diff --git a/src/librustc/hir/map/mod.rs b/src/librustc/hir/map/mod.rs index d4efe0297b671..b45d3f0396047 100644 --- a/src/librustc/hir/map/mod.rs +++ b/src/librustc/hir/map/mod.rs @@ -23,8 +23,6 @@ use syntax::source_map::Spanned; use syntax::ext::base::MacroKind; use syntax_pos::{Span, DUMMY_SP}; -use std::result::Result::Err; - pub mod blocks; mod collector; mod def_collector; @@ -183,6 +181,44 @@ pub struct Map<'hir> { hir_to_node_id: FxHashMap, } +struct ParentHirIterator<'map> { + current_id: HirId, + map: &'map Map<'map>, +} + +impl<'map> ParentHirIterator<'map> { + fn new(current_id: HirId, map: &'map Map<'map>) -> ParentHirIterator<'map> { + ParentHirIterator { + current_id, + map, + } + } +} + +impl<'map> Iterator for ParentHirIterator<'map> { + type Item = (HirId, Node<'map>); + + fn next(&mut self) -> Option { + if self.current_id == CRATE_HIR_ID { + return None; + } + loop { // There are nodes that do not have entries, so we need to skip them. + let parent_id = self.map.get_parent_node(self.current_id); + + if parent_id == self.current_id { + self.current_id = CRATE_HIR_ID; + return None; + } + + self.current_id = parent_id; + if let Some(entry) = self.map.find_entry(parent_id) { + return Some((parent_id, entry.node)); + } + // If this `HirId` doesn't have an `Entry`, skip it and look for its `parent_id`. + } + } +} + impl<'hir> Map<'hir> { #[inline] fn lookup(&self, id: HirId) -> Option<&Entry<'hir>> { @@ -682,45 +718,6 @@ impl<'hir> Map<'hir> { } } - - /// If there is some error when walking the parents (e.g., a node does not - /// have a parent in the map or a node can't be found), then we return the - /// last good `HirId` we found. Note that reaching the crate root (`id == 0`), - /// is not an error, since items in the crate module have the crate root as - /// parent. - fn walk_parent_nodes(&self, - start_id: HirId, - found: F, - bail_early: F2) - -> Result - where F: Fn(&Node<'hir>) -> bool, F2: Fn(&Node<'hir>) -> bool - { - let mut id = start_id; - loop { - let parent_id = self.get_parent_node(id); - if parent_id == CRATE_HIR_ID { - return Ok(CRATE_HIR_ID); - } - if parent_id == id { - return Err(id); - } - - if let Some(entry) = self.find_entry(parent_id) { - if let Node::Crate = entry.node { - return Err(id); - } - if found(&entry.node) { - return Ok(parent_id); - } else if bail_early(&entry.node) { - return Err(parent_id); - } - id = parent_id; - } else { - return Err(id); - } - } - } - /// Retrieves the `HirId` for `id`'s enclosing method, unless there's a /// `while` or `loop` before reaching it, as block tail returns are not /// available in them. @@ -744,29 +741,46 @@ impl<'hir> Map<'hir> { /// } /// ``` pub fn get_return_block(&self, id: HirId) -> Option { - let match_fn = |node: &Node<'_>| { - match *node { + let mut iter = ParentHirIterator::new(id, &self).peekable(); + let mut ignore_tail = false; + if let Some(entry) = self.find_entry(id) { + if let Node::Expr(Expr { kind: ExprKind::Ret(_), .. }) = entry.node { + // When dealing with `return` statements, we don't care about climbing only tail + // expressions. + ignore_tail = true; + } + } + while let Some((hir_id, node)) = iter.next() { + if let (Some((_, next_node)), false) = (iter.peek(), ignore_tail) { + match next_node { + Node::Block(Block { expr: None, .. }) => return None, + Node::Block(Block { expr: Some(expr), .. }) => { + if hir_id != expr.hir_id { + // The current node is not the tail expression of its parent. + return None; + } + } + _ => {} + } + } + match node { Node::Item(_) | Node::ForeignItem(_) | Node::TraitItem(_) | Node::Expr(Expr { kind: ExprKind::Closure(..), ..