Merge pull request #4017 from benlangmuir/autoclosure-noescape-diag-3.0

Don't emit @NoEscape error on every "@autoclosure is now a ..." error

Author: tkremenek

lib/Sema/TypeCheckAttr.cpp

@@ -1662,9 +1662,11 @@ void TypeChecker::checkNoEscapeAttr(ParamDecl *PD, NoEscapeAttr *attr) {
   }
 
   // This decl attribute has been moved to being a type attribute.
-  diagnose(attr->getLocation(), diag::attr_decl_attr_now_on_type, "@noescape")
-    .fixItRemove(attrRemovalRange) 
-    .fixItInsert(PD->getTypeLoc().getSourceRange().Start, "@noescape ");
+  if (!attr->isImplicit()) {
+    diagnose(attr->getLocation(), diag::attr_decl_attr_now_on_type, "@noescape")
+        .fixItRemove(attrRemovalRange)
+        .fixItInsert(PD->getTypeLoc().getSourceRange().Start, "@noescape ");
+  }
 
   // Stop if we've already applied this attribute.
   if (FTy->isNoEscape())

test/attr/attr_autoclosure.swift

@@ -1,4 +1,7 @@
 // RUN: %target-parse-verify-swift
+// RUN: not %target-swift-frontend -parse %s 2>&1 | FileCheck %s
+// No errors at invalid locations!
+// CHECK-NOT: <unknown>:0:
 
 // Simple case.
 var fn : @autoclosure () -> Int = 4  // expected-error {{@autoclosure may only be used on parameters}}  expected-error {{cannot convert value of type 'Int' to specified type '() -> Int'}}