Add static type inference

crates/ra_hir/src/code_model_api.rs

@@ -612,6 +612,16 @@ impl Static {
     pub fn module(&self, db: &impl PersistentHirDatabase) -> Module {
         self.id.module(db)
     }
+
+    pub fn signature(&self, db: &impl HirDatabase) -> Arc<ConstSignature> {
+        db.static_signature(*self)
+    }
+
+    /// Builds a resolver for code inside this item.
+    pub fn resolver(&self, db: &impl HirDatabase) -> Resolver {
+        // take the outer scope...
+        self.module(db).resolver(db)
+    }
 }
 
 impl Docs for Static {

crates/ra_hir/src/code_model_impl/konst.rs

@@ -3,7 +3,7 @@ use std::sync::Arc;
 use ra_syntax::ast::{NameOwner};
 
 use crate::{
-    Name, AsName, Const, ConstSignature,
+    Name, AsName, Const, ConstSignature, Static,
     type_ref::{TypeRef},
     PersistentHirDatabase,
 };
@@ -23,4 +23,19 @@ impl ConstSignature {
 
         Arc::new(sig)
     }
+
+    pub(crate) fn static_signature_query(
+        db: &impl PersistentHirDatabase,
+        konst: Static,
+    ) -> Arc<ConstSignature> {
+        let (_, node) = konst.source(db);
+
+        let name = node.name().map(|n| n.as_name()).unwrap_or_else(Name::missing);
+
+        let type_ref = TypeRef::from_ast_opt(node.type_ref());
+
+        let sig = ConstSignature { name, type_ref };
+
+        Arc::new(sig)
+    }
 }

crates/ra_hir/src/db.rs

@@ -8,7 +8,7 @@ use crate::{
     SourceFileItems, SourceItemId, Crate, Module, HirInterner,
     Function, FnSignature, ExprScopes, TypeAlias,
     Struct, Enum, StructField,
-    Const, ConstSignature,
+    Const, ConstSignature, Static,
     macros::MacroExpansion,
     module_tree::ModuleTree,
     nameres::{ItemMap, lower::{LoweredModule, ImportSourceMap}},
@@ -86,6 +86,9 @@ pub trait PersistentHirDatabase: SourceDatabase + AsRef<HirInterner> {
 
     #[salsa::invoke(crate::ConstSignature::const_signature_query)]
     fn const_signature(&self, konst: Const) -> Arc<ConstSignature>;
+
+    #[salsa::invoke(crate::ConstSignature::static_signature_query)]
+    fn static_signature(&self, konst: Static) -> Arc<ConstSignature>;
 }
 
 #[salsa::query_group(HirDatabaseStorage)]

crates/ra_hir/src/ty/infer.rs

@@ -485,7 +485,8 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             TypableDef::TypeAlias(_)
             | TypableDef::Function(_)
             | TypableDef::Enum(_)
-            | TypableDef::Const(_) => (Ty::Unknown, None),
+            | TypableDef::Const(_)
+            | TypableDef::Static(_) => (Ty::Unknown, None),
         }
     }
 

crates/ra_hir/src/ty/lower.rs

@@ -11,7 +11,7 @@ use std::sync::Arc;
 use crate::{
     Function, Struct, StructField, Enum, EnumVariant, Path, Name,
     ModuleDef, TypeAlias,
-    Const,
+    Const, Static,
     HirDatabase,
     type_ref::TypeRef,
     name::KnownName,
@@ -126,7 +126,7 @@ impl Ty {
             TypableDef::Enum(e) => e.generic_params(db),
             TypableDef::EnumVariant(var) => var.parent_enum(db).generic_params(db),
             TypableDef::TypeAlias(t) => t.generic_params(db),
-            TypableDef::Const(_) => GenericParams::default().into(),
+            TypableDef::Const(_) | TypableDef::Static(_) => GenericParams::default().into(),
         };
         let parent_param_count = def_generics.count_parent_params();
         substs.extend((0..parent_param_count).map(|_| Ty::Unknown));
@@ -166,6 +166,7 @@ impl Ty {
             | TypableDef::Struct(_)
             | TypableDef::Enum(_)
             | TypableDef::Const(_)
+            | TypableDef::Static(_)
             | TypableDef::TypeAlias(_) => last,
             TypableDef::EnumVariant(_) => {
                 // the generic args for an enum variant may be either specified
@@ -201,6 +202,7 @@ pub(crate) fn type_for_def(db: &impl HirDatabase, def: TypableDef, ns: Namespace
         (TypableDef::EnumVariant(v), Namespace::Values) => type_for_enum_variant_constructor(db, v),
         (TypableDef::TypeAlias(t), Namespace::Types) => type_for_type_alias(db, t),
         (TypableDef::Const(c), Namespace::Values) => type_for_const(db, c),
+        (TypableDef::Static(c), Namespace::Values) => type_for_static(db, c),
 
