| use crate::{AmbiguityError, AmbiguityKind, AmbiguityErrorMisc}; |
| use crate::{CrateLint, Resolver, ResolutionError, ScopeSet, Weak}; |
| use crate::{Module, ModuleKind, NameBinding, NameBindingKind, PathResult, Segment, ToNameBinding}; |
| use crate::{is_known_tool, resolve_error}; |
| use crate::ModuleOrUniformRoot; |
| use crate::Namespace::*; |
| use crate::build_reduced_graph::{BuildReducedGraphVisitor, IsMacroExport}; |
| use crate::resolve_imports::ImportResolver; |
| use rustc::hir::def_id::{CrateNum, DefId, DefIndex, CRATE_DEF_INDEX}; |
| use rustc::hir::def::{self, DefKind, NonMacroAttrKind}; |
| use rustc::hir::map::{self, DefCollector}; |
| use rustc::{ty, lint}; |
| use rustc::{bug, span_bug}; |
| use syntax::ast::{self, Ident}; |
| use syntax::attr; |
| use syntax::errors::DiagnosticBuilder; |
| use syntax::ext::base::{self, Determinacy}; |
| use syntax::ext::base::{MacroKind, SyntaxExtension}; |
| use syntax::ext::expand::{AstFragment, Invocation, InvocationKind}; |
| use syntax::ext::hygiene::Mark; |
| use syntax::ext::tt::macro_rules; |
| use syntax::feature_gate::{ |
| feature_err, is_builtin_attr_name, AttributeGate, GateIssue, Stability, BUILTIN_ATTRIBUTES, |
| }; |
| use syntax::symbol::{Symbol, kw, sym}; |
| use syntax::visit::Visitor; |
| use syntax::util::lev_distance::find_best_match_for_name; |
| use syntax_pos::{Span, DUMMY_SP}; |
| use errors::Applicability; |
| |
| use std::cell::Cell; |
| use std::{mem, ptr}; |
| use rustc_data_structures::sync::Lrc; |
| |
| type Res = def::Res<ast::NodeId>; |
| |
| #[derive(Clone, Debug)] |
| pub struct InvocationData<'a> { |
| def_index: DefIndex, |
| /// The module in which the macro was invoked. |
| crate module: Cell<Module<'a>>, |
| /// The legacy scope in which the macro was invoked. |
| /// The invocation path is resolved in this scope. |
| crate parent_legacy_scope: Cell<LegacyScope<'a>>, |
| /// The legacy scope *produced* by expanding this macro invocation, |
| /// includes all the macro_rules items, other invocations, etc generated by it. |
| /// `None` if the macro is not expanded yet. |
| crate output_legacy_scope: Cell<Option<LegacyScope<'a>>>, |
| } |
| |
| impl<'a> InvocationData<'a> { |
| pub fn root(graph_root: Module<'a>) -> Self { |
| InvocationData { |
| module: Cell::new(graph_root), |
| def_index: CRATE_DEF_INDEX, |
| parent_legacy_scope: Cell::new(LegacyScope::Empty), |
| output_legacy_scope: Cell::new(Some(LegacyScope::Empty)), |
| } |
| } |
| } |
| |
| /// Binding produced by a `macro_rules` item. |
| /// Not modularized, can shadow previous legacy bindings, etc. |
| #[derive(Debug)] |
| pub struct LegacyBinding<'a> { |
| binding: &'a NameBinding<'a>, |
| /// Legacy scope into which the `macro_rules` item was planted. |
| parent_legacy_scope: LegacyScope<'a>, |
| ident: Ident, |
| } |
| |
| /// The scope introduced by a `macro_rules!` macro. |
| /// This starts at the macro's definition and ends at the end of the macro's parent |
| /// module (named or unnamed), or even further if it escapes with `#[macro_use]`. |
| /// Some macro invocations need to introduce legacy scopes too because they |
| /// can potentially expand into macro definitions. |
| #[derive(Copy, Clone, Debug)] |
| pub enum LegacyScope<'a> { |
| /// Created when invocation data is allocated in the arena; |
| /// must be replaced with a proper scope later. |
| Uninitialized, |
| /// Empty "root" scope at the crate start containing no names. |
| Empty, |
| /// The scope introduced by a `macro_rules!` macro definition. |
| Binding(&'a LegacyBinding<'a>), |
| /// The scope introduced by a macro invocation that can potentially |
| /// create a `macro_rules!` macro definition. |
| Invocation(&'a InvocationData<'a>), |
| } |
| |
| /// Everything you need to resolve a macro or import path. |
| #[derive(Clone, Debug)] |
| pub struct ParentScope<'a> { |
| crate module: Module<'a>, |
| crate expansion: Mark, |
| crate legacy: LegacyScope<'a>, |
| crate derives: Vec<ast::Path>, |
| } |
| |
| // Macro namespace is separated into two sub-namespaces, one for bang macros and |
| // one for attribute-like macros (attributes, derives). |
| // We ignore resolutions from one sub-namespace when searching names in scope for another. |
| fn sub_namespace_match(candidate: Option<MacroKind>, requirement: Option<MacroKind>) -> bool { |
| #[derive(PartialEq)] |
| enum SubNS { Bang, AttrLike } |
| let sub_ns = |kind| match kind { |
| MacroKind::Bang => Some(SubNS::Bang), |
| MacroKind::Attr | MacroKind::Derive => Some(SubNS::AttrLike), |
| MacroKind::ProcMacroStub => None, |
| }; |
| let requirement = requirement.and_then(|kind| sub_ns(kind)); |
| let candidate = candidate.and_then(|kind| sub_ns(kind)); |
| // "No specific sub-namespace" means "matches anything" for both requirements and candidates. |
| candidate.is_none() || requirement.is_none() || candidate == requirement |
| } |
| |
| impl<'a> base::Resolver for Resolver<'a> { |
| fn next_node_id(&mut self) -> ast::NodeId { |
| self.session.next_node_id() |
| } |
| |
| fn get_module_scope(&mut self, id: ast::NodeId) -> Mark { |
| let mark = Mark::fresh(Mark::root()); |
| let module = self.module_map[&self.definitions.local_def_id(id)]; |
| self.invocations.insert(mark, self.arenas.alloc_invocation_data(InvocationData { |
| module: Cell::new(module), |
