Handle impl generics in method calls

7 files changed, 122 insertions, 77 deletions

diff --git a/crates/ra_hir/src/code_model_api.rs b/crates/ra_hir/src/code_model_api.rs
index 99f004905..26ebc445b 100644
--- a/crates/ra_hir/src/code_model_api.rs
+++ b/crates/ra_hir/src/code_model_api.rs
@@ -463,7 +463,7 @@ impl Function {
         self.id.source(db)
     }
 
-    pub fn module(&self, db: &impl HirDatabase) -> Module {
+    pub fn module(&self, db: &impl PersistentHirDatabase) -> Module {
         self.id.module(db)
     }
 
@@ -497,6 +497,12 @@ impl Function {
         db.generic_params((*self).into())
     }
 
+    /// The containing impl block, if this is a method.
+    pub fn impl_block(&self, db: &impl PersistentHirDatabase) -> Option<ImplBlock> {
+        let module_impls = db.impls_in_module(self.module(db));
+        ImplBlock::containing(module_impls, (*self).into())
+    }
+
     // TODO: move to a more general type for 'body-having' items
     /// Builds a resolver for code inside this item.
     pub fn resolver(&self, db: &impl HirDatabase) -> Resolver {
@@ -527,6 +533,16 @@ impl Const {
     pub fn source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, TreeArc<ast::ConstDef>) {
         self.id.source(db)
     }
+
+    pub fn module(&self, db: &impl PersistentHirDatabase) -> Module {
+        self.id.module(db)
+    }
+
+    /// The containing impl block, if this is a method.
+    pub fn impl_block(&self, db: &impl PersistentHirDatabase) -> Option<ImplBlock> {
+        let module_impls = db.impls_in_module(self.module(db));
+        ImplBlock::containing(module_impls, (*self).into())
+    }
 }
 
 impl Docs for Const {
@@ -544,6 +560,10 @@ impl Static {
     pub fn source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, TreeArc<ast::StaticDef>) {
         self.id.source(db)
     }
+
+    pub fn module(&self, db: &impl PersistentHirDatabase) -> Module {
+        self.id.module(db)
+    }
 }
 
 impl Docs for Static {
@@ -562,6 +582,10 @@ impl Trait {
         self.id.source(db)
     }
 
+    pub fn module(&self, db: &impl PersistentHirDatabase) -> Module {
+        self.id.module(db)
+    }
+
     pub fn generic_params(&self, db: &impl PersistentHirDatabase) -> Arc<GenericParams> {
         db.generic_params((*self).into())
     }
@@ -586,6 +610,16 @@ impl Type {
     pub fn generic_params(&self, db: &impl PersistentHirDatabase) -> Arc<GenericParams> {
         db.generic_params((*self).into())
     }
+
+    pub fn module(&self, db: &impl PersistentHirDatabase) -> Module {
+        self.id.module(db)
+    }
+
+    /// The containing impl block, if this is a method.
+    pub fn impl_block(&self, db: &impl PersistentHirDatabase) -> Option<ImplBlock> {
+        let module_impls = db.impls_in_module(self.module(db));
+        ImplBlock::containing(module_impls, (*self).into())
+    }
 }
 
 impl Docs for Type {
diff --git a/crates/ra_hir/src/code_model_impl/function.rs b/crates/ra_hir/src/code_model_impl/function.rs
index b9438fdb7..c401528c6 100644
--- a/crates/ra_hir/src/code_model_impl/function.rs
+++ b/crates/ra_hir/src/code_model_impl/function.rs
@@ -3,22 +3,11 @@ use std::sync::Arc;
 use ra_syntax::ast::{self, NameOwner};
 
 use crate::{
-    HirDatabase, Name, AsName, Function, FnSignature,
+    Name, AsName, Function, FnSignature,
     type_ref::{TypeRef, Mutability},
     PersistentHirDatabase,
-    impl_block::ImplBlock,
 };
 
