DebugInfo: Add the ability to disable DWARF name tables entirely

This changes the current default behavior (from emitting pubnames by
default, to not emitting them by default) & moves to matching GCC's
behavior* with one significant difference: -gno(-gnu)-pubnames disables
pubnames even in the presence of -gsplit-dwarf (though -gsplit-dwarf
still by default enables -ggnu-pubnames). This allows users to disable
pubnames (& the new DWARF5 accelerated access tables) when they might
not be worth the size overhead.

* GCC's behavior is that -ggnu-pubnames and -gpubnames override each
other, and that -gno-gnu-pubnames and -gno-pubnames act as synonyms and
disable either kind of pubnames if they come last. (eg: -gpubnames
-gno-gnu-pubnames causes no pubnames (neither gnu or standard) to be
emitted)

llvm-svn: 340206

1 files changed, 7 insertions, 1 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index a4beeabdaef..ded2d421995 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -55,6 +55,7 @@
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/ADT/Twine.h"
+#include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/Linker/Linker.h"
 #include "llvm/MC/MCTargetOptions.h"
 #include "llvm/Option/Arg.h"
@@ -643,7 +644,12 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   Opts.SampleProfileFile = Args.getLastArgValue(OPT_fprofile_sample_use_EQ);
   Opts.DebugInfoForProfiling = Args.hasFlag(
       OPT_fdebug_info_for_profiling, OPT_fno_debug_info_for_profiling, false);
-  Opts.GnuPubnames = Args.hasArg(OPT_ggnu_pubnames);
+  Opts.DebugNameTable = static_cast<unsigned>(
+      Args.hasArg(OPT_ggnu_pubnames)
+          ? llvm::DICompileUnit::DebugNameTableKind::GNU
+          : Args.hasArg(OPT_gpubnames)
+                ? llvm::DICompileUnit::DebugNameTableKind::Default
+                : llvm::DICompileUnit::DebugNameTableKind::None);
 
   setPGOInstrumentor(Opts, Args, Diags);
   Opts.InstrProfileOutput =