[Async Refactoring] Get semantics providing expr to decide if call is to completion handler

Resolves rdar://78011350

Author: ahoppen

lib/IDE/Refactoring.cpp

@@ -4258,10 +4258,12 @@ struct AsyncHandlerDesc {
     if (!isValid())
       return nullptr;
 
-    if (Node.isExpr(swift::ExprKind::Call)) {
-      CallExpr *CE = cast<CallExpr>(Node.dyn_cast<Expr *>());
-      if (CE->getFn()->getReferencedDecl().getDecl() == getHandler())
-        return CE;
+    if (auto E = Node.dyn_cast<Expr *>()) {
+      if (auto *CE = dyn_cast<CallExpr>(E->getSemanticsProvidingExpr())) {
+        if (CE->getFn()->getReferencedDecl().getDecl() == getHandler()) {
+          return CE;
+        }
+      }
     }
     return nullptr;
   }
@@ -6343,10 +6345,10 @@ class AsyncConverter : private SourceEntityWalker {
       }
     } else if (CallExpr *CE = TopHandler.getAsHandlerCall(E)) {
       if (Scopes.back().isWrappedInContination()) {
-        return addCustom(CE->getSourceRange(),
+        return addCustom(E->getSourceRange(),
                          [&]() { addHandlerCallToContinuation(CE); });
       } else if (NestedExprCount == 0) {
-        return addCustom(CE->getSourceRange(), [&]() { addHandlerCall(CE); });
+        return addCustom(E->getSourceRange(), [&]() { addHandlerCall(CE); });
       }
     } else if (auto *CE = dyn_cast<CallExpr>(E)) {
       // Try and hoist a call's completion handler. Don't do so if

test/refactoring/ConvertAsync/convert_function.swift

@@ -287,15 +287,12 @@ func testReturnHandling2(completion: @escaping (String) -> ()) {
 // RETURN-HANDLING2-NEXT:   }
 // RETURN-HANDLING2-NEXT: }
 
-// FIXME: We should arguably be able to handle transforming this completion handler call (rdar://78011350).
-// RUN: %refactor -add-async-alternative -dump-text -source-filename %s -pos=%(line+1):1 | %FileCheck -check-prefix=RETURN-HANDLING3 %s
+// RUN: %refactor-check-compiles -add-async-alternative -dump-text -source-filename %s -pos=%(line+1):1 | %FileCheck -check-prefix=RETURN-HANDLING3 %s
 func testReturnHandling3(_ completion: (String?, Error?) -> Void) {
   return (completion("", nil))
 }
 // RETURN-HANDLING3:      func testReturnHandling3() async throws -> String {
-// RETURN-HANDLING3-NEXT:   return try await withCheckedThrowingContinuation { continuation in  
-// RETURN-HANDLING3-NEXT:     (continuation.resume(returning: ""))
-// RETURN-HANDLING3-NEXT:   }
+// RETURN-HANDLING3-NEXT:   {{^}} return ""{{$}}
 // RETURN-HANDLING3-NEXT: }
 
 // RUN: %refactor -convert-to-async -dump-text -source-filename %s -pos=%(line+1):1 | %FileCheck -check-prefix=RDAR78693050 %s

test/refactoring/ConvertAsync/convert_to_continuation.swift

@@ -26,6 +26,20 @@ func testCreateContinuation(completionHandler: (Int) -> Void) {
 // CREATE-CONTINUATION-NEXT:   }
 // CREATE-CONTINUATION-NEXT: }
 
+// RUN: %refactor-check-compiles -convert-to-async -dump-text -source-filename %s -pos=%(line+1):1 | %FileCheck -check-prefix=CREATE-CONTINUATION-HANDLER-CALL-IN-PARENS %s
+func testCreateContinuationWithCompletionHandlerCallInParens(completionHandler: (Int) -> Void) {
+  withoutAsyncAlternativeBecauseOfMismatchedCompletionHandlerName {
+    (completionHandler($0))
+  }
+}
+// CREATE-CONTINUATION-HANDLER-CALL-IN-PARENS:      func testCreateContinuationWithCompletionHandlerCallInParens() async -> Int {
+// CREATE-CONTINUATION-HANDLER-CALL-IN-PARENS-NEXT:   return await withCheckedContinuation { continuation in 
+// CREATE-CONTINUATION-HANDLER-CALL-IN-PARENS-NEXT:     withoutAsyncAlternativeBecauseOfMismatchedCompletionHandlerName {
+// CREATE-CONTINUATION-HANDLER-CALL-IN-PARENS-NEXT:       continuation.resume(returning: $0)
+// CREATE-CONTINUATION-HANDLER-CALL-IN-PARENS-NEXT:     }
+// CREATE-CONTINUATION-HANDLER-CALL-IN-PARENS-NEXT:   }
+// CREATE-CONTINUATION-HANDLER-CALL-IN-PARENS-NEXT: }
+
 // RUN: %refactor-check-compiles -convert-to-async -dump-text -source-filename %s -pos=%(line+1):1 | %FileCheck -check-prefix=CREATE-CONTINUATION-BECAUSE-RETURN-VALUE %s
 func testCreateContinuationBecauseOfReturnValue(completionHandler: (Int) -> Void) {
   _ = withoutAsyncAlternativeBecauseOfReturnValue {