From 37d76dc2f793ba6317efbcd45f2d998565bfa0d6 Mon Sep 17 00:00:00 2001 From: Mazdak Farrokhzad Date: Tue, 7 Jan 2020 17:30:29 +0100 Subject: {rustc::hir -> rustc_hir}::intravisit --- src/librustc/hir/intravisit.rs | 1181 --------------------------------------- src/librustc/hir/mod.rs | 3 +- src/librustc_hir/intravisit.rs | 1183 ++++++++++++++++++++++++++++++++++++++++ src/librustc_hir/lib.rs | 1 + 4 files changed, 1186 insertions(+), 1182 deletions(-) delete mode 100644 src/librustc/hir/intravisit.rs create mode 100644 src/librustc_hir/intravisit.rs (limited to 'src') diff --git a/src/librustc/hir/intravisit.rs b/src/librustc/hir/intravisit.rs deleted file mode 100644 index 13b5be08d8a..00000000000 --- a/src/librustc/hir/intravisit.rs +++ /dev/null @@ -1,1181 +0,0 @@ -//! HIR walker for walking the contents of nodes. -//! -//! **For an overview of the visitor strategy, see the docs on the -//! `super::itemlikevisit::ItemLikeVisitor` trait.** -//! -//! If you have decided to use this visitor, here are some general -//! notes on how to do so: -//! -//! Each overridden visit method has full control over what -//! happens with its node, it can do its own traversal of the node's children, -//! call `intravisit::walk_*` to apply the default traversal algorithm, or prevent -//! deeper traversal by doing nothing. -//! -//! When visiting the HIR, the contents of nested items are NOT visited -//! by default. This is different from the AST visitor, which does a deep walk. -//! Hence this module is called `intravisit`; see the method `visit_nested_item` -//! for more details. -//! -//! Note: it is an important invariant that the default visitor walks -//! the body of a function in "execution order" - more concretely, if -//! we consider the reverse post-order (RPO) of the CFG implied by the HIR, -//! then a pre-order traversal of the HIR is consistent with the CFG RPO -//! on the *initial CFG point* of each HIR node, while a post-order traversal -//! of the HIR is consistent with the CFG RPO on each *final CFG point* of -//! each CFG node. -//! -//! One thing that follows is that if HIR node A always starts/ends executing -//! before HIR node B, then A appears in traversal pre/postorder before B, -//! respectively. (This follows from RPO respecting CFG domination). -//! -//! This order consistency is required in a few places in rustc, for -//! example generator inference, and possibly also HIR borrowck. - -use rustc_hir::itemlikevisit::{ItemLikeVisitor, ParItemLikeVisitor}; -use rustc_hir::*; -use rustc_span::Span; -use syntax::ast::{Attribute, Ident, Label, Name}; - -pub struct DeepVisitor<'v, V> { - visitor: &'v mut V, -} - -impl<'v, V> DeepVisitor<'v, V> { - pub fn new(base: &'v mut V) -> Self { - DeepVisitor { visitor: base } - } -} - -impl<'v, 'hir, V> ItemLikeVisitor<'hir> for DeepVisitor<'v, V> -where - V: Visitor<'hir>, -{ - fn visit_item(&mut self, item: &'hir Item<'hir>) { - self.visitor.visit_item(item); - } - - fn visit_trait_item(&mut self, trait_item: &'hir TraitItem<'hir>) { - self.visitor.visit_trait_item(trait_item); - } - - fn visit_impl_item(&mut self, impl_item: &'hir ImplItem<'hir>) { - self.visitor.visit_impl_item(impl_item); - } -} - -pub trait IntoVisitor<'hir> { - type Visitor: Visitor<'hir>; - fn into_visitor(&self) -> Self::Visitor; -} - -pub struct ParDeepVisitor(pub V); - -impl<'hir, V> ParItemLikeVisitor<'hir> for ParDeepVisitor -where - V: IntoVisitor<'hir>, -{ - fn visit_item(&self, item: &'hir Item<'hir>) { - self.0.into_visitor().visit_item(item); - } - - fn visit_trait_item(&self, trait_item: &'hir TraitItem<'hir>) { - self.0.into_visitor().visit_trait_item(trait_item); - } - - fn visit_impl_item(&self, impl_item: &'hir ImplItem<'hir>) { - self.0.into_visitor().visit_impl_item(impl_item); - } -} - -#[derive(Copy, Clone)] -pub enum FnKind<'a> { - /// `#[xxx] pub async/const/extern "Abi" fn foo()` - ItemFn(Ident, &'a Generics<'a>, FnHeader, &'a Visibility<'a>, &'a [Attribute]), - - /// `fn foo(&self)` - Method(Ident, &'a FnSig<'a>, Option<&'a Visibility<'a>>, &'a [Attribute]), - - /// `|x, y| {}` - Closure(&'a [Attribute]), -} - -impl<'a> FnKind<'a> { - pub fn attrs(&self) -> &'a [Attribute] { - match *self { - FnKind::ItemFn(.., attrs) => attrs, - FnKind::Method(.., attrs) => attrs, - FnKind::Closure(attrs) => attrs, - } - } - - pub fn header(&self) -> Option<&FnHeader> { - match *self { - FnKind::ItemFn(_, _, ref header, _, _) => Some(header), - FnKind::Method(_, ref sig, _, _) => Some(&sig.header), - FnKind::Closure(_) => None, - } - } -} - -/// An abstract representation of the HIR `rustc::hir::map::Map`. -pub trait Map<'hir> { - fn body(&self, id: BodyId) -> &'hir Body<'hir>; - fn item(&self, id: HirId) -> &'hir Item<'hir>; - fn trait_item(&self, id: TraitItemId) -> &'hir TraitItem<'hir>; - fn impl_item(&self, id: ImplItemId) -> &'hir ImplItem<'hir>; -} - -/// Specifies what nested things a visitor wants to visit. The most -/// common choice is `OnlyBodies`, which will cause the visitor to -/// visit fn bodies for fns that it encounters, but skip over nested -/// item-like things. -/// -/// See the comments on `ItemLikeVisitor` for more details on the overall -/// visit strategy. -pub enum NestedVisitorMap<'this, M> { - /// Do not visit any nested things. When you add a new - /// "non-nested" thing, you will want to audit such uses to see if - /// they remain valid. - /// - /// Use this if you are only walking some particular kind of tree - /// (i.e., a type, or fn signature) and you don't want to thread a - /// HIR map around. - None, - - /// Do not visit nested item-like things, but visit nested things - /// that are inside of an item-like. - /// - /// **This is the most common choice.** A very common pattern is - /// to use `visit_all_item_likes()` as an outer loop, - /// and to have the visitor that visits the contents of each item - /// using this setting. - OnlyBodies(&'this M), - - /// Visits all nested things, including item-likes. - /// - /// **This is an unusual choice.** It is used when you want to - /// process everything within their lexical context. Typically you - /// kick off the visit by doing `walk_krate()`. - All(&'this M), -} - -impl<'this, M> NestedVisitorMap<'this, M> { - /// Returns the map to use for an "intra item-like" thing (if any). - /// E.g., function body. - fn intra(self) -> Option<&'this M> { - match self { - NestedVisitorMap::None => None, - NestedVisitorMap::OnlyBodies(map) => Some(map), - NestedVisitorMap::All(map) => Some(map), - } - } - - /// Returns the map to use for an "item-like" thing (if any). - /// E.g., item, impl-item. - fn inter(self) -> Option<&'this M> { - match self { - NestedVisitorMap::None => None, - NestedVisitorMap::OnlyBodies(_) => None, - NestedVisitorMap::All(map) => Some(map), - } - } -} - -/// Each method of the Visitor trait is a hook to be potentially -/// overridden. Each method's default implementation recursively visits -/// the substructure of the input via the corresponding `walk` method; -/// e.g., the `visit_mod` method by default calls `intravisit::walk_mod`. -/// -/// Note that this visitor does NOT visit nested items by default -/// (this is why the module is called `intravisit`, to distinguish it -/// from the AST's `visit` module, which acts differently). If you -/// simply want to visit all items in the crate in some order, you -/// should call `Crate::visit_all_items`. Otherwise, see the comment -/// on `visit_nested_item` for details on how to visit nested items. -/// -/// If you want to ensure that your code handles every variant -/// explicitly, you need to override each method. (And you also need -/// to monitor future changes to `Visitor` in case a new method with a -/// new default implementation gets introduced.) -pub trait Visitor<'v>: Sized { - type Map: Map<'v>; - - /////////////////////////////////////////////////////////////////////////// - // Nested items. - - /// The default versions of the `visit_nested_XXX` routines invoke - /// this method to get a map to use. By selecting an enum variant, - /// you control which kinds of nested HIR are visited; see - /// `NestedVisitorMap` for details. By "nested HIR", we are - /// referring to bits of HIR that are not directly embedded within - /// one another but rather indirectly, through a table in the - /// crate. This is done to control dependencies during incremental - /// compilation: the non-inline bits of HIR can be tracked and - /// hashed separately. - /// - /// **If for some reason you want the nested behavior, but don't - /// have a `Map` at your disposal:** then you should override the - /// `visit_nested_XXX` methods, and override this method to - /// `panic!