//! The core of the module-level name resolution algorithm. //! //! `DefCollector::collect` contains the fixed-point iteration loop which //! resolves imports and expands macros. use std::iter; use base_db::{CrateId, FileId, ProcMacroId}; use cfg::{CfgExpr, CfgOptions}; use hir_expand::{ ast_id_map::FileAstId, builtin_derive::find_builtin_derive, builtin_macro::find_builtin_macro, name::{AsName, Name}, proc_macro::ProcMacroExpander, HirFileId, MacroCallId, MacroCallKind, MacroDefId, MacroDefKind, }; use hir_expand::{InFile, MacroCallLoc}; use rustc_hash::{FxHashMap, FxHashSet}; use syntax::ast; use test_utils::mark; use tt::{Leaf, TokenTree}; use crate::{ attr::Attrs, db::DefDatabase, item_scope::{ImportType, PerNsGlobImports}, item_tree::{ self, FileItemTreeId, ItemTree, ItemTreeId, MacroCall, MacroRules, Mod, ModItem, ModKind, StructDefKind, }, nameres::{ diagnostics::DefDiagnostic, mod_resolution::ModDir, path_resolution::ReachedFixedPoint, BuiltinShadowMode, DefMap, ModuleData, ModuleOrigin, ResolveMode, }, path::{ImportAlias, ModPath, PathKind}, per_ns::PerNs, visibility::{RawVisibility, Visibility}, AdtId, AsMacroCall, AstId, AstIdWithPath, ConstLoc, ContainerId, EnumLoc, EnumVariantId, FunctionLoc, ImplLoc, Intern, LocalModuleId, ModuleDefId, StaticLoc, StructLoc, TraitLoc, TypeAliasLoc, UnionLoc, }; const GLOB_RECURSION_LIMIT: usize = 100; const EXPANSION_DEPTH_LIMIT: usize = 128; const FIXED_POINT_LIMIT: usize = 8192; pub(super) fn collect_defs( db: &dyn DefDatabase, mut def_map: DefMap, block: Option>, ) -> DefMap { let crate_graph = db.crate_graph(); // populate external prelude for dep in &crate_graph[def_map.krate].dependencies { log::debug!("crate dep {:?} -> {:?}", dep.name, dep.crate_id); let dep_def_map = db.crate_def_map(dep.crate_id); def_map .extern_prelude .insert(dep.as_name(), dep_def_map.module_id(dep_def_map.root).into()); // look for the prelude // If the dependency defines a prelude, we overwrite an already defined // prelude. This is necessary to import the "std" prelude if a crate // depends on both "core" and "std". if dep_def_map.prelude.is_some() { def_map.prelude = dep_def_map.prelude; } } let cfg_options = &crate_graph[def_map.krate].cfg_options; let proc_macros = &crate_graph[def_map.krate].proc_macro; let proc_macros = proc_macros .iter() .enumerate() .map(|(idx, it)| { // FIXME: a hacky way to create a Name from string. let name = tt::Ident { text: it.name.clone(), id: tt::TokenId::unspecified() }; (name.as_name(), ProcMacroExpander::new(def_map.krate, ProcMacroId(idx as u32))) }) .collect(); let mut collector = DefCollector { db, def_map, glob_imports: FxHashMap::default(), unresolved_imports: Vec::new(), resolved_imports: Vec::new(), unexpanded_macros: Vec::new(), unexpanded_attribute_macros: Vec::new(), mod_dirs: FxHashMap::default(), cfg_options, proc_macros, exports_proc_macros: false, from_glob_import: Default::default(), }; match block { Some(block) => { collector.seed_with_inner(block); } None => { collector.seed_with_top_level(); } } collector.collect(); collector.finish() } #[derive(Copy, Clone, Debug, Eq, PartialEq)] enum PartialResolvedImport { /// None of any namespaces is resolved Unresolved, /// One of namespaces is resolved Indeterminate(PerNs), /// All namespaces are resolved, OR it is came from other crate Resolved(PerNs), } impl PartialResolvedImport { fn namespaces(&self) -> PerNs { match self { PartialResolvedImport::Unresolved => PerNs::none(), PartialResolvedImport::Indeterminate(ns) => *ns, PartialResolvedImport::Resolved(ns) => *ns, } } } #[derive(Clone, Debug, Eq, PartialEq)] enum ImportSource { Import(ItemTreeId), ExternCrate(ItemTreeId), } #[derive(Clone, Debug, Eq, PartialEq)] struct Import { path: ModPath, alias: Option, visibility: RawVisibility, is_glob: bool, is_prelude: bool, is_extern_crate: bool, is_macro_use: bool, source: ImportSource, } impl Import { fn from_use( db: &dyn DefDatabase, krate: CrateId, tree: &ItemTree, id: ItemTreeId, ) -> Self { let it = &tree[id.value]; let attrs = &tree.attrs(db, krate, ModItem::from(id.value).into()); let visibility = &tree[it.visibility]; Self { path: it.path.clone(), alias: it.alias.clone(), visibility: visibility.clone(), is_glob: it.is_glob, is_prelude: attrs.by_key("prelude_import").exists(), is_extern_crate: false, is_macro_use: false, source: ImportSource::Import(id), } } fn from_extern_crate( db: &dyn DefDatabase, krate: CrateId, tree: &ItemTree, id: ItemTreeId, ) -> Self { let it = &tree[id.value]; let attrs = &tree.attrs(db, krate, ModItem::from(id.value).into()); let visibility = &tree[it.visibility]; Self { path: ModPath::from_segments(PathKind::Plain, iter::once(it.name.clone())), alias: it.alias.clone(), visibility: visibility.clone(), is_glob: false, is_prelude: false, is_extern_crate: true, is_macro_use: attrs.by_key("macro_use").exists(), source: ImportSource::ExternCrate(id), } } } #[derive(Clone, Debug, Eq, PartialEq)] struct ImportDirective { module_id: LocalModuleId, import: Import, status: PartialResolvedImport, } #[derive(Clone, Debug, Eq, PartialEq)] struct MacroDirective { module_id: LocalModuleId, ast_id: AstIdWithPath, legacy: Option, depth: usize, } #[derive(Clone, Debug, Eq, PartialEq)] struct DeriveDirective { module_id: LocalModuleId, ast_id: