From e8af4c15528932f02473c703f819bbd6e021d7c1 Mon Sep 17 00:00:00 2001 From: Vadim Petrochenkov Date: Thu, 10 Oct 2019 01:08:17 +0300 Subject: [PATCH 1/2] resolve: Mark macros starting with an underscore as used --- src/librustc_resolve/build_reduced_graph.rs | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/src/librustc_resolve/build_reduced_graph.rs b/src/librustc_resolve/build_reduced_graph.rs index f76aa95dd2cc8..47885e165fb98 100644 --- a/src/librustc_resolve/build_reduced_graph.rs +++ b/src/librustc_resolve/build_reduced_graph.rs @@ -1061,8 +1061,17 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> { None } + // Mark the given macro as unused unless its name starts with `_`. + // Macro uses will remove items from this set, and the remaining + // items will be reported as `unused_macros`. + fn insert_unused_macro(&mut self, ident: Ident, node_id: NodeId, span: Span) { + if !ident.as_str().starts_with("_") { + self.r.unused_macros.insert(node_id, span); + } + } + fn define_macro(&mut self, item: &ast::Item) -> LegacyScope<'a> { - let parent_scope = &self.parent_scope; + let parent_scope = self.parent_scope; let expansion = parent_scope.expansion; let (ext, ident, span, is_legacy) = match &item.kind { ItemKind::MacroDef(def) => { @@ -1102,7 +1111,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> { (res, vis, span, expansion, IsMacroExport)); } else { self.r.check_reserved_macro_name(ident, res); - self.r.unused_macros.insert(item.id, span); + self.insert_unused_macro(ident, item.id, span); } LegacyScope::Binding(self.r.arenas.alloc_legacy_binding(LegacyBinding { parent_legacy_scope: parent_scope.legacy, binding, ident @@ -1111,7 +1120,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> { let module = parent_scope.module; let vis = self.resolve_visibility(&item.vis); if vis != ty::Visibility::Public { - self.r.unused_macros.insert(item.id, span); + self.insert_unused_macro(ident, item.id, span); } self.r.define(module, ident, MacroNS, (res, vis, span, expansion)); self.parent_scope.legacy From 1270140c124a93ffdada2f2422560ea498f0e7e4 Mon Sep 17 00:00:00 2001 From: Vadim Petrochenkov Date: Thu, 10 Oct 2019 01:41:47 +0300 Subject: [PATCH 2/2] expand: Simplify expansion of derives And make it more uniform with other macros. By merging placeholders for future derives' outputs into the derive container's output fragment early. --- src/librustc/hir/map/def_collector.rs | 2 +- src/librustc_resolve/build_reduced_graph.rs | 10 ------- src/librustc_resolve/macros.rs | 8 ++--- src/libsyntax/ext/base.rs | 3 +- src/libsyntax/ext/expand.rs | 33 ++++++++++++++------- src/libsyntax/ext/placeholders.rs | 13 ++------ src/libsyntax/lib.rs | 1 + 7 files changed, 29 insertions(+), 41 deletions(-) diff --git a/src/librustc/hir/map/def_collector.rs b/src/librustc/hir/map/def_collector.rs index 1997e2aab35e8..ca6b2d03001ce 100644 --- a/src/librustc/hir/map/def_collector.rs +++ b/src/librustc/hir/map/def_collector.rs @@ -90,7 +90,7 @@ impl<'a> DefCollector<'a> { } } - pub fn visit_macro_invoc(&mut self, id: NodeId) { + fn visit_macro_invoc(&mut self, id: NodeId) { self.definitions.set_invocation_parent(id.placeholder_to_expn_id(), self.parent_def); } } diff --git a/src/librustc_resolve/build_reduced_graph.rs b/src/librustc_resolve/build_reduced_graph.rs index 47885e165fb98..6bc13d00f7200 100644 --- a/src/librustc_resolve/build_reduced_graph.rs +++ b/src/librustc_resolve/build_reduced_graph.rs @@ -161,25 +161,15 @@ impl<'a> Resolver<'a> { Some(ext) } - // FIXME: `extra_placeholders` should be included into the `fragment` as regular placeholders. crate fn build_reduced_graph( &mut self, fragment: &AstFragment, - extra_placeholders: &[NodeId], parent_scope: ParentScope<'a>, ) -> LegacyScope<'a> { let mut def_collector = DefCollector::new(&mut self.definitions, parent_scope.expansion); fragment.visit_with(&mut def_collector); - for placeholder in extra_placeholders { - def_collector.visit_macro_invoc(*placeholder); - } - let mut visitor = BuildReducedGraphVisitor { r: self, parent_scope }; fragment.visit_with(&mut visitor); - for placeholder in extra_placeholders { - visitor.parent_scope.legacy = visitor.visit_invoc(*placeholder); - } - visitor.parent_scope.legacy } diff --git a/src/librustc_resolve/macros.rs b/src/librustc_resolve/macros.rs index ae483354a40d3..de9f865393b64 100644 --- a/src/librustc_resolve/macros.rs +++ b/src/librustc_resolve/macros.rs @@ -107,15 +107,11 @@ impl<'a> base::Resolver for Resolver<'a> { }); } - // FIXME: `extra_placeholders` should be included into the `fragment` as regular placeholders. - fn visit_ast_fragment_with_placeholders( - &mut self, expansion: ExpnId, fragment: &AstFragment, extra_placeholders: &[NodeId] - ) { + fn visit_ast_fragment_with_placeholders(&mut self, expansion: ExpnId, fragment: &AstFragment) { // Integrate the new AST fragment into all the definition and module structures. // We are inside the `expansion` now, but other parent scope components are still the same. let parent_scope = ParentScope { expansion, ..self.invocation_parent_scopes[&expansion] }; - let output_legacy_scope = - self.build_reduced_graph(fragment, extra_placeholders, parent_scope); + let output_legacy_scope = self.build_reduced_graph(fragment, parent_scope); self.output_legacy_scopes.insert(expansion, output_legacy_scope); parent_scope.module.unexpanded_invocations.borrow_mut().remove(&expansion); diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs index 583fb3f770183..0bf21c45a347c 100644 --- a/src/libsyntax/ext/base.rs +++ b/src/libsyntax/ext/base.rs @@ -849,8 +849,7 @@ pub trait Resolver { fn next_node_id(&mut self) -> NodeId; fn resolve_dollar_crates(&mut self); - fn visit_ast_fragment_with_placeholders(&mut self, expn_id: ExpnId, fragment: &AstFragment, - extra_placeholders: &[NodeId]); + fn visit_ast_fragment_with_placeholders(&mut self, expn_id: ExpnId, fragment: &AstFragment); fn register_builtin_macro(&mut self, ident: ast::Ident, ext: SyntaxExtension); fn expansion_for_ast_pass( diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs index bbd8da2acef05..328311041bfc8 100644 --- a/src/libsyntax/ext/expand.rs +++ b/src/libsyntax/ext/expand.rs @@ -23,7 +23,6 @@ use errors::{Applicability, FatalError}; use smallvec::{smallvec, SmallVec}; use syntax_pos::{Span, DUMMY_SP, FileName}; -use rustc_data_structures::fx::FxHashMap; use rustc_data_structures::sync::Lrc; use std::io::ErrorKind; use std::{iter, mem, slice}; @@ -72,6 +71,22 @@ macro_rules! ast_fragments { } impl AstFragment { + pub fn add_placeholders(&mut self, placeholders: &[NodeId]) { + if placeholders.is_empty() { + return; + } + match self { + $($(AstFragment::$Kind(ast) => ast.extend(placeholders.iter().flat_map(|id| { + // We are repeating through arguments with `many`, to do that we have to + // mention some macro variable from those arguments even if it's not used. + #[cfg_attr(bootstrap, allow(unused_macros))] + macro _repeating($flat_map_ast_elt) {} + placeholder(AstFragmentKind::$Kind, *id).$make_ast() + })),)?)* + _ => panic!