()`. This way, if a new `visit_nested_XXX` variant is - /// added in the future, we will see the panic in your code and - /// fix it appropriately. - fn nested_visit_map(&mut self) -> NestedVisitorMap<'_, Self::Map>; - - /// Invoked when a nested item is encountered. By default does - /// nothing unless you override `nested_visit_map` to return other than - /// `None`, in which case it will walk the item. **You probably - /// don't want to override this method** -- instead, override - /// `nested_visit_map` or use the "shallow" or "deep" visit - /// patterns described on `itemlikevisit::ItemLikeVisitor`. The only - /// reason to override this method is if you want a nested pattern - /// but cannot supply a `Map`; see `nested_visit_map` for advice. - #[allow(unused_variables)] - fn visit_nested_item(&mut self, id: ItemId) { - let opt_item = self.nested_visit_map().inter().map(|map| map.item(id.id)); - if let Some(item) = opt_item { - self.visit_item(item); - } - } - - /// Like `visit_nested_item()`, but for trait items. See - /// `visit_nested_item()` for advice on when to override this - /// method. - #[allow(unused_variables)] - fn visit_nested_trait_item(&mut self, id: TraitItemId) { - let opt_item = self.nested_visit_map().inter().map(|map| map.trait_item(id)); - if let Some(item) = opt_item { - self.visit_trait_item(item); - } - } - - /// Like `visit_nested_item()`, but for impl items. See - /// `visit_nested_item()` for advice on when to override this - /// method. - #[allow(unused_variables)] - fn visit_nested_impl_item(&mut self, id: ImplItemId) { - let opt_item = self.nested_visit_map().inter().map(|map| map.impl_item(id)); - if let Some(item) = opt_item { - self.visit_impl_item(item); - } - } - - /// Invoked to visit the body of a function, method or closure. Like - /// visit_nested_item, does nothing by default unless you override - /// `nested_visit_map` to return other than `None`, in which case it will walk - /// the body. - fn visit_nested_body(&mut self, id: BodyId) { - let opt_body = self.nested_visit_map().intra().map(|map| map.body(id)); - if let Some(body) = opt_body { - self.visit_body(body); - } - } - - fn visit_param(&mut self, param: &'v Param<'v>) { - walk_param(self, param) - } - - /// Visits the top-level item and (optionally) nested items / impl items. See - /// `visit_nested_item` for details. - fn visit_item(&mut self, i: &'v Item<'v>) { - walk_item(self, i) - } - - fn visit_body(&mut self, b: &'v Body<'v>) { - walk_body(self, b); - } - - /// When invoking `visit_all_item_likes()`, you need to supply an - /// item-like visitor. This method converts a "intra-visit" - /// visitor into an item-like visitor that walks the entire tree. - /// If you use this, you probably don't want to process the - /// contents of nested item-like things, since the outer loop will - /// visit them as well. - fn as_deep_visitor<'s>(&'s mut self) -> DeepVisitor<'s, Self> { - DeepVisitor::new(self) - } - - /////////////////////////////////////////////////////////////////////////// - - fn visit_id(&mut self, _hir_id: HirId) { - // Nothing to do. - } - fn visit_name(&mut self, _span: Span, _name: Name) { - // Nothing to do. - } - fn visit_ident(&mut self, ident: Ident) { - walk_ident(self, ident) - } - fn visit_mod(&mut self, m: &'v Mod<'v>, _s: Span, n: HirId) { - walk_mod(self, m, n) - } - fn visit_foreign_item(&mut self, i: &'v ForeignItem<'v>) { - walk_foreign_item(self, i) - } - fn visit_local(&mut self, l: &'v Local<'v>) { - walk_local(self, l) - } - fn visit_block(&mut self, b: &'v Block<'v>) { - walk_block(self, b) - } - fn visit_stmt(&mut self, s: &'v Stmt<'v>) { - walk_stmt(self, s) - } - fn visit_arm(&mut self, a: &'v Arm<'v>) { - walk_arm(self, a) - } - fn visit_pat(&mut self, p: &'v Pat<'v>) { - walk_pat(self, p) - } - fn visit_anon_const(&mut self, c: &'v AnonConst) { - walk_anon_const(self, c) - } - fn visit_expr(&mut self, ex: &'v Expr<'v>) { - walk_expr(self, ex) - } - fn visit_ty(&mut self, t: &'v Ty<'v>) { - walk_ty(self, t) - } - fn visit_generic_param(&mut self, p: &'v GenericParam<'v>) { - walk_generic_param(self, p) - } - fn visit_generics(&mut self, g: &'v Generics<'v>) { - walk_generics(self, g) - } - fn visit_where_predicate(&mut self, predicate: &'v WherePredicate<'v>) { - walk_where_predicate(self, predicate) - } - fn visit_fn_decl(&mut self, fd: &'v FnDecl<'v>) { - walk_fn_decl(self, fd) - } - fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl<'v>, b: BodyId, s: Span, id: HirId) { - walk_fn(self, fk, fd, b, s, id) - } - fn visit_use(&mut self, path: &'v Path<'v>, hir_id: HirId) { - walk_use(self, path, hir_id) - } - fn visit_trait_item(&mut self, ti: &'v TraitItem<'v>) { - walk_trait_item(self, ti) - } - fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) { - walk_trait_item_ref(self, ii) - } - fn visit_impl_item(&mut self, ii: &'v ImplItem<'v>) { - walk_impl_item(self, ii) - } - fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef<'v>) { - walk_impl_item_ref(self, ii) - } - fn visit_trait_ref(&mut self, t: &'v TraitRef<'v>) { - walk_trait_ref(self, t) - } - fn visit_param_bound(&mut self, bounds: &'v GenericBound<'v>) { - walk_param_bound(self, bounds) - } - fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef<'v>, m: TraitBoundModifier) { - walk_poly_trait_ref(self, t, m) - } - fn visit_variant_data( - &mut self, - s: &'v VariantData<'v>, - _: Name, - _: &'v Generics<'v>, - _parent_id: HirId, - _: Span, - ) { - walk_struct_def(self, s) - } - fn visit_struct_field(&mut self, s: &'v StructField<'v>) { - walk_struct_field(self, s) - } - fn visit_enum_def( - &mut self, - enum_definition: &'v EnumDef<'v>, - generics: &'v Generics<'v>, - item_id: HirId, - _: Span, - ) { - walk_enum_def(self, enum_definition, generics, item_id) - } - fn visit_variant(&mut self, v: &'v Variant<'v>, g: &'v Generics<'v>, item_id: HirId) { - walk_variant(self, v, g, item_id) - } - fn visit_label(&mut self, label: &'v Label) { - walk_label(self, label) - } - fn visit_generic_arg(&mut self, generic_arg: &'v GenericArg<'v>) { - match generic_arg { - GenericArg::Lifetime(lt) => self.visit_lifetime(lt), - GenericArg::Type(ty) => self.visit_ty(ty), - GenericArg::Const(ct) => self.visit_anon_const(&ct.value), - } - } - fn visit_lifetime(&mut self, lifetime: &'v Lifetime) { - walk_lifetime(self, lifetime) - } - fn visit_qpath(&mut self, qpath: &'v QPath<'v>, id: HirId, span: Span) { - walk_qpath(self, qpath, id, span) - } - fn visit_path(&mut self, path: &'v Path<'v>, _id: HirId) { - walk_path(self, path) - } - fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v PathSegment<'v>) { - walk_path_segment(self, path_span, path_segment) - } - fn visit_generic_args(&mut self, path_span: Span, generic_args: &'v GenericArgs<'v>) { - walk_generic_args(self, path_span, generic_args) - } - fn visit_assoc_type_binding(&mut self, type_binding: &'v TypeBinding<'v>) { - walk_assoc_type_binding(self, type_binding) - } - fn visit_attribute(&mut self, _attr: &'v Attribute) {} - fn visit_macro_def(&mut self, macro_def: &'v MacroDef<'v>) { - walk_macro_def(self, macro_def) - } - fn visit_vis(&mut self, vis: &'v Visibility<'v>) { - walk_vis(self, vis) - } - fn visit_associated_item_kind(&mut self, kind: &'v AssocItemKind) { - walk_associated_item_kind(self, kind); - } - fn visit_defaultness(&mut self, defaultness: &'v Defaultness) { - walk_defaultness(self, defaultness); - } -} - -/// Walks the contents of a crate. See also `Crate::visit_all_items`. -pub fn walk_crate<'v, V: Visitor<'v>>(visitor: &mut V, krate: &'v Crate<'v>) { - visitor.visit_mod(&krate.module, krate.span, CRATE_HIR_ID); - walk_list!(visitor, visit_attribute, krate.attrs); - walk_list!(visitor, visit_macro_def, krate.exported_macros); -} - -pub fn walk_macro_def<'v, V: Visitor<'v>>(visitor: &mut V, macro_def: &'v MacroDef<'v>) { - visitor.visit_id(macro_def.hir_id); - visitor.visit_name(macro_def.span, macro_def.name); - walk_list!(visitor, visit_attribute, macro_def.attrs); -} - -pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod<'v>, mod_hir_id: HirId) { - visitor.visit_id(mod_hir_id); - for &item_id in module.item_ids { - visitor.visit_nested_item(item_id); - } -} - -pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body<'v>) { - walk_list!(visitor, visit_param, body.params); - visitor.visit_expr(&body.value); -} - -pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local<'v>) { - // Intentionally visiting the expr first - the initialization expr - // dominates the local's definition. - walk_list!(visitor, visit_expr, &local.init); - walk_list!(visitor, visit_attribute, local.attrs.iter()); - visitor.visit_id(local.hir_id); - visitor.visit_pat(&local.pat); - walk_list!(visitor, visit_ty, &local.ty); -} - -pub fn walk_ident<'v, V: Visitor<'v>>(visitor: &mut V, ident: Ident) { - visitor.visit_name(ident.span, ident.name); -} - -pub fn walk_label<'v, V: Visitor<'v>>(visitor: &mut V, label: &'v Label) { - visitor.visit_ident(label.ident); -} - -pub fn walk_lifetime<'v, V: Visitor<'v>>(visitor: &mut V, lifetime: &'v Lifetime) { - visitor.visit_id(lifetime.hir_id); - match lifetime.name { - LifetimeName::Param(ParamName::Plain(ident)) => { - visitor.visit_ident(ident); - } - LifetimeName::Param(ParamName::Fresh(_)) - | LifetimeName::Param(ParamName::Error) - | LifetimeName::Static - | LifetimeName::Error - | LifetimeName::Implicit - | LifetimeName::ImplicitObjectLifetimeDefault - | LifetimeName::Underscore => {} - } -} - -pub fn walk_poly_trait_ref<'v, V: Visitor<'v>>( - visitor: &mut V, - trait_ref: &'v PolyTraitRef<'v>, - _modifier: TraitBoundModifier, -) { - walk_list!(visitor, visit_generic_param, trait_ref.bound_generic_params); - visitor.visit_trait_ref(&trait_ref.trait_ref); -} - -pub fn walk_trait_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_ref: &'v TraitRef<'v>) { - visitor.visit_id(trait_ref.hir_ref_id); - visitor.visit_path(&trait_ref.path, trait_ref.hir_ref_id) -} - -pub fn walk_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v Param<'v>) { - visitor.visit_id(param.hir_id); - visitor.visit_pat(¶m.pat); - walk_list!(visitor, visit_attribute, param.attrs); -} - -pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) { - visitor.visit_vis(&item.vis); - visitor.visit_ident(item.ident); - match item.kind { - ItemKind::ExternCrate(orig_name) => { - visitor.visit_id(item.hir_id); - if let Some(orig_name) = orig_name { - visitor.visit_name(item.span, orig_name); - } - } - ItemKind::Use(ref path, _) => { - visitor.visit_use(path, item.hir_id); - } - ItemKind::Static(ref typ, _, body) | ItemKind::Const(ref typ, body) => { - visitor.visit_id(item.hir_id); - visitor.visit_ty(typ); - visitor.visit_nested_body(body); - } - ItemKind::Fn(ref sig, ref generics, body_id) => visitor.visit_fn( - FnKind::ItemFn(item.ident, generics, sig.header, &item.vis, &item.attrs), - &sig.decl, - body_id, - item.span, - item.hir_id, - ), - ItemKind::Mod(ref module) => { - // `visit_mod()` takes care of visiting the `Item`'s `HirId`. - visitor.visit_mod(module, item.span, item.hir_id) - } - ItemKind::ForeignMod(ref foreign_module) => { - visitor.visit_id(item.hir_id); - walk_list!