AstIdWithPath, } struct DefData<'a> { id: ModuleDefId, name: &'a Name, visibility: &'a RawVisibility, has_constructor: bool, } /// Walks the tree of module recursively struct DefCollector<'a> { db: &'a dyn DefDatabase, def_map: DefMap, glob_imports: FxHashMap>, unresolved_imports: Vec, resolved_imports: Vec, unexpanded_macros: Vec, unexpanded_attribute_macros: Vec, mod_dirs: FxHashMap, cfg_options: &'a CfgOptions, /// List of procedural macros defined by this crate. This is read from the dynamic library /// built by the build system, and is the list of proc. macros we can actually expand. It is /// empty when proc. macro support is disabled (in which case we still do name resolution for /// them). proc_macros: Vec<(Name, ProcMacroExpander)>, exports_proc_macros: bool, from_glob_import: PerNsGlobImports, } impl DefCollector<'_> { fn seed_with_top_level(&mut self) { let file_id = self.db.crate_graph()[self.def_map.krate].root_file_id; let item_tree = self.db.item_tree(file_id.into()); let module_id = self.def_map.root; self.def_map.modules[module_id].origin = ModuleOrigin::CrateRoot { definition: file_id }; if item_tree .top_level_attrs(self.db, self.def_map.krate) .cfg() .map_or(true, |cfg| self.cfg_options.check(&cfg) != Some(false)) { ModCollector { def_collector: &mut *self, macro_depth: 0, module_id, file_id: file_id.into(), item_tree: &item_tree, mod_dir: ModDir::root(), } .collect(item_tree.top_level_items()); } } fn seed_with_inner(&mut self, block: FileAstId) { let file_id = self.db.crate_graph()[self.def_map.krate].root_file_id; let item_tree = self.db.item_tree(file_id.into()); let module_id = self.def_map.root; self.def_map.modules[module_id].origin = ModuleOrigin::CrateRoot { definition: file_id }; if item_tree .top_level_attrs(self.db, self.def_map.krate) .cfg() .map_or(true, |cfg| self.cfg_options.check(&cfg) != Some(false)) { ModCollector { def_collector: &mut *self, macro_depth: 0, module_id, file_id: file_id.into(), item_tree: &item_tree, mod_dir: ModDir::root(), } .collect(item_tree.inner_items_of_block(block)); } } fn collect(&mut self) { // main name resolution fixed-point loop. let mut i = 0; loop { self.db.check_canceled(); self.resolve_imports(); match self.resolve_macros() { ReachedFixedPoint::Yes => break, ReachedFixedPoint::No => i += 1, } if i == FIXED_POINT_LIMIT { log::error!("name resolution is stuck"); break; } } // Resolve all indeterminate resolved imports again // As some of the macros will expand newly import shadowing partial resolved imports // FIXME: We maybe could skip this, if we handle the indeterminate imports in `resolve_imports` // correctly let partial_resolved = self.resolved_imports.iter().filter_map(|directive| { if let PartialResolvedImport::Indeterminate(_) = directive.status { let mut directive = directive.clone(); directive.status = PartialResolvedImport::Unresolved; Some(directive) } else { None } }); self.unresolved_imports.extend(partial_resolved); self.resolve_imports(); let unresolved_imports = std::mem::replace(&mut self.unresolved_imports, Vec::new()); // show unresolved imports in completion, etc for directive in &unresolved_imports { self.record_resolved_import(directive) } self.unresolved_imports = unresolved_imports; // FIXME: This condition should instead check if this is a `proc-macro` type crate. if self.exports_proc_macros { // A crate exporting procedural macros is not allowed to export anything else. // // Additionally, while the proc macro entry points must be `pub`, they are not publicly // exported in type/value namespace. This function reduces the visibility of all items // in the crate root that aren't proc macros. let root = self.def_map.root; let module_id = self.def_map.module_id(root); let root = &mut self.def_map.modules[root]; root.scope.censor_non_proc_macros(module_id); } } /// Adds a definition of procedural macro `name` to the root module. /// /// # Notes on procedural macro resolution /// /// Procedural macro functionality is provided by the build system: It has to build the proc /// macro and pass the resulting dynamic library to rust-analyzer. /// /// When procedural macro support is enabled, the list of proc macros exported by a crate is /// known before we resolve names in the crate. This list is stored in `self.proc_macros` and is /// derived from the dynamic library. /// /// However, we *also* would like to be able to at least *resolve* macros on our own, without /// help by the build system. So, when the macro isn't found in `self.proc_macros`, we instead /// use a dummy expander that always errors. This comes with the drawback of macros potentially /// going out of sync with what the build system sees (since we resolve using VFS state, but /// Cargo builds only on-disk files). We could and probably should add diagnostics for that. fn resolve_proc_macro(&mut self, name: &Name) { self.exports_proc_macros = true; let macro_def = match self.proc_macros.iter().find(|(n, _)| n == name) { Some((_, expander)) => MacroDefId { ast_id: None, krate: self.def_map.krate, kind: MacroDefKind::ProcMacro(*expander), local_inner: false, }, None => MacroDefId { ast_id: None, krate: self.def_map.krate, kind: MacroDefKind::ProcMacro(ProcMacroExpander::dummy(self.def_map.krate)), local_inner: false, }, }; self.define_proc_macro(name.clone(), macro_def); } /// Define a macro with `macro_rules`. /// /// It will define the macro in legacy textual scope, and if it has `#[macro_export]`, /// then it is also defined in the root module scope. /// You can `use` or invoke it by `crate::macro_name` anywhere, before or after the definition. /// /// It is surprising that the macro will never be in the current module scope. /// These code fails with "unresolved import/macro", /// ```rust,compile_fail /// mod m { macro_rules! foo { () => {} } } /// use m::foo as bar; /// ``` /// /// ```rust,compile_fail /// macro_rules! foo { () => {} } /// self::foo!