| def_index: module.def_id().unwrap().index, |
| parent_legacy_scope: Cell::new(LegacyScope::Empty), |
| output_legacy_scope: Cell::new(Some(LegacyScope::Empty)), |
| })); |
| mark |
| } |
| |
| fn resolve_dollar_crates(&mut self, fragment: &AstFragment) { |
| struct ResolveDollarCrates<'a, 'b: 'a> { |
| resolver: &'a mut Resolver<'b> |
| } |
| impl<'a> Visitor<'a> for ResolveDollarCrates<'a, '_> { |
| fn visit_ident(&mut self, ident: Ident) { |
| if ident.name == kw::DollarCrate { |
| let name = match self.resolver.resolve_crate_root(ident).kind { |
| ModuleKind::Def(.., name) if name != kw::Invalid => name, |
| _ => kw::Crate, |
| }; |
| ident.span.ctxt().set_dollar_crate_name(name); |
| } |
| } |
| fn visit_mac(&mut self, _: &ast::Mac) {} |
| } |
| |
| fragment.visit_with(&mut ResolveDollarCrates { resolver: self }); |
| } |
| |
| fn visit_ast_fragment_with_placeholders(&mut self, mark: Mark, fragment: &AstFragment, |
| derives: &[Mark]) { |
| let invocation = self.invocations[&mark]; |
| self.collect_def_ids(mark, invocation, fragment); |
| |
| self.current_module = invocation.module.get(); |
| self.current_module.unresolved_invocations.borrow_mut().remove(&mark); |
| self.current_module.unresolved_invocations.borrow_mut().extend(derives); |
| self.invocations.extend(derives.iter().map(|&derive| (derive, invocation))); |
| let mut visitor = BuildReducedGraphVisitor { |
| resolver: self, |
| current_legacy_scope: invocation.parent_legacy_scope.get(), |
| expansion: mark, |
| }; |
| fragment.visit_with(&mut visitor); |
| invocation.output_legacy_scope.set(Some(visitor.current_legacy_scope)); |
| } |
| |
| fn add_builtin(&mut self, ident: ast::Ident, ext: Lrc<SyntaxExtension>) { |
| let def_id = DefId { |
| krate: CrateNum::BuiltinMacros, |
| index: DefIndex::from(self.macro_map.len()), |
| }; |
| let kind = ext.kind(); |
| self.macro_map.insert(def_id, ext); |
| let binding = self.arenas.alloc_name_binding(NameBinding { |
| kind: NameBindingKind::Res(Res::Def(DefKind::Macro(kind), def_id), false), |
| ambiguity: None, |
| span: DUMMY_SP, |
| vis: ty::Visibility::Public, |
| expansion: Mark::root(), |
| }); |
| if self.builtin_macros.insert(ident.name, binding).is_some() { |
| self.session.span_err(ident.span, |
| &format!("built-in macro `{}` was already defined", ident)); |
| } |
| } |
| |
| fn resolve_imports(&mut self) { |
| ImportResolver { resolver: self }.resolve_imports() |
| } |
| |
| fn resolve_macro_invocation(&mut self, invoc: &Invocation, invoc_id: Mark, force: bool) |
| -> Result<Option<Lrc<SyntaxExtension>>, Determinacy> { |
| let (path, kind, derives_in_scope, after_derive) = match invoc.kind { |
| InvocationKind::Attr { attr: None, .. } => |
| return Ok(None), |
| InvocationKind::Attr { attr: Some(ref attr), ref traits, after_derive, .. } => |
| (&attr.path, MacroKind::Attr, traits.clone(), after_derive), |
| InvocationKind::Bang { ref mac, .. } => |
| (&mac.node.path, MacroKind::Bang, Vec::new(), false), |
| InvocationKind::Derive { ref path, .. } => |
| (path, MacroKind::Derive, Vec::new(), false), |
| }; |
| |
| let parent_scope = self.invoc_parent_scope(invoc_id, derives_in_scope); |
| let (res, ext) = match self.resolve_macro_to_res(path, kind, &parent_scope, true, force) { |
| Ok((res, ext)) => (res, ext), |
| Err(Determinacy::Determined) if kind == MacroKind::Attr => { |
| // Replace unresolved attributes with used inert attributes for better recovery. |
| return Ok(Some(Lrc::new(SyntaxExtension::NonMacroAttr { mark_used: true }))); |
| } |
| Err(determinacy) => return Err(determinacy), |
| }; |
| |
| if let Res::Def(DefKind::Macro(_), def_id) = res { |
| if after_derive { |
| self.session.span_err(invoc.span(), |
| "macro attributes must be placed before `#[derive]`"); |
| } |
| self.macro_defs.insert(invoc.expansion_data.mark, def_id); |
| let normal_module_def_id = |
| self.macro_def_scope(invoc.expansion_data.mark).normal_ancestor_id; |
| self.definitions.add_parent_module_of_macro_def(invoc.expansion_data.mark, |
| normal_module_def_id); |
| invoc.expansion_data.mark.set_default_transparency(ext.default_transparency()); |
| } |
| |
| Ok(Some(ext)) |
| } |
| |
| fn resolve_macro_path(&mut self, path: &ast::Path, kind: MacroKind, invoc_id: Mark, |
| derives_in_scope: Vec<ast::Path>, force: bool) |
| -> Result<Lrc<SyntaxExtension>, Determinacy> { |
| let parent_scope = self.invoc_parent_scope(invoc_id, derives_in_scope); |
| Ok(self.resolve_macro_to_res(path, kind, &parent_scope, false, force)?.1) |
| } |
| |
| fn check_unused_macros(&self) { |
| for did in self.unused_macros.iter() { |
| let id_span = match *self.macro_map[did] { |
| SyntaxExtension::LegacyBang { def_info, .. } => def_info, |
| _ => None, |
| }; |
| if let Some((id, span)) = id_span { |
| let lint = lint::builtin::UNUSED_MACROS; |
| let msg = "unused macro definition"; |
| self.session.buffer_lint(lint, id, span, msg); |
| } else { |
| bug!("attempted to create unused macro error, but span not available"); |
| } |
| } |
| } |
| } |
| |
| impl<'a> Resolver<'a> { |
| pub fn dummy_parent_scope(&self) -> ParentScope<'a> { |
| self.invoc_parent_scope(Mark::root(), Vec::new()) |
| } |
| |
| fn invoc_parent_scope(&self, invoc_id: Mark, derives: Vec<ast::Path>) -> ParentScope<'a> { |
| let invoc = self.invocations[&invoc_id]; |
| ParentScope { |
