1 files changed, 57 insertions, 1 deletions
diff --git a/tools/clang-scan-deps/ClangScanDeps.cpp b/tools/clang-scan-deps/ClangScanDeps.cpp
index 5e567fef9d..bee4b479b2 100644
--- a/tools/clang-scan-deps/ClangScanDeps.cpp
+++ b/tools/clang-scan-deps/ClangScanDeps.cpp
@@ -51,11 +51,67 @@ public:
                          SharedStream &OS, SharedStream &Errs)
       : Worker(Service), Compilations(Compilations), OS(OS), Errs(Errs) {}
 
+  /// Print out the dependency information into a string using the dependency
+  /// file format that is specified in the options (-MD is the default) and
+  /// return it.
+  ///
+  /// \returns A \c StringError with the diagnostic output if clang errors
+  /// occurred, dependency file contents otherwise.
+  llvm::Expected<std::string> getDependencyFile(const std::string &Input,
+                                                StringRef CWD) {
+    /// Prints out all of the gathered dependencies into a string.
+    class DependencyPrinterConsumer : public DependencyConsumer {
+    public:
+      void handleFileDependency(const DependencyOutputOptions &Opts,
+                                StringRef File) override {
+        if (!this->Opts)
+          this->Opts = std::make_unique<DependencyOutputOptions>(Opts);
+        Dependencies.push_back(File);
+      }
+
+      void printDependencies(std::string &S) {
+        if (!Opts)
+          return;
+
+        class DependencyPrinter : public DependencyFileGenerator {
+        public:
+          DependencyPrinter(DependencyOutputOptions &Opts,
+                            ArrayRef<std::string> Dependencies)
+              : DependencyFileGenerator(Opts) {
+            for (const auto &Dep : Dependencies)
+              addDependency(Dep);
+          }
+
+          void printDependencies(std::string &S) {
+            llvm::raw_string_ostream OS(S);
+            outputDependencyFile(OS);
+          }
+        };
+
+        DependencyPrinter Generator(*Opts, Dependencies);
+        Generator.printDependencies(S);
+      }
+
+    private:
+      std::unique_ptr<DependencyOutputOptions> Opts;
+      std::vector<std::string> Dependencies;
+    };
+
+    DependencyPrinterConsumer Consumer;
+    auto Result =
+        Worker.computeDependencies(Input, CWD, Compilations, Consumer);
+    if (Result)
+      return std::move(Result);
+    std::string Output;
+    Consumer.printDependencies(Output);
+    return Output;
+  }
+
   /// Computes the dependencies for the given file and prints them out.
   ///
   /// \returns True on error.
   bool runOnFile(const std::string &Input, StringRef CWD) {
-    auto MaybeFile = Worker.getDependencyFile(Input, CWD, Compilations);
+    auto MaybeFile = getDependencyFile(Input, CWD);
     if (!MaybeFile) {
       llvm::handleAllErrors(
           MaybeFile.takeError(), [this, &Input](llvm::StringError &Err) {