(); /// crate::foo!(); /// ``` /// /// Well, this code compiles, because the plain path `foo` in `use` is searched /// in the legacy textual scope only. /// ```rust /// macro_rules! foo { () => {} } /// use foo as bar; /// ``` fn define_macro( &mut self, module_id: LocalModuleId, name: Name, macro_: MacroDefId, export: bool, ) { // Textual scoping self.define_legacy_macro(module_id, name.clone(), macro_); // Module scoping // In Rust, `#[macro_export]` macros are unconditionally visible at the // crate root, even if the parent modules is **not** visible. if export { self.update( self.def_map.root, &[(Some(name), PerNs::macros(macro_, Visibility::Public))], Visibility::Public, ImportType::Named, ); } } /// Define a legacy textual scoped macro in module /// /// We use a map `legacy_macros` to store all legacy textual scoped macros visible per module. /// It will clone all macros from parent legacy scope, whose definition is prior to /// the definition of current module. /// And also, `macro_use` on a module will import all legacy macros visible inside to /// current legacy scope, with possible shadowing. fn define_legacy_macro(&mut self, module_id: LocalModuleId, name: Name, mac: MacroDefId) { // Always shadowing self.def_map.modules[module_id].scope.define_legacy_macro(name, mac); } /// Define a proc macro /// /// A proc macro is similar to normal macro scope, but it would not visible in legacy textual scoped. /// And unconditionally exported. fn define_proc_macro(&mut self, name: Name, macro_: MacroDefId) { self.update( self.def_map.root, &[(Some(name), PerNs::macros(macro_, Visibility::Public))], Visibility::Public, ImportType::Named, ); } /// Import macros from `#[macro_use] extern crate`. fn import_macros_from_extern_crate( &mut self, current_module_id: LocalModuleId, extern_crate: &item_tree::ExternCrate, ) { log::debug!( "importing macros from extern crate: {:?} ({:?})", extern_crate, self.def_map.edition, ); let res = self.def_map.resolve_name_in_extern_prelude(&extern_crate.name); if let Some(ModuleDefId::ModuleId(m)) = res.take_types() { mark::hit!(macro_rules_from_other_crates_are_visible_with_macro_use); self.import_all_macros_exported(current_module_id, m.krate); } } /// Import all exported macros from another crate /// /// Exported macros are just all macros in the root module scope. /// Note that it contains not only all `#[macro_export]` macros, but also all aliases /// created by `use` in the root module, ignoring the visibility of `use`. fn import_all_macros_exported(&mut self, current_module_id: LocalModuleId, krate: CrateId) { let def_map = self.db.crate_def_map(krate); for (name, def) in def_map[def_map.root].scope.macros() { // `macro_use` only bring things into legacy scope. self.define_legacy_macro(current_module_id, name.clone(), def); } } /// Import resolution /// /// This is a fix point algorithm. We resolve imports until no forward /// progress in resolving imports is made fn resolve_imports(&mut self) { let mut n_previous_unresolved = self.unresolved_imports.len() + 1; while self.unresolved_imports.len() < n_previous_unresolved { n_previous_unresolved = self.unresolved_imports.len(); let imports = std::mem::replace(&mut self.unresolved_imports, Vec::new()); for mut directive in imports { directive.status = self.resolve_import(directive.module_id, &directive.import); match directive.status { PartialResolvedImport::Indeterminate(_) => { self.record_resolved_import(&directive); // FIXME: For avoid performance regression, // we consider an imported resolved if it is indeterminate (i.e not all namespace resolved) self.resolved_imports.push(directive) } PartialResolvedImport::Resolved(_) => { self.record_resolved_import(&directive); self.resolved_imports.push(directive) } PartialResolvedImport::Unresolved => { self.unresolved_imports.push(directive); } } } } } fn resolve_import(&self, module_id: LocalModuleId, import: &Import) -> PartialResolvedImport { log::debug!("resolving import: {:?} ({:?})", import, self.def_map.edition); if import.is_extern_crate { let res = self.def_map.resolve_name_in_extern_prelude( &import .path .as_ident() .expect("extern crate should have been desugared to one-element path"), ); if res.is_none() { PartialResolvedImport::Unresolved } else { PartialResolvedImport::Resolved(res) } } else { let res = self.def_map.resolve_path_fp_with_macro( self.db, ResolveMode::Import, module_id, &import.path, BuiltinShadowMode::Module, ); let def = res.resolved_def; if res.reached_fixedpoint == ReachedFixedPoint::No || def.is_none() { return PartialResolvedImport::Unresolved; } if let Some(krate) = res.krate { if krate != self.def_map.krate { return PartialResolvedImport::Resolved(def); } } // Check whether all namespace is resolved if def.take_types().is_some() && def.take_values().is_some() && def.take_macros().is_some() { PartialResolvedImport::Resolved(def) } else { PartialResolvedImport::Indeterminate(def) } } } fn record_resolved_import(&mut self, directive: &ImportDirective) { let module_id = directive.module_id; let import = &directive.import; let def = directive.status.namespaces(); let vis = self .def_map .resolve_visibility(self.db, module_id, &directive.import.visibility) .unwrap_or(Visibility::Public); if import.is_glob { log::debug!