| module: invoc.module.get().nearest_item_scope(), |
| expansion: invoc_id.parent(), |
| legacy: invoc.parent_legacy_scope.get(), |
| derives, |
| } |
| } |
| |
| fn resolve_macro_to_res( |
| &mut self, |
| path: &ast::Path, |
| kind: MacroKind, |
| parent_scope: &ParentScope<'a>, |
| trace: bool, |
| force: bool, |
| ) -> Result<(Res, Lrc<SyntaxExtension>), Determinacy> { |
| let res = self.resolve_macro_to_res_inner(path, kind, parent_scope, trace, force); |
| |
| // Report errors and enforce feature gates for the resolved macro. |
| if res != Err(Determinacy::Undetermined) { |
| // Do not report duplicated errors on every undetermined resolution. |
| for segment in &path.segments { |
| if let Some(args) = &segment.args { |
| self.session.span_err(args.span(), "generic arguments in macro path"); |
| } |
| } |
| } |
| |
| let res = res?; |
| |
| match res { |
| Res::Def(DefKind::Macro(macro_kind), def_id) => { |
| self.unused_macros.remove(&def_id); |
| if macro_kind == MacroKind::ProcMacroStub { |
| let msg = "can't use a procedural macro from the same crate that defines it"; |
| self.session.span_err(path.span, msg); |
| return Err(Determinacy::Determined); |
| } |
| } |
| Res::NonMacroAttr(attr_kind) => { |
| if kind == MacroKind::Attr { |
| let features = self.session.features_untracked(); |
| if attr_kind == NonMacroAttrKind::Custom { |
| assert!(path.segments.len() == 1); |
| let name = path.segments[0].ident.as_str(); |
| if name.starts_with("rustc_") { |
| if !features.rustc_attrs { |
| let msg = "unless otherwise specified, attributes with the prefix \ |
| `rustc_` are reserved for internal compiler diagnostics"; |
| self.report_unknown_attribute(path.span, &name, msg, |
| sym::rustc_attrs); |
| } |
| } else if !features.custom_attribute { |
| let msg = format!("The attribute `{}` is currently unknown to the \ |
| compiler and may have meaning added to it in the \ |
| future", path); |
| self.report_unknown_attribute( |
| path.span, |
| &name, |
| &msg, |
| sym::custom_attribute, |
| ); |
| } |
| } |
| } else { |
| // Not only attributes, but anything in macro namespace can result in |
| // `Res::NonMacroAttr` definition (e.g., `inline!()`), so we must report |
| // an error for those cases. |
| let msg = format!("expected a macro, found {}", res.descr()); |
| self.session.span_err(path.span, &msg); |
| return Err(Determinacy::Determined); |
| } |
| } |
| Res::Err => { |
| return Err(Determinacy::Determined); |
| } |
| _ => panic!("expected `DefKind::Macro` or `Res::NonMacroAttr`"), |
| } |
| |
| Ok((res, self.get_macro(res))) |
| } |
| |
| fn report_unknown_attribute(&self, span: Span, name: &str, msg: &str, feature: Symbol) { |
| let mut err = feature_err( |
| &self.session.parse_sess, |
| feature, |
| span, |
| GateIssue::Language, |
| &msg, |
| ); |
| |
| let features = self.session.features_untracked(); |
| |
| let attr_candidates = BUILTIN_ATTRIBUTES |
| .iter() |
| .filter_map(|&(name, _, _, ref gate)| { |
| if name.as_str().starts_with("rustc_") && !features.rustc_attrs { |
| return None; |
| } |
| |
| match gate { |
| AttributeGate::Gated(Stability::Unstable, ..) |
| if self.session.opts.unstable_features.is_nightly_build() => |
| { |
| Some(name) |
| } |
| AttributeGate::Gated(Stability::Deprecated(..), ..) => Some(name), |
| AttributeGate::Ungated => Some(name), |
| _ => None, |
| } |
| }) |
| .chain( |
| // Add built-in macro attributes as well. |
| self.builtin_macros.iter().filter_map(|(name, binding)| { |
| match binding.macro_kind() { |
| Some(MacroKind::Attr) => Some(*name), |
| _ => None, |
| } |
| }), |
| ) |
| .collect::<Vec<_>>(); |
| |
| let lev_suggestion = find_best_match_for_name(attr_candidates.iter(), &name, None); |
| |
| if let Some(suggestion) = lev_suggestion { |
| err.span_suggestion( |
| span, |
| "a built-in attribute with a similar name exists", |
| suggestion.to_string(), |
| Applicability::MaybeIncorrect, |
| ); |
| } |
| |
| err.emit(); |
| } |
| |
| pub fn resolve_macro_to_res_inner( |
| &mut self, |
| path: &ast::Path, |
| kind: MacroKind, |
| parent_scope: &ParentScope<'a>, |
| trace: bool, |
| force: bool, |
| ) -> Result<Res, Determinacy> { |
| let path_span = path.span; |
| let mut path = Segment::from_path(path); |
| |
| // Possibly apply the macro helper hack |
| if kind == MacroKind::Bang && path.len() == 1 && |
| path[0].ident.span.ctxt().outer_expn_info() |
| .map_or(false, |info| info.local_inner_macros) { |
| let root = Ident::new(kw::DollarCrate, path[0].ident.span); |
| path.insert(0, Segment::from_ident(root)); |
| } |
| |
| if path.len() > 1 { |
| let res = match self.resolve_path(&path, Some(MacroNS), parent_scope, |
| false, path_span, CrateLint::No) { |
| PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 => { |
| Ok(path_res.base_res()) |
| } |
| PathResult::Indeterminate if !force => return Err(Determinacy::Undetermined), |
| PathResult::NonModule(..) |
| | PathResult::Indeterminate |
| | PathResult::Failed { .. } => Err(Determinacy::Determined), |
| PathResult::Module(..) => unreachable!(), |
| }; |
| |
| if trace { |
| parent_scope.module.multi_segment_macro_resolutions.borrow_mut() |
| .push((path, path_span, kind, parent_scope.clone(), res.ok())); |
| } |
| |
| self.prohibit_imported_non_macro_attrs(None, res.ok(), path_span); |
| res |
| } else { |
