diff options
Diffstat (limited to 'compiler/rustc_resolve/src/ident.rs')
| -rw-r--r-- | compiler/rustc_resolve/src/ident.rs | 81 |
1 files changed, 36 insertions, 45 deletions
diff --git a/compiler/rustc_resolve/src/ident.rs b/compiler/rustc_resolve/src/ident.rs index 34941398a2b..f5bc46bf053 100644 --- a/compiler/rustc_resolve/src/ident.rs +++ b/compiler/rustc_resolve/src/ident.rs @@ -93,20 +93,21 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { // 6. Language prelude: builtin attributes (closed, controlled). let rust_2015 = ctxt.edition().is_rust_2015(); - let (ns, macro_kind, is_absolute_path) = match scope_set { - ScopeSet::All(ns) => (ns, None, false), - ScopeSet::AbsolutePath(ns) => (ns, None, true), - ScopeSet::Macro(macro_kind) => (MacroNS, Some(macro_kind), false), - ScopeSet::Late(ns, ..) => (ns, None, false), + let (ns, macro_kind) = match scope_set { + ScopeSet::All(ns) + | ScopeSet::ModuleAndExternPrelude(ns, _) + | ScopeSet::Late(ns, ..) => (ns, None), + ScopeSet::Macro(macro_kind) => (MacroNS, Some(macro_kind)), }; let module = match scope_set { // Start with the specified module. - ScopeSet::Late(_, module, _) => module, + ScopeSet::Late(_, 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 mut scope = match ns { - _ if is_absolute_path => Scope::CrateRoot, + _ if module_and_extern_prelude => Scope::Module(module, None), TypeNS | ValueNS => Scope::Module(module, None), MacroNS => Scope::DeriveHelpers(parent_scope.expansion), }; @@ -134,11 +135,10 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { } true } - Scope::CrateRoot => true, Scope::Module(..) => true, Scope::MacroUsePrelude => use_prelude || rust_2015, Scope::BuiltinAttrs => true, - Scope::ExternPrelude => use_prelude || is_absolute_path, + Scope::ExternPrelude => use_prelude || module_and_extern_prelude, Scope::ToolPrelude => use_prelude, Scope::StdLibPrelude => use_prelude || ns == MacroNS, Scope::BuiltinTypes => true, @@ -174,7 +174,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { } MacroRulesScope::Empty => Scope::Module(module, None), }, - Scope::CrateRoot => match ns { + Scope::Module(..) if module_and_extern_prelude => match ns { TypeNS => { ctxt.adjust(ExpnId::root()); Scope::ExternPrelude @@ -203,7 +203,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { } Scope::MacroUsePrelude => Scope::StdLibPrelude, Scope::BuiltinAttrs => break, // nowhere else to search - Scope::ExternPrelude if is_absolute_path => break, + Scope::ExternPrelude if module_and_extern_prelude => break, Scope::ExternPrelude => Scope::ToolPrelude, Scope::ToolPrelude => Scope::StdLibPrelude, Scope::StdLibPrelude => match ns { @@ -404,10 +404,10 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { } let (ns, macro_kind) = match scope_set { - ScopeSet::All(ns) => (ns, None), - ScopeSet::AbsolutePath(ns) => (ns, None), + ScopeSet::All(ns) + | ScopeSet::ModuleAndExternPrelude(ns, _) + | ScopeSet::Late(ns, ..) => (ns, None), ScopeSet::Macro(macro_kind) => (MacroNS, Some(macro_kind)), - ScopeSet::Late(ns, ..) => (ns, None), }; // This is *the* result, resolution from the scope closest to the resolved identifier. @@ -487,31 +487,16 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { MacroRulesScope::Invocation(_) => Err(Determinacy::Undetermined), _ => Err(Determinacy::Determined), }, - Scope::CrateRoot => { - let root_ident = Ident::new(kw::PathRoot, ident.span); - let root_module = this.resolve_crate_root(root_ident); - let binding = this.resolve_ident_in_module( - ModuleOrUniformRoot::Module(root_module), - ident, - ns, - parent_scope, - finalize, - ignore_binding, - ignore_import, - ); - match binding { - Ok(binding) => Ok((binding, Flags::MODULE | Flags::MISC_SUGGEST_CRATE)), - Err((Determinacy::Undetermined, Weak::No)) => { - return Some(Err(Determinacy::determined(force))); - } - Err((Determinacy::Undetermined, Weak::Yes)) => { - Err(Determinacy::Undetermined) - } - Err((Determinacy::Determined, _)) => Err(Determinacy::Determined), - } - } Scope::Module(module, derive_fallback_lint_id) => { - let adjusted_parent_scope = &ParentScope { module, ..*parent_scope }; + let (adjusted_parent_scope, finalize) = + if matches!(scope_set, ScopeSet::ModuleAndExternPrelude(..)) { + (parent_scope, finalize) + } else { + ( + &ParentScope { module, ..*parent_scope }, + finalize.map(|f| Finalize { used: Used::Scope, ..f }), + ) + }; let binding = this.resolve_ident_in_module_unadjusted( ModuleOrUniformRoot::Module(module), ident, @@ -522,7 +507,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { } else { Shadowing::Restricted }, - finalize.map(|finalize| Finalize { used: Used::Scope, ..finalize }), + finalize, ignore_binding, ignore_import, ); @@ -776,7 +761,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { ModuleOrUniformRoot::ExternPrelude => { ident.span.normalize_to_macros_2_0_and_adjust(ExpnId::root()); } - ModuleOrUniformRoot::CrateRootAndExternPrelude | ModuleOrUniformRoot::CurrentScope => { + ModuleOrUniformRoot::ModuleAndExternPrelude(..) | ModuleOrUniformRoot::CurrentScope => { // No adjustments } } @@ -810,11 +795,11 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { ) -> Result<NameBinding<'ra>, (Determinacy, Weak)> { let module = match module { ModuleOrUniformRoot::Module(module) => module, - ModuleOrUniformRoot::CrateRootAndExternPrelude => { + ModuleOrUniformRoot::ModuleAndExternPrelude(module) => { assert_eq!(shadowing, Shadowing::Unrestricted); let binding = self.early_resolve_ident_in_lexical_scope( ident, - ScopeSet::AbsolutePath(ns), + ScopeSet::ModuleAndExternPrelude(ns, module), parent_scope, finalize, finalize.is_some(), @@ -863,8 +848,13 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { }; let key = BindingKey::new(ident, ns); - let resolution = - self.resolution(module, key).try_borrow_mut().map_err(|_| (Determined, Weak::No))?; // This happens when there is a cycle of imports. + // `try_borrow_mut` is required to ensure exclusive access, even if the resulting binding + // doesn't need to be mutable. It will fail when there is a cycle of imports, and without + // the exclusive access infinite recursion will crash the compiler with stack overflow. + let resolution = &*self + .resolution_or_default(module, key) + .try_borrow_mut() + .map_err(|_| (Determined, Weak::No))?; // If the primary binding is unusable, search further and return the shadowed glob // binding if it exists. What we really want here is having two separate scopes in @@ -1531,7 +1521,8 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { && self.tcx.sess.at_least_rust_2018() { // `::a::b` from 2015 macro on 2018 global edition - module = Some(ModuleOrUniformRoot::CrateRootAndExternPrelude); + let crate_root = self.resolve_crate_root(ident); + module = Some(ModuleOrUniformRoot::ModuleAndExternPrelude(crate_root)); continue; } if name == kw::PathRoot || name == kw::Crate || name == kw::DollarCrate { |