[ClangImporter] Collect deps via subclass of clang::DependencyCollector.

lib/AST/ModuleLoader.cpp

@@ -0,0 +1,50 @@
+//===--- ModuleLoader.cpp - Swift Language Module Implementation ----------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2017 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
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file implements the ModuleLoader class and/or any helpers.
+//
+//===----------------------------------------------------------------------===//
+
+#include "swift/AST/ModuleLoader.h"
+#include "clang/Frontend/Utils.h"
+#include "swift/ClangImporter/ClangImporter.h"
+
+namespace swift {
+
+DependencyTracker::DependencyTracker(const ClangImporterOptions &Options)
+  : clangCollector(ClangImporter::createDependencyCollector(Options))
+{
+}
+
+void
+DependencyTracker::addDependency(StringRef File, bool IsSystem) {
+  // DependencyTracker exposes an interface that (intentionally) does not talk
+  // about clang at all, nor about missing deps. It does expose an IsSystem
+  // dimension, though it is presently always false, we accept it and pass it
+  // along to the clang DependencyCollector in case Swift callers start setting
+  // it to true someday.
+  clangCollector->maybeAddDependency(File, /*FromClangModule=*/false,
+                                     IsSystem, /*IsClangModuleFile=*/false,
+                                     /*IsMissing=*/false);
+}
+
+ArrayRef<std::string>
+DependencyTracker::getDependencies() const {
+  return clangCollector->getDependencies();
+}
+
+std::shared_ptr<clang::DependencyCollector>
+DependencyTracker::getClangCollector() {
+  return clangCollector;
+}
+
+}