From 53945841bea2d8016586889ccd8f8bd8c487547b Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Sat, 9 Nov 2019 00:17:17 +0300 Subject: Extract path resolution submodule --- crates/ra_hir_def/src/nameres/collector.rs | 4 +- crates/ra_hir_def/src/nameres/path_resolution.rs | 261 +++++++++++++++++++++++ 2 files changed, 263 insertions(+), 2 deletions(-) create mode 100644 crates/ra_hir_def/src/nameres/path_resolution.rs (limited to 'crates/ra_hir_def/src/nameres') diff --git a/crates/ra_hir_def/src/nameres/collector.rs b/crates/ra_hir_def/src/nameres/collector.rs index 9ab378d54..aacd50df8 100644 --- a/crates/ra_hir_def/src/nameres/collector.rs +++ b/crates/ra_hir_def/src/nameres/collector.rs @@ -14,8 +14,8 @@ use crate::{ attr::Attr, db::DefDatabase2, nameres::{ - diagnostics::DefDiagnostic, mod_resolution::ModDir, per_ns::PerNs, raw, CrateDefMap, - ModuleData, ReachedFixedPoint, Resolution, ResolveMode, + diagnostics::DefDiagnostic, mod_resolution::ModDir, path_resolution::ReachedFixedPoint, + per_ns::PerNs, raw, CrateDefMap, ModuleData, Resolution, ResolveMode, }, path::{Path, PathKind}, AdtId, AstId, AstItemDef, ConstId, CrateModuleId, EnumId, EnumVariantId, FunctionId, diff --git a/crates/ra_hir_def/src/nameres/path_resolution.rs b/crates/ra_hir_def/src/nameres/path_resolution.rs new file mode 100644 index 000000000..95692f826 --- /dev/null +++ b/crates/ra_hir_def/src/nameres/path_resolution.rs @@ -0,0 +1,261 @@ +//! This modules implements a function to resolve a path `foo::bar::baz` to a +//! def, which is used within the name resolution. +//! +//! When name resolution is finished, the result of resolving a path is either +//! `Some(def)` or `None`. However, when we are in process of resolving imports +//! or macros, there's a third possibility: +//! +//! I can't resolve this path right now, but I might be resolve this path +//! later, when more macros are expanded. +//! +//! `ReachedFixedPoint` signals about this. + +use hir_expand::name::Name; +use ra_db::Edition; +use test_utils::tested_by; + +use crate::{ + db::DefDatabase2, + nameres::{per_ns::PerNs, CrateDefMap}, + path::{Path, PathKind}, + AdtId, CrateModuleId, EnumVariantId, ModuleDefId, ModuleId, +}; + +#[derive(Debug, Clone, Copy, PartialEq, Eq)] +pub(super) enum ResolveMode { + Import, + Other, +} + +#[derive(Debug, Clone, Copy, PartialEq, Eq)] +pub(super) enum ReachedFixedPoint { + Yes, + No, +} + +#[derive(Debug, Clone)] +pub(super) struct ResolvePathResult { + pub(super) resolved_def: PerNs, + pub(super) segment_index: Option, + pub(super) reached_fixedpoint: ReachedFixedPoint, +} + +impl ResolvePathResult { + fn empty(reached_fixedpoint: ReachedFixedPoint) -> ResolvePathResult { + ResolvePathResult::with(PerNs::none(), reached_fixedpoint, None) + } + + fn with( + resolved_def: PerNs, + reached_fixedpoint: ReachedFixedPoint, + segment_index: Option, + ) -> ResolvePathResult { + ResolvePathResult { resolved_def, reached_fixedpoint, segment_index } + } +} + +impl CrateDefMap { + pub(super) fn resolve_name_in_extern_prelude(&self, name: &Name) -> PerNs { + self.extern_prelude.get(name).map_or(PerNs::none(), |&it| PerNs::types(it)) + } + + // Returns Yes if we are sure that additions to `ItemMap` wouldn't change + // the result. + pub(super) fn resolve_path_fp_with_macro( + &self, + db: &impl DefDatabase2, + mode: ResolveMode, + original_module: CrateModuleId, + path: &Path, + ) -> ResolvePathResult { + let mut segments = path.segments.iter().enumerate(); + let mut curr_per_ns: PerNs = match path.kind { + PathKind::DollarCrate(krate) => { + if krate == self.krate { + tested_by!(macro_dollar_crate_self); + PerNs::types(ModuleId { krate: self.krate, module_id: self.root }.into()) + } else { + let def_map = db.crate_def_map(krate); + let module = ModuleId { krate, module_id: def_map.root }; + tested_by!(macro_dollar_crate_other); + PerNs::types(module.into()) + } + } + PathKind::Crate => { + PerNs::types(ModuleId { krate: self.krate, module_id: self.root }.into()) + } + PathKind::Self_ => { + PerNs::types(ModuleId { krate: self.krate, module_id: original_module }.into()) + } + // plain import or absolute path in 2015: crate-relative with + // fallback to extern prelude (with the simplification in + // rust-lang/rust#57745) + // FIXME there must be a nicer way to write this condition + PathKind::Plain | PathKind::Abs + if self.edition == Edition::Edition2015 + && (path.kind == PathKind::Abs || mode == ResolveMode::Import) => + { + let segment = match segments.next() { + Some((_, segment)) => segment, + None => return ResolvePathResult::empty(ReachedFixedPoint::Yes), + }; + log::debug!("resolving {:?