Index: clang/include/clang/Basic/CodeGenOptions.h
===================================================================
--- clang/include/clang/Basic/CodeGenOptions.h
+++ clang/include/clang/Basic/CodeGenOptions.h
@@ -171,6 +171,9 @@
   /// The ABI to use for passing floating point arguments.
   std::string FloatABI;
 
+  /// The file to use for dumping bug report by `debugify` in `original` mode.
+  std::string DIOriginalBugsReportFilePath;
+
   /// The floating-point denormal mode to use.
   llvm::DenormalMode FPDenormalMode = llvm::DenormalMode::getIEEE();
 
Index: clang/include/clang/Basic/CodeGenOptions.def
===================================================================
--- clang/include/clang/Basic/CodeGenOptions.def
+++ clang/include/clang/Basic/CodeGenOptions.def
@@ -65,6 +65,10 @@
 CODEGENOPT(DisableRedZone    , 1, 0) ///< Set when -mno-red-zone is enabled.
 CODEGENOPT(EmitCallSiteInfo, 1, 0) ///< Emit call site info only in the case of
                                    ///< '-g' + 'O>0' level.
+CODEGENOPT(EnableDebugifyEachOriginal, 1, 0) ///< Enable debugify each in
+                                             ///< original mode (it means check
+                                             ///< the original debug info
+                                             ///< metadata preservation).
 CODEGENOPT(IndirectTlsSegRefs, 1, 0) ///< Set when -mno-tls-direct-seg-refs
                                      ///< is specified.
 CODEGENOPT(DisableTailCalls  , 1, 0) ///< Do not emit tail calls.
Index: clang/include/clang/Driver/CC1Options.td
===================================================================
--- clang/include/clang/Driver/CC1Options.td
+++ clang/include/clang/Driver/CC1Options.td
@@ -389,6 +389,16 @@
     HelpText<"Prints debug information for the new pass manager">;
 def fno_debug_pass_manager : Flag<["-"], "fno-debug-pass-manager">,
     HelpText<"Disables debug printing for the new pass manager">;
+def fenable_debugify_each_original
+    : Flag<["-"], "fenable-debugify-each-original">,
+      HelpText<"Enable Debug Info Metadata preservation testing in "
+               "optimizations.">;
+def fenable_debugify_original_export
+    : Joined<["-"], "fenable-debugify-original-export=">,
+      MetaVarName<"<file>">,
+      HelpText<"Export debugify (by testing original Debug Info) failures into "
+               "specified (JSON) file (should be abs path as we use "
+               "append mode to insert new JSON objects).">;
 // The driver option takes the key as a parameter to the -msign-return-address=
 // and -mbranch-protection= options, but CC1 has a separate option so we
 // don't have to parse the parameter twice.
Index: clang/lib/CodeGen/BackendUtil.cpp
===================================================================
--- clang/lib/CodeGen/BackendUtil.cpp
+++ clang/lib/CodeGen/BackendUtil.cpp
@@ -76,6 +76,7 @@
 #include "llvm/Transforms/Scalar/GVN.h"
 #include "llvm/Transforms/Utils.h"
 #include "llvm/Transforms/Utils/CanonicalizeAliases.h"
+#include "llvm/Transforms/Utils/Debugify.h"
 #include "llvm/Transforms/Utils/EntryExitInstrumenter.h"
 #include "llvm/Transforms/Utils/NameAnonGlobals.h"
 #include "llvm/Transforms/Utils/SymbolRewriter.h"
@@ -851,6 +852,67 @@
   return true;
 }
 
