diff --git a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningWorker.h b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningWorker.h
--- a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningWorker.h
+++ b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningWorker.h
@@ -80,9 +80,8 @@
   ///
   /// \returns A \c StringError with the diagnostic output if clang errors
   /// occurred, success otherwise.
-  llvm::Error computeDependencies(const std::string &Input,
-                                  StringRef WorkingDirectory,
-                                  const CompilationDatabase &CDB,
+  llvm::Error computeDependencies(StringRef WorkingDirectory,
+                                  const std::vector<std::string> &CommandLine,
                                   DependencyConsumer &Consumer);
 
 private:
diff --git a/clang/lib/Tooling/DependencyScanning/DependencyScanningTool.cpp b/clang/lib/Tooling/DependencyScanning/DependencyScanningTool.cpp
--- a/clang/lib/Tooling/DependencyScanning/DependencyScanningTool.cpp
+++ b/clang/lib/Tooling/DependencyScanning/DependencyScanningTool.cpp
@@ -109,10 +109,12 @@
   // behavior.
   assert(Compilations.getAllCompileCommands().size() == 1 &&
          "Expected a compilation database with a single command!");
-  std::string Input = Compilations.getAllCompileCommands().front().Filename;
+  // FIXME: Avoid this copy.
+  std::vector<std::string> CommandLine =
+      Compilations.getAllCompileCommands().front().CommandLine;
 
   MakeDependencyPrinterConsumer Consumer;
-  auto Result = Worker.computeDependencies(Input, CWD, Compilations, Consumer);
+  auto Result = Worker.computeDependencies(CWD, CommandLine, Consumer);
   if (Result)
     return std::move(Result);
   std::string Output;
@@ -193,11 +195,12 @@
   // behavior.
   assert(Compilations.getAllCompileCommands().size() == 1 &&
          "Expected a compilation database with a single command!");
-  std::string Input = Compilations.getAllCompileCommands().front().Filename;
+  // FIXME: Avoid this copy.
+  std::vector<std::string> CommandLine =
+      Compilations.getAllCompileCommands().front().CommandLine;
 
   FullDependencyPrinterConsumer Consumer(AlreadySeen);
-  llvm::Error Result =
-      Worker.computeDependencies(Input, CWD, Compilations, Consumer);
+  llvm::Error Result = Worker.computeDependencies(CWD, CommandLine, Consumer);
   if (Result)
     return std::move(Result);
   return Consumer.getFullDependencies();
diff --git a/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp b/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
--- a/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
+++ b/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
@@ -306,18 +306,13 @@
 }
 
 llvm::Error DependencyScanningWorker::computeDependencies(
-    const std::string &Input, StringRef WorkingDirectory,
-    const CompilationDatabase &CDB, DependencyConsumer &Consumer) {
+    StringRef WorkingDirectory, const std::vector<std::string> &CommandLine,
+    DependencyConsumer &Consumer) {
   RealFS->setCurrentWorkingDirectory(WorkingDirectory);
 
   llvm::IntrusiveRefCntPtr<FileManager> CurrentFiles =
       Files ? Files : new FileManager(FileSystemOptions(), RealFS);
 
-  // FIXME: Avoid this copy.
-  std::vector<CompileCommand> CompileCommands = CDB.getCompileCommands(Input);
-  const std::vector<std::string> &CommandLine =
-      CompileCommands.front().CommandLine;
-
   return runWithDiags(DiagOpts.get(), [&](DiagnosticConsumer &DC) {
     DependencyScanningAction Action(WorkingDirectory, Consumer, DepFS,
                                     PPSkipMappings.get(), Format);