(visitor, visit_foreign_item, foreign_module.items); - } - ItemKind::GlobalAsm(_) => { - visitor.visit_id(item.hir_id); - } - ItemKind::TyAlias(ref ty, ref generics) => { - visitor.visit_id(item.hir_id); - visitor.visit_ty(ty); - visitor.visit_generics(generics) - } - ItemKind::OpaqueTy(OpaqueTy { ref generics, bounds, .. }) => { - visitor.visit_id(item.hir_id); - walk_generics(visitor, generics); - walk_list!(visitor, visit_param_bound, bounds); - } - ItemKind::Enum(ref enum_definition, ref generics) => { - visitor.visit_generics(generics); - // `visit_enum_def()` takes care of visiting the `Item`'s `HirId`. - visitor.visit_enum_def(enum_definition, generics, item.hir_id, item.span) - } - ItemKind::Impl(.., ref generics, ref opt_trait_reference, ref typ, impl_item_refs) => { - visitor.visit_id(item.hir_id); - visitor.visit_generics(generics); - walk_list!(visitor, visit_trait_ref, opt_trait_reference); - visitor.visit_ty(typ); - walk_list!(visitor, visit_impl_item_ref, impl_item_refs); - } - ItemKind::Struct(ref struct_definition, ref generics) - | ItemKind::Union(ref struct_definition, ref generics) => { - visitor.visit_generics(generics); - visitor.visit_id(item.hir_id); - visitor.visit_variant_data( - struct_definition, - item.ident.name, - generics, - item.hir_id, - item.span, - ); - } - ItemKind::Trait(.., ref generics, bounds, trait_item_refs) => { - visitor.visit_id(item.hir_id); - visitor.visit_generics(generics); - walk_list!(visitor, visit_param_bound, bounds); - walk_list!(visitor, visit_trait_item_ref, trait_item_refs); - } - ItemKind::TraitAlias(ref generics, bounds) => { - visitor.visit_id(item.hir_id); - visitor.visit_generics(generics); - walk_list!(visitor, visit_param_bound, bounds); - } - } - walk_list!(visitor, visit_attribute, item.attrs); -} - -pub fn walk_use<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>, hir_id: HirId) { - visitor.visit_id(hir_id); - visitor.visit_path(path, hir_id); -} - -pub fn walk_enum_def<'v, V: Visitor<'v>>( - visitor: &mut V, - enum_definition: &'v EnumDef<'v>, - generics: &'v Generics<'v>, - item_id: HirId, -) { - visitor.visit_id(item_id); - walk_list!(visitor, visit_variant, enum_definition.variants, generics, item_id); -} - -pub fn walk_variant<'v, V: Visitor<'v>>( - visitor: &mut V, - variant: &'v Variant<'v>, - generics: &'v Generics<'v>, - parent_item_id: HirId, -) { - visitor.visit_ident(variant.ident); - visitor.visit_id(variant.id); - visitor.visit_variant_data( - &variant.data, - variant.ident.name, - generics, - parent_item_id, - variant.span, - ); - walk_list!(visitor, visit_anon_const, &variant.disr_expr); - walk_list!(visitor, visit_attribute, variant.attrs); -} - -pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty<'v>) { - visitor.visit_id(typ.hir_id); - - match typ.kind { - TyKind::Slice(ref ty) => visitor.visit_ty(ty), - TyKind::Ptr(ref mutable_type) => visitor.visit_ty(&mutable_type.ty), - TyKind::Rptr(ref lifetime, ref mutable_type) => { - visitor.visit_lifetime(lifetime); - visitor.visit_ty(&mutable_type.ty) - } - TyKind::Never => {} - TyKind::Tup(tuple_element_types) => { - walk_list!(visitor, visit_ty, tuple_element_types); - } - TyKind::BareFn(ref function_declaration) => { - walk_list!(visitor, visit_generic_param, function_declaration.generic_params); - visitor.visit_fn_decl(&function_declaration.decl); - } - TyKind::Path(ref qpath) => { - visitor.visit_qpath(qpath, typ.hir_id, typ.span); - } - TyKind::Def(item_id, lifetimes) => { - visitor.visit_nested_item(item_id); - walk_list!(visitor, visit_generic_arg, lifetimes); - } - TyKind::Array(ref ty, ref length) => { - visitor.visit_ty(ty); - visitor.visit_anon_const(length) - } - TyKind::TraitObject(bounds, ref lifetime) => { - for bound in bounds { - visitor.visit_poly_trait_ref(bound, TraitBoundModifier::None); - } - visitor.visit_lifetime(lifetime); - } - TyKind::Typeof(ref expression) => visitor.visit_anon_const(expression), - TyKind::Infer | TyKind::Err => {} - } -} - -pub fn walk_qpath<'v, V: Visitor<'v>>( - visitor: &mut V, - qpath: &'v QPath<'v>, - id: HirId, - span: Span, -) { - match *qpath { - QPath::Resolved(ref maybe_qself, ref path) => { - if let Some(ref qself) = *maybe_qself { - visitor.visit_ty(qself); - } - visitor.visit_path(path, id) - } - QPath::TypeRelative(ref qself, ref segment) => { - visitor.visit_ty(qself); - visitor.visit_path_segment(span, segment); - } - } -} - -pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>) { - for segment in path.segments { - visitor.visit_path_segment(path.span, segment); - } -} - -pub fn walk_path_segment<'v, V: Visitor<'v>>( - visitor: &mut V, - path_span: Span, - segment: &'v PathSegment<'v>, -) { - visitor.visit_ident(segment.ident); - if let Some(id) = segment.hir_id { - visitor.visit_id(id); - } - if let Some(ref args) = segment.args { - visitor.visit_generic_args(path_span, args); - } -} - -pub fn walk_generic_args<'v, V: Visitor<'v>>( - visitor: &mut V, - _path_span: Span, - generic_args: &'v GenericArgs<'v>, -) { - walk_list!(visitor, visit_generic_arg, generic_args.args); - walk_list!(visitor, visit_assoc_type_binding, generic_args.bindings); -} - -pub fn walk_assoc_type_binding<'v, V: Visitor<'v>>( - visitor: &mut V, - type_binding: &'v TypeBinding<'v>, -) { - visitor.visit_id(type_binding.hir_id); - visitor.visit_ident(type_binding.ident); - match type_binding.kind { - TypeBindingKind::Equality { ref ty } => { - visitor.visit_ty(ty); - } - TypeBindingKind::Constraint { bounds } => { - walk_list!(visitor, visit_param_bound, bounds); - } - } -} - -pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat<'v>) { - visitor.visit_id(pattern.hir_id); - match pattern.kind { - PatKind::TupleStruct(ref qpath, children, _) => { - visitor.visit_qpath(qpath, pattern.hir_id, pattern.span); - walk_list!(visitor, visit_pat, children); - } - PatKind::Path(ref qpath) => { - visitor.visit_qpath(qpath, pattern.hir_id, pattern.span); - } - PatKind::Struct(ref qpath, fields, _) => { - visitor.visit_qpath(qpath, pattern.hir_id, pattern.span); - for field in fields { - visitor.visit_id(field.hir_id); - visitor.visit_ident(field.ident); - visitor.visit_pat(&field.pat) - } - } - PatKind::Or(pats) => walk_list!(visitor, visit_pat, pats), - PatKind::Tuple(tuple_elements, _) => { - walk_list!(visitor, visit_pat, tuple_elements); - } - PatKind::Box(ref subpattern) | PatKind::Ref(ref subpattern, _) => { - visitor.visit_pat(subpattern) - } - PatKind::Binding(_, _hir_id, ident, ref optional_subpattern) => { - visitor.visit_ident(ident); - walk_list!(visitor, visit_pat, optional_subpattern); - } - PatKind::Lit(ref expression) => visitor.visit_expr(expression), - PatKind::Range(ref lower_bound, ref upper_bound, _) => { - visitor.visit_expr(lower_bound); - visitor.visit_expr(upper_bound) - } - PatKind::Wild => (), - PatKind::Slice(prepatterns, ref slice_pattern, postpatterns) => { - walk_list!(visitor, visit_pat, prepatterns); - walk_list!(visitor, visit_pat, slice_pattern); - walk_list!(visitor, visit_pat, postpatterns); - } - } -} - -pub fn walk_foreign_item<'v, V: Visitor<'v>>(visitor: &mut V, foreign_item: &'v ForeignItem<'v>) { - visitor.visit_id(foreign_item.hir_id); - visitor.visit_vis(&foreign_item.vis); - visitor.visit_ident(foreign_item.ident); - - match foreign_item.kind { - ForeignItemKind::Fn(ref function_declaration, param_names, ref generics) => { - visitor.visit_generics(generics); - visitor.visit_fn_decl(function_declaration); - for ¶m_name in param_names { - visitor.visit_ident(param_name); - } - } - ForeignItemKind::Static(ref typ, _) => visitor.visit_ty(typ), - ForeignItemKind::Type => (), - } - - walk_list!(visitor, visit_attribute, foreign_item.attrs); -} - -pub fn walk_param_bound<'v, V: Visitor<'v>>(visitor: &mut V, bound: &'v GenericBound<'v>) { - match *bound { - GenericBound::Trait(ref typ, modifier) => { - visitor.visit_poly_trait_ref(typ, modifier); - } - GenericBound::Outlives(ref lifetime) => visitor.visit_lifetime(lifetime), - } -} - -pub fn walk_generic_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v GenericParam<'v>) { - visitor.visit_id(param.hir_id); - walk_list!(visitor, visit_attribute, param.attrs); - match param.name { - ParamName::Plain(ident) => visitor.visit_ident(ident), - ParamName::Error | ParamName::Fresh(_) => {} - } - match param.kind { - GenericParamKind::Lifetime { .. } => {} - GenericParamKind::Type { ref default, .. } => walk_list!(visitor, visit_ty, default), - GenericParamKind::Const { ref ty } => visitor.visit_ty(ty), - } - walk_list!(visitor, visit_param_bound, param.bounds); -} - -pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics<'v>) { - walk_list!(visitor, visit_generic_param, generics.params); - walk_list!(visitor, visit_where_predicate, generics.where_clause.predicates); -} - -pub fn walk_where_predicate<'v, V: Visitor<'v>>( - visitor: &mut V, - predicate: &'v WherePredicate<'v>, -) { - match predicate { - &WherePredicate::BoundPredicate(WhereBoundPredicate { - ref bounded_ty, - bounds, - bound_generic_params, - .. - }) => { - visitor.visit_ty(bounded_ty); - walk_list!(visitor, visit_param_bound, bounds); - walk_list!(visitor, visit_generic_param, bound_generic_params); - } - &WherePredicate::RegionPredicate(WhereRegionPredicate { ref lifetime, bounds, .. }) => { - visitor.visit_lifetime(lifetime); - walk_list!