+class ClangCustomPassManager : public legacy::PassManager {
+public:
+  void add(Pass *P) override {
+    bool WrapWithDebugifyOriginal = DebugifyEachOriginalEnabled &&
+                                    !P->getAsImmutablePass() &&
+                                    !isIRPrintingPass(P);
+    if (!WrapWithDebugifyOriginal) {
+      PassManager::add(P);
+      return;
+    }
+
+    PassKind Kind = P->getPassKind();
+    StringRef Name = P->getPassName();
+
+    // TODO: Implement Debugify for LoopPass.
+    switch (Kind) {
+    case PT_Function:
+      assert(Mode == DebugifyMode::OriginalDebugInfo &&
+             "Must be original mode");
+      PassManager::add(createDebugifyFunctionPass(DebugifyMode::OriginalDebugInfo,
+                                            Name, &DIPreservationMap));
+      PassManager::add(P);
+      PassManager::add(createCheckDebugifyFunctionPass(
+          false, Name, nullptr, DebugifyMode::OriginalDebugInfo,
+          &DIPreservationMap, getDebugifyEachOriginalPath()));
+      break;
+    case PT_Module:
+      assert(Mode == DebugifyMode::OriginalDebugInfo &&
+             "Must be original mode");
+      PassManager::add(createDebugifyModulePass(DebugifyMode::OriginalDebugInfo,
+                                          Name, &DIPreservationMap));
+      PassManager::add(P);
+      PassManager::add(createCheckDebugifyModulePass(
+          false, Name, nullptr, DebugifyMode::OriginalDebugInfo,
+          &DIPreservationMap, getDebugifyEachOriginalPath()));
+      break;
+    default:
+      PassManager::add(P);
+      break;
+    }
+  }
+
+  void enableDebugifyEachOriginal() {
+    DebugifyEachOriginalEnabled = true;
+  }
+
+  void setDIOriginalBugsReportFilePath(
+      StringRef DIOriginalBugsReportFilePath_) {
+    DIOriginalBugsReportFilePath = DIOriginalBugsReportFilePath_;
+  }
+
+  llvm::StringRef getDebugifyEachOriginalPath() const {
+    return DIOriginalBugsReportFilePath;
+  }
+
+private:
+  DebugInfoPerPassMap DIPreservationMap;
+  llvm::StringRef DIOriginalBugsReportFilePath = "";
+  bool DebugifyEachOriginalEnabled = false;
+};
+
 void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
                                       std::unique_ptr<raw_pwrite_stream> OS) {
   TimeRegion Region(FrontendTimesIsEnabled ? &CodeGenerationTime : nullptr);
@@ -867,7 +929,14 @@
   if (TM)
     TheModule->setDataLayout(TM->createDataLayout());
 
-  legacy::PassManager PerModulePasses;
+  ClangCustomPassManager PerModulePasses;
+  if (CodeGenOpts.EnableDebugifyEachOriginal) {
+    PerModulePasses.enableDebugifyEachOriginal();
+
+    if (!CodeGenOpts.DIOriginalBugsReportFilePath.empty())
+      PerModulePasses.setDIOriginalBugsReportFilePath(
+          CodeGenOpts.DIOriginalBugsReportFilePath);
+  }
   PerModulePasses.add(
       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
 
Index: clang/lib/Frontend/CompilerInvocation.cpp
===================================================================
--- clang/lib/Frontend/CompilerInvocation.cpp
+++ clang/lib/Frontend/CompilerInvocation.cpp
@@ -791,6 +791,16 @@
       llvm::is_contained(DebugEntryValueArchs, T.getArch()))
     Opts.EmitCallSiteInfo = true;
 
