diff options
Diffstat (limited to 'compiler/rustc_resolve/src/ident.rs')
| -rw-r--r-- | compiler/rustc_resolve/src/ident.rs | 205 |
1 files changed, 107 insertions, 98 deletions
diff --git a/compiler/rustc_resolve/src/ident.rs b/compiler/rustc_resolve/src/ident.rs index 87b3fc76c96..dae42645bec 100644 --- a/compiler/rustc_resolve/src/ident.rs +++ b/compiler/rustc_resolve/src/ident.rs @@ -19,7 +19,7 @@ use crate::{ AmbiguityError, AmbiguityErrorMisc, AmbiguityKind, BindingKey, CmResolver, Determinacy, Finalize, ImportKind, LexicalScopeBinding, Module, ModuleKind, ModuleOrUniformRoot, NameBinding, NameBindingKind, ParentScope, PathResult, PrivacyError, Res, ResolutionError, - Resolver, Scope, ScopeSet, Segment, Used, Weak, errors, + Resolver, Scope, ScopeSet, Segment, Stage, Used, Weak, errors, }; #[derive(Copy, Clone)] @@ -49,6 +49,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { scope_set: ScopeSet<'ra>, parent_scope: &ParentScope<'ra>, ctxt: SyntaxContext, + derive_fallback_lint_id: Option<NodeId>, mut visitor: impl FnMut( &mut CmResolver<'r, 'ra, 'tcx>, Scope<'ra>, @@ -99,20 +100,21 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { let rust_2015 = ctxt.edition().is_rust_2015(); let (ns, macro_kind) = match scope_set { - ScopeSet::All(ns) - | ScopeSet::ModuleAndExternPrelude(ns, _) - | ScopeSet::Late(ns, ..) => (ns, None), + ScopeSet::All(ns) | ScopeSet::ModuleAndExternPrelude(ns, _) => (ns, None), + ScopeSet::ExternPrelude => (TypeNS, None), ScopeSet::Macro(macro_kind) => (MacroNS, Some(macro_kind)), }; let module = match scope_set { // Start with the specified module. - ScopeSet::Late(_, module, _) | ScopeSet::ModuleAndExternPrelude(_, module) => module, + ScopeSet::ModuleAndExternPrelude(_, module) => module, // Jump out of trait or enum modules, they do not act as scopes. _ => parent_scope.module.nearest_item_scope(), }; let module_and_extern_prelude = matches!(scope_set, ScopeSet::ModuleAndExternPrelude(..)); + let extern_prelude = matches!(scope_set, ScopeSet::ExternPrelude); let mut scope = match ns { _ if module_and_extern_prelude => Scope::Module(module, None), + _ if extern_prelude => Scope::ExternPreludeItems, TypeNS | ValueNS => Scope::Module(module, None), MacroNS => Scope::DeriveHelpers(parent_scope.expansion), }; @@ -143,7 +145,9 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { Scope::Module(..) => true, Scope::MacroUsePrelude => use_prelude || rust_2015, Scope::BuiltinAttrs => true, - Scope::ExternPrelude => use_prelude || module_and_extern_prelude, + Scope::ExternPreludeItems | Scope::ExternPreludeFlags => { + use_prelude || module_and_extern_prelude || extern_prelude + } Scope::ToolPrelude => use_prelude, Scope::StdLibPrelude => use_prelude || ns == MacroNS, Scope::BuiltinTypes => true, @@ -182,16 +186,12 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { Scope::Module(..) if module_and_extern_prelude => match ns { TypeNS => { ctxt.adjust(ExpnId::root()); - Scope::ExternPrelude + Scope::ExternPreludeItems } ValueNS | MacroNS => break, }, Scope::Module(module, prev_lint_id) => { use_prelude = !module.no_implicit_prelude; - let derive_fallback_lint_id = match scope_set { - ScopeSet::Late(.., lint_id) => lint_id, - _ => None, - }; match self.hygienic_lexical_parent(module, &mut ctxt, derive_fallback_lint_id) { Some((parent_module, lint_id)) => { Scope::Module(parent_module, lint_id.or(prev_lint_id)) @@ -199,7 +199,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { None => { ctxt.adjust(ExpnId::root()); match ns { - TypeNS => Scope::ExternPrelude, + TypeNS => Scope::ExternPreludeItems, ValueNS => Scope::StdLibPrelude, MacroNS => Scope::MacroUsePrelude, } @@ -208,8 +208,9 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { } Scope::MacroUsePrelude => Scope::StdLibPrelude, Scope::BuiltinAttrs => break, // nowhere else to search - Scope::ExternPrelude if module_and_extern_prelude => break, - Scope::ExternPrelude => Scope::ToolPrelude, + Scope::ExternPreludeItems => Scope::ExternPreludeFlags, + Scope::ExternPreludeFlags if module_and_extern_prelude || extern_prelude => break, + Scope::ExternPreludeFlags => Scope::ToolPrelude, Scope::ToolPrelude => Scope::StdLibPrelude, Scope::StdLibPrelude => match ns { TypeNS => Scope::BuiltinTypes, @@ -312,7 +313,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { let normalized_ident = Ident { span: normalized_span, ..ident }; // Walk backwards up the ribs in scope. - let mut module = self.graph_root; for (i, rib) in ribs.iter().enumerate().rev() { debug!