fix: Fix general find-path inconsistencies

Author: Veykril

src/tools/rust-analyzer/crates/hir-def/src/find_path.rs

@@ -1,13 +1,12 @@
 //! A map of all publicly exported items in a crate.
 
-use std::{fmt, hash::BuildHasherDefault};
+use std::fmt;
 
 use base_db::CrateId;
 use fst::{raw::IndexedValue, Automaton, Streamer};
 use hir_expand::name::Name;
-use indexmap::IndexMap;
 use itertools::Itertools;
-use rustc_hash::{FxHashSet, FxHasher};
+use rustc_hash::FxHashSet;
 use smallvec::SmallVec;
 use stdx::{format_to, TupleExt};
 use triomphe::Arc;
@@ -17,7 +16,7 @@ use crate::{
     item_scope::{ImportOrExternCrate, ItemInNs},
     nameres::DefMap,
     visibility::Visibility,
-    AssocItemId, ModuleDefId, ModuleId, TraitId,
+    AssocItemId, FxIndexMap, ModuleDefId, ModuleId, TraitId,
 };
 
 /// Item import details stored in the `ImportMap`.
@@ -58,7 +57,6 @@ enum IsTraitAssocItem {
     No,
 }
 
-type FxIndexMap<K, V> = IndexMap<K, V, BuildHasherDefault<FxHasher>>;
 type ImportMapIndex = FxIndexMap<ItemInNs, (SmallVec<[ImportInfo; 1]>, IsTraitAssocItem)>;
 
 impl ImportMap {

src/tools/rust-analyzer/crates/hir-def/src/import_map.rs

@@ -295,7 +295,7 @@ impl ItemScope {
     pub(crate) fn names_of<T>(
         &self,
         item: ItemInNs,
-        mut cb: impl FnMut(&Name, Visibility, bool) -> Option<T>,
+        mut cb: impl FnMut(&Name, Visibility, /*declared*/ bool) -> Option<T>,
     ) -> Option<T> {
         match item {
             ItemInNs::Macros(def) => self

src/tools/rust-analyzer/crates/hir-def/src/item_scope.rs

@@ -106,6 +106,9 @@ use crate::{
     },
 };
 
+type FxIndexMap<K, V> =
+    indexmap::IndexMap<K, V, std::hash::BuildHasherDefault<rustc_hash::FxHasher>>;
+
 #[derive(Debug)]
 pub struct ItemLoc<N: ItemTreeNode> {
     pub container: ModuleId,
@@ -455,6 +458,26 @@ impl ModuleId {
     pub fn is_block_module(self) -> bool {
         self.block.is_some() && self.local_id == DefMap::ROOT
     }
+
+    pub fn is_within_block(self) -> bool {
+        self.block.is_some()
+    }
+
+    pub fn as_crate_root(&self) -> Option<CrateRootModuleId> {
+        if self.local_id == DefMap::ROOT && self.block.is_none() {
+            Some(CrateRootModuleId { krate: self.krate })
+        } else {
+            None
+        }
+    }
+
+    pub fn derive_crate_root(&self) -> CrateRootModuleId {
+        CrateRootModuleId { krate: self.krate }
+    }
+
+    fn is_crate_root(&self) -> bool {
+        self.local_id == DefMap::ROOT && self.block.is_none()
+    }
 }
 
 impl PartialEq<CrateRootModuleId> for ModuleId {

src/tools/rust-analyzer/crates/hir-def/src/lib.rs

@@ -81,7 +81,7 @@ use crate::{
     per_ns::PerNs,
     visibility::{Visibility, VisibilityExplicitness},
     AstId, BlockId, BlockLoc, CrateRootModuleId, EnumId, EnumVariantId, ExternCrateId, FunctionId,
-    LocalModuleId, Lookup, MacroExpander, MacroId, ModuleId, ProcMacroId, UseId,
+    FxIndexMap, LocalModuleId, Lookup, MacroExpander, MacroId, ModuleId, ProcMacroId, UseId,
 };
 
 /// Contains the results of (early) name resolution.
@@ -129,7 +129,7 @@ pub struct DefMap {
 #[derive(Clone, Debug, PartialEq, Eq)]
 struct DefMapCrateData {
     /// The extern prelude which contains all root modules of external crates that are in scope.
-    extern_prelude: FxHashMap<Name, (CrateRootModuleId, Option<ExternCrateId>)>,
+    extern_prelude: FxIndexMap<Name, (CrateRootModuleId, Option<ExternCrateId>)>,
 
     /// Side table for resolving derive helpers.
     exported_derives: FxHashMap<MacroDefId, Box<[Name]>>,
@@ -155,7 +155,7 @@ struct DefMapCrateData {
 impl DefMapCrateData {
     fn new(edition: Edition) -> Self {
         Self {
-            extern_prelude: FxHashMap::default(),
+            extern_prelude: FxIndexMap::default(),
             exported_derives: FxHashMap::default(),
             fn_proc_macro_mapping: FxHashMap::default(),
             proc_macro_loading_error: None,
@@ -578,7 +578,8 @@ impl DefMap {
 
     pub(crate) fn extern_prelude(
         &self,
-    ) -> impl Iterator<Item = (&Name, (CrateRootModuleId, Option<ExternCrateId>))> + '_ {
+    ) -> impl DoubleEndedIterator<Item = (&Name, (CrateRootModuleId, Option<ExternCrateId>))> + '_
+    {
         self.data.extern_prelude.iter().map(|(name, &def)| (name, def))
     }
 

