[Clang] Remove unused -split-dwarf and obsolete -enable-split-dwarf

Summary:
The changes in D59673 made the choice redundant, since we can achieve
single-file split DWARF just by not setting an output file name.
Like llc we can also derive whether to enable Split DWARF from whether
-split-dwarf-file is set, so we don't need the flag at all anymore.

The test CodeGen/split-debug-filename.c distinguished between having set
or not set -enable-split-dwarf with -split-dwarf-file, but we can
probably just always emit the metadata into the IR.

The flag -split-dwarf wasn't used at all anymore.

Reviewers: dblaikie, echristo

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D63167

llvm-svn: 364479

1 files changed, 2 insertions, 12 deletions

diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 3e7158ae80b..f292944a2ef 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -3292,18 +3292,8 @@ static void RenderDebugOptions(const ToolChain &TC, const Driver &D,
       }
     }
 
-  // -gsplit-dwarf enables the backend dwarf splitting and extraction.
-  if (T.isOSBinFormatELF()) {
-    if (!SplitDWARFInlining)
-      CmdArgs.push_back("-fno-split-dwarf-inlining");
-
-    if (DwarfFission != DwarfFissionKind::None) {
-      if (DwarfFission == DwarfFissionKind::Single)
-        CmdArgs.push_back("-enable-split-dwarf=single");
-      else
-        CmdArgs.push_back("-enable-split-dwarf");
-    }
-  }
+  if (T.isOSBinFormatELF() && !SplitDWARFInlining)
+    CmdArgs.push_back("-fno-split-dwarf-inlining");
 
   // After we've dealt with all combinations of things that could
   // make DebugInfoKind be other than None or DebugLineTablesOnly,