diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index 0991582005b85d..918411b818be70 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -1625,7 +1625,7 @@ static void runThinLTOBackend(
   if (Error E =
           thinBackend(Conf, -1, AddStream, *M, *CombinedIndex, ImportList,
                       ModuleToDefinedGVSummaries[M->getModuleIdentifier()],
-                      ModuleMap, &CGOpts.CmdArgs)) {
+                      ModuleMap, CGOpts.CmdArgs)) {
     handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
       errs() << "Error running ThinLTO backend: " << EIB.message() << '\n';
     });
@@ -1709,5 +1709,5 @@ void clang::EmbedBitcode(llvm::Module *M, const CodeGenOptions &CGOpts,
   llvm::EmbedBitcodeInModule(
       *M, Buf, CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Marker,
       CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Bitcode,
-      &CGOpts.CmdArgs);
+      CGOpts.CmdArgs);
 }
diff --git a/llvm/include/llvm/Bitcode/BitcodeWriter.h b/llvm/include/llvm/Bitcode/BitcodeWriter.h
index 74e9d103b7f3b2..36c3cb5eb24930 100644
--- a/llvm/include/llvm/Bitcode/BitcodeWriter.h
+++ b/llvm/include/llvm/Bitcode/BitcodeWriter.h
@@ -152,14 +152,18 @@ class raw_ostream;
                         const std::map<std::string, GVSummaryMapTy>
                             *ModuleToSummariesForIndex = nullptr);
 
-  /// Save a copy of the llvm IR as data in the __LLVM,__bitcode section.
+  /// If EmbedBitcode is set, save a copy of the llvm IR as data in the
+  ///  __LLVM,__bitcode section (.llvmbc on non-MacOS).
   /// If available, pass the serialized module via the Buf parameter. If not,
   /// pass an empty (default-initialized) MemoryBufferRef, and the serialization
   /// will be handled by this API. The same behavior happens if the provided Buf
   /// is not bitcode (i.e. if it's invalid data or even textual LLVM assembly).
+  /// If EmbedMarker is set, the command line is also exported in
+  /// the corresponding section (__LLVM,_cmdline / .llvmcmd) - even if CmdArgs
+  /// were empty.
   void EmbedBitcodeInModule(Module &M, MemoryBufferRef Buf, bool EmbedBitcode,
                             bool EmbedMarker,
-                            const std::vector<uint8_t> *CmdArgs);
+                            const std::vector<uint8_t> &CmdArgs);
 
 } // end namespace llvm
 
diff --git a/llvm/include/llvm/LTO/LTOBackend.h b/llvm/include/llvm/LTO/LTOBackend.h
index 63414b5c80dcea..db3c8c092ef902 100644
--- a/llvm/include/llvm/LTO/LTOBackend.h
+++ b/llvm/include/llvm/LTO/LTOBackend.h
@@ -45,7 +45,7 @@ Error thinBackend(const Config &C, unsigned Task, AddStreamFn AddStream,
                   const FunctionImporter::ImportMapTy &ImportList,
                   const GVSummaryMapTy &DefinedGlobals,
                   MapVector<StringRef, BitcodeModule> &ModuleMap,
-                  const std::vector<uint8_t> *CmdArgs = nullptr);
+                  const std::vector<uint8_t> &CmdArgs = std::vector<uint8_t>());
 
 Error finalizeOptimizationRemarks(
     std::unique_ptr<ToolOutputFile> DiagOutputFile);
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index d64dcd33d1bfc9..7cfa458128552f 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -4819,7 +4819,7 @@ static const char *getSectionNameForCommandline(const Triple &T) {
 