(visitor, visit_param_bound, bounds); - } - &WherePredicate::EqPredicate(WhereEqPredicate { - hir_id, ref lhs_ty, ref rhs_ty, .. - }) => { - visitor.visit_id(hir_id); - visitor.visit_ty(lhs_ty); - visitor.visit_ty(rhs_ty); - } - } -} - -pub fn walk_fn_ret_ty<'v, V: Visitor<'v>>(visitor: &mut V, ret_ty: &'v FunctionRetTy<'v>) { - if let FunctionRetTy::Return(ref output_ty) = *ret_ty { - visitor.visit_ty(output_ty) - } -} - -pub fn walk_fn_decl<'v, V: Visitor<'v>>(visitor: &mut V, function_declaration: &'v FnDecl<'v>) { - for ty in function_declaration.inputs { - visitor.visit_ty(ty) - } - walk_fn_ret_ty(visitor, &function_declaration.output) -} - -pub fn walk_fn_kind<'v, V: Visitor<'v>>(visitor: &mut V, function_kind: FnKind<'v>) { - match function_kind { - FnKind::ItemFn(_, generics, ..) => { - visitor.visit_generics(generics); - } - FnKind::Method(..) | FnKind::Closure(_) => {} - } -} - -pub fn walk_fn<'v, V: Visitor<'v>>( - visitor: &mut V, - function_kind: FnKind<'v>, - function_declaration: &'v FnDecl<'v>, - body_id: BodyId, - _span: Span, - id: HirId, -) { - visitor.visit_id(id); - visitor.visit_fn_decl(function_declaration); - walk_fn_kind(visitor, function_kind); - visitor.visit_nested_body(body_id) -} - -pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem<'v>) { - visitor.visit_ident(trait_item.ident); - walk_list!(visitor, visit_attribute, trait_item.attrs); - visitor.visit_generics(&trait_item.generics); - match trait_item.kind { - TraitItemKind::Const(ref ty, default) => { - visitor.visit_id(trait_item.hir_id); - visitor.visit_ty(ty); - walk_list!(visitor, visit_nested_body, default); - } - TraitItemKind::Method(ref sig, TraitMethod::Required(param_names)) => { - visitor.visit_id(trait_item.hir_id); - visitor.visit_fn_decl(&sig.decl); - for ¶m_name in param_names { - visitor.visit_ident(param_name); - } - } - TraitItemKind::Method(ref sig, TraitMethod::Provided(body_id)) => { - visitor.visit_fn( - FnKind::Method(trait_item.ident, sig, None, &trait_item.attrs), - &sig.decl, - body_id, - trait_item.span, - trait_item.hir_id, - ); - } - TraitItemKind::Type(bounds, ref default) => { - visitor.visit_id(trait_item.hir_id); - walk_list!(visitor, visit_param_bound, bounds); - walk_list!(visitor, visit_ty, default); - } - } -} - -pub fn walk_trait_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_item_ref: &'v TraitItemRef) { - // N.B., deliberately force a compilation error if/when new fields are added. - let TraitItemRef { id, ident, ref kind, span: _, ref defaultness } = *trait_item_ref; - visitor.visit_nested_trait_item(id); - visitor.visit_ident(ident); - visitor.visit_associated_item_kind(kind); - visitor.visit_defaultness(defaultness); -} - -pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem<'v>) { - // N.B., deliberately force a compilation error if/when new fields are added. - let ImplItem { - hir_id: _, - ident, - ref vis, - ref defaultness, - attrs, - ref generics, - ref kind, - span: _, - } = *impl_item; - - visitor.visit_ident(ident); - visitor.visit_vis(vis); - visitor.visit_defaultness(defaultness); - walk_list!(visitor, visit_attribute, attrs); - visitor.visit_generics(generics); - match *kind { - ImplItemKind::Const(ref ty, body) => { - visitor.visit_id(impl_item.hir_id); - visitor.visit_ty(ty); - visitor.visit_nested_body(body); - } - ImplItemKind::Method(ref sig, body_id) => { - visitor.visit_fn( - FnKind::Method(impl_item.ident, sig, Some(&impl_item.vis), &impl_item.attrs), - &sig.decl, - body_id, - impl_item.span, - impl_item.hir_id, - ); - } - ImplItemKind::TyAlias(ref ty) => { - visitor.visit_id(impl_item.hir_id); - visitor.visit_ty(ty); - } - ImplItemKind::OpaqueTy(bounds) => { - visitor.visit_id(impl_item.hir_id); - walk_list!(visitor, visit_param_bound, bounds); - } - } -} - -pub fn walk_impl_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, impl_item_ref: &'v ImplItemRef<'v>) { - // N.B., deliberately force a compilation error if/when new fields are added. - let ImplItemRef { id, ident, ref kind, span: _, ref vis, ref defaultness } = *impl_item_ref; - visitor.visit_nested_impl_item(id); - visitor.visit_ident(ident); - visitor.visit_associated_item_kind(kind); - visitor.visit_vis(vis); - visitor.visit_defaultness(defaultness); -} - -pub fn walk_struct_def<'v, V: Visitor<'v>>( - visitor: &mut V, - struct_definition: &'v VariantData<'v>, -) { - if let Some(ctor_hir_id) = struct_definition.ctor_hir_id() { - visitor.visit_id(ctor_hir_id); - } - walk_list!(visitor, visit_struct_field, struct_definition.fields()); -} - -pub fn walk_struct_field<'v, V: Visitor<'v>>(visitor: &mut V, struct_field: &'v StructField<'v>) { - visitor.visit_id(struct_field.hir_id); - visitor.visit_vis(&struct_field.vis); - visitor.visit_ident(struct_field.ident); - visitor.visit_ty(&struct_field.ty); - walk_list!(visitor, visit_attribute, struct_field.attrs); -} - -pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block<'v>) { - visitor.visit_id(block.hir_id); - walk_list!(visitor, visit_stmt, block.stmts); - walk_list!(visitor, visit_expr, &block.expr); -} - -pub fn walk_stmt<'v, V: Visitor<'v>>(visitor: &mut V, statement: &'v Stmt<'v>) { - visitor.visit_id(statement.hir_id); - match statement.kind { - StmtKind::Local(ref local) => visitor.visit_local(local), - StmtKind::Item(item) => visitor.visit_nested_item(item), - StmtKind::Expr(ref expression) | StmtKind::Semi(ref expression) => { - visitor.visit_expr(expression) - } - } -} - -pub fn walk_anon_const<'v, V: Visitor<'v>>(visitor: &mut V, constant: &'v AnonConst) { - visitor.visit_id(constant.hir_id); - visitor.visit_nested_body(constant.body); -} - -pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>) { - visitor.visit_id(expression.hir_id); - walk_list!(visitor, visit_attribute, expression.attrs.iter()); - match expression.kind { - ExprKind::Box(ref subexpression) => visitor.visit_expr(subexpression), - ExprKind::Array(subexpressions) => { - walk_list!(visitor, visit_expr, subexpressions); - } - ExprKind::Repeat(ref element, ref count) => { - visitor.visit_expr(element); - visitor.visit_anon_const(count) - } - ExprKind::Struct(ref qpath, fields, ref optional_base) => { - visitor.visit_qpath(qpath, expression.hir_id, expression.span); - for field in fields { - visitor.visit_id(field.hir_id); - visitor.visit_ident(field.ident); - visitor.visit_expr(&field.expr) - } - walk_list!(visitor, visit_expr, optional_base); - } - ExprKind::Tup(subexpressions) => { - walk_list!(visitor, visit_expr, subexpressions); - } - ExprKind::Call(ref callee_expression, arguments) => { - visitor.visit_expr(callee_expression); - walk_list!(visitor, visit_expr, arguments); - } - ExprKind::MethodCall(ref segment, _, arguments) => { - visitor.visit_path_segment(expression.span, segment); - walk_list!(visitor, visit_expr, arguments); - } - ExprKind::Binary(_, ref left_expression, ref right_expression) => { - visitor.visit_expr(left_expression); - visitor.visit_expr(right_expression) - } - ExprKind::AddrOf(_, _, ref subexpression) | ExprKind::Unary(_, ref subexpression) => { - visitor.visit_expr(subexpression) - } - ExprKind::Cast(ref subexpression, ref typ) | ExprKind::Type(ref subexpression, ref typ) => { - visitor.visit_expr(subexpression); - visitor.visit_ty(typ) - } - ExprKind::DropTemps(ref subexpression) => { - visitor.visit_expr(subexpression); - } - ExprKind::Loop(ref block, ref opt_label, _) => { - walk_list!(visitor, visit_label, opt_label); - visitor.visit_block(block); - } - ExprKind::Match(ref subexpression, arms, _) => { - visitor.visit_expr(subexpression); - walk_list!(visitor, visit_arm, arms); - } - ExprKind::Closure(_, ref function_declaration, body, _fn_decl_span, _gen) => visitor - .visit_fn( - FnKind::Closure(&expression.attrs), - function_declaration, - body, - expression.span, - expression.hir_id, - ), - ExprKind::Block(ref block, ref opt_label) => { - walk_list!(visitor, visit_label, opt_label); - visitor.visit_block(block); - } - ExprKind::Assign(ref lhs, ref rhs, _) => { - visitor.visit_expr(rhs); - visitor.visit_expr(lhs) - } - ExprKind::AssignOp(_, ref left_expression, ref right_expression) => { - visitor.visit_expr(right_expression); - visitor.visit_expr(left_expression); - } - ExprKind::Field(ref subexpression, ident) => { - visitor.visit_expr(subexpression); - visitor.visit_ident(ident); - } - ExprKind::Index(ref main_expression, ref index_expression) => { - visitor.visit_expr(main_expression); - visitor.visit_expr(index_expression) - } - ExprKind::Path(ref qpath) => { - visitor.visit_qpath(qpath, expression.hir_id, expression.span); - } - ExprKind::Break(ref destination, ref opt_expr) => { - if let Some(ref label) = destination.label { - visitor.visit_label(label); - } - walk_list!(visitor, visit_expr, opt_expr); - } - ExprKind::Continue(ref destination) => { - if let Some(ref label) = destination.label { - visitor.visit_label(label); - } - } - ExprKind::Ret(ref optional_expression) => { - walk_list!(visitor, visit_expr, optional_expression); - } - ExprKind::InlineAsm(ref asm) => { - walk_list!(visitor, visit_expr, asm.outputs_exprs); - walk_list!(visitor, visit_expr, asm.inputs_exprs); - } - ExprKind::Yield(ref subexpression, _) => { - visitor.visit_expr(subexpression); - } - ExprKind::Lit(_) | ExprKind::Err => {} - } -} - -pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm<'v>) { - visitor.visit_id(arm.hir_id); - visitor.visit_pat(&arm.pat); - if let Some(ref g) = arm.guard { - match g { - Guard::If(ref e) => visitor.visit_expr(e), - } - } - visitor.visit_expr(&arm.body); - walk_list!(visitor, visit_attribute, arm.attrs); -} - -pub fn walk_vis<'v, V: Visitor<'v>>(visitor: &mut V, vis: &'v Visibility<'v>) { - if let VisibilityKind::Restricted { ref path, hir_id } = vis.node { - visitor.visit_id(hir_id); - visitor.visit_path(path, hir_id) - } -} - -pub fn walk_associated_item_kind<'v, V: Visitor<'v>>(_: &mut V, _: &'v AssocItemKind) { - // No visitable content here: this fn exists so you can call it if - // the right thing to do, should content be added in the future, - // would be to walk it. -} - -pub fn walk_defaultness<'v, V: Visitor<'v>>(_: &mut V, _: &'v Defaultness) { - // No visitable content here: this fn exists so you can call it if - // the right thing to do, should content be added in the future, - // would be to walk it. -} diff --git a/src/librustc/hir/mod.rs b/src/librustc/hir/mod.rs index 3087fc3c1f2..abbff7b65f2 100644 --- a/src/librustc/hir/mod.rs +++ b/src/librustc/hir/mod.rs @@ -4,10 +4,11 @@ pub mod check_attr; pub mod exports; -pub mod intravisit; pub mod map; pub mod upvars; +pub use rustc_hir::intravisit; + use crate::ty::query::Providers; pub fn provide(providers: &mut Providers<'_>) { diff --git a/src/librustc_hir/intravisit.rs b/src/librustc_hir/intravisit.rs new file mode 100644 index 00000000000..f4348add4d6 --- /dev/null +++ b/src/librustc_hir/intravisit.rs @@ -0,0 +1,1183 @@ +//! HIR walker for walking the contents of nodes. +//! +//! **For an overview of the visitor strategy, see the docs on the +//! `super::itemlikevisit::ItemLikeVisitor` trait.