diff options
Diffstat (limited to 'compiler/rustc_expand/src/expand.rs')
| -rw-r--r-- | compiler/rustc_expand/src/expand.rs | 107 |
1 files changed, 73 insertions, 34 deletions
diff --git a/compiler/rustc_expand/src/expand.rs b/compiler/rustc_expand/src/expand.rs index 81d4d59ee04..82a2719ca96 100644 --- a/compiler/rustc_expand/src/expand.rs +++ b/compiler/rustc_expand/src/expand.rs @@ -3,15 +3,14 @@ use std::rc::Rc; use std::sync::Arc; use std::{iter, mem}; -use rustc_ast as ast; use rustc_ast::mut_visit::*; use rustc_ast::ptr::P; use rustc_ast::tokenstream::TokenStream; use rustc_ast::visit::{self, AssocCtxt, Visitor, VisitorResult, try_visit, walk_list}; use rustc_ast::{ - AssocItemKind, AstNodeWrapper, AttrArgs, AttrStyle, AttrVec, ExprKind, ForeignItemKind, - HasAttrs, HasNodeId, Inline, ItemKind, MacStmtStyle, MetaItemInner, MetaItemKind, ModKind, - NodeId, PatKind, StmtKind, TyKind, token, + self as ast, AssocItemKind, AstNodeWrapper, AttrArgs, AttrStyle, AttrVec, DUMMY_NODE_ID, + ExprKind, ForeignItemKind, HasAttrs, HasNodeId, Inline, ItemKind, MacStmtStyle, MetaItemInner, + MetaItemKind, ModKind, NodeId, PatKind, StmtKind, TyKind, token, }; use rustc_ast_pretty::pprust; use rustc_data_structures::flat_map_in_place::FlatMapInPlace; @@ -131,13 +130,9 @@ macro_rules! ast_fragments { pub(crate) fn mut_visit_with<F: MutVisitor>(&mut self, vis: &mut F) { match self { AstFragment::OptExpr(opt_expr) => { - visit_clobber(opt_expr, |opt_expr| { - if let Some(expr) = opt_expr { - vis.filter_map_expr(expr) - } else { - None - } - }); + if let Some(expr) = opt_expr.take() { + *opt_expr = vis.filter_map_expr(expr) + } } AstFragment::MethodReceiverExpr(expr) => vis.visit_method_receiver_expr(expr), $($(AstFragment::$Kind(ast) => vis.$mut_visit_ast(ast),)?)* @@ -1319,10 +1314,10 @@ impl InvocationCollectorNode for P<ast::Item> { let mut idents = Vec::new(); collect_use_tree_leaves(ut, &mut idents); - return idents; + idents + } else { + self.kind.ident().into_iter().collect() } - - if let Some(ident) = self.kind.ident() { vec![ident] } else { vec![] } } } @@ -1782,11 +1777,7 @@ impl InvocationCollectorNode for AstNodeWrapper<P<ast::Expr>, OptExprTag> { /// This struct is a hack to workaround unstable of `stmt_expr_attributes`. /// It can be removed once that feature is stabilized. struct MethodReceiverTag; -impl DummyAstNode for MethodReceiverTag { - fn dummy() -> MethodReceiverTag { - MethodReceiverTag - } -} + impl InvocationCollectorNode for AstNodeWrapper<P<ast::Expr>, MethodReceiverTag> { type OutputTy = Self; const KIND: AstFragmentKind = AstFragmentKind::MethodReceiverExpr; @@ -1852,6 +1843,57 @@ fn build_single_delegations<'a, Node: InvocationCollectorNode>( }) } +/// Required for `visit_node` obtained an owned `Node` from `&mut Node`. +trait DummyAstNode { + fn dummy() -> Self; +} + +impl DummyAstNode for ast::Crate { + fn dummy() -> Self { + ast::Crate { + attrs: Default::default(), + items: Default::default(), + spans: Default::default(), + id: DUMMY_NODE_ID, + is_placeholder: Default::default(), + } + } +} + +impl DummyAstNode for P<ast::Ty> { + fn dummy() -> Self { + P(ast::Ty { + id: DUMMY_NODE_ID, + kind: TyKind::Dummy, + span: Default::default(), + tokens: Default::default(), + }) + } +} + +impl DummyAstNode for P<ast::Pat> { + fn dummy() -> Self { + P(ast::Pat { + id: DUMMY_NODE_ID, + kind: PatKind::Wild, + span: Default::default(), + tokens: Default::default(), + }) + } +} + +impl DummyAstNode for P<ast::Expr> { + fn dummy() -> Self { + ast::Expr::dummy() + } +} + +impl DummyAstNode for AstNodeWrapper<P<ast::Expr>, MethodReceiverTag> { + fn dummy() -> Self { + AstNodeWrapper::new(ast::Expr::dummy(), MethodReceiverTag) + } +} + struct InvocationCollector<'a, 'b> { cx: &'a mut ExtCtxt<'b>, invocations: Vec<(Invocation, Option<Arc<SyntaxExtension>>)>, @@ -2155,18 +2197,19 @@ impl<'a, 'b> InvocationCollector<'a, 'b> { self.expand_cfg_attr(node, &attr, pos); continue; } - _ => visit_clobber(node, |node| { - self.collect_attr((attr, pos, derives), node.to_annotatable(), Node::KIND) + _ => { + let n = mem::replace(node, Node::dummy()); + *node = self + .collect_attr((attr, pos, derives), n.to_annotatable(), Node::KIND) .make_ast::<Node>() - }), + } }, None if node.is_mac_call() => { - visit_clobber(node, |node| { - // Do not clobber unless it's actually a macro (uncommon case). - let (mac, attrs, _) = node.take_mac_call(); - self.check_attributes(&attrs, &mac); - self.collect_bang(mac, Node::KIND).make_ast::<Node>() - }) + let n = mem::replace(node, Node::dummy()); + let (mac, attrs, _) = n.take_mac_call(); + self.check_attributes(&attrs, &mac); + + *node = self.collect_bang(mac, Node::KIND).make_ast::<Node>() } None if node.delegation().is_some() => unreachable!(), None => { @@ -2293,18 +2336,14 @@ impl<'a, 'b> MutVisitor for InvocationCollector<'a, 'b> { } fn visit_method_receiver_expr(&mut self, node: &mut P<ast::Expr>) { - visit_clobber(node, |node| { - let mut wrapper = AstNodeWrapper::new(node, MethodReceiverTag); - self.visit_node(&mut wrapper); - wrapper.wrapped - }) + self.visit_node(AstNodeWrapper::from_mut(node, MethodReceiverTag)) } fn filter_map_expr(&mut self, node: P<ast::Expr>) -> Option<P<ast::Expr>> { self.flat_map_node(AstNodeWrapper::new(node, OptExprTag)) } - fn visit_block(&mut self, node: &mut P<ast::Block>) { + fn visit_block(&mut self, node: &mut ast::Block) { let orig_dir_ownership = mem::replace( &mut self.cx.current_expansion.dir_ownership, DirOwnership::UnownedViaBlock, |