fix: Various find path fixes

crates/hir-def/src/import_map.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 {

crates/hir-def/src/item_scope.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

crates/hir-def/src/lib.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 {

crates/hir-def/src/nameres.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))
     }
 

crates/hir-def/src/resolver.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]>>,

crates/hir-ty/src/display.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,
                         ) {

crates/hir/src/lib.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,
         )

crates/hir/src/term_search/expr.rs

@@ -1,6 +1,5 @@
 //! Type tree for term search
 
-use hir_def::find_path::PrefixKind;
 use hir_expand::mod_path::ModPath;
 use hir_ty::{
     db::HirDatabase,
@@ -21,28 +20,8 @@ fn mod_item_path(
     prefer_prelude: bool,
 ) -> Option<ModPath> {
     let db = sema_scope.db;
-    // Account for locals shadowing items from module
-    let name_hit_count = def.name(db).map(|def_name| {
-        let mut name_hit_count = 0;
-        sema_scope.process_all_names(&mut |name, _| {
-            if name == def_name {
-                name_hit_count += 1;
-            }
-        });
-        name_hit_count
-    });
-
     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,
-        ),
-    }
+    m.find_path(db.upcast(), *def, prefer_no_std, prefer_prelude)
 }
 
 /// Helper function to get path to `ModuleDef` as string

crates/ide-assists/src/handlers/add_missing_match_arms.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,

crates/ide-assists/src/handlers/bool_to_enum.rs

@@ -341,7 +341,7 @@ fn augment_references_with_imports(
 
                 let import_scope = ImportScope::find_insert_use_container(name.syntax(), &ctx.sema);
                 let path = ref_module
-                    .find_use_path_prefixed(
+                    .find_use_path(
                         ctx.sema.db,
                         ModuleDef::Module(*target_module),
                         ctx.config.insert_use.prefix_kind,
@@ -1521,7 +1521,7 @@ mod foo {
 }
 "#,
             r#"
-use crate::foo::Bool;
+use foo::Bool;
 
 fn main() {
     use foo::FOO;
@@ -1602,7 +1602,7 @@ pub mod bar {
 "#,
             r#"
 //- /main.rs
-use crate::foo::bar::Bool;
+use foo::bar::Bool;
 
 mod foo;
 

crates/ide-assists/src/handlers/convert_into_to_from.rs

@@ -50,7 +50,7 @@ pub(crate) fn convert_into_to_from(acc: &mut Assists, ctx: &AssistContext<'_>) -
             _ => return None,
         };
 
-        mod_path_to_ast(&module.find_use_path(
+        mod_path_to_ast(&module.find_path(
             ctx.db(),
             src_type_def,
             ctx.config.prefer_no_std,

crates/ide-assists/src/handlers/convert_tuple_return_type_to_struct.rs

@@ -201,7 +201,7 @@ fn augment_references_with_imports(
                 let import_scope =
                     ImportScope::find_insert_use_container(new_name.syntax(), &ctx.sema);
                 let path = ref_module
-                    .find_use_path_prefixed(
+                    .find_use_path(
                         ctx.sema.db,
                         ModuleDef::Module(*target_module),
                         ctx.config.insert_use.prefix_kind,
@@ -811,7 +811,7 @@ pub mod bar {
 "#,
             r#"
 //- /main.rs
-use crate::foo::bar::BarResult;
+use foo::bar::BarResult;
 
 mod foo;
 

crates/ide-assists/src/handlers/destructure_struct_binding.rs

@@ -90,7 +90,7 @@ fn collect_data(ident_pat: ast::IdentPat, ctx: &AssistContext<'_>) -> Option<Str
     let module = ctx.sema.scope(ident_pat.syntax())?.module();
     let struct_def = hir::ModuleDef::from(struct_type);
     let kind = struct_type.kind(ctx.db());
-    let struct_def_path = module.find_use_path(
+    let struct_def_path = module.find_path(
         ctx.db(),
         struct_def,
         ctx.config.prefer_no_std,