("glob import: {:?}", import); match def.take_types() { Some(ModuleDefId::ModuleId(m)) => { if import.is_prelude { mark::hit!(std_prelude); self.def_map.prelude = Some(m); } else if m.krate != self.def_map.krate { mark::hit!(glob_across_crates); // glob import from other crate => we can just import everything once let item_map = m.def_map(self.db); let scope = &item_map[m.local_id].scope; // Module scoped macros is included let items = scope .resolutions() // only keep visible names... .map(|(n, res)| { (n, res.filter_visibility(|v| v.is_visible_from_other_crate())) }) .filter(|(_, res)| !res.is_none()) .collect::>(); self.update(module_id, &items, vis, ImportType::Glob); } else { // glob import from same crate => we do an initial // import, and then need to propagate any further // additions let scope = &self.def_map[m.local_id].scope; // Module scoped macros is included let items = scope .resolutions() // only keep visible names... .map(|(n, res)| { ( n, res.filter_visibility(|v| { v.is_visible_from_def_map(&self.def_map, module_id) }), ) }) .filter(|(_, res)| !res.is_none()) .collect::>(); self.update(module_id, &items, vis, ImportType::Glob); // record the glob import in case we add further items let glob = self.glob_imports.entry(m.local_id).or_default(); if !glob.iter().any(|(mid, _)| *mid == module_id) { glob.push((module_id, vis)); } } } Some(ModuleDefId::AdtId(AdtId::EnumId(e))) => { mark::hit!(glob_enum); // glob import from enum => just import all the variants // XXX: urgh, so this works by accident! Here, we look at // the enum data, and, in theory, this might require us to // look back at the crate_def_map, creating a cycle. For // example, `enum E { crate::some_macro!(); }`. Luckily, the // only kind of macro that is allowed inside enum is a // `cfg_macro`, and we don't need to run name resolution for // it, but this is sheer luck! let enum_data = self.db.enum_data(e); let resolutions = enum_data .variants .iter() .map(|(local_id, variant_data)| { let name = variant_data.name.clone(); let variant = EnumVariantId { parent: e, local_id }; let res = PerNs::both(variant.into(), variant.into(), vis); (Some(name), res) }) .collect::>(); self.update(module_id, &resolutions, vis, ImportType::Glob); } Some(d) => { log::debug!("glob import {:?} from non-module/enum {:?}", import, d); } None => { log::debug!("glob import {:?} didn't resolve as type", import); } } } else { match import.path.segments.last() { Some(last_segment) => { let name = match &import.alias { Some(ImportAlias::Alias(name)) => Some(name.clone()), Some(ImportAlias::Underscore) => None, None => Some(last_segment.clone()), }; log::debug!("resolved import {:?} ({:?}) to {:?}", name, import, def); // extern crates in the crate root are special-cased to insert entries into the extern prelude: rust-lang/rust#54658 if import.is_extern_crate && module_id == self.def_map.root { if let (Some(def), Some(name)) = (def.take_types(), name.as_ref()) { self.def_map.extern_prelude.insert(name.clone(), def); } } self.update(module_id, &[(name, def)], vis, ImportType::Named); } None => mark::hit!(bogus_paths), } } } fn update( &mut self, module_id: LocalModuleId, resolutions: &[(Option, PerNs)], vis: Visibility, import_type: ImportType, ) { self.db.check_canceled(); self.update_recursive(module_id, resolutions, vis, import_type, 0) } fn update_recursive( &mut self, module_id: LocalModuleId, resolutions: &[(Option, PerNs)], // All resolutions are imported with this visibility; the visibilities in // the `PerNs` values are ignored and overwritten vis: Visibility, import_type: ImportType, depth: usize, ) { if depth > GLOB_RECURSION_LIMIT { // prevent stack overflows (but this shouldn't be possible) panic!("infinite recursion in glob imports!"); } let mut changed = false; for (name, res) in resolutions { match name { Some(name) => { let scope = &mut self.def_map.modules[module_id].scope; changed |= scope.push_res_with_import( &mut self.from_glob_import, (module_id, name.clone()), res.with_visibility(vis), import_type, ); } None => { let tr = match res.take_types() { Some(ModuleDefId::TraitId(tr)) => tr, Some(other) => { log::debug!("non-trait `_` import of {:?}", other); continue; } None => continue, }; let old_vis = self.def_map.modules[module_id].scope.unnamed_trait_vis(tr); let should_update = match old_vis { None => true, Some(old_vis) => { let max_vis = old_vis.max(vis, &self.def_map).unwrap_or_else(|| { panic!("`Tr as _` imports with unrelated visibilities {:?} and {:?} (trait {:?})", old_vis, vis, tr); }); if max_vis == old_vis { false } else { mark::hit!