Don't expose hir::Path out of hir

Conjecture: it's impossible to use hir::Path *correctly* from an IDE.

I am not entirely sure about this, and we might need to add it back at
some point, but I have to arguments that convince me that we probably
won't:

* `hir::Path` has to know about hygiene, which an IDE can't set up
  properly.

* `hir::Path` lacks identity, but you actually have to know identity
  to resolve it correctly

4 files changed, 14 insertions, 45 deletions

diff --git a/crates/hir/src/code_model.rs b/crates/hir/src/code_model.rs
index 5dc3ae3b1..c442654dd 100644
--- a/crates/hir/src/code_model.rs
+++ b/crates/hir/src/code_model.rs
@@ -12,6 +12,7 @@ use hir_def::{
     docs::Documentation,
     expr::{BindingAnnotation, Pat, PatId},
     import_map,
+    path::ModPath,
     per_ns::PerNs,
     resolver::{HasResolver, Resolver},
     src::HasSource as _,
@@ -344,11 +345,7 @@ 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(
-        self,
-        db: &dyn DefDatabase,
-        item: impl Into<ItemInNs>,
-    ) -> Option<hir_def::path::ModPath> {
+    pub fn find_use_path(self, db: &dyn DefDatabase, item: impl Into<ItemInNs>) -> Option<ModPath> {
         hir_def::find_path::find_path(db, item.into(), self.into())
     }
 }
@@ -1126,7 +1123,7 @@ impl ImplDef {
             .value
             .attrs()
             .filter_map(|it| {
-                let path = hir_def::path::ModPath::from_src(it.path()?, &hygenic)?;
+                let path = ModPath::from_src(it.path()?, &hygenic)?;
                 if path.as_ident()?.to_string() == "derive" {
                     Some(it)
                 } else {
diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index 4ae2bd085..8961ba8fd 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -48,7 +48,7 @@ pub use hir_def::{
     builtin_type::BuiltinType,
     docs::Documentation,
     nameres::ModuleSource,
-    path::{ModPath, Path, PathKind},
+    path::ModPath,
     type_ref::{Mutability, TypeRef},
 };
 pub use hir_expand::{
@@ -60,4 +60,7 @@ pub use hir_ty::display::HirDisplay;
 // These are negative re-exports: pub using these names is forbidden, they
 // should remain private to hir internals.
 #[allow(unused)]
-use hir_expand::hygiene::Hygiene;
+use {
+    hir_def::path::{Path, PathKind},
+    hir_expand::hygiene::Hygiene,
+};
diff --git a/crates/hir/src/semantics.rs b/crates/hir/src/semantics.rs
index 3953017c3..c693176fa 100644
--- a/crates/hir/src/semantics.rs
+++ b/crates/hir/src/semantics.rs
@@ -6,7 +6,7 @@ use std::{cell::RefCell, fmt, iter::successors};
 
 use base_db::{FileId, FileRange};
 use hir_def::{
-    resolver::{self, HasResolver, Resolver},
+    resolver::{self, HasResolver, Resolver, TypeNs},
     AsMacroCall, FunctionId, TraitId, VariantId,
 };
 use hir_expand::{hygiene::Hygiene, name::AsName, ExpansionInfo};
@@ -22,12 +22,11 @@ use crate::{
     db::HirDatabase,
     diagnostics::Diagnostic,
     semantics::source_to_def::{ChildContainer, SourceToDefCache, SourceToDefCtx},
-    source_analyzer::{resolve_hir_path, resolve_hir_path_qualifier, SourceAnalyzer},
+    source_analyzer::{resolve_hir_path, SourceAnalyzer},
     AssocItem, Callable, Crate, Field, Function, HirFileId, ImplDef, InFile, Local, MacroDef,
     Module, ModuleDef, Name, Origin, Path, ScopeDef, Trait, Type, TypeAlias, TypeParam, TypeRef,
     VariantDef,
 };
-use resolver::TypeNs;
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum PathResolution {
@@ -228,10 +227,6 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         self.imp.resolve_variant(record_lit).map(VariantDef::from)
     }
 
