NFC, refactor importer::requiresCPlusPlus into reusable function

Author: hyp

include/swift/ClangImporter/ClangImporter.h

@@ -572,6 +572,13 @@ getModuleCachePathFromClang(const clang::CompilerInstance &Instance);
 /// Whether the given parameter name identifies a completion handler.
 bool isCompletionHandlerParamName(StringRef paramName);
 
+namespace importer {
+
+/// Returns true if the given module has a 'cplusplus' requirement.
+bool requiresCPlusPlus(const clang::Module *module);
+
+} // namespace importer
+
 } // end namespace swift
 
 #endif

lib/ClangImporter/ClangImporter.cpp

@@ -6569,3 +6569,19 @@ void ClangImporter::enableSymbolicImportFeature(bool isEnabled) {
   Impl.importSymbolicCXXDecls = isEnabled;
   Impl.nameImporter->enableSymbolicImportFeature(isEnabled);
 }
+
+bool importer::requiresCPlusPlus(const clang::Module *module) {
+  // The libc++ modulemap doesn't currently declare the requirement.
+  if (module->getTopLevelModuleName() == "std")
+    return true;
+
+  // Modulemaps often declare the requirement for the top-level module only.
+  if (auto parent = module->Parent) {
+    if (requiresCPlusPlus(parent))
+      return true;
+  }
+
+  return llvm::any_of(module->Requirements, [](clang::Module::Requirement req) {
+    return req.first == "cplusplus";
+  });
+}

lib/ClangImporter/ImporterImpl.h

@@ -1927,22 +1927,6 @@ inline Optional<const clang::EnumDecl *> findAnonymousEnumForTypedef(
   return None;
 }
 
-inline bool requiresCPlusPlus(const clang::Module *module) {
-  // The libc++ modulemap doesn't currently declare the requirement.
-  if (module->getTopLevelModuleName() == "std")
-    return true;
-
-  // Modulemaps often declare the requirement for the top-level module only.
-  if (auto parent = module->Parent) {
-    if (requiresCPlusPlus(parent))
-      return true;
-  }
-
-  return llvm::any_of(module->Requirements, [](clang::Module::Requirement req) {
-    return req.first == "cplusplus";
-  });
-}
-
 inline std::string getPrivateOperatorName(const std::string &OperatorToken) {
 #define OVERLOADED_OPERATOR(Name, Spelling, Token, Unary, Binary, MemberOnly)  \
   if (OperatorToken == Spelling) {                                             \

lib/Index/IndexRecord.cpp

@@ -396,23 +396,6 @@ emitDataForSwiftSerializedModule(ModuleDecl *module,
                                  const PathRemapper &pathRemapper,
                                  SourceFile *initialFile);
 
-// FIXME (Alex): Share code with importer.
-inline bool requiresCPlusPlus(const clang::Module *module) {
-  // The libc++ modulemap doesn't currently declare the requirement.
-  if (module->getTopLevelModuleName() == "std")
-    return true;
-
-  // Modulemaps often declare the requirement for the top-level module only.
-  if (auto parent = module->Parent) {
-    if (requiresCPlusPlus(parent))
-      return true;
-  }
-
-  return llvm::any_of(module->Requirements, [](clang::Module::Requirement req) {
-    return req.first == "cplusplus";
-  });
-}
-
 static void
 appendSymbolicInterfaceToIndexStorePath(SmallVectorImpl<char> &resultingPath) {
   llvm::sys::path::append(resultingPath, "interfaces");
@@ -490,7 +473,7 @@ static void emitSymbolicInterfaceForClangModule(
     return;
   // Skip system modules without an explicit 'cplusplus' requirement.
   bool isSystem = clangModUnit->isSystemModule();
-  if (isSystem && !requiresCPlusPlus(clangModule))
+  if (isSystem && !importer::requiresCPlusPlus(clangModule))
     return;
 
   // Make sure the `interfaces` directory is created.