** +//! +//! If you have decided to use this visitor, here are some general +//! notes on how to do so: +//! +//! Each overridden visit method has full control over what +//! happens with its node, it can do its own traversal of the node's children, +//! call `intravisit::walk_*` to apply the default traversal algorithm, or prevent +//! deeper traversal by doing nothing. +//! +//! When visiting the HIR, the contents of nested items are NOT visited +//! by default. This is different from the AST visitor, which does a deep walk. +//! Hence this module is called `intravisit`; see the method `visit_nested_item` +//! for more details. +//! +//! Note: it is an important invariant that the default visitor walks +//! the body of a function in "execution order" - more concretely, if +//! we consider the reverse post-order (RPO) of the CFG implied by the HIR, +//! then a pre-order traversal of the HIR is consistent with the CFG RPO +//! on the *initial CFG point* of each HIR node, while a post-order traversal +//! of the HIR is consistent with the CFG RPO on each *final CFG point* of +//! each CFG node. +//! +//! One thing that follows is that if HIR node A always starts/ends executing +//! before HIR node B, then A appears in traversal pre/postorder before B, +//! respectively. (This follows from RPO respecting CFG domination). +//! +//! This order consistency is required in a few places in rustc, for +//! example generator inference, and possibly also HIR borrowck. + +use crate::hir::*; +use crate::hir_id::CRATE_HIR_ID; +use crate::itemlikevisit::{ItemLikeVisitor, ParItemLikeVisitor}; +use rustc_span::Span; +use syntax::ast::{Attribute, Ident, Label, Name}; +use syntax::walk_list; + +pub struct DeepVisitor<'v, V> { + visitor: &'v mut V, +} + +impl<'v, V> DeepVisitor<'v, V> { + pub fn new(base: &'v mut V) -> Self { + DeepVisitor { visitor: base } + } +} + +impl<'v, 'hir, V> ItemLikeVisitor<'hir> for DeepVisitor<'v, V> +where + V: Visitor<'hir>, +{ + fn visit_item(&mut self, item: &'hir Item<'hir>) { + self.visitor.visit_item(item); + } + + fn visit_trait_item(&mut self, trait_item: &'hir TraitItem<'hir>) { + self.visitor.visit_trait_item(trait_item); + } + + fn visit_impl_item(&mut self, impl_item: &'hir ImplItem<'hir>) { + self.visitor.visit_impl_item(impl_item); + } +} + +pub trait IntoVisitor<'hir> { + type Visitor: Visitor<'hir>; + fn into_visitor(&self) -> Self::Visitor; +} + +pub struct ParDeepVisitor(pub V); + +impl<'hir, V> ParItemLikeVisitor<'hir> for ParDeepVisitor +where + V: IntoVisitor<'hir>, +{ + fn visit_item(&self, item: &'hir Item<'hir>) { + self.0.into_visitor().visit_item(item); + } + + fn visit_trait_item(&self, trait_item: &'hir TraitItem<'hir>) { + self.0.into_visitor().visit_trait_item(trait_item); + } + + fn visit_impl_item(&self, impl_item: &'hir ImplItem<'hir>) { + self.0.into_visitor().visit_impl_item(impl_item); + } +} + +#[derive(Copy, Clone)] +pub enum FnKind<'a> { + /// `#[xxx] pub async/const/extern "Abi" fn foo()` + ItemFn(Ident, &'a Generics<'a>, FnHeader, &'a Visibility<'a>, &'a [Attribute]), + + /// `fn foo(&self)` + Method(Ident, &'a FnSig<'a>, Option<&'a Visibility<'a>>, &'a [Attribute]), + + /// `|x, y| {}` + Closure(&'a [Attribute]), +} + +impl<'a> FnKind<'a> { + pub fn attrs(&self) -> &'a [Attribute] { + match *self { + FnKind::ItemFn(.., attrs) => attrs, + FnKind::Method(.., attrs) => attrs, + FnKind::Closure(attrs) => attrs, + } + } + + pub fn header(&self) -> Option<&FnHeader> { + match *self { + FnKind::ItemFn(_, _, ref header, _, _) => Some(header), + FnKind::Method(_, ref sig, _, _) => Some(&sig.header), + FnKind::Closure(_) => None, + } + } +} + +/// An abstract representation of the HIR `rustc::hir::map::Map`. +pub trait Map<'hir> { + fn body(&self, id: BodyId) -> &'hir Body<'hir>; + fn item(&self, id: HirId) -> &'hir Item<'hir>; + fn trait_item(&self, id: TraitItemId) -> &'hir TraitItem<'hir>; + fn impl_item(&self, id: ImplItemId) -> &'hir ImplItem<'hir>; +} + +/// Specifies what nested things a visitor wants to visit. The most +/// common choice is `OnlyBodies`, which will cause the visitor to +/// visit fn bodies for fns that it encounters, but skip over nested +/// item-like things. +/// +/// See the comments on `ItemLikeVisitor` for more details on the overall +/// visit strategy. +pub enum NestedVisitorMap<'this, M> { + /// Do not visit any nested things. When you add a new + /// "non-nested" thing, you will want to audit such uses to see if + /// they remain valid. + /// + /// Use this if you are only walking some particular kind of tree + /// (i.e., a type, or fn signature) and you don't want to thread a + /// HIR map around. + None, + + /// Do not visit nested item-like things, but visit nested things + /// that are inside of an item-like. + /// + /// **This is the most common choice.** A very common pattern is + /// to use `visit_all_item_likes()` as an outer loop, + /// and to have the visitor that visits the contents of each item + /// using this setting. + OnlyBodies(&'this M), + + /// Visits all nested things, including item-likes. + /// + /// **This is an unusual choice.** It is used when you want to + /// process everything within their lexical context. Typically you + /// kick off the visit by doing `walk_krate()`. + All(&'this M), +} + +impl<'this, M> NestedVisitorMap<'this, M> { + /// Returns the map to use for an "intra item-like" thing (if any). + /// E.g., function body. + fn intra(self) -> Option<&'this M> { + match self { + NestedVisitorMap::None => None, + NestedVisitorMap::OnlyBodies(map) => Some(map), + NestedVisitorMap::All(map) => Some(map), + } + } + + /// Returns the map to use for an "item-like" thing (if any). + /// E.g., item, impl-item. + fn inter(self) -> Option<&'this M> { + match self { + NestedVisitorMap::None => None, + NestedVisitorMap::OnlyBodies(_) => None, + NestedVisitorMap::All(map) => Some(map), + } + } +} + +/// Each method of the Visitor trait is a hook to be potentially +/// overridden. Each method's default implementation recursively visits +/// the substructure of the input via the corresponding `walk` method; +/// e.g., the `visit_mod` method by default calls `intravisit::walk_mod`. +/// +/// Note that this visitor does NOT visit nested items by default +/// (this is why the module is called `intravisit`, to distinguish it +/// from the AST's `visit` module, which acts differently). If you +/// simply want to visit all items in the crate in some order, you +/// should call `Crate::visit_all_items`. Otherwise, see the comment +/// on `visit_nested_item` for details on how to visit nested items. +/// +/// If you want to ensure that your code handles every variant +/// explicitly, you need to override each method. (And you also need +/// to monitor future changes to `Visitor` in case a new method with a +/// new default implementation gets introduced.) +pub trait Visitor<'v>: Sized { + type Map: Map<'v>; + + /////////////////////////////////////////////////////////////////////////// + // Nested items. + + /// The default versions of the `visit_nested_XXX` routines invoke + /// this method to get a map to use. By selecting an enum variant, + /// you control which kinds of nested HIR are visited; see + /// `NestedVisitorMap` for details. By "nested HIR", we are + /// referring to bits of HIR that are not directly embedded within + /// one another but rather indirectly, through a table in the + /// crate. This is done to control dependencies during incremental + /// compilation: the non-inline bits of HIR can be tracked and + /// hashed separately. + /// + /// **If for some reason you want the nested behavior, but don't + /// have a `Map` at your disposal:** then you should override the + /// `visit_nested_XXX` methods, and override this method to + /// `panic!