5 files changed, 58 insertions, 11 deletions

diff --git a/crates/hir_ty/src/diagnostics.rs b/crates/hir_ty/src/diagnostics.rs
index ae0cf8d09..9ba005fab 100644
--- a/crates/hir_ty/src/diagnostics.rs
+++ b/crates/hir_ty/src/diagnostics.rs
@@ -6,7 +6,7 @@ mod unsafe_check;
 use std::any::Any;
 
 use hir_def::DefWithBodyId;
-use hir_expand::diagnostics::{Diagnostic, DiagnosticSink};
+use hir_expand::diagnostics::{Diagnostic, DiagnosticCode, DiagnosticSink};
 use hir_expand::{name::Name, HirFileId, InFile};
 use stdx::format_to;
 use syntax::{ast, AstPtr, SyntaxNodePtr};
@@ -32,6 +32,10 @@ pub struct NoSuchField {
 }
 
 impl Diagnostic for NoSuchField {
+    fn code(&self) -> DiagnosticCode {
+        DiagnosticCode("no-such-field")
+    }
+
     fn message(&self) -> String {
         "no such field".to_string()
     }
@@ -54,6 +58,9 @@ pub struct MissingFields {
 }
 
 impl Diagnostic for MissingFields {
+    fn code(&self) -> DiagnosticCode {
+        DiagnosticCode("missing-structure-fields")
+    }
     fn message(&self) -> String {
         let mut buf = String::from("Missing structure fields:\n");
         for field in &self.missed_fields {
@@ -87,6 +94,9 @@ pub struct MissingPatFields {
 }
 
 impl Diagnostic for MissingPatFields {
+    fn code(&self) -> DiagnosticCode {
+        DiagnosticCode("missing-pat-fields")
+    }
     fn message(&self) -> String {
         let mut buf = String::from("Missing structure fields:\n");
         for field in &self.missed_fields {
@@ -117,6 +127,9 @@ pub struct MissingMatchArms {
 }
 
 impl Diagnostic for MissingMatchArms {
+    fn code(&self) -> DiagnosticCode {
+        DiagnosticCode("missing-match-arm")
+    }
     fn message(&self) -> String {
         String::from("Missing match arm")
     }
@@ -135,6 +148,9 @@ pub struct MissingOkInTailExpr {
 }
 
 impl Diagnostic for MissingOkInTailExpr {
+    fn code(&self) -> DiagnosticCode {
+        DiagnosticCode("missing-ok-in-tail-expr")
+    }
     fn message(&self) -> String {
         "wrap return expression in Ok".to_string()
     }
@@ -153,6 +169,9 @@ pub struct BreakOutsideOfLoop {
 }
 
 impl Diagnostic for BreakOutsideOfLoop {
+    fn code(&self) -> DiagnosticCode {
+        DiagnosticCode("break-outside-of-loop")
+    }
     fn message(&self) -> String {
         "break outside of loop".to_string()
     }
@@ -171,6 +190,9 @@ pub struct MissingUnsafe {
 }
 
 impl Diagnostic for MissingUnsafe {
+    fn code(&self) -> DiagnosticCode {
+        DiagnosticCode("missing-unsafe")
+    }
     fn message(&self) -> String {
         format!("This operation is unsafe and requires an unsafe function or block")
     }
@@ -191,6 +213,9 @@ pub struct MismatchedArgCount {
 }
 
 impl Diagnostic for MismatchedArgCount {
+    fn code(&self) -> DiagnosticCode {
+        DiagnosticCode("mismatched-arg-count")
+    }
     fn message(&self) -> String {
         let s = if self.expected == 1 { "" } else { "s" };
         format!("Expected {} argument{}, found {}", self.expected, s, self.found)
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/tests.rs b/crates/hir_ty/src/tests.rs
index c953925ec..91c9d38c5 100644
--- a/crates/hir_ty/src/tests.rs
+++ b/crates/hir_ty/src/tests.rs
@@ -8,7 +8,7 @@ mod method_resolution;
 mod macros;
 mod display_source_code;
 
-use std::sync::Arc;
+use std::{env, sync::Arc};
 
 use base_db::{fixture::WithFixture, FileRange, SourceDatabase, SourceDatabaseExt};
 use expect::Expect;
@@ -22,12 +22,14 @@ use hir_def::{
     AssocItemId, DefWithBodyId, LocalModuleId, Lookup, ModuleDefId,
 };
 use hir_expand::{db::AstDatabase, InFile};
-use stdx::format_to;
+use stdx::{format_to, RacyFlag};
 use syntax::{
     algo,
     ast::{self, AstNode},
     SyntaxNode,
 };
+use tracing_subscriber::{layer::SubscriberExt, EnvFilter, Registry};
+use tracing_tree::HierarchicalLayer;
 
 use crate::{
     db::HirDatabase, display::HirDisplay, infer::TypeMismatch, test_db::TestDB, InferenceResult, Ty,
@@ -37,9 +39,12 @@ use crate::{
 // against snapshots of the expected results using expect. Use
 // `env UPDATE_EXPECT=1 cargo test -p hir_ty` to update the snapshots.
 
-fn setup_tracing() -> tracing::subscriber::DefaultGuard {
-    use tracing_subscriber::{layer::SubscriberExt, EnvFilter, Registry};
-    use tracing_tree::HierarchicalLayer;
+fn setup_tracing() -> Option<tracing::subscriber::DefaultGuard> {
+    static ENABLE: RacyFlag = RacyFlag::new();
+    if !ENABLE.get(|| env::var("CHALK_DEBUG").is_ok()) {
+        return None;
+    }
+
     let filter = EnvFilter::from_env("CHALK_DEBUG");
     let layer = HierarchicalLayer::default()
         .with_indent_lines(true)
@@ -47,7 +52,7 @@ fn setup_tracing() -> tracing::subscriber::DefaultGuard {
         .with_indent_amount(2)
         .with_writer(std::io::stderr);
     let subscriber = Registry::default().with(filter).with(layer);
-    tracing::subscriber::set_default(subscriber)
+    Some(tracing::subscriber::set_default(subscriber))
 }
 
 fn check_types(ra_fixture: &str) {
diff --git a/crates/hir_ty/src/traits.rs b/crates/hir_ty/src/traits.rs
index 1c3abb18f..14cd3a2b4 100644
--- a/crates/hir_ty/src/traits.rs
+++ b/crates/hir_ty/src/traits.rs
@@ -170,11 +170,11 @@ fn solve(
     let mut solve = || {
         if is_chalk_print() {
             let logging_db = LoggingRustIrDatabase::new(context);
-            let solution = solver.solve_limited(&logging_db, goal, should_continue);
+            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)
+            solver.solve_limited(&context, goal, &should_continue)
         }
     };