("walk rib\n{:?}", rib.bindings); // Use the rib kind to determine whether we are resolving parameters @@ -328,60 +328,54 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { *original_rib_ident_def, ribs, ))); + } else if let RibKind::Block(Some(module)) = rib.kind + && let Ok(binding) = self.cm().resolve_ident_in_module_unadjusted( + ModuleOrUniformRoot::Module(module), + ident, + ns, + parent_scope, + Shadowing::Unrestricted, + finalize.map(|finalize| Finalize { used: Used::Scope, ..finalize }), + ignore_binding, + None, + ) + { + // The ident resolves to an item in a block. + return Some(LexicalScopeBinding::Item(binding)); + } else if let RibKind::Module(module) = rib.kind { + // Encountered a module item, abandon ribs and look into that module and preludes. + let parent_scope = &ParentScope { module, ..*parent_scope }; + let finalize = finalize.map(|f| Finalize { stage: Stage::Late, ..f }); + return self + .cm() + .resolve_ident_in_scope_set( + orig_ident, + ScopeSet::All(ns), + parent_scope, + finalize, + finalize.is_some(), + ignore_binding, + None, + ) + .ok() + .map(LexicalScopeBinding::Item); } - module = match rib.kind { - RibKind::Module(module) => module, - RibKind::MacroDefinition(def) if def == self.macro_def(ident.span.ctxt()) => { - // If an invocation of this macro created `ident`, give up on `ident` - // and switch to `ident`'s source from the macro definition. - ident.span.remove_mark(); - continue; - } - _ => continue, - }; - - match module.kind { - ModuleKind::Block => {} // We can see through blocks - _ => break, - } - - let item = self.cm().resolve_ident_in_module_unadjusted( - ModuleOrUniformRoot::Module(module), - ident, - ns, - parent_scope, - Shadowing::Unrestricted, - finalize.map(|finalize| Finalize { used: Used::Scope, ..finalize }), - ignore_binding, - None, - ); - if let Ok(binding) = item { - // The ident resolves to an item. - return Some(LexicalScopeBinding::Item(binding)); + if let RibKind::MacroDefinition(def) = rib.kind + && def == self.macro_def(ident.span.ctxt()) + { + // If an invocation of this macro created `ident`, give up on `ident` + // and switch to `ident`'s source from the macro definition. + ident.span.remove_mark(); } } - self.cm() - .early_resolve_ident_in_lexical_scope( - orig_ident, - ScopeSet::Late(ns, module, finalize.map(|finalize| finalize.node_id)), - parent_scope, - finalize, - finalize.is_some(), - ignore_binding, - None, - ) - .ok() - .map(LexicalScopeBinding::Item) + + unreachable!() } - /// Resolve an identifier in lexical scope. - /// This is a variation of `fn resolve_ident_in_lexical_scope` that can be run during - /// expansion and import resolution (perhaps they can be merged in the future). - /// The function is used for resolving initial segments of macro paths (e.g., `foo` in - /// `foo::bar!();` or `foo!();`) and also for import paths on 2018 edition. + /// Resolve an identifier in the specified set of scopes. #[instrument(level = "debug", skip(self))] - pub(crate) fn early_resolve_ident_in_lexical_scope<'r>( + pub(crate) fn resolve_ident_in_scope_set<'r>( self: CmResolver<'r, 'ra, 'tcx>, orig_ident: Ident, scope_set: ScopeSet<'ra>, @@ -410,9 +404,8 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { } let (ns, macro_kind) = match scope_set { - ScopeSet::All(ns) - | ScopeSet::ModuleAndExternPrelude(ns, _) - | ScopeSet::Late(ns, ..) => (ns, None), + ScopeSet::All(ns) | ScopeSet::ModuleAndExternPrelude(ns, _) => (ns, None), + ScopeSet::ExternPrelude => (TypeNS, None), ScopeSet::Macro(macro_kind) => (MacroNS, Some(macro_kind)), }; @@ -429,12 +422,21 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { // to detect potential ambiguities. let mut innermost_result: Option<(NameBinding<'_>, Flags)> = None; let mut determinacy = Determinacy::Determined; + // Shadowed bindings don't need to be marked as used or non-speculatively loaded. + macro finalize_scope() { + if innermost_result.is_none() { finalize } else { None } + } // Go through all the scopes and try to resolve the name. + let derive_fallback_lint_id = match finalize { + Some(Finalize { node_id, stage: Stage::Late, .. }) => Some(node_id), + _ => None, + }; let break_result = self.visit_scopes( scope_set, parent_scope, orig_ident.span.ctxt(), + derive_fallback_lint_id, |this, scope, use_prelude, ctxt| { let ident = Ident::new(orig_ident.name, orig_ident.span.with_ctxt(ctxt)); let result = match scope { @@ -448,17 +450,12 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { } } Scope::DeriveHelpersCompat => { - // FIXME: Try running this logic earlier, to allocate name bindings for - // legacy derive helpers when creating an attribute invocation with - // following derives. Legacy derive helpers are not common, so it shouldn't - // affect performance. It should also allow to remove the `derives` - // component from `ParentScope`. let mut result = Err(Determinacy::Determined); for derive in parent_scope.derives { let parent_scope = &ParentScope { derives: &[], ..*parent_scope }; match this.reborrow().resolve_macro_path( derive, - Some(MacroKind::Derive), + MacroKind::Derive, parent_scope, true, force, @@ -494,7 +491,8 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { _ => Err(Determinacy::Determined), }, Scope::Module(module, derive_fallback_lint_id) => { - let (adjusted_parent_scope, finalize) = + // FIXME: use `finalize_scope` here. + let (adjusted_parent_scope, adjusted_finalize) = if matches!(scope_set, ScopeSet::ModuleAndExternPrelude(..)) { (parent_scope, finalize) } else { @@ -508,12 +506,8 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { ident, ns, adjusted_parent_scope, - if matches!(scope_set, ScopeSet::Late(..)) { - Shadowing::Unrestricted - } else { - Shadowing::Restricted - }, - finalize, + Shadowing::Restricted, + adjusted_finalize, ignore_binding, ignore_import, ); @@ -526,7 +520,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { orig_ident.span, BuiltinLintDiag::ProcMacroDeriveResolutionFallback { span: orig_ident.span, - ns, + ns_descr: ns.descr(), ident, }, ); @@ -561,14 +555,21 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { Some(binding) => Ok((*binding, Flags::empty())), None => Err(Determinacy::Determined), }, - Scope::ExternPrelude => { - match this.reborrow().extern_prelude_get(ident, finalize.is_some()) { + Scope::ExternPreludeItems => { + // FIXME: use `finalize_scope` here. + match this.reborrow().extern_prelude_get_item(ident, finalize.is_some()) { Some(binding) => Ok((binding, Flags::empty())), None => Err(Determinacy::determined( this.graph_root.unexpanded_invocations.borrow().is_empty(), )), } } + Scope::ExternPreludeFlags => { + match this.extern_prelude_get_flag(ident, finalize_scope!().is_some()) { + Some(binding) => Ok((binding, Flags::empty())), + None => Err(Determinacy::Determined), + } + } Scope::ToolPrelude => match this.registered_tool_bindings.get(&ident) { Some(binding) => Ok((*binding, Flags::empty())), None => Err(Determinacy::Determined), @@ -599,8 +600,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { if matches!(ident.name, sym::f16) && !this.tcx.features().f16() && !ident.span.allows_unstable(sym::f16) - && finalize.is_some() - && innermost_result.is_none() + && finalize_scope!().is_some() { feature_err( this.tcx.sess, @@ -613,8 +613,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { if matches!(ident.name, sym::f128) && !this.tcx.features().f128() && !ident.span.allows_unstable(sym::f128) - && finalize.is_some() - && innermost_result.is_none() + && finalize_scope!