(upgrade_underscore_visibility); true } } }; if should_update { changed = true; self.def_map.modules[module_id].scope.push_unnamed_trait(tr, vis); } } } } if !changed { return; } let glob_imports = self .glob_imports .get(&module_id) .into_iter() .flat_map(|v| v.iter()) .filter(|(glob_importing_module, _)| { // we know all resolutions have the same visibility (`vis`), so we // just need to check that once vis.is_visible_from_def_map(&self.def_map, *glob_importing_module) }) .cloned() .collect::>(); for (glob_importing_module, glob_import_vis) in glob_imports { self.update_recursive( glob_importing_module, resolutions, glob_import_vis, ImportType::Glob, depth + 1, ); } } fn resolve_macros(&mut self) -> ReachedFixedPoint { let mut macros = std::mem::replace(&mut self.unexpanded_macros, Vec::new()); let mut attribute_macros = std::mem::replace(&mut self.unexpanded_attribute_macros, Vec::new()); let mut resolved = Vec::new(); let mut res = ReachedFixedPoint::Yes; macros.retain(|directive| { if let Some(call_id) = directive.legacy { res = ReachedFixedPoint::No; resolved.push((directive.module_id, call_id, directive.depth)); return false; } if let Some(call_id) = directive.ast_id.as_call_id(self.db, self.def_map.krate, |path| { let resolved_res = self.def_map.resolve_path_fp_with_macro( self.db, ResolveMode::Other, directive.module_id, &path, BuiltinShadowMode::Module, ); resolved_res.resolved_def.take_macros() }) { resolved.push((directive.module_id, call_id, directive.depth)); res = ReachedFixedPoint::No; return false; } true }); attribute_macros.retain(|directive| { if let Some(call_id) = directive.ast_id.as_call_id(self.db, self.def_map.krate, |path| { self.resolve_attribute_macro(&directive, &path) }) { resolved.push((directive.module_id, call_id, 0)); res = ReachedFixedPoint::No; return false; } true }); self.unexpanded_macros = macros; self.unexpanded_attribute_macros = attribute_macros; for (module_id, macro_call_id, depth) in resolved { self.collect_macro_expansion(module_id, macro_call_id, depth); } res } fn resolve_attribute_macro( &self, directive: &DeriveDirective, path: &ModPath, ) -> Option { let resolved_res = self.def_map.resolve_path_fp_with_macro( self.db, ResolveMode::Other, directive.module_id, &path, BuiltinShadowMode::Module, ); resolved_res.resolved_def.take_macros() } fn collect_macro_expansion( &mut self, module_id: LocalModuleId, macro_call_id: MacroCallId, depth: usize, ) { if depth > EXPANSION_DEPTH_LIMIT { mark::hit!(macro_expansion_overflow); log::warn!("macro expansion is too deep"); return; } let file_id = macro_call_id.as_file(); // First, fetch the raw expansion result for purposes of error reporting. This goes through // `macro_expand_error` to avoid depending on the full expansion result (to improve // incrementality). let err = self.db.macro_expand_error(macro_call_id); if let Some(err) = err { if let MacroCallId::LazyMacro(id) = macro_call_id { let loc: MacroCallLoc = self.db.lookup_intern_macro(id); let diag = match err { hir_expand::ExpandError::UnresolvedProcMacro => { // Missing proc macros are non-fatal, so they are handled specially. DefDiagnostic::unresolved_proc_macro(module_id, loc.kind) } _ => DefDiagnostic::macro_error(module_id, loc.kind, err.to_string()), }; self.def_map.diagnostics.push(diag); } // FIXME: Handle eager macros. } // Then, fetch and process the item tree. This will reuse the expansion result from above. let item_tree = self.db.item_tree(file_id); let mod_dir = self.mod_dirs[&module_id].clone(); ModCollector { def_collector: &mut *self, macro_depth: depth, file_id, module_id, item_tree: &item_tree, mod_dir, } .collect(item_tree.top_level_items()); } fn finish(mut self) -> DefMap { // Emit diagnostics for all remaining unexpanded macros. for directive in &self.unexpanded_macros { let mut error = None; directive.ast_id.as_call_id_with_errors( self.db, self.def_map.krate, |path| { let resolved_res = self.def_map.resolve_path_fp_with_macro( self.db, ResolveMode::Other, directive.module_id, &path, BuiltinShadowMode::Module, ); resolved_res.resolved_def.take_macros() }, &mut |e| { error.get_or_insert(e); }, ); if let Some(err) = error { self.def_map.diagnostics.push(DefDiagnostic::macro_error( directive.module_id, MacroCallKind::FnLike(directive.ast_id.ast_id), err.to_string(), )); } } // Emit diagnostics for all remaining unresolved imports. // We'd like to avoid emitting a diagnostics avalanche when some `extern crate` doesn't // resolve. We first emit diagnostics for unresolved extern crates and collect the missing // crate names. Then we emit diagnostics for unresolved imports, but only if the import // doesn't start with an unresolved crate's name. Due to renaming and reexports, this is a // heuristic, but it works in practice. let mut diagnosed_extern_crates = FxHashSet::default(); for directive in &self.unresolved_imports { if let ImportSource::ExternCrate(krate) = directive.import.source { let item_tree = self.db.item_tree(krate.file_id); let extern_crate = &item_tree[krate.value]; diagnosed_extern_crates.insert(extern_crate.name.clone()); self.def_map.diagnostics.push(DefDiagnostic::unresolved_extern_crate( directive.module_id, InFile::new(krate.file_id, extern_crate.ast_id), )); } } for directive in &self.unresolved_imports { if let ImportSource::Import(import) = &directive.import.source { let item_tree = self.db.item_tree(import.file_id); let import_data = &item_tree[import.value]; match (import_data.path.segments.first(), &import_data.path.kind) { (Some(krate), PathKind::Plain) | (Some(krate), PathKind::Abs) => { if diagnosed_extern_crates.contains(krate) { continue; } } _ => {} } self.def_map.diagnostics.push(DefDiagnostic::unresolved_import( directive.module_id, InFile::new(import.file_id, import_data.ast_id), import_data.index, )); } } self.def_map } } /// Walks a single module, populating defs, imports and macros struct ModCollector<'a, 'b> { def_collector: &'a mut DefCollector<'b>, macro_depth: usize, module_id: LocalModuleId, file_id: HirFileId, item_tree: &'a ItemTree, mod_dir: ModDir, } impl ModCollector<'_, '_> { fn collect(&mut self, items: &[ModItem]) { let krate = self.def_collector.def_map.krate; // Note: don't assert that inserted value is fresh: it's simply not true // for macros. self.def_collector.mod_dirs.insert(self.module_id, self.mod_dir.clone()); // Prelude module is always considered to be `#[macro_use]`. if let Some(prelude_module) = self.def_collector.def_map.prelude { if prelude_module.krate != self.def_collector.def_map.krate { mark::hit!(prelude_is_macro_use); self.def_collector.import_all_macros_exported(self.module_id, prelude_module.krate); } } // This should be processed eagerly instead of deferred to resolving. // `#[macro_use] extern crate` is hoisted to imports macros before collecting // any other items. for item in items { let attrs = self.item_tree.attrs(self.def_collector.db, krate, (*item).into()); if attrs.cfg().map_or(true, |cfg| self.is_cfg_enabled(&cfg)) { if let ModItem::ExternCrate(id) = item { let import = self.item_tree[*id].clone(); let attrs = self.item_tree.attrs( self.def_collector.db, krate, ModItem::from(*id).into(), ); if attrs.by_key("macro_use").exists() { self.def_collector.import_macros_from_extern_crate(self.module_id, &import); } } } } for &item in items { let attrs = self.item_tree.attrs(self.def_collector.db, krate, item.into()); if let Some(cfg) = attrs.cfg() { if !self.is_cfg_enabled(&cfg) { self.emit_unconfigured_diagnostic(item, &cfg); continue; } } let module = self.def_collector.def_map.module_id(self.module_id); let container = ContainerId::ModuleId(module); let mut def = None; match item { ModItem::Mod(m) => self.collect_module(&self.item_tree[m], &attrs), ModItem::Import(import_id) => { self.def_collector.unresolved_imports.push(ImportDirective { module_id: self.module_id, import: Import::from_use( self.def_collector.db, krate, &self.item_tree, InFile::new(self.file_id, import_id), ), status: PartialResolvedImport::Unresolved, }) } ModItem::ExternCrate(import_id) => { self.def_collector.unresolved_imports.push(ImportDirective { module_id: self.module_id, import: Import::from_extern_crate( self.def_collector.db, krate, &self.item_tree, InFile::new(self.file_id, import_id), ), status: PartialResolvedImport::Unresolved, }) } ModItem::MacroCall(mac) => self.collect_macro_call(&self.item_tree[mac]), ModItem::MacroRules(id) => self.collect_macro_rules(id), ModItem::MacroDef(id) => { let mac = &self.item_tree[id]; let ast_id = InFile::new(self.file_id, mac.ast_id.upcast()); // "Macro 2.0" is not currently supported by rust-analyzer, but libcore uses it // to define builtin macros, so we support at least that part. let attrs = self.item_tree.attrs( self.def_collector.db, krate, ModItem::from(id).into(), ); if attrs.by_key("rustc_builtin_macro").exists() { let krate = self.def_collector.def_map.krate; let macro_id = find_builtin_macro(&mac.name, krate, ast_id) .or_else(|| find_builtin_derive(&mac.name, krate, ast_id)); if let Some(macro_id) = macro_id { let vis = self .def_collector .def_map .resolve_visibility( self.def_collector.db, self.module_id, &self.item_tree[mac.visibility], ) .unwrap_or(Visibility::Public); self.def_collector.update( self.module_id, &[(Some(mac.name.clone()), PerNs::macros(macro_id, vis))], vis, ImportType::Named, ); } } } ModItem::Impl(imp) => { let module = self.def_collector.def_map.module_id(self.module_id); let container = ContainerId::ModuleId(module); let impl_id = ImplLoc { container, id: ItemTreeId::new(self.file_id, imp) } .intern(self.def_collector.db); self.def_collector.def_map.modules[self.module_id].scope.define_impl(impl_id) } ModItem::Function(id) => { let func = &self.item_tree[id]; self.collect_proc_macro_def(&func.name, &attrs); def = Some(DefData { id: FunctionLoc { container: container.into(), id: ItemTreeId::new(self.file_id, id), } .intern(self.def_collector.db) .into(), name: &func.name, visibility: &self.item_tree[func.visibility], has_constructor: false, }); } ModItem::Struct(id) => { let it = &self.item_tree[id]; // FIXME: check attrs to see if this is an attribute macro invocation; // in which case we don't add the invocation, just a single attribute // macro invocation self.collect_derives(&attrs, it.ast_id.upcast()); def = Some(DefData { id: StructLoc { container, id: ItemTreeId::new(self.file_id, id) } .intern(self.def_collector.db) .into(), name: &it.name, visibility: &self.item_tree[it.visibility], has_constructor: it.kind != StructDefKind::Record, }); } ModItem::Union(id) => { let it = &self.item_tree[id]; // FIXME: check attrs to see if this is an attribute macro