummy() -> Self { + Block { + stmts: Default::default(), + id: DUMMY_NODE_ID, + rules: BlockCheckMode::Default, + span: Default::default(), + tokens: Default::default(), + could_be_bare_literal: Default::default(), + } + } +} + +impl DummyAstNode for Crate { + fn dummy() -> Self { + Crate { + attrs: Default::default(), + items: Default::default(), + spans: Default::default(), + id: DUMMY_NODE_ID, + is_placeholder: Default::default(), + } + } +} -- cgit v1.2.3