[Clang] - Add '-gsplit-dwarf[=split,=single]' version for '-gsplit-dwarf' option.

The DWARF5 specification says(Appendix F.1):

"The sections that do not require relocation, however, can be
written to the relocatable object (.o) file but ignored by the
linker or they can be written to a separate DWARF object (.dwo)
file that need not be accessed by the linker."

The first part describes a single file split DWARF feature and there
is no way to trigger this behavior atm. 
Fortunately, no many changes are required to keep *.dwo sections
in a .o, the patch does that.

Differential revision: https://reviews.llvm.org/D52296

llvm-svn: 346837

1 files changed, 17 insertions, 1 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 32937d83fb4..4a3195c69c3 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -596,9 +596,25 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   Opts.MacroDebugInfo = Args.hasArg(OPT_debug_info_macro);
   Opts.WholeProgramVTables = Args.hasArg(OPT_fwhole_program_vtables);
   Opts.LTOVisibilityPublicStd = Args.hasArg(OPT_flto_visibility_public_std);
-  Opts.EnableSplitDwarf = Args.hasArg(OPT_enable_split_dwarf);
   Opts.SplitDwarfFile = Args.getLastArgValue(OPT_split_dwarf_file);
   Opts.SplitDwarfInlining = !Args.hasArg(OPT_fno_split_dwarf_inlining);
+
+  if (Arg *A =
+          Args.getLastArg(OPT_enable_split_dwarf, OPT_enable_split_dwarf_EQ)) {
+    if (A->getOption().matches(options::OPT_enable_split_dwarf)) {
+      Opts.setSplitDwarfMode(CodeGenOptions::SplitFileFission);
+    } else {
+      StringRef Name = A->getValue();
+      if (Name == "single")
+        Opts.setSplitDwarfMode(CodeGenOptions::SingleFileFission);
+      else if (Name == "split")
+        Opts.setSplitDwarfMode(CodeGenOptions::SplitFileFission);
+      else
+        Diags.Report(diag::err_drv_invalid_value)
+            << A->getAsString(Args) << Name;
+    }
+  }
+
   Opts.DebugTypeExtRefs = Args.hasArg(OPT_dwarf_ext_refs);
   Opts.DebugExplicitImport = Args.hasArg(OPT_dwarf_explicit_import);
   Opts.DebugFwdTemplateParams = Args.hasArg(OPT_debug_forward_template_params);