 void llvm::EmbedBitcodeInModule(llvm::Module &M, llvm::MemoryBufferRef Buf,
                                 bool EmbedBitcode, bool EmbedMarker,
-                                const std::vector<uint8_t> *CmdArgs) {
+                                const std::vector<uint8_t> &CmdArgs) {
   // Save llvm.compiler.used and remove it.
   SmallVector<Constant *, 2> UsedArray;
   SmallPtrSet<GlobalValue *, 4> UsedGlobals;
@@ -4878,8 +4878,8 @@ void llvm::EmbedBitcodeInModule(llvm::Module &M, llvm::MemoryBufferRef Buf,
   // Skip if only bitcode needs to be embedded.
   if (EmbedMarker) {
     // Embed command-line options.
-    ArrayRef<uint8_t> CmdData(const_cast<uint8_t *>(CmdArgs->data()),
-                              CmdArgs->size());
+    ArrayRef<uint8_t> CmdData(const_cast<uint8_t *>(CmdArgs.data()),
+                              CmdArgs.size());
     llvm::Constant *CmdConstant =
         llvm::ConstantDataArray::get(M.getContext(), CmdData);
     GV = new llvm::GlobalVariable(M, CmdConstant->getType(), true,
diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp
index fc39c1a57c8ede..f4da6d87f71944 100644
--- a/llvm/lib/LTO/LTOBackend.cpp
+++ b/llvm/lib/LTO/LTOBackend.cpp
@@ -358,7 +358,7 @@ static void runOldPMPasses(const Config &Conf, Module &Mod, TargetMachine *TM,
 bool opt(const Config &Conf, TargetMachine *TM, unsigned Task, Module &Mod,
          bool IsThinLTO, ModuleSummaryIndex *ExportSummary,
          const ModuleSummaryIndex *ImportSummary,
-         const std::vector<uint8_t> *CmdArgs = nullptr) {
+         const std::vector<uint8_t> &CmdArgs) {
   if (EmbedBitcode == LTOBitcodeEmbedding::EmbedPostMergePreOptimized) {
     // FIXME: the motivation for capturing post-merge bitcode and command line
     // is replicating the compilation environment from bitcode, without needing
@@ -368,13 +368,14 @@ bool opt(const Config &Conf, TargetMachine *TM, unsigned Task, Module &Mod,
     // It's not very clear how the above motivation would map in the
     // linker-based case, so we currently don't plumb the command line args in
     // that case.
-    if (CmdArgs == nullptr)
+    if (CmdArgs.empty())
       LLVM_DEBUG(
           dbgs() << "Post-(Thin)LTO merge bitcode embedding was requested, but "
                     "command line arguments are not available");
     llvm::EmbedBitcodeInModule(Mod, llvm::MemoryBufferRef(),
                                /*EmbedBitcode*/ true,
-                               /*EmbedMarker*/ false, CmdArgs);
+                               /*EmbedMarker*/ false,
+                               /*Cmdline*/ CmdArgs);
   }
   // FIXME: Plumb the combined index into the new pass manager.
   if (!Conf.OptPipeline.empty())
@@ -397,7 +398,8 @@ void codegen(const Config &Conf, TargetMachine *TM, AddStreamFn AddStream,
   if (EmbedBitcode == LTOBitcodeEmbedding::EmbedOptimized)
     llvm::EmbedBitcodeInModule(Mod, llvm::MemoryBufferRef(),
                                /*EmbedBitcode*/ true,
-                               /*EmbedMarker*/ false, /*CmdArgs*/ nullptr);
+                               /*EmbedMarker*/ false,
+                               /*CmdArgs*/ std::vector<uint8_t>());
 
   std::unique_ptr<ToolOutputFile> DwoOut;
   SmallString<1024> DwoFile(Conf.SplitDwarfOutput);
@@ -522,7 +524,8 @@ Error lto::backend(const Config &C, AddStreamFn AddStream,
 
   if (!C.CodeGenOnly) {
     if (!opt(C, TM.get(), 0, *Mod, /*IsThinLTO=*/false,
-             /*ExportSummary=*/&CombinedIndex, /*ImportSummary=*/nullptr))
+             /*ExportSummary=*/&CombinedIndex, /*ImportSummary=*/nullptr,
+             /*CmdArgs*/ std::vector<uint8_t>()))
       return Error::success();
   }
 
@@ -561,7 +564,7 @@ Error lto::thinBackend(const Config &Conf, unsigned Task, AddStreamFn AddStream,
                        const FunctionImporter::ImportMapTy &ImportList,
                        const GVSummaryMapTy &DefinedGlobals,
                        MapVector<StringRef, BitcodeModule> &ModuleMap,
-                       const std::vector<uint8_t> *CmdArgs) {
+                       const std::vector<uint8_t> &CmdArgs) {
   Expected<const Target *> TOrErr = initAndLookupTarget(Conf, Mod);
   if (!TOrErr)
     return TOrErr.takeError();