         // 'error' cases:
         (TypableDef::Function(_), Namespace::Types) => Ty::Unknown,
@@ -208,6 +210,7 @@ pub(crate) fn type_for_def(db: &impl HirDatabase, def: TypableDef, ns: Namespace
         (TypableDef::EnumVariant(_), Namespace::Types) => Ty::Unknown,
         (TypableDef::TypeAlias(_), Namespace::Values) => Ty::Unknown,
         (TypableDef::Const(_), Namespace::Types) => Ty::Unknown,
+        (TypableDef::Static(_), Namespace::Types) => Ty::Unknown,
     }
 }
 
@@ -246,6 +249,14 @@ fn type_for_const(db: &impl HirDatabase, def: Const) -> Ty {
     Ty::from_hir(db, &resolver, signature.type_ref())
 }
 
+/// Build the declared type of a static.
+fn type_for_static(db: &impl HirDatabase, def: Static) -> Ty {
+    let signature = def.signature(db);
+    let resolver = def.resolver(db);
+
+    Ty::from_hir(db, &resolver, signature.type_ref())
+}
+
 /// Build the type of a tuple struct constructor.
 fn type_for_struct_constructor(db: &impl HirDatabase, def: Struct) -> Ty {
     let var_data = def.variant_data(db);
@@ -332,8 +343,9 @@ pub enum TypableDef {
     EnumVariant(EnumVariant),
     TypeAlias(TypeAlias),
     Const(Const),
+    Static(Static),
 }
-impl_froms!(TypableDef: Function, Struct, Enum, EnumVariant, TypeAlias, Const);
+impl_froms!(TypableDef: Function, Struct, Enum, EnumVariant, TypeAlias, Const, Static);
 
 impl From<ModuleDef> for Option<TypableDef> {
     fn from(def: ModuleDef) -> Option<TypableDef> {
@@ -344,7 +356,8 @@ impl From<ModuleDef> for Option<TypableDef> {
             ModuleDef::EnumVariant(v) => v.into(),
             ModuleDef::TypeAlias(t) => t.into(),
             ModuleDef::Const(v) => v.into(),
-            ModuleDef::Static(_) | ModuleDef::Module(_) | ModuleDef::Trait(_) => return None,
+            ModuleDef::Static(v) => v.into(),
+            ModuleDef::Module(_) | ModuleDef::Trait(_) => return None,
         };
         Some(res)
     }

crates/ra_hir/src/ty/snapshots/tests__infer_static.snap

@@ -1,5 +1,5 @@
 ---
-created: "2019-02-25T07:26:41.480764900Z"
+created: "2019-02-25T08:20:17.807316Z"
 creator: insta@0.6.3
 source: crates/ra_hir/src/ty/tests.rs
 expression: "&result"
@@ -9,8 +9,8 @@ expression: "&result"
 [177; 189) 'LOCAL_STATIC': [unknown]
 [199; 200) 'y': [unknown]
 [203; 219) 'LOCAL_...IC_MUT': [unknown]
-[229; 230) 'z': [unknown]
-[233; 246) 'GLOBAL_STATIC': [unknown]
-[256; 257) 'w': [unknown]
-[260; 277) 'GLOBAL...IC_MUT': [unknown]
+[229; 230) 'z': u32
+[233; 246) 'GLOBAL_STATIC': u32
+[256; 257) 'w': u32
+[260; 277) 'GLOBAL...IC_MUT': u32