+  Opts.EnableDebugifyEachOriginal =
+      Args.hasArg(OPT_fenable_debugify_each_original);
+  // Ignore the option if the -fenable-debugify-each-original wasn't enabled.
+  if (Opts.EnableDebugifyEachOriginal &&
+      Args.hasArg(OPT_fenable_debugify_original_export)) {
+      Opts.DIOriginalBugsReportFilePath =
+          std::string(
+              Args.getLastArgValue(OPT_fenable_debugify_original_export));
+  }
+
   Opts.DisableO0ImplyOptNone = Args.hasArg(OPT_disable_O0_optnone);
   Opts.DisableRedZone = Args.hasArg(OPT_disable_red_zone);
   Opts.IndirectTlsSegRefs = Args.hasArg(OPT_mno_tls_direct_seg_refs);
Index: clang/test/DebugInfo/debugify-each-original.c
===================================================================
--- /dev/null
+++ clang/test/DebugInfo/debugify-each-original.c
@@ -0,0 +1,57 @@
+// RUN: %clang -g -Xclang -fenable-debugify-each-original -emit-llvm -S \
+// RUN:     -O1 -o - %s 2>&1 | FileCheck %s
+
+int main()
+{
+  int x = 1;
+  int y = 2;
+  return x + y;
+}
+
+// CHECK: Force set function attributes: PASS
+// CHECK-NEXT: Infer set function attributes: PASS
+// CHECK-NEXT: Interprocedural Sparse Conditional Constant Propagation: PASS
+// CHECK-NEXT: Called Value Propagation: PASS
+// CHECK-NEXT: Global Variable Optimizer: PASS
+// CHECK-NEXT: Promote Memory to Register: PASS
+// CHECK-NEXT: Dead Argument Elimination: PASS
+// CHECK-NEXT: Combine redundant instructions: PASS
+// CHECK-NEXT: Simplify the CFG: PASS
+// CHECK-NEXT: Globals Alias Analysis: PASS
+// CHECK-NEXT: SROA: PASS
+// CHECK-NEXT: Early CSE w/ MemorySSA: PASS
+// CHECK-NEXT: Simplify the CFG: PASS
+// CHECK-NEXT: Combine redundant instructions: PASS
+// CHECK-NEXT: Conditionally eliminate dead library calls: PASS
+// CHECK-NEXT: PGOMemOPSize: PASS
+// CHECK-NEXT: Simplify the CFG: PASS
+// CHECK-NEXT: Reassociate expressions: PASS
+// CHECK-NEXT: Simplify the CFG: PASS
+// CHECK-NEXT: Combine redundant instructions: PASS
+// CHECK-NEXT: MemCpy Optimization: PASS
+// CHECK-NEXT: Sparse Conditional Constant Propagation: PASS
+// CHECK-NEXT: Bit-Tracking Dead Code Elimination: PASS
+// CHECK-NEXT: Combine redundant instructions: PASS
+// CHECK-NEXT: Aggressive Dead Code Elimination: PASS
+// CHECK-NEXT: Simplify the CFG: PASS
+// CHECK-NEXT: Combine redundant instructions: PASS
+// CHECK-NEXT: A No-Op Barrier Pass: PASS
+// CHECK-NEXT: Deduce function attributes in RPO: PASS
+// CHECK-NEXT: Global Variable Optimizer: PASS
+// CHECK-NEXT: Dead Global Elimination: PASS
+// CHECK-NEXT: Globals Alias Analysis: PASS
+// CHECK-NEXT: Float to int: PASS
+// CHECK-NEXT: Lower constant intrinsics: PASS
+// CHECK-NEXT: Loop Distribution: PASS
+// CHECK-NEXT: Loop Vectorization: PASS
+// CHECK-NEXT: Loop Load Elimination: PASS
+// CHECK-NEXT: Combine redundant instructions: PASS
+// CHECK-NEXT: Simplify the CFG: PASS
+// CHECK-NEXT: Optimize scalar/vector ops: PASS
+// CHECK-NEXT: Combine redundant instructions: PASS
+// CHECK-NEXT: Warn about non-applied transformations: PASS
+// CHECK-NEXT: Alignment from assumptions: PASS
+// CHECK-NEXT: Strip Unused Function Prototypes: PASS
+// CHECK-NEXT: Remove redundant instructions: PASS
+// CHECK-NEXT: Hoist/decompose integer division and remainder: PASS
+// CHECK-NEXT: Simplify the CFG: PASS
Index: llvm/docs/HowToUpdateDebugInfo.rst
===================================================================
--- llvm/docs/HowToUpdateDebugInfo.rst
+++ llvm/docs/HowToUpdateDebugInfo.rst
@@ -317,6 +317,16 @@
 
   $ llvm-debugify-original.py sample.json sample.html
 
+The `original` mode can be invoked from front-end level as follows:
+
+.. code-block:: bash
+
+  # Test each pass.
+  $ clang -Xclang -fenable-debugify-each-original -g -O2 sample.c
+
+  # Test each pass and export the issues report into the JSON file.
+  $ clang -Xclang -fenable-debugify-each-original -Xclang -fenable-debugify-original-export=sample.json -g -O2 sample.c
+
 Using ``debugify``
 ^^^^^^^^^^^^^^^^^^