| let binding = self.early_resolve_ident_in_lexical_scope( |
| path[0].ident, ScopeSet::Macro(kind), parent_scope, false, force, path_span |
| ); |
| if let Err(Determinacy::Undetermined) = binding { |
| return Err(Determinacy::Undetermined); |
| } |
| |
| if trace { |
| parent_scope.module.single_segment_macro_resolutions.borrow_mut() |
| .push((path[0].ident, kind, parent_scope.clone(), binding.ok())); |
| } |
| |
| let res = binding.map(|binding| binding.res()); |
| self.prohibit_imported_non_macro_attrs(binding.ok(), res.ok(), path_span); |
| res |
| } |
| } |
| |
| // 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. |
| crate fn early_resolve_ident_in_lexical_scope( |
| &mut self, |
| orig_ident: Ident, |
| scope_set: ScopeSet, |
| parent_scope: &ParentScope<'a>, |
| record_used: bool, |
| force: bool, |
| path_span: Span, |
| ) -> Result<&'a NameBinding<'a>, Determinacy> { |
| // General principles: |
| // 1. Not controlled (user-defined) names should have higher priority than controlled names |
| // built into the language or standard library. This way we can add new names into the |
| // language or standard library without breaking user code. |
| // 2. "Closed set" below means new names cannot appear after the current resolution attempt. |
| // Places to search (in order of decreasing priority): |
| // (Type NS) |
| // 1. FIXME: Ribs (type parameters), there's no necessary infrastructure yet |
| // (open set, not controlled). |
| // 2. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents |
| // (open, not controlled). |
| // 3. Extern prelude (closed, not controlled). |
| // 4. Tool modules (closed, controlled right now, but not in the future). |
| // 5. Standard library prelude (de-facto closed, controlled). |
| // 6. Language prelude (closed, controlled). |
| // (Value NS) |
| // 1. FIXME: Ribs (local variables), there's no necessary infrastructure yet |
| // (open set, not controlled). |
| // 2. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents |
| // (open, not controlled). |
| // 3. Standard library prelude (de-facto closed, controlled). |
| // (Macro NS) |
| // 1-3. Derive helpers (open, not controlled). All ambiguities with other names |
| // are currently reported as errors. They should be higher in priority than preludes |
| // and probably even names in modules according to the "general principles" above. They |
| // also should be subject to restricted shadowing because are effectively produced by |
| // derives (you need to resolve the derive first to add helpers into scope), but they |
| // should be available before the derive is expanded for compatibility. |
| // It's mess in general, so we are being conservative for now. |
| // 1-3. `macro_rules` (open, not controlled), loop through legacy scopes. Have higher |
| // priority than prelude macros, but create ambiguities with macros in modules. |
| // 1-3. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents |
| // (open, not controlled). Have higher priority than prelude macros, but create |
| // ambiguities with `macro_rules`. |
| // 4. `macro_use` prelude (open, the open part is from macro expansions, not controlled). |
| // 4a. User-defined prelude from macro-use |
| // (open, the open part is from macro expansions, not controlled). |
| // 4b. Standard library prelude is currently implemented as `macro-use` (closed, controlled) |
| // 5. Language prelude: builtin macros (closed, controlled, except for legacy plugins). |
| // 6. Language prelude: builtin attributes (closed, controlled). |
| // 4-6. Legacy plugin helpers (open, not controlled). Similar to derive helpers, |
| // but introduced by legacy plugins using `register_attribute`. Priority is somewhere |
| // in prelude, not sure where exactly (creates ambiguities with any other prelude names). |
| |
| enum WhereToResolve<'a> { |
| DeriveHelpers, |
| MacroRules(LegacyScope<'a>), |
| CrateRoot, |
| Module(Module<'a>), |
| MacroUsePrelude, |
| BuiltinMacros, |
| BuiltinAttrs, |
| LegacyPluginHelpers, |
| ExternPrelude, |
| ToolPrelude, |
| StdLibPrelude, |
| BuiltinTypes, |
| } |
| |
| bitflags::bitflags! { |
| struct Flags: u8 { |
| const MACRO_RULES = 1 << 0; |
| const MODULE = 1 << 1; |
| const PRELUDE = 1 << 2; |
| const MISC_SUGGEST_CRATE = 1 << 3; |
| const MISC_SUGGEST_SELF = 1 << 4; |
| const MISC_FROM_PRELUDE = 1 << 5; |
| } |
| } |
| |
| assert!(force || !record_used); // `record_used` implies `force` |
| let mut ident = orig_ident.modern(); |
| |
| // Make sure `self`, `super` etc produce an error when passed to here. |
| if ident.is_path_segment_keyword() { |
| return Err(Determinacy::Determined); |
| } |
| |
| // This is *the* result, resolution from the scope closest to the resolved identifier. |
| // However, sometimes this result is "weak" because it comes from a glob import or |
| // a macro expansion, and in this case it cannot shadow names from outer scopes, e.g. |
| // mod m { ... } // solution in outer scope |
| // { |
| // use prefix::*; // imports another `m` - innermost solution |
| // // weak, cannot shadow the outer `m`, need to report ambiguity error |
| // m::mac!(); |
| // } |
| // So we have to save the innermost solution and continue searching in outer scopes |
| // to detect potential ambiguities. |
| let mut innermost_result: Option<(&NameBinding<'_>, Flags)> = None; |
