[interop] NFC, refactor DeclAndTypePrinter::shouldInclude to its own function

Author: hyp

lib/PrintAsClang/DeclAndTypePrinter.cpp

@@ -12,6 +12,7 @@
 
 #include "DeclAndTypePrinter.h"
 #include "ClangSyntaxPrinter.h"
+#include "ExposedDeclFilter.h"
 #include "PrimitiveTypeMapping.h"
 #include "PrintClangFunction.h"
 #include "PrintClangValueType.h"
@@ -2026,11 +2027,7 @@ auto DeclAndTypePrinter::getImpl() -> Implementation {
 }
 
 bool DeclAndTypePrinter::shouldInclude(const ValueDecl *VD) {
-  return !VD->isInvalid() &&
-         (outputLang == OutputLanguageMode::Cxx
-              ? cxx_translation::isVisibleToCxx(VD, minRequiredAccess)
-              : isVisibleToObjC(VD, minRequiredAccess)) &&
-         !VD->getAttrs().hasAttribute<ImplementationOnlyAttr>();
+  return clang_translation::shouldExpose(VD, outputLang, minRequiredAccess);
 }
 
 void DeclAndTypePrinter::print(const Decl *D) {

lib/PrintAsClang/ExposedDeclFilter.h

@@ -0,0 +1,47 @@
+//===--- ExposedDeclFilter.h - Controls which decls are exposed -*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2022 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SWIFT_PRINTASCLANG_EXPOSEDDECLFILTER_H
+#define SWIFT_PRINTASCLANG_EXPOSEDDECLFILTER_H
+
+#include "OutputLanguageMode.h"
+#include "swift/AST/Decl.h"
+#include "swift/AST/SwiftNameTranslation.h"
+
+namespace swift {
+
+namespace clang_translation {
+
+/// Returns true if the given declaration should be exposed in the generated
+/// Objective-C/C/C++ header, as depending on the specified output language.
+bool shouldExpose(const ValueDecl *VD, OutputLanguageMode outputLang,
+                  AccessLevel minRequiredAccess) {
+  return !VD->isInvalid() &&
+         (outputLang == OutputLanguageMode::Cxx
+              ? cxx_translation::isVisibleToCxx(VD, minRequiredAccess)
+              : objc_translation::isVisibleToObjC(VD, minRequiredAccess)) &&
+         !VD->getAttrs().hasAttribute<ImplementationOnlyAttr>();
+}
+
+/// Returns true if the given declaration should be exposed in generated
+/// Objective-C/C/C++ header, regardless of what language the declaration is
+/// exposed to.
+bool shouldExpose(const ValueDecl *VD, AccessLevel minRequiredAccess) {
+  return shouldExpose(VD, OutputLanguageMode::ObjC, minRequiredAccess) ||
+         shouldExpose(VD, OutputLanguageMode::Cxx, minRequiredAccess);
+}
+
+} // namespace clang_translation
+
+} // end namespace swift
+
+#endif