-    pub fn lower_path(&self, path: &ast::Path) -> Option<Path> {
-        self.imp.lower_path(path)
-    }
-
     pub fn resolve_bind_pat_to_const(&self, pat: &ast::IdentPat) -> Option<ModuleDef> {
         self.imp.resolve_bind_pat_to_const(pat)
     }
@@ -467,11 +462,6 @@ impl<'db> SemanticsImpl<'db> {
         self.analyze(record_lit.syntax()).resolve_variant(self.db, record_lit)
     }
 
-    fn lower_path(&self, path: &ast::Path) -> Option<Path> {
-        let src = self.find_file(path.syntax().clone());
-        Path::from_src(path.clone(), &Hygiene::new(self.db.upcast(), src.file_id.into()))
-    }
-
     fn resolve_bind_pat_to_const(&self, pat: &ast::IdentPat) -> Option<ModuleDef> {
         self.analyze(pat.syntax()).resolve_bind_pat_to_const(self.db, pat)
     }
@@ -758,28 +748,7 @@ impl<'a> SemanticsScope<'a> {
     pub fn speculative_resolve(&self, path: &ast::Path) -> Option<PathResolution> {
         let hygiene = Hygiene::new(self.db.upcast(), self.file_id);
         let path = Path::from_src(path.clone(), &hygiene)?;
-        self.resolve_hir_path(&path)
-    }
-
-    pub fn resolve_hir_path(&self, path: &Path) -> Option<PathResolution> {
-        resolve_hir_path(self.db, &self.resolver, path)
-    }
-
-    /// Resolves a path where we know it is a qualifier of another path.
-    ///
-    /// For example, if we have:
-    /// ```
-    /// mod my {
-    ///     pub mod foo {
-    ///         struct Bar;
-    ///     }
-    ///
-    ///     pub fn foo() {}
-    /// }
-    /// ```
-    /// then we know that `foo` in `my::foo::Bar` refers to the module, not the function.
-    pub fn resolve_hir_path_qualifier(&self, path: &Path) -> Option<PathResolution> {
-        resolve_hir_path_qualifier(self.db, &self.resolver, path)
+        resolve_hir_path(self.db, &self.resolver, &path)
     }
 }
 
diff --git a/crates/hir/src/source_analyzer.rs b/crates/hir/src/source_analyzer.rs
index 8750584f9..1d13c4f1d 100644
--- a/crates/hir/src/source_analyzer.rs
+++ b/crates/hir/src/source_analyzer.rs
@@ -13,6 +13,7 @@ use hir_def::{
         Body, BodySourceMap,
     },
     expr::{ExprId, Pat, PatId},
+    path::{ModPath, Path, PathKind},
     resolver::{resolver_for_scope, Resolver, TypeNs, ValueNs},
     AsMacroCall, DefWithBodyId, FieldId, FunctionId, LocalFieldId, VariantId,
 };
@@ -28,8 +29,7 @@ use syntax::{
 
 use crate::{
     db::HirDatabase, semantics::PathResolution, Adt, Const, EnumVariant, Field, Function, Local,
-    MacroDef, ModPath, ModuleDef, Path, PathKind, Static, Struct, Trait, Type, TypeAlias,
-    TypeParam,
+    MacroDef, ModuleDef, Static, Struct, Trait, Type, TypeAlias, TypeParam,
 };
 use base_db::CrateId;
 
@@ -508,7 +508,7 @@ pub(crate) fn resolve_hir_path(
 /// }
 /// ```
 /// then we know that `foo` in `my::foo::Bar` refers to the module, not the function.
-pub(crate) fn resolve_hir_path_qualifier(
+fn resolve_hir_path_qualifier(
     db: &dyn HirDatabase,
     resolver: &Resolver,
     path: &Path,