3 files changed, 22 insertions, 1 deletions
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index d76fee5c844..18c56b0dae2 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -190,6 +190,11 @@ void CodeGenModule::Release() {
       (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) {
     EmitModuleLinkOptions();
   }
+  if (CodeGenOpts.DwarfVersion)
+    // We actually want the latest version when there are conflicts.
+    // We can change from Warning to Latest if such mode is supported.
+    getModule().addModuleFlag(llvm::Module::Warning, "Dwarf Version",
+                              CodeGenOpts.DwarfVersion);
 
   SimplifyPersonality();
 
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 373939cd933..7f22d6ff091 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -2489,6 +2489,12 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
   if (Arg *A = Args.getLastArg(options::OPT_g_Group)) {
     if (A->getOption().matches(options::OPT_gline_tables_only))
       CmdArgs.push_back("-gline-tables-only");
+    else if (A->getOption().matches(options::OPT_gdwarf_2))
+      CmdArgs.push_back("-gdwarf-2");
+    else if (A->getOption().matches(options::OPT_gdwarf_3))
+      CmdArgs.push_back("-gdwarf-3");
+    else if (A->getOption().matches(options::OPT_gdwarf_4))
+      CmdArgs.push_back("-gdwarf-4");
     else if (!A->getOption().matches(options::OPT_g0) &&
              !A->getOption().matches(options::OPT_ggdb0))
       CmdArgs.push_back("-g");
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 1407e105f24..d9316ec4f0f 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -318,7 +318,8 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
 
   if (Args.hasArg(OPT_gline_tables_only)) {
     Opts.setDebugInfo(CodeGenOptions::DebugLineTablesOnly);
-  } else if (Args.hasArg(OPT_g_Flag)) {
+  } else if (Args.hasArg(OPT_g_Flag) || Args.hasArg(OPT_gdwarf_2) ||
+             Args.hasArg(OPT_gdwarf_3) || Args.hasArg(OPT_gdwarf_4)) {
     if (Args.hasFlag(OPT_flimit_debug_info, OPT_fno_limit_debug_info, true))
       Opts.setDebugInfo(CodeGenOptions::LimitedDebugInfo);
     else
@@ -326,6 +327,15 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   }
   Opts.DebugColumnInfo = Args.hasArg(OPT_dwarf_column_info);
   Opts.SplitDwarfFile = Args.getLastArgValue(OPT_split_dwarf_file);
+  if (Args.hasArg(OPT_gdwarf_2))
+    Opts.DwarfVersion = 2;
+  else if (Args.hasArg(OPT_gdwarf_3))
+    Opts.DwarfVersion = 3;
+  else if (Args.hasArg(OPT_gdwarf_4))
+    Opts.DwarfVersion = 4;
+  else if (Opts.getDebugInfo() != CodeGenOptions::NoDebugInfo)
+    // Default Dwarf version is 3 if we are generating debug information.
+    Opts.DwarfVersion = 3;
 
   Opts.DisableLLVMOpts = Args.hasArg(OPT_disable_llvm_optzns);
   Opts.DisableRedZone = Args.hasArg(OPT_disable_red_zone);