Issue-60730: Addressing the situation where we were saying that (any …

lib/Sema/CSSimplify.cpp

@@ -3627,18 +3627,29 @@ ConstraintSystem::matchExistentialTypes(Type type1, Type type2,
 
           if (last.is<LocatorPathElt::ApplyArgToParam>()) {
             auto proto = protoDecl->getDeclaredInterfaceType();
-            auto *fix = AllowArgumentMismatch::create(
-                *this, type1, proto, getConstraintLocator(anchor, path));
-
             // Impact is 2 here because there are two failures
             // 1 - missing conformance and 2 - incorrect argument type.
             //
             // This would make sure that arguments with incorrect
             // conformances are not prioritized over general argument
             // mismatches.
+            if (type1->isOptional()) {
+              auto unwrappedType = type1->lookThroughAllOptionalTypes();
+              auto result = simplifyConformsToConstraint(
+                  unwrappedType, protoDecl, kind, locator,
+                  subflags | TMF_ApplyingFix);
+              if (result == SolutionKind::Solved) {
+                auto fix = ForceOptional::create(*this, type1, proto,
+                                                 getConstraintLocator(locator));
+                if (recordFix(fix))
+                  return getTypeMatchFailure(locator);
+                break;
+              }
+            }
+            auto fix = AllowArgumentMismatch::create(
+                  *this, type1, proto, getConstraintLocator(anchor, path));
             if (recordFix(fix, /*impact=*/2))
               return getTypeMatchFailure(locator);
-
             break;
           }
 

test/Constraints/optional.swift

@@ -565,3 +565,27 @@ func testFunctionContainerMethodCall(container: FunctionContainer?) {
   // expected-note@-3 {{coalesce}}
   // expected-note@-4 {{force-unwrap}}
 }
+
+// Test for https://github.com/apple/swift/issues/60730
+// rdar://94037733
+do {
+  struct S: P {}
+  func takesP(_: any P) {}
+  func passOptional(value: (any P)?) {
+    takesP(value)
+    // expected-error@-1 {{value of optional type '(any P)?' must be unwrapped to a value of type 'any P'}}
+    // expected-note@-2 {{coalesce using '??' to provide a default when the optional value contains 'nil'}}
+    // expected-note@-3 {{force-unwrap using '!' to abort execution if the optional value contains 'nil'}}
+  }
+  func passLayersOfOptional(value: (any P)??) {
+    // FIXME(diagnostics): Consider recording multiple ForceUnwrap fixes based on number of optionals 
+    takesP(value)
+    // expected-error@-1 {{value of optional type '(any P)??' must be unwrapped to a value of type '(any P)?}}
+    // expected-note@-2 {{coalesce using '??' to provide a default when the optional value contains 'nil'}}
+    // expected-note@-3 {{force-unwrap using '!' to abort execution if the optional value contains 'nil'}}
+  }
+  func passNonConformingValue(value: (any BinaryInteger)?){
+    takesP(value)
+    // expected-error@-1 {{argument type '(any BinaryInteger)?' does not conform to expected type 'P'}}
+  }
+}