5 files changed, 52 insertions, 19 deletions

diff --git a/crates/hir_ty/Cargo.toml b/crates/hir_ty/Cargo.toml
index 83b5013a9..a319b0ce8 100644
--- a/crates/hir_ty/Cargo.toml
+++ b/crates/hir_ty/Cargo.toml
@@ -16,9 +16,9 @@ ena = "0.14.0"
 log = "0.4.8"
 rustc-hash = "1.1.0"
 scoped-tls = "1"
-chalk-solve = { version = "0.21.0" }
-chalk-ir = { version = "0.21.0" }
-chalk-recursive = { version = "0.21.0" }
+chalk-solve = { version = "0.23.0" }
+chalk-ir = { version = "0.23.0" }
+chalk-recursive = { version = "0.23.0" }
 
 stdx = { path = "../stdx" }
 hir_def = { path = "../hir_def" }
diff --git a/crates/hir_ty/src/diagnostics/expr.rs b/crates/hir_ty/src/diagnostics/expr.rs
index fb76e2e4e..278a4b947 100644
--- a/crates/hir_ty/src/diagnostics/expr.rs
+++ b/crates/hir_ty/src/diagnostics/expr.rs
@@ -223,10 +223,10 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
             db.body_with_source_map(self.owner.into());
 
         let match_expr_ty = match infer.type_of_expr.get(match_expr) {
-            Some(ty) => ty,
             // If we can't resolve the type of the match expression
             // we cannot perform exhaustiveness checks.
-            None => return,
+            None | Some(Ty::Unknown) => return,
+            Some(ty) => ty,
         };
 
         let cx = MatchCheckCtx { match_expr, body, infer: infer.clone(), db };
diff --git a/crates/hir_ty/src/diagnostics/match_check.rs b/crates/hir_ty/src/diagnostics/match_check.rs
index 7f007f1d6..5bd03f2ac 100644
--- a/crates/hir_ty/src/diagnostics/match_check.rs
+++ b/crates/hir_ty/src/diagnostics/match_check.rs
@@ -1335,6 +1335,23 @@ fn panic(a: Category, b: Category) {
         );
     }
 
+    #[test]
+    fn unknown_type() {
+        check_diagnostics(
+            r#"
+enum Option<T> { Some(T), None }
+
+fn main() {
+    // `Never` is deliberately not defined so that it's an uninferred type.
+    match Option::<Never>::None {
+        None => (),
+        Some(never) => match never {},
+    }
+}
+"#,
+        );
+    }
+
     mod false_negatives {
         //! The implementation of match checking here is a work in progress. As we roll this out, we
         //! prefer false negatives to false positives (ideally there would be no false positives). This
diff --git a/crates/hir_ty/src/traits.rs b/crates/hir_ty/src/traits.rs
index 255323717..14cd3a2b4 100644
--- a/crates/hir_ty/src/traits.rs
+++ b/crates/hir_ty/src/traits.rs
@@ -3,7 +3,7 @@ use std::sync::Arc;
 
 use base_db::CrateId;
 use chalk_ir::cast::Cast;
-use chalk_solve::Solver;
+use chalk_solve::{logging_db::LoggingRustIrDatabase, Solver};
 use hir_def::{lang_item::LangItemTarget, TraitId};
 
 use crate::{db::HirDatabase, DebruijnIndex, Substs};
@@ -166,16 +166,25 @@ fn solve(
         }
         remaining > 0
     };
+
     let mut solve = || {
-        let solution = solver.solve_limited(&context, goal, should_continue);
-        log::debug!("solve({:?}) => {:?}", goal, solution);
-        solution
+        if is_chalk_print() {
+            let logging_db = LoggingRustIrDatabase::new(context);
+            let solution = solver.solve_limited(&logging_db, goal, &should_continue);
+            log::debug!("chalk program:\n{}", logging_db);
+            solution
+        } else {
+            solver.solve_limited(&context, goal, &should_continue)
+        }
     };
+
     // don't set the TLS for Chalk unless Chalk debugging is active, to make
     // extra sure we only use it for debugging
     let solution =
         if is_chalk_debug() { chalk::tls::set_current_program(db, solve) } else { solve() };
 
+    log::debug!("solve({:?}) => {:?}", goal, solution);
+
     solution
 }
 
@@ -183,6 +192,10 @@ fn is_chalk_debug() -> bool {
     std::env::var("CHALK_DEBUG").is_ok()
 }
 
+fn is_chalk_print() -> bool {
+    std::env::var("CHALK_PRINT").is_ok()
+}
+
 fn solution_from_chalk(
     db: &dyn HirDatabase,
     solution: chalk_solve::Solution<Interner>,
diff --git a/crates/hir_ty/src/traits/chalk.rs b/crates/hir_ty/src/traits/chalk.rs
index b33653417..17c83b6a4 100644
--- a/crates/hir_ty/src/traits/chalk.rs
+++ b/crates/hir_ty/src/traits/chalk.rs
@@ -240,20 +240,23 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         Substs::empty().to_chalk(self.db)
     }
 
-    fn trait_name(&self, _trait_id: chalk_ir::TraitId<Interner>) -> String {
-        unimplemented!()
+    fn trait_name(&self, trait_id: chalk_ir::TraitId<Interner>) -> String {
+        let id = from_chalk(self.db, trait_id);
+        self.db.trait_data(id).name.to_string()
     }
-    fn adt_name(&self, _struct_id: chalk_ir::AdtId<Interner>) -> String {
-        unimplemented!()
+    // FIXME: lookup names
+    fn adt_name(&self, struct_id: chalk_ir::AdtId<Interner>) -> String {
+        let datum = self.db.struct_datum(self.krate, struct_id);
+        format!("{:?}", datum.name(&Interner))
     }
-    fn assoc_type_name(&self, _assoc_ty_id: chalk_ir::AssocTypeId<Interner>) -> String {
-        unimplemented!()
+    fn assoc_type_name(&self, assoc_ty_id: chalk_ir::AssocTypeId<Interner>) -> String {
+        format!("Assoc_{}", assoc_ty_id.0)
     }
-    fn opaque_type_name(&self, _opaque_ty_id: chalk_ir::OpaqueTyId<Interner>) -> String {
-        unimplemented!()
+    fn opaque_type_name(&self, opaque_ty_id: chalk_ir::OpaqueTyId<Interner>) -> String {
+        format!("Opaque_{}", opaque_ty_id.0)
     }
-    fn fn_def_name(&self, _fn_def_id: chalk_ir::FnDefId<Interner>) -> String {
-        unimplemented!()
+    fn fn_def_name(&self, fn_def_id: chalk_ir::FnDefId<Interner>) -> String {
+        format!("fn_{}", fn_def_id.0)
     }
 }