-impl Function {
-    // TODO impl_block should probably also be part of the code model API?
-
-    /// The containing impl block, if this is a method.
-    pub(crate) fn impl_block(&self, db: &impl HirDatabase) -> Option<ImplBlock> {
-        let module_impls = db.impls_in_module(self.module(db));
-        ImplBlock::containing(module_impls, (*self).into())
-    }
-}
-
 impl FnSignature {
     pub(crate) fn fn_signature_query(
         db: &impl PersistentHirDatabase,
diff --git a/crates/ra_hir/src/generics.rs b/crates/ra_hir/src/generics.rs
index 6ae0ead1b..fcc513353 100644
--- a/crates/ra_hir/src/generics.rs
+++ b/crates/ra_hir/src/generics.rs
@@ -20,6 +20,7 @@ pub struct GenericParam {
 /// Data about the generic parameters of a function, struct, impl, etc.
 #[derive(Clone, PartialEq, Eq, Debug, Default)]
 pub struct GenericParams {
+    pub(crate) parent_params: Option<Arc<GenericParams>>,
     pub(crate) params: Vec<GenericParam>,
 }
 
@@ -40,28 +41,36 @@ impl GenericParams {
         def: GenericDef,
     ) -> Arc<GenericParams> {
         let mut generics = GenericParams::default();
+        let parent = match def {
+            GenericDef::Function(it) => it.impl_block(db),
+            GenericDef::Type(it) => it.impl_block(db),
+            GenericDef::Struct(_) | GenericDef::Enum(_) | GenericDef::Trait(_) => None,
+            GenericDef::ImplBlock(_) => None,
+        };
+        generics.parent_params = parent.map(|p| p.generic_params(db));
+        let start = generics.parent_params.as_ref().map(|p| p.params.len()).unwrap_or(0) as u32;
         match def {
-            GenericDef::Function(it) => generics.fill(&*it.source(db).1),
-            GenericDef::Struct(it) => generics.fill(&*it.source(db).1),
-            GenericDef::Enum(it) => generics.fill(&*it.source(db).1),
-            GenericDef::Trait(it) => generics.fill(&*it.source(db).1),
-            GenericDef::Type(it) => generics.fill(&*it.source(db).1),
-            GenericDef::ImplBlock(it) => generics.fill(&*it.source(db).1),
+            GenericDef::Function(it) => generics.fill(&*it.source(db).1, start),
+            GenericDef::Struct(it) => generics.fill(&*it.source(db).1, start),
+            GenericDef::Enum(it) => generics.fill(&*it.source(db).1, start),
+            GenericDef::Trait(it) => generics.fill(&*it.source(db).1, start),
+            GenericDef::Type(it) => generics.fill(&*it.source(db).1, start),
+            GenericDef::ImplBlock(it) => generics.fill(&*it.source(db).1, start),
         }
 
         Arc::new(generics)
     }
 
-    fn fill(&mut self, node: &impl TypeParamsOwner) {
+    fn fill(&mut self, node: &impl TypeParamsOwner, start: u32) {
         if let Some(params) = node.type_param_list() {
-            self.fill_params(params)
+            self.fill_params(params, start)
         }
     }
 
-    fn fill_params(&mut self, params: &ast::TypeParamList) {
+    fn fill_params(&mut self, params: &ast::TypeParamList, start: u32) {
         for (idx, type_param) in params.type_params().enumerate() {
             let name = type_param.name().map(AsName::as_name).unwrap_or_else(Name::missing);
-            let param = GenericParam { idx: idx as u32, name };
+            let param = GenericParam { idx: idx as u32 + start, name };
             self.params.push(param);
         }
     }
@@ -69,4 +78,13 @@ impl GenericParams {
     pub(crate) fn find_by_name(&self, name: &Name) -> Option<&GenericParam> {
         self.params.iter().find(|p| &p.name == name)
     }
+
+    pub fn count_parent_params(&self) -> usize {
+        self.parent_params.as_ref().map(|p| p.count_params_including_parent()).unwrap_or(0)
+    }
+
+    pub fn count_params_including_parent(&self) -> usize {
+        let parent_count = self.count_parent_params();
+        parent_count + self.params.len()
+    }
 }
diff --git a/crates/ra_hir/src/ids.rs b/crates/ra_hir/src/ids.rs
index 3e11dd6ad..6df037859 100644
--- a/crates/ra_hir/src/ids.rs
+++ b/crates/ra_hir/src/ids.rs
@@ -9,7 +9,6 @@ use ra_syntax::{TreeArc, SyntaxNode, SourceFile, AstNode, SyntaxNodePtr, ast};
 use ra_arena::{Arena, RawId, ArenaId, impl_arena_id};
 
