Merge #2213

2213: Hir generic param r=flodiebold a=matklad

r? @flodiebold 

This should make the life of IDE easier: before, it got `GenericParam(u32)` which was of questionable utility. Now, it's a proper code_model type, so it can gain `source`, `name`, `module` and all the other hir methods, should the IDE need them. Moreover, IDE now doesn't care about internal representation of generic param, which seems like a long-term win. 

The problem is, of course, that we now have to types named `GenericParam` in hir: this code_model type, and an internal type with an index which doesn't know about the parent. I think it's fine for the time being, but, after we finish cratefication of hir, this local `GenericParam` should move to `hir_def` or `hir_ty`, and *maybe* restrucured as `ParamId / PramData` pair. 

Co-authored-by: Aleksey Kladov <[email protected]>

8 files changed, 32 insertions, 21 deletions

diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 09c4e97fa..5a0bd0c19 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -23,7 +23,7 @@ use crate::{
     adt::VariantDef,
     db::{AstDatabase, DefDatabase, HirDatabase},
     expr::{validation::ExprValidator, BindingAnnotation, Body, BodySourceMap, Pat, PatId},
-    generics::HasGenericParams,
+    generics::{GenericDef, HasGenericParams},
     ids::{
         AstItemDef, ConstId, EnumId, FunctionId, MacroDefId, StaticId, StructId, TraitId,
         TypeAliasId,
@@ -1121,3 +1121,9 @@ impl Local {
         src.map(|ast| ast.map(|it| it.cast().unwrap().to_node(&root), |it| it.to_node(&root)))
     }
 }
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub struct GenericParam {
+    pub(crate) parent: GenericDef,
+    pub(crate) idx: u32,
+}
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 806f1daed..92d71b9e8 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -39,7 +39,7 @@ mod ty;
 mod impl_block;
 mod expr;
 mod lang_item;
-mod generics;
+pub mod generics;
 mod resolve;
 pub mod diagnostics;
 mod util;
@@ -65,12 +65,12 @@ pub use crate::{
         docs::{DocDef, Docs, Documentation},
         src::{HasBodySource, HasSource},
         Adt, AssocItem, Const, ConstData, Container, Crate, CrateDependency, DefWithBody, Enum,
-        EnumVariant, FieldSource, FnData, Function, HasBody, Local, MacroDef, Module, ModuleDef,
-        ModuleSource, Static, Struct, StructField, Trait, TypeAlias, Union,
+        EnumVariant, FieldSource, FnData, Function, GenericParam, HasBody, Local, MacroDef, Module,
+        ModuleDef, ModuleSource, Static, Struct, StructField, Trait, TypeAlias, Union,
     },
     expr::ExprScopes,
     from_source::FromSource,
-    generics::{GenericDef, GenericParam, GenericParams, HasGenericParams},
+    generics::GenericDef,
     ids::{HirFileId, MacroCallId, MacroCallLoc, MacroDefId, MacroFile},
     impl_block::ImplBlock,
     resolve::ScopeDef,
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index c5fdf3bab..fe4211819 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -28,8 +28,8 @@ use crate::{
     ids::LocationCtx,
     resolve::{ScopeDef, TypeNs, ValueNs},
     ty::method_resolution::{self, implements_trait},
-    AssocItem, Const, DefWithBody, Either, Enum, FromSource, Function, HasBody, HirFileId, Local,
-    MacroDef, Module, Name, Path, Resolver, Static, Struct, Ty,
+    AssocItem, Const, DefWithBody, Either, Enum, FromSource, Function, GenericParam, HasBody,
+    HirFileId, Local, MacroDef, Module, Name, Path, Resolver, Static, Struct, Ty,
 };
 
 fn try_get_resolver_for_node(
@@ -107,7 +107,7 @@ pub enum PathResolution {
     /// A local binding (only value namespace)
     Local(Local),
     /// A generic parameter
-    GenericParam(u32),
+    GenericParam(GenericParam),
     SelfType(crate::ImplBlock),
     Macro(MacroDef),
     AssocItem(crate::AssocItem),
@@ -227,7 +227,10 @@ impl SourceAnalyzer {
     ) -> Option<PathResolution> {
         let types = self.resolver.resolve_path_in_type_ns_fully(db, &path).map(|ty| match ty {
             TypeNs::SelfType(it) => PathResolution::SelfType(it),
-            TypeNs::GenericParam(it) => PathResolution::GenericParam(it),
+            TypeNs::GenericParam(idx) => PathResolution::GenericParam(GenericParam {
+                parent: self.resolver.generic_def().unwrap(),
+                idx,
+            }),
             TypeNs::AdtSelfType(it) | TypeNs::Adt(it) => PathResolution::Def(it.into()),
             TypeNs::EnumVariant(it) => PathResolution::Def(it.into()),
             TypeNs::TypeAlias(it) => PathResolution::Def(it.into()),
diff --git a/crates/ra_hir/src/ty.rs b/crates/ra_hir/src/ty.rs
index cd2ac0e8b..6f24cfad6 100644
--- a/crates/ra_hir/src/ty.rs
+++ b/crates/ra_hir/src/ty.rs
@@ -17,8 +17,11 @@ use std::sync::Arc;
 use std::{fmt, iter, mem};
 