| |
| // Go through all the scopes and try to resolve the name. |
| let rust_2015 = orig_ident.span.rust_2015(); |
| let (ns, macro_kind, is_import, is_absolute_path) = match scope_set { |
| ScopeSet::Import(ns) => (ns, None, true, false), |
| ScopeSet::AbsolutePath(ns) => (ns, None, false, true), |
| ScopeSet::Macro(macro_kind) => (MacroNS, Some(macro_kind), false, false), |
| ScopeSet::Module => (TypeNS, None, false, false), |
| }; |
| let mut where_to_resolve = match ns { |
| _ if is_absolute_path => WhereToResolve::CrateRoot, |
| TypeNS | ValueNS => WhereToResolve::Module(parent_scope.module), |
| MacroNS => WhereToResolve::DeriveHelpers, |
| }; |
| let mut use_prelude = !parent_scope.module.no_implicit_prelude; |
| let mut determinacy = Determinacy::Determined; |
| loop { |
| let result = match where_to_resolve { |
| WhereToResolve::DeriveHelpers => { |
| let mut result = Err(Determinacy::Determined); |
| for derive in &parent_scope.derives { |
| let parent_scope = ParentScope { derives: Vec::new(), ..*parent_scope }; |
| match self.resolve_macro_to_res(derive, MacroKind::Derive, |
| &parent_scope, true, force) { |
| Ok((_, ext)) => { |
| if let SyntaxExtension::Derive(_, helpers, _) = &*ext { |
| if helpers.contains(&ident.name) { |
| let binding = |
| (Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper), |
| ty::Visibility::Public, derive.span, Mark::root()) |
| .to_name_binding(self.arenas); |
| result = Ok((binding, Flags::empty())); |
| break; |
| } |
| } |
| } |
| Err(Determinacy::Determined) => {} |
| Err(Determinacy::Undetermined) => |
| result = Err(Determinacy::Undetermined), |
| } |
| } |
| result |
| } |
| WhereToResolve::MacroRules(legacy_scope) => match legacy_scope { |
| LegacyScope::Binding(legacy_binding) if ident == legacy_binding.ident => |
| Ok((legacy_binding.binding, Flags::MACRO_RULES)), |
| LegacyScope::Invocation(invoc) if invoc.output_legacy_scope.get().is_none() => |
| Err(Determinacy::Undetermined), |
| _ => Err(Determinacy::Determined), |
| } |
| WhereToResolve::CrateRoot => { |
| let root_ident = Ident::new(kw::PathRoot, orig_ident.span); |
| let root_module = self.resolve_crate_root(root_ident); |
| let binding = self.resolve_ident_in_module_ext( |
| ModuleOrUniformRoot::Module(root_module), |
| orig_ident, |
| ns, |
| None, |
| record_used, |
| path_span, |
| ); |
| match binding { |
| Ok(binding) => Ok((binding, Flags::MODULE | Flags::MISC_SUGGEST_CRATE)), |
| Err((Determinacy::Undetermined, Weak::No)) => |
| return Err(Determinacy::determined(force)), |
| Err((Determinacy::Undetermined, Weak::Yes)) => |
| Err(Determinacy::Undetermined), |
| Err((Determinacy::Determined, _)) => Err(Determinacy::Determined), |
| } |
| } |
| WhereToResolve::Module(module) => { |
| let orig_current_module = mem::replace(&mut self.current_module, module); |
| let binding = self.resolve_ident_in_module_unadjusted_ext( |
| ModuleOrUniformRoot::Module(module), |
| ident, |
| ns, |
| None, |
| true, |
| record_used, |
| path_span, |
| ); |
| self.current_module = orig_current_module; |
| match binding { |
| Ok(binding) => { |
| let misc_flags = if ptr::eq(module, self.graph_root) { |
| Flags::MISC_SUGGEST_CRATE |
| } else if module.is_normal() { |
| Flags::MISC_SUGGEST_SELF |
| } else { |
| Flags::empty() |
| }; |
| Ok((binding, Flags::MODULE | misc_flags)) |
| } |
| Err((Determinacy::Undetermined, Weak::No)) => |
| return Err(Determinacy::determined(force)), |
| Err((Determinacy::Undetermined, Weak::Yes)) => |
| Err(Determinacy::Undetermined), |
| Err((Determinacy::Determined, _)) => Err(Determinacy::Determined), |
| } |
| } |
| WhereToResolve::MacroUsePrelude => { |
| if use_prelude || rust_2015 { |
| match self.macro_use_prelude.get(&ident.name).cloned() { |
| Some(binding) => |
| Ok((binding, Flags::PRELUDE | Flags::MISC_FROM_PRELUDE)), |
| None => Err(Determinacy::determined( |
| self.graph_root.unresolved_invocations.borrow().is_empty() |
| )) |
| } |
| } else { |
| Err(Determinacy::Determined) |
| } |
| } |
| WhereToResolve::BuiltinMacros => { |
| match self.builtin_macros.get(&ident.name).cloned() { |
| Some(binding) => Ok((binding, Flags::PRELUDE)), |
| None => Err(Determinacy::Determined), |
| } |
| } |
| WhereToResolve::BuiltinAttrs => { |
| if is_builtin_attr_name(ident.name) { |
| let binding = (Res::NonMacroAttr(NonMacroAttrKind::Builtin), |
| ty::Visibility::Public, DUMMY_SP, Mark::root()) |
| .to_name_binding(self.arenas); |
| Ok((binding, Flags::PRELUDE)) |
| } else { |
| Err(Determinacy::Determined) |
| } |
| } |
| WhereToResolve::LegacyPluginHelpers => { |
| if (use_prelude || rust_2015) && |
| self.session.plugin_attributes.borrow().iter() |
| .any(|(name, _)| ident.name == *name) { |
| let binding = (Res::NonMacroAttr(NonMacroAttrKind::LegacyPluginHelper), |
| ty::Visibility::Public, DUMMY_SP, Mark::root()) |
| .to_name_binding(self.arenas); |
| Ok((binding, Flags::PRELUDE)) |
| } else { |
| Err(Determinacy::Determined) |
| } |
| } |
| WhereToResolve::ExternPrelude => { |
| if use_prelude || is_absolute_path { |
| match self.extern_prelude_get(ident, !record_used) { |
| Some(binding) => Ok((binding, Flags::PRELUDE)), |
| None => Err(Determinacy::determined( |
| self.graph_root.unresolved_invocations.borrow().is_empty() |
| )), |
| } |
| } else { |
| Err(Determinacy::Determined) |
| } |
| } |