()`. This way, if a new `visit_nested_XXX` variant is + /// added in the future, we will see the panic in your code and + /// fix it appropriately. + fn nested_visit_map(&mut self) -> NestedVisitorMap<'_, Self::Map>; + + /// Invoked when a nested item is encountered. By default does + /// nothing unless you override `nested_visit_map` to return other than + /// `None`, in which case it will walk the item. **You probably + /// don't want to override this method** -- instead, override + /// `nested_visit_map` or use the "shallow" or "deep" visit + /// patterns described on `itemlikevisit::ItemLikeVisitor`. The only + /// reason to override this method is if you want a nested pattern + /// but cannot supply a `Map`; see `nested_visit_map` for advice. + #[allow(unused_variables)] + fn visit_nested_item(&mut self, id: ItemId) { + let opt_item = self.nested_visit_map().inter().map(|map| map.item(id.id)); + if let Some(item) = opt_item { + self.visit_item(item); + } + } + + /// Like `visit_nested_item()`, but for trait items. See + /// `visit_nested_item()` for advice on when to override this + /// method. + #[allow(unused_variables)] + fn visit_nested_trait_item(&mut self, id: TraitItemId) { + let opt_item = self.nested_visit_map().inter().map(|map| map.trait_item(id)); + if let Some(item) = opt_item { + self.visit_trait_item(item); + } + } + + /// Like `visit_nested_item()`, but for impl items. See + /// `visit_nested_item()` for advice on when to override this + /// method. + #[allow(unused_variables)] + fn visit_nested_impl_item(&mut self, id: ImplItemId) { + let opt_item = self.nested_visit_map().inter().map(|map| map.impl_item(id)); + if let Some(item) = opt_item { + self.visit_impl_item(item); + } + } + + /// Invoked to visit the body of a function, method or closure. Like + /// visit_nested_item, does nothing by default unless you override + /// `nested_visit_map` to return other than `None`, in which case it will walk + /// the body. + fn visit_nested_body(&mut self, id: BodyId) { + let opt_body = self.nested_visit_map().intra().map(|map| map.body(id)); + if let Some(body) = opt_body { + self.visit_body(body); + } + } + + fn visit_param(&mut self, param: &'v Param<'v>) { + walk_param(self, param) + } + + /// Visits the top-level item and (optionally) nested items / impl items. See + /// `visit_nested_item` for details. + fn visit_item(&mut self, i: &'v Item<'v>) { + walk_item(self, i) + } + + fn visit_body(&mut self, b: &'v Body<'v>) { + walk_body(self, b); + } + + /// When invoking `visit_all_item_likes()`, you need to supply an + /// item-like visitor. This method converts a "intra-visit" + /// visitor into an item-like visitor that walks the entire tree. + /// If you use this, you probably don't want to process the + /// contents of nested item-like things, since the outer loop will + /// visit them as well. + fn as_deep_visitor<'s>(&'s mut self) -> DeepVisitor<'s, Self> { + DeepVisitor::new(self) + } + + /////////////////////////////////////////////////////////////////////////// + + fn visit_id(&mut self, _hir_id: HirId) { + // Nothing to do. + } + fn visit_name(&mut self, _span: Span, _name: Name) { + // Nothing to do. + } + fn visit_ident(&mut self, ident: Ident) { + walk_ident(self, ident) + } + fn visit_mod(&mut self, m: &'v Mod<'v>, _s: Span, n: HirId) { + walk_mod(self, m, n) + } + fn visit_foreign_item(&mut self, i: &'v ForeignItem<'v>) { + walk_foreign_item(self, i) + } + fn visit_local(&mut self, l: &'v Local<'v>) { + walk_local(self, l) + } + fn visit_block(&mut self, b: &'v Block<'v>) { + walk_block(self, b) + } + fn visit_stmt(&mut self, s: &'v Stmt<'v>) { + walk_stmt(self, s) + } + fn visit_arm(&mut self, a: &'v Arm<'v>) { + walk_arm(self, a) + } + fn visit_pat(&mut self, p: &'v Pat<'v>) { + walk_pat(self, p) + } + fn visit_anon_const(&mut self, c: &'v AnonConst) { + walk_anon_const(self, c) + } + fn visit_expr(&mut self, ex: &'v Expr<'v>) { + walk_expr(self, ex) + } + fn visit_ty(&mut self, t: &'v Ty<'v>) { + walk_ty(self, t) + } + fn visit_generic_param(&mut self, p: &'v GenericParam<'v>) { + walk_generic_param(self, p) + } + fn visit_generics(&mut self, g: &'v Generics<'v>) { + walk_generics(self, g) + } + fn visit_where_predicate(&mut self, predicate: &'v WherePredicate<'v>) { + walk_where_predicate(self, predicate) + } + fn visit_fn_decl(&mut self, fd: &'v FnDecl<'v>) { + walk_fn_decl(self, fd) + } + fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl<'v>, b: BodyId, s: Span, id: HirId) { + walk_fn(self, fk, fd, b, s, id) + } + fn visit_use(&mut self, path: &'v Path<'v>, hir_id: HirId) { + walk_use(self, path, hir_id) + } + fn visit_trait_item(&mut self, ti: &'v TraitItem<'v>) { + walk_trait_item(self, ti) + } + fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) { + walk_trait_item_ref(self, ii) + } + fn visit_impl_item(&mut self, ii: &'v ImplItem<'v>) { + walk_impl_item(self, ii) + } + fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef<'v>) { + walk_impl_item_ref(self, ii) + } + fn visit_trait_ref(&mut self, t: &'v TraitRef<'v>) { + walk_trait_ref(self, t) + } + fn visit_param_bound(&mut self, bounds: &'v GenericBound<'v>) { + walk_param_bound(self, bounds) + } + fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef<'v>, m: TraitBoundModifier) { + walk_poly_trait_ref(self, t, m) + } + fn visit_variant_data( + &mut self, + s: &'v VariantData<'v>, + _: Name, + _: &'v Generics<'v>, + _parent_id: HirId, + _: Span, + ) { + walk_struct_def(self, s) + } + fn visit_struct_field(&mut self, s: &'v StructField<'v>) { + walk_struct_field(self, s) + } + fn visit_enum_def( + &mut self, + enum_definition: &'v EnumDef<'v>, + generics: &'v Generics<'v>, + item_id: HirId, + _: Span, + ) { + walk_enum_def(self, enum_definition, generics, item_id) + } + fn visit_variant(&mut self, v: &'v Variant<'v>, g: &'v Generics<'v>, item_id: HirId) { + walk_variant(self, v, g, item_id) + } + fn visit_label(&mut self, label: &'v Label) { + walk_label(self, label) + } + fn visit_generic_arg(&mut self, generic_arg: &'v GenericArg<'v>) { + match generic_arg { + GenericArg::Lifetime(lt) => self.visit_lifetime(lt), + GenericArg::Type(ty) => self.visit_ty(ty), + GenericArg::Const(ct) => self.visit_anon_const(&ct.value), + } + } + fn visit_lifetime(&mut self, lifetime: &'v Lifetime) { + walk_lifetime(self, lifetime) + } + fn visit_qpath(&mut self, qpath: &'v QPath<'v>, id: HirId, span: Span) { + walk_qpath(self, qpath, id, span) + } + fn visit_path(&mut self, path: &'v Path<'v>, _id: HirId) { + walk_path(self, path) + } + fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v PathSegment<'v>) { + walk_path_segment(self, path_span, path_segment) + } + fn visit_generic_args(&mut self, path_span: Span, generic_args: &'v GenericArgs<'v>) { + walk_generic_args(self, path_span, generic_args) + } + fn visit_assoc_type_binding(&mut self, type_binding: &'v TypeBinding<'v>) { + walk_assoc_type_binding(self, type_binding) + } + fn visit_attribute(&mut self, _attr: &'v Attribute) {} + fn visit_macro_def(&mut self, macro_def: &'v MacroDef<'v>) { + walk_macro_def(self, macro_def) + } + fn visit_vis(&mut self, vis: &'v Visibility<'v>) { + walk_vis(self, vis) + } + fn visit_associated_item_kind(&mut self, kind: &'v AssocItemKind) { + walk_associated_item_kind(self, kind); + } + fn visit_defaultness(&mut self, defaultness: &'v Defaultness) { + walk_defaultness(self, defaultness); + } +} + +/// Walks the contents of a crate. See also `Crate::visit_all_items`. +pub fn walk_crate<'v, V: Visitor<'v>>(visitor: &mut V, krate: &'v Crate<'v>) { + visitor.visit_mod(&krate.module, krate.span, CRATE_HIR_ID); + walk_list!(visitor, visit_attribute, krate.attrs); + walk_list!(visitor, visit_macro_def, krate.exported_macros); +} + +pub fn walk_macro_def<'v, V: Visitor<'v>>(visitor: &mut V, macro_def: &'v MacroDef<'v>) { + visitor.visit_id(macro_def.hir_id); + visitor.visit_name(macro_def.span, macro_def.name); + walk_list!(visitor, visit_attribute, macro_def.attrs); +} + +pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod<'v>, mod_hir_id: HirId) { + visitor.visit_id(mod_hir_id); + for &item_id in module.item_ids { + visitor.visit_nested_item(item_id); + } +} + +pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body<'v>) { + walk_list!(visitor, visit_param, body.params); + visitor.visit_expr(&body.value); +} + +pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local<'v>) { + // Intentionally visiting the expr first - the initialization expr + // dominates the local's definition. + walk_list!(visitor, visit_expr, &local.init); + walk_list!(visitor, visit_attribute, local.attrs.iter()); + visitor.visit_id(local.hir_id); + visitor.visit_pat(&local.pat); + walk_list!(visitor, visit_ty, &local.ty); +} + +pub fn walk_ident<'v, V: Visitor<'v>>(visitor: &mut V, ident: Ident) { + visitor.visit_name(ident.span, ident.name); +} + +pub fn walk_label<'v, V: Visitor<'v>>(visitor: &mut V, label: &'v Label) { + visitor.visit_ident(label.ident); +} + +pub fn walk_lifetime<'v, V: Visitor<'v>>(visitor: &mut V, lifetime: &'v Lifetime) { + visitor.visit_id(lifetime.hir_id); + match lifetime.name { + LifetimeName::Param(ParamName::Plain(ident)) => { + visitor.visit_ident(ident); + } + LifetimeName::Param(ParamName::Fresh(_)) + | LifetimeName::Param(ParamName::Error) + | LifetimeName::Static + | LifetimeName::Error + | LifetimeName::Implicit + | LifetimeName::ImplicitObjectLifetimeDefault + | LifetimeName::Underscore => {} + } +} + +pub fn walk_poly_trait_ref<'v, V: Visitor<'v>>( + visitor: &mut V, + trait_ref: &'v PolyTraitRef<'v>, + _modifier: TraitBoundModifier, +) { + walk_list!(visitor, visit_generic_param, trait_ref.bound_generic_params); + visitor.visit_trait_ref(&trait_ref.trait_ref); +} + +pub fn walk_trait_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_ref: &'v TraitRef<'v>) { + visitor.visit_id(trait_ref.hir_ref_id); + visitor.visit_path(&trait_ref.path, trait_ref.hir_ref_id) +} + +pub fn walk_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v Param<'v>) { + visitor.visit_id(param.hir_id); + visitor.visit_pat(¶m.pat); + walk_list!(visitor, visit_attribute, param.attrs); +} + +pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) { + visitor.visit_vis(&item.vis); + visitor.visit_ident(item.ident); + match item.kind { + ItemKind::ExternCrate(orig_name) => { + visitor.visit_id(item.hir_id); + if let Some(orig_name) = orig_name { + visitor.visit_name(item.span, orig_name); + } + } + ItemKind::Use(ref path, _) => { + visitor.visit_use(path, item.hir_id); + } + ItemKind::Static(ref typ, _, body) | ItemKind::Const(ref typ, body) => { + visitor.visit_id(item.hir_id); + visitor.visit_ty(typ); + visitor.visit_nested_body(body); + } + ItemKind::Fn(ref sig, ref generics, body_id) => visitor.visit_fn( + FnKind::ItemFn(item.ident, generics, sig.header, &item.vis, &item.attrs), + &sig.decl, + body_id, + item.span, + item.hir_id, + ), + ItemKind::Mod(ref module) => { + // `visit_mod()` takes care of visiting the `Item`'s `HirId`. + visitor.visit_mod(module, item.span, item.hir_id) + } + ItemKind::ForeignMod(ref foreign_module) => { + visitor.visit_id(item.hir_id); + walk_list!