Merge pull request #80672 from hamishknight/interfate-type

[Sema] Try limit kicking interface type in `filterForEnumElement`

Author: hamishknight

lib/Sema/TypeCheckPattern.cpp

@@ -90,25 +90,39 @@ filterForEnumElement(DeclContext *DC, SourceLoc UseLoc,
     ValueDecl *e = result.getValueDecl();
     assert(e);
 
-    // Skip if the enum element was referenced as an instance member
+    // We only care about enum members, and must either have an EnumElementDecl,
+    // or a VarDecl which could be wrapping an underlying enum element.
+    // FIXME: We check this up-front to avoid kicking InterfaceTypeRequest
+    // below to help workaround https://github.com/swiftlang/swift/issues/80657
+    // for non-enum cases. The proper fix is to move this filtering logic
+    // into the constraint system.
+    if (!e->getDeclContext()->getSelfEnumDecl())
+      continue;
+
+    auto *EED = dyn_cast<EnumElementDecl>(e);
+    auto *VD = dyn_cast<VarDecl>(e);
+    if (!EED && !VD)
+      continue;
+
+    // Skip if referenced as an instance member
     if (unqualifiedLookup) {
       if (!result.getBaseDecl() ||
           !result.getBaseDecl()->getInterfaceType()->is<MetatypeType>()) {
         continue;
       }
     }
 
-    if (auto *oe = dyn_cast<EnumElementDecl>(e)) {
+    if (EED) {
       // Note that there could be multiple elements with the same
       // name, such results in a re-declaration error, so let's
       // just always pick the last element, just like in `foundConstant`
       // case.
-      foundElement = oe;
+      foundElement = EED;
       continue;
     }
 
-    if (auto *var = dyn_cast<VarDecl>(e)) {
-      foundConstant = var;
+    if (VD) {
+      foundConstant = VD;
       continue;
     }
   }

validation-test/compiler_crashers_2/issue-80657.swift

@@ -0,0 +1,17 @@
+// RUN: not --crash %target-swift-frontend -emit-sil %s
+
+// https://github.com/swiftlang/swift/issues/80657
+enum E {
+  case e
+
+  static func foo() {
+    _ = { [self] in
+      switch e {
+      case e:
+        break
+      default:
+        break
+      }
+    }
+  }
+}

validation-test/compiler_crashers_2_fixed/rdar146952007.swift

@@ -0,0 +1,45 @@
+// RUN: %target-swift-frontend -emit-sil %s
+
+// These cases are similar to https://github.com/swiftlang/swift/issues/80657,
+// but we can avoid hitting the same issue for non-enum members.
+
+struct S {
+  let y = 0
+  func foo(_ x: Int) {
+    let _ = { [self] in
+      switch x {
+      case y: break
+      default: break
+      }
+    }
+  }
+}
+
+class C {
+  let y = 0
+  func foo(_ x: Int) {
+    let _ = { [self] in
+      switch x {
+      case y: break
+      default: break
+      }
+    }
+  }
+}
+
+enum E {
+  case e
+
+  func bar() -> Int {0}
+
+  func foo() {
+    _ = { [self] in
+      switch 0 {
+      case bar():
+        break
+      default:
+        break
+      }
+    }
+  }
+}