| WhereToResolve::ToolPrelude => { |
| if use_prelude && is_known_tool(ident.name) { |
| let binding = (Res::ToolMod, ty::Visibility::Public, |
| DUMMY_SP, Mark::root()).to_name_binding(self.arenas); |
| Ok((binding, Flags::PRELUDE)) |
| } else { |
| Err(Determinacy::Determined) |
| } |
| } |
| WhereToResolve::StdLibPrelude => { |
| let mut result = Err(Determinacy::Determined); |
| if use_prelude { |
| if let Some(prelude) = self.prelude { |
| if let Ok(binding) = self.resolve_ident_in_module_unadjusted( |
| ModuleOrUniformRoot::Module(prelude), |
| ident, |
| ns, |
| false, |
| path_span, |
| ) { |
| result = Ok((binding, Flags::PRELUDE | Flags::MISC_FROM_PRELUDE)); |
| } |
| } |
| } |
| result |
| } |
| WhereToResolve::BuiltinTypes => { |
| match self.primitive_type_table.primitive_types.get(&ident.name).cloned() { |
| Some(prim_ty) => { |
| let binding = (Res::PrimTy(prim_ty), ty::Visibility::Public, |
| DUMMY_SP, Mark::root()).to_name_binding(self.arenas); |
| Ok((binding, Flags::PRELUDE)) |
| } |
| None => Err(Determinacy::Determined) |
| } |
| } |
| }; |
| |
| match result { |
| Ok((binding, flags)) if sub_namespace_match(binding.macro_kind(), macro_kind) => { |
| if !record_used { |
| return Ok(binding); |
| } |
| |
| if let Some((innermost_binding, innermost_flags)) = innermost_result { |
| // Found another solution, if the first one was "weak", report an error. |
| let (res, innermost_res) = (binding.res(), innermost_binding.res()); |
| if res != innermost_res { |
| let builtin = Res::NonMacroAttr(NonMacroAttrKind::Builtin); |
| let derive_helper = Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper); |
| let legacy_helper = |
| Res::NonMacroAttr(NonMacroAttrKind::LegacyPluginHelper); |
| |
| let ambiguity_error_kind = if is_import { |
| Some(AmbiguityKind::Import) |
| } else if innermost_res == builtin || res == builtin { |
| Some(AmbiguityKind::BuiltinAttr) |
| } else if innermost_res == derive_helper || res == derive_helper { |
| Some(AmbiguityKind::DeriveHelper) |
| } else if innermost_res == legacy_helper && |
| flags.contains(Flags::PRELUDE) || |
| res == legacy_helper && |
| innermost_flags.contains(Flags::PRELUDE) { |
| Some(AmbiguityKind::LegacyHelperVsPrelude) |
| } else if innermost_flags.contains(Flags::MACRO_RULES) && |
| flags.contains(Flags::MODULE) && |
| !self.disambiguate_legacy_vs_modern(innermost_binding, |
| binding) || |
| flags.contains(Flags::MACRO_RULES) && |
| innermost_flags.contains(Flags::MODULE) && |
| !self.disambiguate_legacy_vs_modern(binding, |
| innermost_binding) { |
| Some(AmbiguityKind::LegacyVsModern) |
| } else if innermost_binding.is_glob_import() { |
| Some(AmbiguityKind::GlobVsOuter) |
| } else if innermost_binding.may_appear_after(parent_scope.expansion, |
| binding) { |
| Some(AmbiguityKind::MoreExpandedVsOuter) |
| } else { |
| None |
| }; |
| if let Some(kind) = ambiguity_error_kind { |
| let misc = |f: Flags| if f.contains(Flags::MISC_SUGGEST_CRATE) { |
| AmbiguityErrorMisc::SuggestCrate |
| } else if f.contains(Flags::MISC_SUGGEST_SELF) { |
| AmbiguityErrorMisc::SuggestSelf |
| } else if f.contains(Flags::MISC_FROM_PRELUDE) { |
| AmbiguityErrorMisc::FromPrelude |
| } else { |
| AmbiguityErrorMisc::None |
| }; |
| self.ambiguity_errors.push(AmbiguityError { |
| kind, |
| ident: orig_ident, |
| b1: innermost_binding, |
| b2: binding, |
| misc1: misc(innermost_flags), |
| misc2: misc(flags), |
| }); |
| return Ok(innermost_binding); |
| } |
| } |
| } else { |
| // Found the first solution. |
| innermost_result = Some((binding, flags)); |
| } |
| } |
| Ok(..) | Err(Determinacy::Determined) => {} |
| Err(Determinacy::Undetermined) => determinacy = Determinacy::Undetermined |
| } |
| |
| where_to_resolve = match where_to_resolve { |
| WhereToResolve::DeriveHelpers => |
| WhereToResolve::MacroRules(parent_scope.legacy), |
| WhereToResolve::MacroRules(legacy_scope) => match legacy_scope { |
| LegacyScope::Binding(binding) => WhereToResolve::MacroRules( |
| binding.parent_legacy_scope |
| ), |
| LegacyScope::Invocation(invoc) => WhereToResolve::MacroRules( |
| invoc.output_legacy_scope.get().unwrap_or(invoc.parent_legacy_scope.get()) |
| ), |
| LegacyScope::Empty => WhereToResolve::Module(parent_scope.module), |
| LegacyScope::Uninitialized => unreachable!(), |
| } |
| WhereToResolve::CrateRoot => match ns { |
| TypeNS => { |
| ident.span.adjust(Mark::root()); |
| WhereToResolve::ExternPrelude |
| } |
| ValueNS | MacroNS => break, |
| } |
| WhereToResolve::Module(module) => { |
| match self.hygienic_lexical_parent(module, &mut ident.span) { |
| Some(parent_module) => WhereToResolve::Module(parent_module), |
| None => { |
| use_prelude = !module.no_implicit_prelude; |
| match ns { |
| TypeNS => WhereToResolve::ExternPrelude, |
| ValueNS => WhereToResolve::StdLibPrelude, |
| MacroNS => WhereToResolve::MacroUsePrelude, |
| } |
| } |
| } |
| } |
| WhereToResolve::MacroUsePrelude => WhereToResolve::BuiltinMacros, |
| WhereToResolve::BuiltinMacros => WhereToResolve::BuiltinAttrs, |
| WhereToResolve::BuiltinAttrs => WhereToResolve::LegacyPluginHelpers, |
| WhereToResolve::LegacyPluginHelpers => break, // nowhere else to search |
| WhereToResolve::ExternPrelude if is_absolute_path => break, |
| WhereToResolve::ExternPrelude => WhereToResolve::ToolPrelude, |
| WhereToResolve::ToolPrelude => WhereToResolve::StdLibPrelude, |