(visitor, visit_foreign_item, foreign_module.items); + } + ItemKind::GlobalAsm(_) => { + visitor.visit_id(item.hir_id); + } + ItemKind::TyAlias(ref ty, ref generics) => { + visitor.visit_id(item.hir_id); + visitor.visit_ty(ty); + visitor.visit_generics(generics) + } + ItemKind::OpaqueTy(OpaqueTy { ref generics, bounds, .. }) => { + visitor.visit_id(item.hir_id); + walk_generics(visitor, generics); + walk_list!(visitor, visit_param_bound, bounds); + } + ItemKind::Enum(ref enum_definition, ref generics) => { + visitor.visit_generics(generics); + // `visit_enum_def()` takes care of visiting the `Item`'s `HirId`. + visitor.visit_enum_def(enum_definition, generics, item.hir_id, item.span) + } + ItemKind::Impl(.., ref generics, ref opt_trait_reference, ref typ, impl_item_refs) => { + visitor.visit_id(item.hir_id); + visitor.visit_generics(generics); + walk_list!(visitor, visit_trait_ref, opt_trait_reference); + visitor.visit_ty(typ); + walk_list!(visitor, visit_impl_item_ref, impl_item_refs); + } + ItemKind::Struct(ref struct_definition, ref generics) + | ItemKind::Union(ref struct_definition, ref generics) => { + visitor.visit_generics(generics); + visitor.visit_id(item.hir_id); + visitor.visit_variant_data( + struct_definition, + item.ident.name, + generics, + item.hir_id, + item.span, + ); + } + ItemKind::Trait(.., ref generics, bounds, trait_item_refs) => { + visitor.visit_id(item.hir_id); + visitor.visit_generics(generics); + walk_list!(visitor, visit_param_bound, bounds); + walk_list!(visitor, visit_trait_item_ref, trait_item_refs); + } + ItemKind::TraitAlias(ref generics, bounds) => { + visitor.visit_id(item.hir_id); + visitor.visit_generics(generics); + walk_list!(visitor, visit_param_bound, bounds); + } + } + walk_list!(visitor, visit_attribute, item.attrs); +} + +pub fn walk_use<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>, hir_id: HirId) { + visitor.visit_id(hir_id); + visitor.visit_path(path, hir_id); +} + +pub fn walk_enum_def<'v, V: Visitor<'v>>( + visitor: &mut V, + enum_definition: &'v EnumDef<'v>, + generics: &'v Generics<'v>, + item_id: HirId, +) { + visitor.visit_id(item_id); + walk_list!(visitor, visit_variant, enum_definition.variants, generics, item_id); +} + +pub fn walk_variant<'v, V: Visitor<'v>>( + visitor: &mut V, + variant: &'v Variant<'v>, + generics: &'v Generics<'v>, + parent_item_id: HirId, +) { + visitor.visit_ident(variant.ident); + visitor.visit_id(variant.id); + visitor.visit_variant_data( + &variant.data, + variant.ident.name, + generics, + parent_item_id, + variant.span, + ); + walk_list!(visitor, visit_anon_const, &variant.disr_expr); + walk_list!(visitor, visit_attribute, variant.attrs); +} + +pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty<'v>) { + visitor.visit_id(typ.hir_id); + + match typ.kind { + TyKind::Slice(ref ty) => visitor.visit_ty(ty), + TyKind::Ptr(ref mutable_type) => visitor.visit_ty(&mutable_type.ty), + TyKind::Rptr(ref lifetime, ref mutable_type) => { + visitor.visit_lifetime(lifetime); + visitor.visit_ty(&mutable_type.ty) + } + TyKind::Never => {} + TyKind::Tup(tuple_element_types) => { + walk_list!(visitor, visit_ty, tuple_element_types); + } + TyKind::BareFn(ref function_declaration) => { + walk_list!(visitor, visit_generic_param, function_declaration.generic_params); + visitor.visit_fn_decl(&function_declaration.decl); + } + TyKind::Path(ref qpath) => { + visitor.visit_qpath(qpath, typ.hir_id, typ.span); + } + TyKind::Def(item_id, lifetimes) => { + visitor.visit_nested_item(item_id); + walk_list!(visitor, visit_generic_arg, lifetimes); + } + TyKind::Array(ref ty, ref length) => { + visitor.visit_ty(ty); + visitor.visit_anon_const(length) + } + TyKind::TraitObject(bounds, ref lifetime) => { + for bound in bounds { + visitor.visit_poly_trait_ref(bound, TraitBoundModifier::None); + } + visitor.visit_lifetime(lifetime); + } + TyKind::Typeof(ref expression) => visitor.visit_anon_const(expression), + TyKind::Infer | TyKind::Err => {} + } +} + +pub fn walk_qpath<'v, V: Visitor<'v>>( + visitor: &mut V, + qpath: &'v QPath<'v>, + id: HirId, + span: Span, +) { + match *qpath { + QPath::Resolved(ref maybe_qself, ref path) => { + if let Some(ref qself) = *maybe_qself { + visitor.visit_ty(qself); + } + visitor.visit_path(path, id) + } + QPath::TypeRelative(ref qself, ref segment) => { + visitor.visit_ty(qself); + visitor.visit_path_segment(span, segment); + } + } +} + +pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>) { + for segment in path.segments { + visitor.visit_path_segment(path.span, segment); + } +} + +pub fn walk_path_segment<'v, V: Visitor<'v>>( + visitor: &mut V, + path_span: Span, + segment: &'v PathSegment<'v>, +) { + visitor.visit_ident(segment.ident); + if let Some(id) = segment.hir_id { + visitor.visit_id(id); + } + if let Some(ref args) = segment.args { + visitor.visit_generic_args(path_span, args); + } +} + +pub fn walk_generic_args<'v, V: Visitor<'v>>( + visitor: &mut V, + _path_span: Span, + generic_args: &'v GenericArgs<'v>, +) { + walk_list!(visitor, visit_generic_arg, generic_args.args); + walk_list!(visitor, visit_assoc_type_binding, generic_args.bindings); +} + +pub fn walk_assoc_type_binding<'v, V: Visitor<'v>>( + visitor: &mut V, + type_binding: &'v TypeBinding<'v>, +) { + visitor.visit_id(type_binding.hir_id); + visitor.visit_ident(type_binding.ident); + match type_binding.kind { + TypeBindingKind::Equality { ref ty } => { + visitor.visit_ty(ty); + } + TypeBindingKind::Constraint { bounds } => { + walk_list!(visitor, visit_param_bound, bounds); + } + } +} + +pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat<'v>) { + visitor.visit_id(pattern.hir_id); + match pattern.kind { + PatKind::TupleStruct(ref qpath, children, _) => { + visitor.visit_qpath(qpath, pattern.hir_id, pattern.span); + walk_list!(visitor, visit_pat, children); + } + PatKind::Path(ref qpath) => { + visitor.visit_qpath(qpath, pattern.hir_id, pattern.span); + } + PatKind::Struct(ref qpath, fields, _) => { + visitor.visit_qpath(qpath, pattern.hir_id, pattern.span); + for field in fields { + visitor.visit_id(field.hir_id); + visitor.visit_ident(field.ident); + visitor.visit_pat(&field.pat) + } + } + PatKind::Or(pats) => walk_list!(visitor, visit_pat, pats), + PatKind::Tuple(tuple_elements, _) => { + walk_list!(visitor, visit_pat, tuple_elements); + } + PatKind::Box(ref subpattern) | PatKind::Ref(ref subpattern, _) => { + visitor.visit_pat(subpattern) + } + PatKind::Binding(_, _hir_id, ident, ref optional_subpattern) => { + visitor.visit_ident(ident); + walk_list!(visitor, visit_pat, optional_subpattern); + } + PatKind::Lit(ref expression) => visitor.visit_expr(expression), + PatKind::Range(ref lower_bound, ref upper_bound, _) => { + visitor.visit_expr(lower_bound); + visitor.visit_expr(upper_bound) + } + PatKind::Wild => (), + PatKind::Slice(prepatterns, ref slice_pattern, postpatterns) => { + walk_list!(visitor, visit_pat, prepatterns); + walk_list!(visitor, visit_pat, slice_pattern); + walk_list!(visitor, visit_pat, postpatterns); + } + } +} + +pub fn walk_foreign_item<'v, V: Visitor<'v>>(visitor: &mut V, foreign_item: &'v ForeignItem<'v>) { + visitor.visit_id(foreign_item.hir_id); + visitor.visit_vis(&foreign_item.vis); + visitor.visit_ident(foreign_item.ident); + + match foreign_item.kind { + ForeignItemKind::Fn(ref function_declaration, param_names, ref generics) => { + visitor.visit_generics(generics); + visitor.visit_fn_decl(function_declaration); + for ¶m_name in param_names { + visitor.visit_ident(param_name); + } + } + ForeignItemKind::Static(ref typ, _) => visitor.visit_ty(typ), + ForeignItemKind::Type => (), + } + + walk_list!(visitor, visit_attribute, foreign_item.attrs); +} + +pub fn walk_param_bound<'v, V: Visitor<'v>>(visitor: &mut V, bound: &'v GenericBound<'v>) { + match *bound { + GenericBound::Trait(ref typ, modifier) => { + visitor.visit_poly_trait_ref(typ, modifier); + } + GenericBound::Outlives(ref lifetime) => visitor.visit_lifetime(lifetime), + } +} + +pub fn walk_generic_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v GenericParam<'v>) { + visitor.visit_id(param.hir_id); + walk_list!(visitor, visit_attribute, param.attrs); + match param.name { + ParamName::Plain(ident) => visitor.visit_ident(ident), + ParamName::Error | ParamName::Fresh(_) => {} + } + match param.kind { + GenericParamKind::Lifetime { .. } => {} + GenericParamKind::Type { ref default, .. } => walk_list!(visitor, visit_ty, default), + GenericParamKind::Const { ref ty } => visitor.visit_ty(ty), + } + walk_list!(visitor, visit_param_bound, param.bounds); +} + +pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics<'v>) { + walk_list!(visitor, visit_generic_param, generics.params); + walk_list!(visitor, visit_where_predicate, generics.where_clause.predicates); +} + +pub fn walk_where_predicate<'v, V: Visitor<'v>>( + visitor: &mut V, + predicate: &'v WherePredicate<'v>, +) { + match predicate { + &WherePredicate::BoundPredicate(WhereBoundPredicate { + ref bounded_ty, + bounds, + bound_generic_params, + .. + }) => { + visitor.visit_ty(bounded_ty); + walk_list!(visitor, visit_param_bound, bounds); + walk_list!(visitor, visit_generic_param, bound_generic_params); + } + &WherePredicate::RegionPredicate(WhereRegionPredicate { ref lifetime, bounds, .. }) => { + visitor.visit_lifetime(lifetime); + walk_list!(visitor, visit_param_bound, bounds); + } + &WherePredicate::EqPredicate(WhereEqPredicate { + hir_id, ref lhs_ty, ref rhs_ty, .. + }) => { + visitor.visit_id(hir_id); + visitor.visit_ty(lhs_ty); + visitor.visit_ty(rhs_ty); + } + } +} + +pub fn walk_fn_ret_ty<'v, V: Visitor<'v>>(visitor: &mut V, ret_ty: &'v FunctionRetTy<'v>) { + if let FunctionRetTy::Return(ref output_ty) = *ret_ty { + visitor.visit_ty(output_ty) + } +} + +pub fn walk_fn_decl<'v, V: Visitor<'v>>(visitor: &mut V, function_declaration: &'v FnDecl<'v>) { + for ty in function_declaration.inputs { + visitor.visit_ty(ty) + } + walk_fn_ret_ty(visitor, &function_declaration.output) +} + +pub fn walk_fn_kind<'v, V: Visitor<'v>>(visitor: &mut V, function_kind: FnKind<'v>) { + match function_kind { + FnKind::ItemFn(_, generics, ..) => { + visitor.visit_generics(generics); + } + FnKind::Method(..) | FnKind::Closure(_) => {} + } +} + +pub fn walk_fn<'v, V: Visitor<'v>>( + visitor: &mut V, + function_kind: FnKind<'v>, + function_declaration: &'v FnDecl<'v>, + body_id: BodyId, + _span: Span, + id: HirId, +) { + visitor.visit_id(id); + visitor.visit_fn_decl(function_declaration); + walk_fn_kind(visitor, function_kind); + visitor.visit_nested_body(body_id) +} + +pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem<'v>) { + visitor.visit_ident(trait_item.ident); + walk_list!