} in crate root (+ extern prelude)", segment); + self.resolve_name_in_crate_root_or_extern_prelude(&segment.name) + } + PathKind::Plain => { + let segment = match segments.next() { + Some((_, segment)) => segment, + None => return ResolvePathResult::empty(ReachedFixedPoint::Yes), + }; + log::debug!("resolving {:?} in module", segment); + self.resolve_name_in_module(db, original_module, &segment.name) + } + PathKind::Super => { + if let Some(p) = self.modules[original_module].parent { + PerNs::types(ModuleId { krate: self.krate, module_id: p }.into()) + } else { + log::debug!("super path in root module"); + return ResolvePathResult::empty(ReachedFixedPoint::Yes); + } + } + PathKind::Abs => { + // 2018-style absolute path -- only extern prelude + let segment = match segments.next() { + Some((_, segment)) => segment, + None => return ResolvePathResult::empty(ReachedFixedPoint::Yes), + }; + if let Some(def) = self.extern_prelude.get(&segment.name) { + log::debug!("absolute path {:?} resolved to crate {:?}", path, def); + PerNs::types(*def) + } else { + return ResolvePathResult::empty(ReachedFixedPoint::No); // extern crate declarations can add to the extern prelude + } + } + PathKind::Type(_) => { + // This is handled in `infer::infer_path_expr` + // The result returned here does not matter + return ResolvePathResult::empty(ReachedFixedPoint::Yes); + } + }; + + for (i, segment) in segments { + let curr = match curr_per_ns.take_types() { + Some(r) => r, + None => { + // we still have path segments left, but the path so far + // didn't resolve in the types namespace => no resolution + // (don't break here because `curr_per_ns` might contain + // something in the value namespace, and it would be wrong + // to return that) + return ResolvePathResult::empty(ReachedFixedPoint::No); + } + }; + // resolve segment in curr + + curr_per_ns = match curr { + ModuleDefId::ModuleId(module) => { + if module.krate != self.krate { + let path = + Path { segments: path.segments[i..].to_vec(), kind: PathKind::Self_ }; + log::debug!("resolving {:?} in other crate", path); + let defp_map = db.crate_def_map(module.krate); + let (def, s) = defp_map.resolve_path(db, module.module_id, &path); + return ResolvePathResult::with( + def, + ReachedFixedPoint::Yes, + s.map(|s| s + i), + ); + } + + // Since it is a qualified path here, it should not contains legacy macros + match self[module.module_id].scope.get(&segment.name) { + Some(res) => res.def, + _ => { + log::debug!("path segment {:?} not found", segment.name); + return ResolvePathResult::empty(ReachedFixedPoint::No); + } + } + } + ModuleDefId::AdtId(AdtId::EnumId(e)) => { + // enum variant + tested_by!(can_import_enum_variant); + let enum_data = db.enum_data(e); + match enum_data.variant(&segment.name) { + Some(local_id) => { + let variant = EnumVariantId { parent: e, local_id }; + PerNs::both(variant.into(), variant.into()) + } + None => { + return ResolvePathResult::with( + PerNs::types(e.into()), + ReachedFixedPoint::Yes, + Some(i), + ); + } + } + } + s => { + // could be an inherent method call in UFCS form + // (`Struct::method`), or some other kind of associated item + log::debug!( + "path segment {:?} resolved to non-module {:?}, but is not last", + segment.name, + curr, + ); + + return ResolvePathResult::with( + PerNs::types(s), + ReachedFixedPoint::Yes, + Some(i), + ); + } + }; + } + ResolvePathResult::with(curr_per_ns, ReachedFixedPoint::Yes, None) + } + + fn resolve_name_in_module( + &self, + db: &impl DefDatabase2, + module: CrateModuleId, + name: &Name, + ) -> PerNs { + // Resolve in: + // - legacy scope of macro + // - current module / scope + // - extern prelude + // - std prelude + let from_legacy_macro = + self[module].scope.get_legacy_macro(name).map_or_else(PerNs::none, PerNs::macros); + let from_scope = self[module].scope.get(name).map_or_else(PerNs::none, |res| res.def); + let from_extern_prelude = + self.extern_prelude.get(name).map_or(PerNs::none(), |&it| PerNs::types(it)); + let from_prelude = self.resolve_in_prelude(db, name); + + from_legacy_macro.or(from_scope).or(from_extern_prelude).or(from_prelude) + } + + fn resolve_name_in_crate_root_or_extern_prelude(&self, name: &Name) -> PerNs { + let from_crate_root = + self[self.root].scope.get(name).map_or_else(PerNs::none, |res| res.def); + let from_extern_prelude = self.resolve_name_in_extern_prelude(name); + + from_crate_root.or(from_extern_prelude) + } + + fn resolve_in_prelude(&self, db: &impl DefDatabase2, name: &Name) -> PerNs { + if let Some(prelude) = self.prelude { + let keep; + let def_map = if prelude.krate == self.krate { + self + } else { + // Extend lifetime + keep = db.crate_def_map(prelude.krate); + &keep + }; + def_map[prelude.module_id].scope.get(name).map_or_else(PerNs::none, |res| res.def) + } else { + PerNs::none() + } + } +} -- cgit v1.2.3