crates/ide-assists/src/handlers/extract_function.rs

@@ -209,7 +209,7 @@ pub(crate) fn extract_function(acc: &mut Assists, ctx: &AssistContext<'_>) -> Op
                     FamousDefs(&ctx.sema, module.krate()).core_ops_ControlFlow();
 
                 if let Some(control_flow_enum) = control_flow_enum {
-                    let mod_path = module.find_use_path_prefixed(
+                    let mod_path = module.find_use_path(
                         ctx.sema.db,
                         ModuleDef::from(control_flow_enum),
                         ctx.config.insert_use.prefix_kind,

crates/ide-assists/src/handlers/extract_struct_from_enum_variant.rs

@@ -386,7 +386,7 @@ fn process_references(
             let segment = builder.make_mut(segment);
             let scope_node = builder.make_syntax_mut(scope_node);
             if !visited_modules.contains(&module) {
-                let mod_path = module.find_use_path_prefixed(
+                let mod_path = module.find_use_path(
                     ctx.sema.db,
                     *enum_module_def,
                     ctx.config.insert_use.prefix_kind,
@@ -881,7 +881,7 @@ fn another_fn() {
             r#"use my_mod::my_other_mod::MyField;
 
 mod my_mod {
-    use self::my_other_mod::MyField;
+    use my_other_mod::MyField;
 
     fn another_fn() {
         let m = my_other_mod::MyEnum::MyField(MyField(1, 1));

crates/ide-assists/src/handlers/generate_deref.rs

@@ -58,7 +58,7 @@ fn generate_record_deref(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option<(
 
     let module = ctx.sema.to_def(&strukt)?.module(ctx.db());
     let trait_ = deref_type_to_generate.to_trait(&ctx.sema, module.krate())?;
-    let trait_path = module.find_use_path(
+    let trait_path = module.find_path(
         ctx.db(),
         ModuleDef::Trait(trait_),
         ctx.config.prefer_no_std,
@@ -103,7 +103,7 @@ fn generate_tuple_deref(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option<()
 
     let module = ctx.sema.to_def(&strukt)?.module(ctx.db());
     let trait_ = deref_type_to_generate.to_trait(&ctx.sema, module.krate())?;
-    let trait_path = module.find_use_path(
+    let trait_path = module.find_path(
         ctx.db(),
         ModuleDef::Trait(trait_),
         ctx.config.prefer_no_std,

crates/ide-assists/src/handlers/generate_new.rs

@@ -58,7 +58,7 @@ pub(crate) fn generate_new(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option
 
                 let item_in_ns = hir::ItemInNs::from(hir::ModuleDef::from(ty.as_adt()?));
 
-                let type_path = current_module.find_use_path(
+                let type_path = current_module.find_path(
                     ctx.sema.db,
                     item_for_path_search(ctx.sema.db, item_in_ns)?,
                     ctx.config.prefer_no_std,

crates/ide-assists/src/handlers/qualify_method_call.rs

@@ -44,7 +44,7 @@ pub(crate) fn qualify_method_call(acc: &mut Assists, ctx: &AssistContext<'_>) ->
     let current_module = ctx.sema.scope(call.syntax())?.module();
     let target_module_def = ModuleDef::from(resolved_call);
     let item_in_ns = ItemInNs::from(target_module_def);
-    let receiver_path = current_module.find_use_path(
+    let receiver_path = current_module.find_path(
         ctx.sema.db,
         item_for_path_search(ctx.sema.db, item_in_ns)?,
         ctx.config.prefer_no_std,

crates/ide-assists/src/handlers/replace_derive_with_manual_impl.rs

@@ -83,7 +83,7 @@ pub(crate) fn replace_derive_with_manual_impl(
     })
     .flat_map(|trait_| {
         current_module
-            .find_use_path(
+            .find_path(
                 ctx.sema.db,
                 hir::ModuleDef::Trait(trait_),
                 ctx.config.prefer_no_std,