("unexpected AST fragment kind") + } + } + pub fn make_opt_expr(self) -> Option> { match self { AstFragment::OptExpr(expr) => expr, @@ -339,7 +354,6 @@ impl<'a, 'b> MacroExpander<'a, 'b> { // Unresolved macros produce dummy outputs as a recovery measure. invocations.reverse(); let mut expanded_fragments = Vec::new(); - let mut all_derive_placeholders: FxHashMap> = FxHashMap::default(); let mut undetermined_invocations = Vec::new(); let (mut progress, mut force) = (false, !self.monotonic); loop { @@ -416,9 +430,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> { self.cx.resolver.add_derives(invoc.expansion_data.id, SpecialDerives::COPY); } - let derive_placeholders = - all_derive_placeholders.entry(invoc.expansion_data.id).or_default(); - derive_placeholders.reserve(derives.len()); + let mut derive_placeholders = Vec::with_capacity(derives.len()); invocations.reserve(derives.len()); for path in derives { let expn_id = ExpnId::fresh(None); @@ -434,7 +446,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> { } let fragment = invoc.fragment_kind .expect_from_annotatables(::std::iter::once(item)); - self.collect_invocations(fragment, derive_placeholders) + self.collect_invocations(fragment, &derive_placeholders) } }; @@ -453,10 +465,8 @@ impl<'a, 'b> MacroExpander<'a, 'b> { let mut placeholder_expander = PlaceholderExpander::new(self.cx, self.monotonic); while let Some(expanded_fragments) = expanded_fragments.pop() { for (expn_id, expanded_fragment) in expanded_fragments.into_iter().rev() { - let derive_placeholders = - all_derive_placeholders.remove(&expn_id).unwrap_or_else(Vec::new); placeholder_expander.add(NodeId::placeholder_from_expn_id(expn_id), - expanded_fragment, derive_placeholders); + expanded_fragment); } } fragment_with_placeholders.mut_visit_with(&mut placeholder_expander); @@ -489,13 +499,14 @@ impl<'a, 'b> MacroExpander<'a, 'b> { monotonic: self.monotonic, }; fragment.mut_visit_with(&mut collector); + fragment.add_placeholders(extra_placeholders); collector.invocations }; - // FIXME: Merge `extra_placeholders` into the `fragment` as regular placeholders. if self.monotonic { self.cx.resolver.visit_ast_fragment_with_placeholders( - self.cx.current_expansion.id, &fragment, extra_placeholders); + self.cx.current_expansion.id, &fragment + ); } (fragment, invocations) diff --git a/src/libsyntax/ext/placeholders.rs b/src/libsyntax/ext/placeholders.rs index 8eecef1020d0a..6efd5397129dc 100644 --- a/src/libsyntax/ext/placeholders.rs +++ b/src/libsyntax/ext/placeholders.rs @@ -1,4 +1,4 @@ -use crate::ast::{self, NodeId}; +use crate::ast; use crate::source_map::{DUMMY_SP, dummy_spanned}; use crate::ext::base::ExtCtxt; use crate::ext::expand::{AstFragment, AstFragmentKind}; @@ -170,17 +170,8 @@ impl<'a, 'b> PlaceholderExpander<'a, 'b> { } } - pub fn add(&mut self, id: ast::NodeId, mut fragment: AstFragment, placeholders: Vec) { + pub fn add(&mut self, id: ast::NodeId, mut fragment: AstFragment) { fragment.mut_visit_with(self); - if let AstFragment::Items(mut items) = fragment { - for placeholder in placeholders { - match self.remove(placeholder) { - AstFragment::Items(derived_items) => items.extend(derived_items), - _ => unreachable!(), - } - } - fragment = AstFragment::Items(items); - } self.expanded_fragments.insert(id, fragment); } diff --git a/src/libsyntax/lib.rs b/src/libsyntax/lib.rs index d2c76b669dd5f..65611ae97285d 100644 --- a/src/libsyntax/lib.rs +++ b/src/libsyntax/lib.rs @@ -11,6 +11,7 @@ #![feature(const_fn)] #![feature(const_transmute)] #![feature(crate_visibility_modifier)] +#![feature(decl_macro)] #![feature(label_break_value)] #![feature(mem_take)] #![feature(nll)]