 use crate::{
-    HirDatabase,
     Module,
     PersistentHirDatabase,
 };
@@ -215,7 +214,7 @@ pub(crate) trait AstItemDef<N: AstNode>: ArenaId + Clone {
             N::cast(&syntax).unwrap_or_else(|| panic!("invalid ItemLoc: {:?}", loc.raw)).to_owned();
         (loc.raw.file_id, ast)
     }
-    fn module(self, db: &impl HirDatabase) -> Module {
+    fn module(self, db: &impl PersistentHirDatabase) -> Module {
         let int = Self::interner(db.as_ref());
         let loc = int.id2loc(self);
         loc.module
diff --git a/crates/ra_hir/src/ty.rs b/crates/ra_hir/src/ty.rs
index f28a7e731..db0a20514 100644
--- a/crates/ra_hir/src/ty.rs
+++ b/crates/ra_hir/src/ty.rs
@@ -421,7 +421,8 @@ impl Ty {
                 (var.parent_enum(db).generic_params(db), segment)
             }
         };
-        // substs_from_path
+        let parent_param_count = def_generics.count_parent_params();
+        substs.extend((0..parent_param_count).map(|_| Ty::Unknown));
         if let Some(generic_args) = &segment.args_and_bindings {
             // if args are provided, it should be all of them, but we can't rely on that
             let param_count = def_generics.params.len();
@@ -436,9 +437,8 @@ impl Ty {
         }
         // add placeholders for args that were not provided
         // TODO: handle defaults
-        let supplied_params =
-            segment.args_and_bindings.as_ref().map(|ga| ga.args.len()).unwrap_or(0);
-        for _ in supplied_params..def_generics.params.len() {
+        let supplied_params = substs.len();
+        for _ in supplied_params..def_generics.count_params_including_parent() {
             substs.push(Ty::Unknown);
         }
         assert_eq!(substs.len(), def_generics.params.len());
@@ -666,7 +666,12 @@ fn type_for_fn(db: &impl HirDatabase, def: Function) -> Ty {
 }
 
 fn make_substs(generics: &GenericParams) -> Substs {
-    Substs(generics.params.iter().map(|_p| Ty::Unknown).collect::<Vec<_>>().into())
+    Substs(
+        (0..generics.count_params_including_parent())
+            .map(|_p| Ty::Unknown)
+            .collect::<Vec<_>>()
+            .into(),
+    )
 }
 
 fn type_for_struct(db: &impl HirDatabase, s: Struct) -> Ty {
diff --git a/crates/ra_hir/src/ty/snapshots/tests__infer_generic_chain.snap b/crates/ra_hir/src/ty/snapshots/tests__infer_generic_chain.snap
index 626f31252..d1ce87b0a 100644
--- a/crates/ra_hir/src/ty/snapshots/tests__infer_generic_chain.snap
+++ b/crates/ra_hir/src/ty/snapshots/tests__infer_generic_chain.snap
@@ -1,36 +1,36 @@
 ---
-created: "2019-01-27T14:52:29.938713255+00:00"
-creator: [email protected]
-expression: "&result"
+created: "2019-02-16T20:53:59.655361804Z"
+creator: [email protected]
 source: crates/ra_hir/src/ty/tests.rs
+expression: "&result"
 ---
-[53; 57) 'self': A<[unknown]>
-[65; 87) '{     ...     }': [unknown]
-[75; 79) 'self': A<[unknown]>
-[75; 81) 'self.x': [unknown]
+[53; 57) 'self': A<T2>
+[65; 87) '{     ...     }': T2
+[75; 79) 'self': A<T2>
+[75; 81) 'self.x': T2
 [99; 100) 't': T
 [110; 115) '{ t }': T
 [112; 113) 't': T
 [135; 261) '{     ....x() }': i128
-[146; 147) 'x': i32
-[150; 151) '1': i32
-[162; 163) 'y': i32
-[166; 168) 'id': fn id<i32>(T) -> T
-[166; 171) 'id(x)': i32
-[169; 170) 'x': i32
-[182; 183) 'a': A<i32>
-[186; 200) 'A { x: id(y) }': A<i32>
-[193; 195) 'id': fn id<i32>(T) -> T
-[193; 198) 'id(y)': i32
-[196; 197) 'y': i32
-[211; 212) 'z': i32
-[215; 217) 'id': fn id<i32>(T) -> T
-[215; 222) 'id(a.x)': i32
-[218; 219) 'a': A<i32>
-[218; 221) 'a.x': i32
-[233; 234) 'b': A<i32>
-[237; 247) 'A { x: z }': A<i32>
-[244; 245) 'z': i32
-[254; 255) 'b': A<i32>
+[146; 147) 'x': i128
+[150; 151) '1': i128
+[162; 163) 'y': i128
+[166; 168) 'id': fn id<i128>(T) -> T
+[166; 171) 'id(x)': i128
+[169; 170) 'x': i128
+[182; 183) 'a': A<i128>
+[186; 200) 'A { x: id(y) }': A<i128>
+[193; 195) 'id': fn id<i128>(T) -> T
+[193; 198) 'id(y)': i128
+[196; 197) 'y': i128
+[211; 212) 'z': i128
+[215; 217) 'id': fn id<i128>(T) -> T
+[215; 222) 'id(a.x)': i128
+[218; 219) 'a': A<i128>
+[218; 221) 'a.x': i128
+[233; 234) 'b': A<i128>
+[237; 247) 'A { x: z }': A<i128>
+[244; 245) 'z': i128
+[254; 255) 'b': A<i128>
 [254; 259) 'b.x()': i128
 