().is_some() { feature_err( this.tcx.sess, @@ -636,7 +635,11 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { return None; } - if finalize.is_none() || matches!(scope_set, ScopeSet::Late(..)) { + // Below we report various ambiguity errors. + // We do not need to report them if we are either in speculative resolution, + // or in late resolution when everything is already imported and expanded + // and no ambiguities exist. + if matches!(finalize, None | Some(Finalize { stage: Stage::Late, .. })) { return Some(Ok(binding)); } @@ -804,7 +807,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { ModuleOrUniformRoot::Module(module) => module, ModuleOrUniformRoot::ModuleAndExternPrelude(module) => { assert_eq!(shadowing, Shadowing::Unrestricted); - let binding = self.early_resolve_ident_in_lexical_scope( + let binding = self.resolve_ident_in_scope_set( ident, ScopeSet::ModuleAndExternPrelude(ns, module), parent_scope, @@ -819,15 +822,17 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { assert_eq!(shadowing, Shadowing::Unrestricted); return if ns != TypeNS { Err((Determined, Weak::No)) - } else if let Some(binding) = - self.reborrow().extern_prelude_get(ident, finalize.is_some()) - { - Ok(binding) - } else if !self.graph_root.unexpanded_invocations.borrow().is_empty() { - // Macro-expanded `extern crate` items can add names to extern prelude. - Err((Undetermined, Weak::No)) } else { - Err((Determined, Weak::No)) + let binding = self.resolve_ident_in_scope_set( + ident, + ScopeSet::ExternPrelude, + parent_scope, + finalize, + finalize.is_some(), + ignore_binding, + ignore_import, + ); + return binding.map_err(|determinacy| (determinacy, Weak::No)); }; } ModuleOrUniformRoot::CurrentScope => { @@ -843,7 +848,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { } } - let binding = self.early_resolve_ident_in_lexical_scope( + let binding = self.resolve_ident_in_scope_set( ident, ScopeSet::All(ns), parent_scope, @@ -936,7 +941,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { // Now we are in situation when new item/import can appear only from a glob or a macro // expansion. With restricted shadowing names from globs and macro expansions cannot // shadow names from outer scopes, so we can freely fallback from module search to search - // in outer scopes. For `early_resolve_ident_in_lexical_scope` to continue search in outer + // in outer scopes. For `resolve_ident_in_scope_set` to continue search in outer // scopes we return `Undetermined` with `Weak::Yes`. // Check if one of unexpanded macros can still define the name, @@ -1031,6 +1036,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { // Forbid expanded shadowing to avoid time travel. if let Some(shadowed_glob) = shadowed_glob && shadowing == Shadowing::Restricted + && finalize.stage == Stage::Early && binding.expansion != LocalExpnId::ROOT && binding.res() != shadowed_glob.res() { @@ -1157,6 +1163,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { for rib in ribs { match rib.kind { RibKind::Normal + | RibKind::Block(..) | RibKind::FnOrCoroutine | RibKind::Module(..) | RibKind::MacroDefinition(..) @@ -1249,6 +1256,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { for rib in ribs { let (has_generic_params, def_kind) = match rib.kind { RibKind::Normal + | RibKind::Block(..) | RibKind::FnOrCoroutine | RibKind::Module(..) | RibKind::MacroDefinition(..) @@ -1342,6 +1350,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { for rib in ribs { let (has_generic_params, def_kind) = match rib.kind { RibKind::Normal + | RibKind::Block(..) | RibKind::FnOrCoroutine | RibKind::Module(..) | RibKind::MacroDefinition(..) @@ -1623,7 +1632,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { _ => Err(Determinacy::determined(finalize.is_some())), } } else { - self.reborrow().early_resolve_ident_in_lexical_scope( + self.reborrow().resolve_ident_in_scope_set( ident, ScopeSet::All(ns), parent_scope, |