[CSDiagnostics] Insert '@escaping' fix-it when type has '@autoclosure' during non-escaping function type diagnostic (#33191)

Author: theblixguy

lib/Sema/CSDiagnostics.cpp

@@ -915,12 +915,21 @@ bool NoEscapeFuncToTypeConversionFailure::diagnoseParameterUse() const {
   // Give a note and fix-it
   auto note = emitDiagnosticAt(PD, diag::noescape_parameter, PD->getName());
 
+  SourceLoc reprLoc;
+  SourceLoc autoclosureEndLoc;
+  if (auto *repr = PD->getTypeRepr()) {
+    reprLoc = repr->getStartLoc();
+    if (auto *attrRepr = dyn_cast<AttributedTypeRepr>(repr)) {
+      autoclosureEndLoc = Lexer::getLocForEndOfToken(
+          getASTContext().SourceMgr,
+          attrRepr->getAttrs().getLoc(TAK_autoclosure));
+    }
+  }
   if (!PD->isAutoClosure()) {
-    SourceLoc reprLoc;
-    if (auto *repr = PD->getTypeRepr())
-      reprLoc = repr->getStartLoc();
     note.fixItInsert(reprLoc, "@escaping ");
-  } // TODO: add in a fixit for autoclosure
+  } else {
+    note.fixItInsertAfter(autoclosureEndLoc, " @escaping");
+  }
 
   return true;
 }

test/attr/attr_escaping.swift

@@ -44,6 +44,11 @@ struct StoresClosure {
     return ["ultimate answer": fn] // expected-error{{using non-escaping parameter 'fn' in a context expecting an @escaping closure}}
   }
 
+  func autoclosureDictPack(_ fn: @autoclosure () -> Int) -> [String: () -> Int] {
+    // expected-note@-1{{parameter 'fn' is implicitly non-escaping}} {{46-46= @escaping}}
+    return ["ultimate answer": fn] // expected-error{{using non-escaping parameter 'fn' in a context expecting an @escaping closure}}
+  }
+
   func arrayPack(_ fn: @escaping () -> Int, _ fn2 : () -> Int) -> [() -> Int] {
     // expected-note@-1{{parameter 'fn2' is implicitly non-escaping}} {{53-53=@escaping }}