invocation; // in which case we don't add the invocation, just a single attribute // macro invocation self.collect_derives(&attrs, it.ast_id.upcast()); def = Some(DefData { id: UnionLoc { container, id: ItemTreeId::new(self.file_id, id) } .intern(self.def_collector.db) .into(), name: &it.name, visibility: &self.item_tree[it.visibility], has_constructor: false, }); } ModItem::Enum(id) => { let it = &self.item_tree[id]; // FIXME: check attrs to see if this is an attribute macro invocation; // in which case we don't add the invocation, just a single attribute // macro invocation self.collect_derives(&attrs, it.ast_id.upcast()); def = Some(DefData { id: EnumLoc { container, id: ItemTreeId::new(self.file_id, id) } .intern(self.def_collector.db) .into(), name: &it.name, visibility: &self.item_tree[it.visibility], has_constructor: false, }); } ModItem::Const(id) => { let it = &self.item_tree[id]; if let Some(name) = &it.name { def = Some(DefData { id: ConstLoc { container: container.into(), id: ItemTreeId::new(self.file_id, id), } .intern(self.def_collector.db) .into(), name, visibility: &self.item_tree[it.visibility], has_constructor: false, }); } } ModItem::Static(id) => { let it = &self.item_tree[id]; def = Some(DefData { id: StaticLoc { container, id: ItemTreeId::new(self.file_id, id) } .intern(self.def_collector.db) .into(), name: &it.name, visibility: &self.item_tree[it.visibility], has_constructor: false, }); } ModItem::Trait(id) => { let it = &self.item_tree[id]; def = Some(DefData { id: TraitLoc { container, id: ItemTreeId::new(self.file_id, id) } .intern(self.def_collector.db) .into(), name: &it.name, visibility: &self.item_tree[it.visibility], has_constructor: false, }); } ModItem::TypeAlias(id) => { let it = &self.item_tree[id]; def = Some(DefData { id: TypeAliasLoc { container: container.into(), id: ItemTreeId::new(self.file_id, id), } .intern(self.def_collector.db) .into(), name: &it.name, visibility: &self.item_tree[it.visibility], has_constructor: false, }); } } if let Some(DefData { id, name, visibility, has_constructor }) = def { self.def_collector.def_map.modules[self.module_id].scope.define_def(id); let vis = self .def_collector .def_map .resolve_visibility(self.def_collector.db, self.module_id, visibility) .unwrap_or(Visibility::Public); self.def_collector.update( self.module_id, &[(Some(name.clone()), PerNs::from_def(id, vis, has_constructor))], vis, ImportType::Named, ) } } } fn collect_module(&mut self, module: &Mod, attrs: &Attrs) { let path_attr = attrs.by_key("path").string_value(); let is_macro_use = attrs.by_key("macro_use").exists(); match &module.kind { // inline module, just recurse ModKind::Inline { items } => { let module_id = self.push_child_module( module.name.clone(), AstId::new(self.file_id, module.ast_id), None, &self.item_tree[module.visibility], ); if let Some(mod_dir) = self.mod_dir.descend_into_definition(&module.name, path_attr) { ModCollector { def_collector: &mut *self.def_collector, macro_depth: self.macro_depth, module_id, file_id: self.file_id, item_tree: self.item_tree, mod_dir, } .collect(&*items); if is_macro_use { self.import_all_legacy_macros(module_id); } } } // out of line module, resolve, parse and recurse ModKind::Outline {} => { let ast_id = AstId::new(self.file_id, module.ast_id); match self.mod_dir.resolve_declaration( self.def_collector.db, self.file_id, &module.name, path_attr, ) { Ok((file_id, is_mod_rs, mod_dir)) => { let module_id = self.push_child_module( module.name.clone(), ast_id, Some((file_id, is_mod_rs)), &self.item_tree[module.visibility], ); let item_tree = self.def_collector.db.item_tree(file_id.into()); ModCollector { def_collector: &mut *self.def_collector, macro_depth: self.macro_depth, module_id, file_id: file_id.into(), item_tree: &item_tree, mod_dir, } .collect(item_tree.top_level_items()); if is_macro_use { self.import_all_legacy_macros(module_id); } } Err(candidate) => { self.def_collector.def_map.diagnostics.push( DefDiagnostic::unresolved_module(self.module_id, ast_id, candidate), ); } }; } } } fn push_child_module( &mut self, name: Name, declaration: AstId, definition: Option<(FileId, bool)>, visibility: &crate::visibility::RawVisibility, ) -> LocalModuleId { let vis = self .def_collector .def_map .resolve_visibility(self.def_collector.db, self.module_id, visibility) .unwrap_or(Visibility::Public); let modules = &mut self.def_collector.def_map.modules; let res = modules.alloc(ModuleData::default()); modules[res].parent = Some(self.module_id); modules[res].origin = match definition { None => ModuleOrigin::Inline { definition: declaration }, Some((definition, is_mod_rs)) => { ModuleOrigin::File { declaration, definition, is_mod_rs } } }; for (name, mac) in modules[self.module_id].scope.collect_legacy_macros() { modules[res].scope.define_legacy_macro(name, mac) } modules[self.module_id].children.insert(name.clone(), res); let module = self.def_collector.def_map.module_id(res); let def: ModuleDefId = module.into(); self.def_collector.def_map.modules[self.module_id].scope.define_def(def); self.def_collector.update( self.module_id, &[(Some(name), PerNs::from_def(def, vis, false))], vis, ImportType::Named, ); res } fn collect_derives(&mut self, attrs: &Attrs, ast_id: FileAstId) { for derive in attrs.by_key("derive").attrs() { match derive.parse_derive() { Some(derive_macros) => { for path in derive_macros { let ast_id = AstIdWithPath::new(self.file_id, ast_id, path); self.def_collector .unexpanded_attribute_macros .push(DeriveDirective { module_id: self.module_id, ast_id }); } } None => { // FIXME: diagnose log::debug!