| WhereToResolve::StdLibPrelude => match ns { |
| TypeNS => WhereToResolve::BuiltinTypes, |
| ValueNS => break, // nowhere else to search |
| MacroNS => unreachable!(), |
| } |
| WhereToResolve::BuiltinTypes => break, // nowhere else to search |
| }; |
| |
| continue; |
| } |
| |
| // The first found solution was the only one, return it. |
| if let Some((binding, _)) = innermost_result { |
| return Ok(binding); |
| } |
| |
| let determinacy = Determinacy::determined(determinacy == Determinacy::Determined || force); |
| if determinacy == Determinacy::Determined && macro_kind == Some(MacroKind::Attr) { |
| // For single-segment attributes interpret determinate "no resolution" as a custom |
| // attribute. (Lexical resolution implies the first segment and attr kind should imply |
| // the last segment, so we are certainly working with a single-segment attribute here.) |
| assert!(ns == MacroNS); |
| let binding = (Res::NonMacroAttr(NonMacroAttrKind::Custom), |
| ty::Visibility::Public, ident.span, Mark::root()) |
| .to_name_binding(self.arenas); |
| Ok(binding) |
| } else { |
| Err(determinacy) |
| } |
| } |
| |
| pub fn finalize_current_module_macro_resolutions(&mut self) { |
| let module = self.current_module; |
| |
| let check_consistency = |this: &mut Self, path: &[Segment], span, kind: MacroKind, |
| initial_res: Option<Res>, res: Res| { |
| if let Some(initial_res) = initial_res { |
| if res != initial_res && res != Res::Err && this.ambiguity_errors.is_empty() { |
| // Make sure compilation does not succeed if preferred macro resolution |
| // has changed after the macro had been expanded. In theory all such |
| // situations should be reported as ambiguity errors, so this is a bug. |
| if initial_res == Res::NonMacroAttr(NonMacroAttrKind::Custom) { |
| // Yeah, legacy custom attributes are implemented using forced resolution |
| // (which is a best effort error recovery tool, basically), so we can't |
| // promise their resolution won't change later. |
| let msg = format!("inconsistent resolution for a macro: first {}, then {}", |
| initial_res.descr(), res.descr()); |
| this.session.span_err(span, &msg); |
| } else { |
| span_bug!(span, "inconsistent resolution for a macro"); |
| } |
| } |
| } else { |
| // It's possible that the macro was unresolved (indeterminate) and silently |
| // expanded into a dummy fragment for recovery during expansion. |
| // Now, post-expansion, the resolution may succeed, but we can't change the |
| // past and need to report an error. |
| // However, non-speculative `resolve_path` can successfully return private items |
| // even if speculative `resolve_path` returned nothing previously, so we skip this |
| // less informative error if the privacy error is reported elsewhere. |
| if this.privacy_errors.is_empty() { |
| let msg = format!("cannot determine resolution for the {} `{}`", |
| kind.descr(), Segment::names_to_string(path)); |
| let msg_note = "import resolution is stuck, try simplifying macro imports"; |
| this.session.struct_span_err(span, &msg).note(msg_note).emit(); |
| } |
| } |
| }; |
| |
| let macro_resolutions = |
| mem::replace(&mut *module.multi_segment_macro_resolutions.borrow_mut(), Vec::new()); |
| for (mut path, path_span, kind, parent_scope, initial_res) in macro_resolutions { |
| // FIXME: Path resolution will ICE if segment IDs present. |
| for seg in &mut path { seg.id = None; } |
| match self.resolve_path(&path, Some(MacroNS), &parent_scope, |
| true, path_span, CrateLint::No) { |
| PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 => { |
| let res = path_res.base_res(); |
| check_consistency(self, &path, path_span, kind, initial_res, res); |
| } |
| path_res @ PathResult::NonModule(..) | path_res @ PathResult::Failed { .. } => { |
| let (span, label) = if let PathResult::Failed { span, label, .. } = path_res { |
| (span, label) |
| } else { |
| (path_span, format!("partially resolved path in {} {}", |
| kind.article(), kind.descr())) |
| }; |
| resolve_error(self, span, ResolutionError::FailedToResolve { |
| label, |
| suggestion: None |
| }); |
| } |
| PathResult::Module(..) | PathResult::Indeterminate => unreachable!(), |
| } |
| } |
| |
| let macro_resolutions = |
| mem::replace(&mut *module.single_segment_macro_resolutions.borrow_mut(), Vec::new()); |
| for (ident, kind, parent_scope, initial_binding) in macro_resolutions { |
| match self.early_resolve_ident_in_lexical_scope(ident, ScopeSet::Macro(kind), |
| &parent_scope, true, true, ident.span) { |
| Ok(binding) => { |
| let initial_res = initial_binding.map(|initial_binding| { |
| self.record_use(ident, MacroNS, initial_binding, false); |
| initial_binding.res() |
| }); |
| let res = binding.res(); |
| let seg = Segment::from_ident(ident); |
| check_consistency(self, &[seg], ident.span, kind, initial_res, res); |
| } |
| Err(..) => { |
| assert!(initial_binding.is_none()); |
| let bang = if kind == MacroKind::Bang { "!" } else { "" }; |
| let msg = |
| format!("cannot find {} `{}{}` in this scope", kind.descr(), ident, bang); |
| let mut err = self.session.struct_span_err(ident.span, &msg); |
| self.suggest_macro_name(ident.name, kind, &mut err, ident.span); |
| err.emit(); |
| } |
| } |
| } |
| |
| let builtin_attrs = mem::replace(&mut *module.builtin_attrs.borrow_mut(), Vec::new()); |
