This patch adds a new Clang compiler flag "-gline-tables-only".

It reduces the amount of emitted debug information:
1) DIEs in .debug_info have types DW_TAG_compile_unit, DW_TAG_subprogram,
DW_TAG_inlined_subroutine (for opt builds) and DW_TAG_lexical_block only.
2) .debug_str contains only function names.
3) No debug data for types/namespaces/variables is emitted.
4) The data in .debug_line is enough to produce valid stack traces with
function names and line numbers.

Reviewed by Eric Christopher.

llvm-svn: 156160

1 files changed, 6 insertions, 1 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index e8345fdfd76..0635be66673 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -184,6 +184,9 @@ static void CodeGenOptsToArgs(const CodeGenOptions &Opts, ToArgsList &Res) {
   switch (Opts.DebugInfo) {
     case CodeGenOptions::NoDebugInfo:
       break;
+    case CodeGenOptions::DebugLineTablesOnly:
+      Res.push_back("-gline-tables-only");
+      break;
     case CodeGenOptions::LimitedDebugInfo:
       Res.push_back("-g");
       Res.push_back("-flimit-debug-info");
@@ -1148,7 +1151,9 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   Opts.Inlining = Args.hasArg(OPT_fno_inline_functions) ?
     CodeGenOptions::OnlyAlwaysInlining : Opts.Inlining;
 
-  if (Args.hasArg(OPT_g_Flag)) {
+  if (Args.hasArg(OPT_gline_tables_only)) {
+    Opts.DebugInfo = CodeGenOptions::DebugLineTablesOnly;
+  } else if (Args.hasArg(OPT_g_Flag)) {
     if (Args.hasFlag(OPT_flimit_debug_info, OPT_fno_limit_debug_info, true))
       Opts.DebugInfo = CodeGenOptions::LimitedDebugInfo;
     else