("malformed derive: {:?}", derive); } } } } /// If `attrs` registers a procedural macro, collects its definition. fn collect_proc_macro_def(&mut self, func_name: &Name, attrs: &Attrs) { // FIXME: this should only be done in the root module of `proc-macro` crates, not everywhere // FIXME: distinguish the type of macro let macro_name = if attrs.by_key("proc_macro").exists() || attrs.by_key("proc_macro_attribute").exists() { func_name.clone() } else { let derive = attrs.by_key("proc_macro_derive"); if let Some(arg) = derive.tt_values().next() { if let [TokenTree::Leaf(Leaf::Ident(trait_name)), ..] = &*arg.token_trees { trait_name.as_name() } else { log::trace!("malformed `#[proc_macro_derive]`: {}", arg); return; } } else { return; } }; self.def_collector.resolve_proc_macro(¯o_name); } fn collect_macro_rules(&mut self, id: FileItemTreeId) { let krate = self.def_collector.def_map.krate; let mac = &self.item_tree[id]; let attrs = self.item_tree.attrs(self.def_collector.db, krate, ModItem::from(id).into()); let ast_id = InFile::new(self.file_id, mac.ast_id.upcast()); let export_attr = attrs.by_key("macro_export"); let is_export = export_attr.exists(); let is_local_inner = if is_export { export_attr.tt_values().map(|it| &it.token_trees).flatten().any(|it| match it { tt::TokenTree::Leaf(tt::Leaf::Ident(ident)) => { ident.text.contains("local_inner_macros") } _ => false, }) } else { false }; // Case 1: builtin macros if attrs.by_key("rustc_builtin_macro").exists() { let krate = self.def_collector.def_map.krate; if let Some(macro_id) = find_builtin_macro(&mac.name, krate, ast_id) { self.def_collector.define_macro( self.module_id, mac.name.clone(), macro_id, is_export, ); return; } } // Case 2: normal `macro_rules!` macro let macro_id = MacroDefId { ast_id: Some(ast_id), krate: self.def_collector.def_map.krate, kind: MacroDefKind::Declarative, local_inner: is_local_inner, }; self.def_collector.define_macro(self.module_id, mac.name.clone(), macro_id, is_export); } fn collect_macro_call(&mut self, mac: &MacroCall) { let mut ast_id = AstIdWithPath::new(self.file_id, mac.ast_id, mac.path.clone()); // Case 1: try to resolve in legacy scope and expand macro_rules if let Some(macro_call_id) = ast_id.as_call_id(self.def_collector.db, self.def_collector.def_map.krate, |path| { path.as_ident().and_then(|name| { self.def_collector .def_map .ancestor_maps(self.module_id) .find_map(|(map, module)| map[module].scope.get_legacy_macro(&name)) }) }) { self.def_collector.unexpanded_macros.push(MacroDirective { module_id: self.module_id, ast_id, legacy: Some(macro_call_id), depth: self.macro_depth + 1, }); return; } // Case 2: resolve in module scope, expand during name resolution. // We rewrite simple path `macro_name` to `self::macro_name` to force resolve in module scope only. if ast_id.path.is_ident() { ast_id.path.kind = PathKind::Super(0); } self.def_collector.unexpanded_macros.push(MacroDirective { module_id: self.module_id, ast_id, legacy: None, depth: self.macro_depth + 1, }); } fn import_all_legacy_macros(&mut self, module_id: LocalModuleId) { let macros = self.def_collector.def_map[module_id].scope.collect_legacy_macros(); for (name, macro_) in macros { self.def_collector.define_legacy_macro(self.module_id, name.clone(), macro_); } } fn is_cfg_enabled(&self, cfg: &CfgExpr) -> bool { self.def_collector.cfg_options.check(cfg) != Some(false) } fn emit_unconfigured_diagnostic(&mut self, item: ModItem, cfg: &CfgExpr) { let ast_id = item.ast_id(self.item_tree); let ast_id = InFile::new(self.file_id, ast_id); self.def_collector.def_map.diagnostics.push(DefDiagnostic::unconfigured_code( self.module_id, ast_id, cfg.clone(), self.def_collector.cfg_options.clone(), )); } } #[cfg(test)] mod tests { use crate::{db::DefDatabase, test_db::TestDB}; use base_db::{fixture::WithFixture, SourceDatabase}; use super::*; fn do_collect_defs(db: &dyn DefDatabase, def_map: DefMap) -> DefMap { let mut collector = DefCollector { db, def_map, glob_imports: FxHashMap::default(), unresolved_imports: Vec::new(), resolved_imports: Vec::new(), unexpanded_macros: Vec::new(), unexpanded_attribute_macros: Vec::new(), mod_dirs: FxHashMap::default(), cfg_options: &CfgOptions::default(), proc_macros: Default::default(), exports_proc_macros: false, from_glob_import: Default::default(), }; collector.seed_with_top_level(); collector.collect(); collector.def_map } fn do_resolve(code: &str) -> DefMap { let (db, _file_id) = TestDB::with_single_file(&code); let krate = db.test_crate(); let edition = db.crate_graph()[krate].edition; let def_map = DefMap::empty(krate, edition); do_collect_defs(&db, def_map) } #[test] fn test_macro_expand_will_stop_1() { do_resolve( r#" macro_rules! foo { ($($ty:ty)*) => { foo!($($ty)*); } } foo!(KABOOM); "#, ); } #[ignore] // this test does succeed, but takes quite a while :/ #[test] fn test_macro_expand_will_stop_2() { do_resolve( r#" macro_rules! foo { ($($ty:ty)*) => { foo!($($ty)* $($ty)*); } } foo!(KABOOM); "#, ); } }