src/tools/rust-analyzer/crates/hir-def/src/nameres.rs

@@ -1,12 +1,11 @@
 //! Name resolution façade.
-use std::{fmt, hash::BuildHasherDefault, iter, mem};
+use std::{fmt, iter, mem};
 
 use base_db::CrateId;
 use hir_expand::{
     name::{name, Name},
     MacroDefId,
 };
-use indexmap::IndexMap;
 use intern::Interned;
 use rustc_hash::FxHashSet;
 use smallvec::{smallvec, SmallVec};
@@ -27,10 +26,10 @@ use crate::{
     type_ref::LifetimeRef,
     visibility::{RawVisibility, Visibility},
     AdtId, ConstId, ConstParamId, CrateRootModuleId, DefWithBodyId, EnumId, EnumVariantId,
-    ExternBlockId, ExternCrateId, FunctionId, GenericDefId, GenericParamId, HasModule, ImplId,
-    ItemContainerId, ItemTreeLoc, LifetimeParamId, LocalModuleId, Lookup, Macro2Id, MacroId,
-    MacroRulesId, ModuleDefId, ModuleId, ProcMacroId, StaticId, StructId, TraitAliasId, TraitId,
-    TypeAliasId, TypeOrConstParamId, TypeOwnerId, TypeParamId, UseId, VariantId,
+    ExternBlockId, ExternCrateId, FunctionId, FxIndexMap, GenericDefId, GenericParamId, HasModule,
+    ImplId, ItemContainerId, ItemTreeLoc, LifetimeParamId, LocalModuleId, Lookup, Macro2Id,
+    MacroId, MacroRulesId, ModuleDefId, ModuleId, ProcMacroId, StaticId, StructId, TraitAliasId,
+    TraitId, TypeAliasId, TypeOrConstParamId, TypeOwnerId, TypeParamId, UseId, VariantId,
 };
 
 #[derive(Debug, Clone)]
@@ -957,7 +956,6 @@ fn to_type_ns(per_ns: PerNs) -> Option<(TypeNs, Option<ImportOrExternCrate>)> {
     Some((res, import))
 }
 
-type FxIndexMap<K, V> = IndexMap<K, V, BuildHasherDefault<rustc_hash::FxHasher>>;
 #[derive(Default)]
 struct ScopeNames {
     map: FxIndexMap<Name, SmallVec<[ScopeDef; 1]>>,

src/tools/rust-analyzer/crates/hir-def/src/resolver.rs

@@ -13,7 +13,7 @@ use either::Either;
 use hir_def::{
     data::adt::VariantData,
     db::DefDatabase,
-    find_path,
+    find_path::{self, PrefixKind},
     generics::{TypeOrConstParamData, TypeParamProvenance},
     item_scope::ItemInNs,
     lang_item::{LangItem, LangItemTarget},
@@ -999,6 +999,8 @@ impl HirDisplay for Ty {
                             db.upcast(),
                             ItemInNs::Types((*def_id).into()),
                             module_id,
+                            PrefixKind::Plain,
+                            false,
                             false,
                             true,
                         ) {

src/tools/rust-analyzer/crates/hir-ty/src/display.rs

@@ -789,7 +789,7 @@ impl Module {
 
     /// Finds a path that can be used to refer to the given item from within
     /// this module, if possible.
-    pub fn find_use_path(
+    pub fn find_path(
         self,
         db: &dyn DefDatabase,
         item: impl Into<ItemInNs>,
@@ -800,26 +800,29 @@ impl Module {
             db,
             item.into().into(),
             self.into(),
+            PrefixKind::Plain,
+            false,
             prefer_no_std,
             prefer_prelude,
         )
     }
 
     /// Finds a path that can be used to refer to the given item from within
     /// this module, if possible. This is used for returning import paths for use-statements.
-    pub fn find_use_path_prefixed(
+    pub fn find_use_path(
         self,
         db: &dyn DefDatabase,
         item: impl Into<ItemInNs>,
         prefix_kind: PrefixKind,
         prefer_no_std: bool,
         prefer_prelude: bool,
     ) -> Option<ModPath> {
-        hir_def::find_path::find_path_prefixed(
+        hir_def::find_path::find_path(
             db,
             item.into().into(),
             self.into(),
             prefix_kind,
+            true,
             prefer_no_std,
             prefer_prelude,
         )

src/tools/rust-analyzer/crates/hir/src/lib.rs

@@ -33,16 +33,11 @@ fn mod_item_path(
     });
 
     let m = sema_scope.module();
-    match name_hit_count {
-        Some(0..=1) | None => m.find_use_path(db.upcast(), *def, prefer_no_std, prefer_prelude),
-        Some(_) => m.find_use_path_prefixed(
-            db.upcast(),
-            *def,
-            PrefixKind::ByCrate,
-            prefer_no_std,
-            prefer_prelude,
-        ),
-    }
+    let prefix = match name_hit_count {
+        Some(0..=1) | None => PrefixKind::Plain,
+        Some(_) => PrefixKind::ByCrate,
+    };
+    m.find_use_path(db.upcast(), *def, prefix, prefer_no_std, prefer_prelude)
 }
 
 /// Helper function to get path to `ModuleDef` as string

src/tools/rust-analyzer/crates/hir/src/term_search/expr.rs

@@ -462,7 +462,7 @@ fn build_pat(
 ) -> Option<ast::Pat> {
     match var {
         ExtendedVariant::Variant(var) => {
-            let path = mod_path_to_ast(&module.find_use_path(
+            let path = mod_path_to_ast(&module.find_path(
                 db,
                 ModuleDef::from(var),
                 prefer_no_std,