Index: include/clang/Basic/CodeGenOptions.def
===================================================================
--- include/clang/Basic/CodeGenOptions.def
+++ include/clang/Basic/CodeGenOptions.def
@@ -61,6 +61,7 @@
 CODEGENOPT(DebugPassManager, 1, 0) ///< Prints debug information for the new
                                    ///< pass manager.
 CODEGENOPT(DisableRedZone    , 1, 0) ///< Set when -mno-red-zone is enabled.
+CODEGENOPT(EnableParamEntryValues, 1, 0) ///< Emit call site parameter dbg info
 CODEGENOPT(IndirectTlsSegRefs, 1, 0) ///< Set when -mno-tls-direct-seg-refs
                                      ///< is specified.
 CODEGENOPT(DisableTailCalls  , 1, 0) ///< Do not emit tail calls.
Index: include/clang/Driver/Options.td
===================================================================
--- include/clang/Driver/Options.td
+++ include/clang/Driver/Options.td
@@ -916,6 +916,9 @@
 def fjump_tables : Flag<["-"], "fjump-tables">, Group<f_Group>;
 def fno_jump_tables : Flag<["-"], "fno-jump-tables">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Do not use jump tables for lowering switches">;
+def femit_param_entry_values : Flag<["-"], "femit-param-entry-values">, Group<f_Group>,
+  Flags<[CC1Option]>,
+  HelpText<"Enables debug info about call site parameter's entry values">;
 def fforce_enable_int128 : Flag<["-"], "fforce-enable-int128">,
   Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Enable support for int128_t type">;
Index: lib/CodeGen/CGDebugInfo.cpp
===================================================================
--- lib/CodeGen/CGDebugInfo.cpp
+++ lib/CodeGen/CGDebugInfo.cpp
@@ -4558,7 +4558,10 @@
   // were part of DWARF v4.
   bool SupportsDWARFv4Ext =
       CGM.getCodeGenOpts().DwarfVersion == 4 &&
-      CGM.getCodeGenOpts().getDebuggerTuning() == llvm::DebuggerKind::LLDB;
+      (CGM.getCodeGenOpts().getDebuggerTuning() == llvm::DebuggerKind::LLDB ||
+       (CGM.getCodeGenOpts().EnableParamEntryValues &&
+       CGM.getCodeGenOpts().getDebuggerTuning() == llvm::DebuggerKind::GDB));
+
   if (!SupportsDWARFv4Ext && CGM.getCodeGenOpts().DwarfVersion < 5)
     return llvm::DINode::FlagZero;
 
Index: lib/Driver/ToolChains/Clang.cpp
===================================================================
--- lib/Driver/ToolChains/Clang.cpp
+++ lib/Driver/ToolChains/Clang.cpp
@@ -3396,6 +3396,10 @@
   if (DebuggerTuning == llvm::DebuggerKind::SCE)
     CmdArgs.push_back("-dwarf-explicit-import");
 
+  // Enable param entry values functionality.
+  if (Args.hasArg(options::OPT_femit_param_entry_values))
+    CmdArgs.push_back("-femit-param-entry-values");
+
   RenderDebugInfoCompressionArgs(Args, CmdArgs, D, TC);
 }
 
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -746,6 +746,7 @@
 
   Opts.DisableLLVMPasses = Args.hasArg(OPT_disable_llvm_passes);
   Opts.DisableLifetimeMarkers = Args.hasArg(OPT_disable_lifetimemarkers);
+  Opts.EnableParamEntryValues = Args.hasArg(OPT_femit_param_entry_values);
   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);