| for (ident, parent_scope) in builtin_attrs { |
| let _ = self.early_resolve_ident_in_lexical_scope( |
| ident, ScopeSet::Macro(MacroKind::Attr), &parent_scope, true, true, ident.span |
| ); |
| } |
| } |
| |
| fn prohibit_imported_non_macro_attrs(&self, binding: Option<&'a NameBinding<'a>>, |
| res: Option<Res>, span: Span) { |
| if let Some(Res::NonMacroAttr(kind)) = res { |
| if kind != NonMacroAttrKind::Tool && binding.map_or(true, |b| b.is_import()) { |
| let msg = format!("cannot use a {} through an import", kind.descr()); |
| let mut err = self.session.struct_span_err(span, &msg); |
| if let Some(binding) = binding { |
| err.span_note(binding.span, &format!("the {} imported here", kind.descr())); |
| } |
| err.emit(); |
| } |
| } |
| } |
| |
| fn suggest_macro_name(&mut self, name: Symbol, kind: MacroKind, |
| err: &mut DiagnosticBuilder<'a>, span: Span) { |
| // First check if this is a locally-defined bang macro. |
| let suggestion = if let MacroKind::Bang = kind { |
| find_best_match_for_name( |
| self.macro_names.iter().map(|ident| &ident.name), &name.as_str(), None) |
| } else { |
| None |
| // Then check global macros. |
| }.or_else(|| { |
| let names = self.builtin_macros.iter().chain(self.macro_use_prelude.iter()) |
| .filter_map(|(name, binding)| { |
| if binding.macro_kind() == Some(kind) { Some(name) } else { None } |
| }); |
| find_best_match_for_name(names, &name.as_str(), None) |
| // Then check modules. |
| }).or_else(|| { |
| let is_macro = |res| { |
| if let Res::Def(DefKind::Macro(def_kind), _) = res { |
| def_kind == kind |
| } else { |
| false |
| } |
| }; |
| let ident = Ident::new(name, span); |
| self.lookup_typo_candidate(&[Segment::from_ident(ident)], MacroNS, is_macro, span) |
| .map(|suggestion| suggestion.candidate) |
| }); |
| |
| if let Some(suggestion) = suggestion { |
| if suggestion != name { |
| if let MacroKind::Bang = kind { |
| err.span_suggestion( |
| span, |
| "you could try the macro", |
| suggestion.to_string(), |
| Applicability::MaybeIncorrect |
| ); |
| } else { |
| err.span_suggestion( |
| span, |
| "try", |
| suggestion.to_string(), |
| Applicability::MaybeIncorrect |
| ); |
| } |
| } else { |
| err.help("have you added the `#[macro_use]` on the module/import?"); |
| } |
| } |
| } |
| |
| fn collect_def_ids(&mut self, |
| mark: Mark, |
| invocation: &'a InvocationData<'a>, |
| fragment: &AstFragment) { |
| let Resolver { ref mut invocations, arenas, graph_root, .. } = *self; |
| let InvocationData { def_index, .. } = *invocation; |
| |
| let visit_macro_invoc = &mut |invoc: map::MacroInvocationData| { |
| invocations.entry(invoc.mark).or_insert_with(|| { |
| arenas.alloc_invocation_data(InvocationData { |
| def_index: invoc.def_index, |
| module: Cell::new(graph_root), |
| parent_legacy_scope: Cell::new(LegacyScope::Uninitialized), |
| output_legacy_scope: Cell::new(None), |
| }) |
| }); |
| }; |
| |
| let mut def_collector = DefCollector::new(&mut self.definitions, mark); |
| def_collector.visit_macro_invoc = Some(visit_macro_invoc); |
| def_collector.with_parent(def_index, |def_collector| { |
| fragment.visit_with(def_collector) |
| }); |
| } |
| |
| pub fn define_macro(&mut self, |
| item: &ast::Item, |
| expansion: Mark, |
| current_legacy_scope: &mut LegacyScope<'a>) { |
| self.local_macro_def_scopes.insert(item.id, self.current_module); |
| let ident = item.ident; |
| if ident.name == sym::macro_rules { |
| self.session.span_err(item.span, "user-defined macros may not be named `macro_rules`"); |
| } |
| |
| let def_id = self.definitions.local_def_id(item.id); |
| let ext = Lrc::new(macro_rules::compile(&self.session.parse_sess, |
| &self.session.features_untracked(), |
| item, self.session.edition())); |
| self.macro_map.insert(def_id, ext); |
| |
| let def = match item.node { ast::ItemKind::MacroDef(ref def) => def, _ => unreachable!() }; |
| if def.legacy { |
| let ident = ident.modern(); |
| self.macro_names.insert(ident); |
| let res = Res::Def(DefKind::Macro(MacroKind::Bang), def_id); |
| let is_macro_export = attr::contains_name(&item.attrs, sym::macro_export); |
| let vis = if is_macro_export { |
| ty::Visibility::Public |
| } else { |
| ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX)) |
| }; |
| let binding = (res, vis, item.span, expansion).to_name_binding(self.arenas); |
| self.set_binding_parent_module(binding, self.current_module); |
| let legacy_binding = self.arenas.alloc_legacy_binding(LegacyBinding { |
| parent_legacy_scope: *current_legacy_scope, binding, ident |
| }); |
| *current_legacy_scope = LegacyScope::Binding(legacy_binding); |
| self.all_macros.insert(ident.name, res); |
| if is_macro_export { |
| let module = self.graph_root; |
| self.define(module, ident, MacroNS, |
| (res, vis, item.span, expansion, IsMacroExport)); |
| } else { |
| if !attr::contains_name(&item.attrs, sym::rustc_doc_only_macro) { |
| self.check_reserved_macro_name(ident, MacroNS); |
| } |
| self.unused_macros.insert(def_id); |
| } |
| } else { |
| let module = self.current_module; |
| let res = Res::Def(DefKind::Macro(MacroKind::Bang), def_id); |
| let vis = self.resolve_visibility(&item.vis); |
| if vis != ty::Visibility::Public { |
| self.unused_macros.insert(def_id); |
| } |
| self.define(module, ident, MacroNS, (res, vis, item.span, expansion)); |
| } |
| } |
| } |