 use crate::{
-    db::HirDatabase, expr::ExprId, util::make_mut_slice, Adt, Crate, DefWithBody, GenericParams,
-    HasGenericParams, Mutability, Name, Trait, TypeAlias,
+    db::HirDatabase,
+    expr::ExprId,
+    generics::{GenericParams, HasGenericParams},
+    util::make_mut_slice,
+    Adt, Crate, DefWithBody, Mutability, Name, Trait, TypeAlias,
 };
 use display::{HirDisplay, HirFormatter};
 
@@ -342,10 +345,7 @@ impl Substs {
         )
     }
 
-    pub fn build_for_def(
-        db: &impl HirDatabase,
-        def: impl crate::HasGenericParams,
-    ) -> SubstsBuilder {
+    pub fn build_for_def(db: &impl HirDatabase, def: impl HasGenericParams) -> SubstsBuilder {
         let params = def.generic_params(db);
         let param_count = params.count_params_including_parent();
         Substs::builder(param_count)
diff --git a/crates/ra_hir/src/ty/autoderef.rs b/crates/ra_hir/src/ty/autoderef.rs
index 3645ee831..872a4517d 100644
--- a/crates/ra_hir/src/ty/autoderef.rs
+++ b/crates/ra_hir/src/ty/autoderef.rs
@@ -9,7 +9,7 @@ use hir_expand::name;
 use log::{info, warn};
 
 use super::{traits::Solution, Canonical, Substs, Ty, TypeWalk};
-use crate::{db::HirDatabase, HasGenericParams, Resolver};
+use crate::{db::HirDatabase, generics::HasGenericParams, Resolver};
 
 const AUTODEREF_RECURSION_LIMIT: usize = 10;
 
diff --git a/crates/ra_hir/src/ty/infer/path.rs b/crates/ra_hir/src/ty/infer/path.rs
index 865ced5a1..31ca675aa 100644
--- a/crates/ra_hir/src/ty/infer/path.rs
+++ b/crates/ra_hir/src/ty/infer/path.rs
@@ -5,9 +5,10 @@ use hir_def::path::PathSegment;
 use super::{ExprOrPatId, InferenceContext, TraitRef};
 use crate::{
     db::HirDatabase,
+    generics::HasGenericParams,
     resolve::{ResolveValueResult, Resolver, TypeNs, ValueNs},
     ty::{method_resolution, Namespace, Substs, Ty, TypableDef, TypeWalk},
-    AssocItem, Container, HasGenericParams, Name, Path,
+    AssocItem, Container, Name, Path,
 };
 
 impl<'a, D: HirDatabase> InferenceContext<'a, D> {
diff --git a/crates/ra_hir/src/ty/traits/chalk.rs b/crates/ra_hir/src/ty/traits/chalk.rs
index c694952f3..14c54b9fb 100644
--- a/crates/ra_hir/src/ty/traits/chalk.rs
+++ b/crates/ra_hir/src/ty/traits/chalk.rs
@@ -16,13 +16,13 @@ use ra_db::salsa::{InternId, InternKey};
 use super::{Canonical, ChalkContext, Impl, Obligation};
 use crate::{
     db::HirDatabase,
-    generics::GenericDef,
+    generics::{GenericDef, HasGenericParams},
     ty::display::HirDisplay,
     ty::{
         ApplicationTy, GenericPredicate, Namespace, ProjectionTy, Substs, TraitRef, Ty, TypeCtor,
         TypeWalk,
     },
-    AssocItem, Crate, HasGenericParams, ImplBlock, Trait, TypeAlias,
+    AssocItem, Crate, ImplBlock, Trait, TypeAlias,
 };
 
 /// This represents a trait whose name we could not resolve.
diff --git a/crates/ra_ide_api/src/references/name_definition.rs b/crates/ra_ide_api/src/references/name_definition.rs
index 450f7ea9b..ccd75278a 100644
--- a/crates/ra_ide_api/src/references/name_definition.rs
+++ b/crates/ra_ide_api/src/references/name_definition.rs
@@ -4,7 +4,8 @@
 //! Note that the reference search is possible for not all of the classified items.
 
 use hir::{
-    Adt, AssocItem, HasSource, Local, MacroDef, Module, ModuleDef, StructField, Ty, VariantDef,
+    Adt, AssocItem, GenericParam, HasSource, Local, MacroDef, Module, ModuleDef, StructField, Ty,
+    VariantDef,
 };
 use ra_syntax::{ast, ast::VisibilityOwner};
 
@@ -18,7 +19,7 @@ pub enum NameKind {
     Def(ModuleDef),
     SelfType(Ty),
     Local(Local),
-    GenericParam(u32),
+    GenericParam(GenericParam),
 }
 
 #[derive(PartialEq, Eq)]