(visitor, visit_attribute, trait_item.attrs); + visitor.visit_generics(&trait_item.generics); + match trait_item.kind { + TraitItemKind::Const(ref ty, default) => { + visitor.visit_id(trait_item.hir_id); + visitor.visit_ty(ty); + walk_list!(visitor, visit_nested_body, default); + } + TraitItemKind::Method(ref sig, TraitMethod::Required(param_names)) => { + visitor.visit_id(trait_item.hir_id); + visitor.visit_fn_decl(&sig.decl); + for ¶m_name in param_names { + visitor.visit_ident(param_name); + } + } + TraitItemKind::Method(ref sig, TraitMethod::Provided(body_id)) => { + visitor.visit_fn( + FnKind::Method(trait_item.ident, sig, None, &trait_item.attrs), + &sig.decl, + body_id, + trait_item.span, + trait_item.hir_id, + ); + } + TraitItemKind::Type(bounds, ref default) => { + visitor.visit_id(trait_item.hir_id); + walk_list!(visitor, visit_param_bound, bounds); + walk_list!(visitor, visit_ty, default); + } + } +} + +pub fn walk_trait_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_item_ref: &'v TraitItemRef) { + // N.B., deliberately force a compilation error if/when new fields are added. + let TraitItemRef { id, ident, ref kind, span: _, ref defaultness } = *trait_item_ref; + visitor.visit_nested_trait_item(id); + visitor.visit_ident(ident); + visitor.visit_associated_item_kind(kind); + visitor.visit_defaultness(defaultness); +} + +pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem<'v>) { + // N.B., deliberately force a compilation error if/when new fields are added. + let ImplItem { + hir_id: _, + ident, + ref vis, + ref defaultness, + attrs, + ref generics, + ref kind, + span: _, + } = *impl_item; + + visitor.visit_ident(ident); + visitor.visit_vis(vis); + visitor.visit_defaultness(defaultness); + walk_list!(visitor, visit_attribute, attrs); + visitor.visit_generics(generics); + match *kind { + ImplItemKind::Const(ref ty, body) => { + visitor.visit_id(impl_item.hir_id); + visitor.visit_ty(ty); + visitor.visit_nested_body(body); + } + ImplItemKind::Method(ref sig, body_id) => { + visitor.visit_fn( + FnKind::Method(impl_item.ident, sig, Some(&impl_item.vis), &impl_item.attrs), + &sig.decl, + body_id, + impl_item.span, + impl_item.hir_id, + ); + } + ImplItemKind::TyAlias(ref ty) => { + visitor.visit_id(impl_item.hir_id); + visitor.visit_ty(ty); + } + ImplItemKind::OpaqueTy(bounds) => { + visitor.visit_id(impl_item.hir_id); + walk_list!(visitor, visit_param_bound, bounds); + } + } +} + +pub fn walk_impl_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, impl_item_ref: &'v ImplItemRef<'v>) { + // N.B., deliberately force a compilation error if/when new fields are added. + let ImplItemRef { id, ident, ref kind, span: _, ref vis, ref defaultness } = *impl_item_ref; + visitor.visit_nested_impl_item(id); + visitor.visit_ident(ident); + visitor.visit_associated_item_kind(kind); + visitor.visit_vis(vis); + visitor.visit_defaultness(defaultness); +} + +pub fn walk_struct_def<'v, V: Visitor<'v>>( + visitor: &mut V, + struct_definition: &'v VariantData<'v>, +) { + if let Some(ctor_hir_id) = struct_definition.ctor_hir_id() { + visitor.visit_id(ctor_hir_id); + } + walk_list!(visitor, visit_struct_field, struct_definition.fields()); +} + +pub fn walk_struct_field<'v, V: Visitor<'v>>(visitor: &mut V, struct_field: &'v StructField<'v>) { + visitor.visit_id(struct_field.hir_id); + visitor.visit_vis(&struct_field.vis); + visitor.visit_ident(struct_field.ident); + visitor.visit_ty(&struct_field.ty); + walk_list!(visitor, visit_attribute, struct_field.attrs); +} + +pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block<'v>) { + visitor.visit_id(block.hir_id); + walk_list!(visitor, visit_stmt, block.stmts); + walk_list!(visitor, visit_expr, &block.expr); +} + +pub fn walk_stmt<'v, V: Visitor<'v>>(visitor: &mut V, statement: &'v Stmt<'v>) { + visitor.visit_id(statement.hir_id); + match statement.kind { + StmtKind::Local(ref local) => visitor.visit_local(local), + StmtKind::Item(item) => visitor.visit_nested_item(item), + StmtKind::Expr(ref expression) | StmtKind::Semi(ref expression) => { + visitor.visit_expr(expression) + } + } +} + +pub fn walk_anon_const<'v, V: Visitor<'v>>(visitor: &mut V, constant: &'v AnonConst) { + visitor.visit_id(constant.hir_id); + visitor.visit_nested_body(constant.body); +} + +pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>) { + visitor.visit_id(expression.hir_id); + walk_list!(visitor, visit_attribute, expression.attrs.iter()); + match expression.kind { + ExprKind::Box(ref subexpression) => visitor.visit_expr(subexpression), + ExprKind::Array(subexpressions) => { + walk_list!(visitor, visit_expr, subexpressions); + } + ExprKind::Repeat(ref element, ref count) => { + visitor.visit_expr(element); + visitor.visit_anon_const(count) + } + ExprKind::Struct(ref qpath, fields, ref optional_base) => { + visitor.visit_qpath(qpath, expression.hir_id, expression.span); + for field in fields { + visitor.visit_id(field.hir_id); + visitor.visit_ident(field.ident); + visitor.visit_expr(&field.expr) + } + walk_list!(visitor, visit_expr, optional_base); + } + ExprKind::Tup(subexpressions) => { + walk_list!(visitor, visit_expr, subexpressions); + } + ExprKind::Call(ref callee_expression, arguments) => { + visitor.visit_expr(callee_expression); + walk_list!(visitor, visit_expr, arguments); + } + ExprKind::MethodCall(ref segment, _, arguments) => { + visitor.visit_path_segment(expression.span, segment); + walk_list!(visitor, visit_expr, arguments); + } + ExprKind::Binary(_, ref left_expression, ref right_expression) => { + visitor.visit_expr(left_expression); + visitor.visit_expr(right_expression) + } + ExprKind::AddrOf(_, _, ref subexpression) | ExprKind::Unary(_, ref subexpression) => { + visitor.visit_expr(subexpression) + } + ExprKind::Cast(ref subexpression, ref typ) | ExprKind::Type(ref subexpression, ref typ) => { + visitor.visit_expr(subexpression); + visitor.visit_ty(typ) + } + ExprKind::DropTemps(ref subexpression) => { + visitor.visit_expr(subexpression); + } + ExprKind::Loop(ref block, ref opt_label, _) => { + walk_list!(visitor, visit_label, opt_label); + visitor.visit_block(block); + } + ExprKind::Match(ref subexpression, arms, _) => { + visitor.visit_expr(subexpression); + walk_list!(visitor, visit_arm, arms); + } + ExprKind::Closure(_, ref function_declaration, body, _fn_decl_span, _gen) => visitor + .visit_fn( + FnKind::Closure(&expression.attrs), + function_declaration, + body, + expression.span, + expression.hir_id, + ), + ExprKind::Block(ref block, ref opt_label) => { + walk_list!(visitor, visit_label, opt_label); + visitor.visit_block(block); + } + ExprKind::Assign(ref lhs, ref rhs, _) => { + visitor.visit_expr(rhs); + visitor.visit_expr(lhs) + } + ExprKind::AssignOp(_, ref left_expression, ref right_expression) => { + visitor.visit_expr(right_expression); + visitor.visit_expr(left_expression); + } + ExprKind::Field(ref subexpression, ident) => { + visitor.visit_expr(subexpression); + visitor.visit_ident(ident); + } + ExprKind::Index(ref main_expression, ref index_expression) => { + visitor.visit_expr(main_expression); + visitor.visit_expr(index_expression) + } + ExprKind::Path(ref qpath) => { + visitor.visit_qpath(qpath, expression.hir_id, expression.span); + } + ExprKind::Break(ref destination, ref opt_expr) => { + if let Some(ref label) = destination.label { + visitor.visit_label(label); + } + walk_list!(visitor, visit_expr, opt_expr); + } + ExprKind::Continue(ref destination) => { + if let Some(ref label) = destination.label { + visitor.visit_label(label); + } + } + ExprKind::Ret(ref optional_expression) => { + walk_list!(visitor, visit_expr, optional_expression); + } + ExprKind::InlineAsm(ref asm) => { + walk_list!(visitor, visit_expr, asm.outputs_exprs); + walk_list!(visitor, visit_expr, asm.inputs_exprs); + } + ExprKind::Yield(ref subexpression, _) => { + visitor.visit_expr(subexpression); + } + ExprKind::Lit(_) | ExprKind::Err => {} + } +} + +pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm<'v>) { + visitor.visit_id(arm.hir_id); + visitor.visit_pat(&arm.pat); + if let Some(ref g) = arm.guard { + match g { + Guard::If(ref e) => visitor.visit_expr(e), + } + } + visitor.visit_expr(&arm.body); + walk_list!(visitor, visit_attribute, arm.attrs); +} + +pub fn walk_vis<'v, V: Visitor<'v>>(visitor: &mut V, vis: &'v Visibility<'v>) { + if let VisibilityKind::Restricted { ref path, hir_id } = vis.node { + visitor.visit_id(hir_id); + visitor.visit_path(path, hir_id) + } +} + +pub fn walk_associated_item_kind<'v, V: Visitor<'v>>(_: &mut V, _: &'v AssocItemKind) { + // No visitable content here: this fn exists so you can call it if + // the right thing to do, should content be added in the future, + // would be to walk it. +} + +pub fn walk_defaultness<'v, V: Visitor<'v>>(_: &mut V, _: &'v Defaultness) { + // No visitable content here: this fn exists so you can call it if + // the right thing to do, should content be added in the future, + // would be to walk it. +} diff --git a/src/librustc_hir/lib.rs b/src/librustc_hir/lib.rs index 8bf2e6299a9..66494d0fa73 100644 --- a/src/librustc_hir/lib.rs +++ b/src/librustc_hir/lib.rs @@ -15,6 +15,7 @@ pub mod def; pub mod def_id; mod hir; pub mod hir_id; +pub mod intravisit; pub mod itemlikevisit; pub mod pat_util; pub mod print; -- cgit 1.4.1-3-g733a5