}) | - Node::ImplItem(_) => true, - _ => false, - } - }; - let match_non_returning_block = |node: &Node<'_>| { - match *node { + Node::ImplItem(_) => return Some(hir_id), Node::Expr(ref expr) => { match expr.kind { - ExprKind::Loop(..) | ExprKind::Ret(..) => true, - _ => false, + // Ignore `return`s on the first iteration + ExprKind::Loop(..) | ExprKind::Ret(..) => return None, + _ => {} } } - _ => false, + Node::Local(_) => return None, + _ => {} } - }; - - self.walk_parent_nodes(id, match_fn, match_non_returning_block).ok() + } + None } /// Retrieves the `HirId` for `id`'s parent item, or `id` itself if no @@ -774,16 +788,17 @@ impl<'hir> Map<'hir> { /// in the HIR which is recorded by the map and is an item, either an item /// in a module, trait, or impl. pub fn get_parent_item(&self, hir_id: HirId) -> HirId { - match self.walk_parent_nodes(hir_id, |node| match *node { - Node::Item(_) | - Node::ForeignItem(_) | - Node::TraitItem(_) | - Node::ImplItem(_) => true, - _ => false, - }, |_| false) { - Ok(id) => id, - Err(id) => id, + for (hir_id, node) in ParentHirIterator::new(hir_id, &self) { + match node { + Node::Crate | + Node::Item(_) | + Node::ForeignItem(_) | + Node::TraitItem(_) | + Node::ImplItem(_) => return hir_id, + _ => {} + } } + hir_id } /// Returns the `DefId` of `id`'s nearest module parent, or `id` itself if no @@ -795,60 +810,64 @@ impl<'hir> Map<'hir> { /// Returns the `HirId` of `id`'s nearest module parent, or `id` itself if no /// module parent is in this map. pub fn get_module_parent_node(&self, hir_id: HirId) -> HirId { - match self.walk_parent_nodes(hir_id, |node| match *node { - Node::Item(&Item { kind: ItemKind::Mod(_), .. }) => true, - _ => false, - }, |_| false) { - Ok(id) => id, - Err(id) => id, + for (hir_id, node) in ParentHirIterator::new(hir_id, &self) { + if let Node::Item(&Item { kind: ItemKind::Mod(_), .. }) = node { + return hir_id; + } } + CRATE_HIR_ID } /// Returns the nearest enclosing scope. A scope is roughly an item or block. pub fn get_enclosing_scope(&self, hir_id: HirId) -> Option { - self.walk_parent_nodes(hir_id, |node| match *node { - Node::Item(i) => { - match i.kind { - ItemKind::Fn(..) - | ItemKind::Mod(..) - | ItemKind::Enum(..) - | ItemKind::Struct(..) - | ItemKind::Union(..) - | ItemKind::Trait(..) - | ItemKind::Impl(..) => true, - _ => false, - } - }, - Node::ForeignItem(fi) => { - match fi.kind { - ForeignItemKind::Fn(..) => true, - _ => false, - } - }, - Node::TraitItem(ti) => { - match ti.kind { - TraitItemKind::Method(..) => true, - _ => false, - } - }, - Node::ImplItem(ii) => { - match ii.kind { - ImplItemKind::Method(..) => true, - _ => false, - } - }, - Node::Block(_) => true, - _ => false, - }, |_| false).ok() + for (hir_id, node) in ParentHirIterator::new(hir_id, &self) { + if match node { + Node::Item(i) => { + match i.kind { + ItemKind::Fn(..) + | ItemKind::Mod(..) + | ItemKind::Enum(..) + | ItemKind::Struct(..) + | ItemKind::Union(..) + | ItemKind::Trait(..) + | ItemKind::Impl(..) => true, + _ => false, + } + }, + Node::ForeignItem(fi) => { + match fi.kind { + ForeignItemKind::Fn(..) => true, + _ => false, + } + }, + Node::TraitItem(ti) => { + match ti.kind { + TraitItemKind::Method(..) => true, + _ => false, + } + }, + Node::ImplItem(ii) => { + match ii.kind { + ImplItemKind::Method(..) => true, + _ => false, + } + }, + Node::Block(_) => true, + _ => false, + } { + return Some(hir_id); + } + } + None } /// Returns the defining scope for an opaque type definition. - pub fn get_defining_scope(&self, id: HirId) -> Option { + pub fn get_defining_scope(&self, id: HirId) -> HirId { let mut scope = id; loop { - scope = self.get_enclosing_scope(scope)?; + scope = self.get_enclosing_scope(scope).unwrap_or(CRATE_HIR_ID); if scope == CRATE_HIR_ID { - return Some(CRATE_HIR_ID); + return CRATE_HIR_ID; } match self.get(scope) { Node::Item(i) => { @@ -861,7 +880,7 @@ impl<'hir> Map<'hir> { _ => break, } } - Some(scope) + scope } pub fn get_parent_did(&self, id: HirId) -> DefId { diff --git a/src/librustc/hir/mod.rs b/src/librustc/hir/mod.rs index 01cb5cc9bc105..0b1fcd0da3a9c 100644 --- a/src/librustc/hir/mod.rs +++ b/src/librustc/hir/mod.rs @@ -1563,7 +1563,7 @@ pub enum ExprKind { /// Thus, `x.foo::(a, b, c, d)` is represented as /// `ExprKind::MethodCall(PathSegment { foo, [Bar, Baz] }, [x, a, b, c, d])`. MethodCall(P, Span, HirVec), - /// A tuple (e.g., `(a, b, c ,d)`). + /// A tuple (e.g., `(a, b, c, d)`). Tup(HirVec), /// A binary operation (e.g., `a + b`, `a * b`). Binary(BinOp, P, P), diff --git a/src/librustc/infer/opaque_types/mod.rs b/src/librustc/infer/opaque_types/mod.rs index 3b3649fd8112f..35f47e252a7c5 100644 --- a/src/librustc/infer/opaque_types/mod.rs +++ b/src/librustc/infer/opaque_types/mod.rs @@ -1215,7 +1215,7 @@ pub fn may_define_opaque_type( let mut hir_id = tcx.hir().as_local_hir_id(def_id).unwrap(); // Named opaque types can be defined by any siblings or children of siblings. - let scope = tcx.hir().get_defining_scope(opaque_hir_id).expect("could not get defining scope"); + let scope = tcx.hir().get_defining_scope(opaque_hir_id); // We walk up the node tree until we hit the root or the scope of the opaque type. while hir_id != scope && hir_id != hir::CRATE_HIR_ID { hir_id = tcx.hir().get_parent_item(hir_id); diff --git a/src/librustc_typeck/check/expr.rs b/src/librustc_typeck/check/expr.rs index 58f41ca4f88f9..317d829d135bf 100644 --- a/src/librustc_typeck/check/expr.rs +++ b/src/librustc_typeck/check/expr.rs @@ -620,8 +620,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { expr: &'tcx hir::Expr ) -> Ty<'tcx> { if self.ret_coercion.is_none() { - struct_span_err!(self.tcx.sess, expr.span, E0572, - "return statement outside of function body").emit(); + struct_span_err!( + self.tcx.sess, + expr.span, + E0572, + "return statement outside of function body", + ).emit(); } else if let Some(ref e) = expr_opt { if self.ret_coercion_span.borrow().is_none() { *self.ret_coercion_span.borrow_mut() = Some(e.span); diff --git a/src/librustc_typeck/collect.rs b/src/librustc_typeck/collect.rs index 3ac3ce2a02c2e..db017394cd5f1 100644 --- a/src/librustc_typeck/collect.rs +++ b/src/librustc_typeck/collect.rs @@ -1717,9 +1717,7 @@ fn find_opaque_ty_constraints(tcx: TyCtxt<'_>, def_id: DefId) -> Ty<'_> { } let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap(); - let scope = tcx.hir() - .get_defining_scope(hir_id) - .expect("could not get defining scope"); + let scope = tcx.hir().get_defining_scope(hir_id); let mut locator = ConstraintLocator { def_id, tcx, diff --git a/src/test/ui/struct-literal-variant-in-if.stderr b/src/test/ui/struct-literal-variant-in-if.stderr index f91b9d7dce60f..85cbc787bc2db 100644 --- a/src/test/ui/struct-literal-variant-in-if.stderr +++ b/src/test/ui/struct-literal-variant-in-if.stderr @@ -49,9 +49,6 @@ LL | if x == E::V { field } {} error[E0308]: mismatched types --> $DIR/struct-literal-variant-in-if.rs:10:20 | -LL | fn test_E(x: E) { - | - help: try adding a return type: `-> bool` -LL | let field = true; LL | if x == E::V { field } {} | ^^^^^ expected (), found bool |