diff --git a/crates/ra_hir/src/ty/snapshots/tests__infer_impl_generics.snap b/crates/ra_hir/src/ty/snapshots/tests__infer_impl_generics.snap
index 99df39fc2..eabbe52fd 100644
--- a/crates/ra_hir/src/ty/snapshots/tests__infer_impl_generics.snap
+++ b/crates/ra_hir/src/ty/snapshots/tests__infer_impl_generics.snap
@@ -1,25 +1,25 @@
 ---
-created: "2019-02-16T19:27:11.573533475Z"
+created: "2019-02-16T20:53:59.657979128Z"
 creator: [email protected]
 source: crates/ra_hir/src/ty/tests.rs
 expression: "&result"
 ---
-[74; 78) 'self': A<[unknown], [unknown]>
-[85; 107) '{     ...     }': [unknown]
-[95; 99) 'self': A<[unknown], [unknown]>
-[95; 101) 'self.x': [unknown]
-[117; 121) 'self': A<[unknown], [unknown]>
-[128; 150) '{     ...     }': [unknown]
-[138; 142) 'self': A<[unknown], [unknown]>
-[138; 144) 'self.y': [unknown]
-[163; 167) 'self': A<[unknown], [unknown]>
+[74; 78) 'self': A<X, Y>
+[85; 107) '{     ...     }': X
+[95; 99) 'self': A<X, Y>
+[95; 101) 'self.x': X
+[117; 121) 'self': A<X, Y>
+[128; 150) '{     ...     }': Y
+[138; 142) 'self': A<X, Y>
+[138; 144) 'self.y': Y
+[163; 167) 'self': A<X, Y>
 [169; 170) 't': T
-[188; 223) '{     ...     }': ([unknown], [unknown], T)
-[198; 217) '(self.....y, t)': ([unknown], [unknown], T)
-[199; 203) 'self': A<[unknown], [unknown]>
-[199; 205) 'self.x': [unknown]
-[207; 211) 'self': A<[unknown], [unknown]>
-[207; 213) 'self.y': [unknown]
+[188; 223) '{     ...     }': (X, Y, T)
+[198; 217) '(self.....y, t)': (X, Y, T)
+[199; 203) 'self': A<X, Y>
+[199; 205) 'self.x': X
+[207; 211) 'self': A<X, Y>
+[207; 213) 'self.y': Y
 [215; 216) 't': T
 [245; 342) '{     ...(1); }': ()
 [255; 256) 'a': A<u64, i64>
@@ -27,13 +27,13 @@ expression: "&result"
 [266; 270) '1u64': u64
 [275; 279) '1i64': i64
 [287; 288) 'a': A<u64, i64>
-[287; 292) 'a.x()': [unknown]
+[287; 292) 'a.x()': u64
 [298; 299) 'a': A<u64, i64>
-[298; 303) 'a.y()': [unknown]
+[298; 303) 'a.y()': i64
 [309; 310) 'a': A<u64, i64>
-[309; 319) 'a.z(1i128)': ([unknown], [unknown], i128)
+[309; 319) 'a.z(1i128)': (u64, i64, i128)
 [313; 318) '1i128': i128
 [325; 326) 'a': A<u64, i64>
-[325; 339) 'a.z::<u128>(1)': ([unknown], [unknown], i32)
+[325; 339) 'a.z::<u128>(1)': (u64, i64, i32)
 [337; 338) '1': i32