diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -6119,6 +6119,9 @@
   NegFlag<SetFalse>, PosFlag<SetTrue, [], "Preserve the type for recovery "
                               "expressions when possible">>;
 
+def dump_tokens_bg : Flag<["-"], "dump-tokens-bg">,
+  HelpText<"Dump internal rep of tokens in the backgroud">;
+
 let Group = Action_Group in {
 
 def Eonly : Flag<["-"], "Eonly">,
diff --git a/clang/include/clang/Frontend/FrontendOptions.h b/clang/include/clang/Frontend/FrontendOptions.h
--- a/clang/include/clang/Frontend/FrontendOptions.h
+++ b/clang/include/clang/Frontend/FrontendOptions.h
@@ -352,6 +352,9 @@
   /// Specifies the output format of the AST.
   ASTDumpOutputFormat ASTDumpFormat = ADOF_Default;
 
+  /// Whether to dump tokens to file in the background
+  unsigned DumpTokensBg : 1;
+
   enum {
     ARCMT_None,
     ARCMT_Check,
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -2570,6 +2570,10 @@
 
   GenerateProgramAction();
 
+  if (Opts.DumpTokensBg == 1) {
+    GenerateArg(Args, OPT_dump_tokens_bg, SA);
+  }
+
   for (const auto &PluginArgs : Opts.PluginArgs) {
     Option Opt = getDriverOptTable().getOption(OPT_plugin_arg);
     const char *Spelling =
@@ -2780,6 +2784,7 @@
   Opts.Plugins = Args.getAllArgValues(OPT_load);
   Opts.ASTDumpDecls = Args.hasArg(OPT_ast_dump, OPT_ast_dump_EQ);
   Opts.ASTDumpAll = Args.hasArg(OPT_ast_dump_all, OPT_ast_dump_all_EQ);
+  Opts.DumpTokensBg = Args.hasArg(OPT_dump_tokens_bg);
   // Only the -fmodule-file=<file> form.
   for (const auto *A : Args.filtered(OPT_fmodule_file)) {
     StringRef Val = A->getValue();
diff --git a/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp b/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
--- a/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
+++ b/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
@@ -262,6 +262,25 @@
   if (!Act)
     return false;
   bool Success = Clang->ExecuteAction(*Act);
+  if (Clang->getFrontendOpts().DumpTokensBg) {
+    SourceManager &SM = Clang->getSourceManager();
+    FileID FID = SM.getMainFileID();
+    auto FileName = SM.getNonBuiltinFilenameForID(FID);
+    Lexer TheLexer(FID, SM.getBufferOrFake(FID), SM, Clang->getLangOpts());
+    auto &OS = llvm::outs();
+    OS << "file token dump begins " << FileName << '\n';
+    Token RawTok;
+    do {
+      TheLexer.LexFromRawLexer(RawTok);
+      OS << tok::getTokenName(RawTok.getKind());
+      if (!RawTok.isAnnotation()) {
+        std::string Spelling =
+            TheLexer.getSpelling(RawTok, SM, Clang->getLangOpts());
+        OS << "\t'" << Spelling << "'\n";
+      }
+    } while (RawTok.isNot(tok::eof));
+    OS << "file token dump ends " << FileName << '\n';
+  }
   if (Clang->getFrontendOpts().DisableFree)
     llvm::BuryPointer(std::move(Act));
   return Success;
diff --git a/clang/test/Preprocessor/dumptokens_bg.c b/clang/test/Preprocessor/dumptokens_bg.c
new file mode 100644
--- /dev/null
+++ b/clang/test/Preprocessor/dumptokens_bg.c
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 -dump-tokens-bg %s | FileCheck %s
+// CHECK: file token dump begins {{.*}}
+// CHECK: raw_identifier
+// CHECK: foo
+// CHECK: file token dump ends {{.*}}
+
+int foo() {
+  return 0;
+}