[Sema] Name the decl in the error on package level without a package

Author: xymus

include/swift/AST/DiagnosticsSema.def

@@ -1935,9 +1935,9 @@ WARNING(access_control_non_objc_open_member,none,
       "non-'@objc' %0 in extensions cannot be overridden; use 'public' instead",
       (DescriptiveDeclKind))
 ERROR(access_control_requires_package_name, none,
-      "the package access level requires a package name; "
-      "set it with the compiler flag -package-name",
-      ())
+      "the package access level %select{|used on %1 }0"
+      "requires a package name; set it with the compiler flag -package-name",
+      (bool, const Decl*))
 ERROR(invalid_decl_attribute,none,
       "'%0' attribute cannot be applied to this declaration", (DeclAttribute))
 ERROR(attr_invalid_on_decl_kind,none,

lib/Sema/TypeCheckAttr.cpp

@@ -1023,7 +1023,8 @@ bool AttributeChecker::visitAbstractAccessControlAttr(
       D->getASTContext().LangOpts.PackageName.empty() &&
       File && File->Kind != SourceFileKind::Interface) {
     // `package` modifier used outside of a package.
-    diagnose(attr->getLocation(), diag::access_control_requires_package_name);
+    diagnose(attr->getLocation(), diag::access_control_requires_package_name,
+             isa<ValueDecl>(D), D);
     return true;
   }
 

test/attr/package-modifier-outside-of-package.swift

@@ -16,8 +16,8 @@ public struct PackageImportType {}
 //--- Client.swift
 package import PackageLib // expected-error {{the package access level requires a package name; set it with the compiler flag -package-name}}
 
-package struct PackageStruct { // expected-error {{the package access level requires a package name; set it with the compiler flag -package-name}}
-  package func explicitlyPackage() {} // expected-error {{the package access level requires a package name; set it with the compiler flag -package-name}}
+package struct PackageStruct { // expected-error {{the package access level used on 'PackageStruct' requires a package name; set it with the compiler flag -package-name}}
+  package func explicitlyPackage() {} // expected-error {{the package access level used on 'explicitlyPackage()' requires a package name; set it with the compiler flag -package-name}}
 }
 
 public struct PublicStruct {}

test/diagnostics/package-name-diagnostics.swift

@@ -3,11 +3,11 @@
 // Package name should not be empty
 // RUN: not %target-swift-frontend -typecheck %s -package-name "" 2>&1 | %FileCheck %s -check-prefix CHECK-EMPTY
 // CHECK-EMPTY: error: package-name is empty
-// CHECK-EMPTY: error: the package access level requires a package name; set it with the compiler flag -package-name
+// CHECK-EMPTY: error: the package access level used on 'log()' requires a package name; set it with the compiler flag -package-name
 
 // If package access level is used but no package-name is passed, it should error
 // RUN: not %target-swift-frontend -typecheck %s 2>&1 | %FileCheck %s -check-prefix CHECK-MISSING
-// CHECK-MISSING: error: the package access level requires a package name; set it with the compiler flag -package-name
+// CHECK-MISSING: error: the package access level used on 'log()' requires a package name; set it with the compiler flag -package-name
 
 // Package name can be same as the module name
 // RUN: %target-swift-frontend -module-name Logging -package-name Logging %s -emit-module -emit-module-path %t/Logging.swiftmodule