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

[aaronpuchert]

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.

[dblaikie]

include/clang/Basic/CodeGenOptions.def

263 ↗

(On Diff #204162)

Could we skip this and rely on "SplitDwarFile" being non-empty?

[aaronpuchert]

include/clang/Basic/CodeGenOptions.def

263 ↗

(On Diff #204162)

I think not, have a look at test/CodeGen/split-debug-filename.c:

// RUN: %clang_cc1 -debug-info-kind=limited -split-dwarf-file foo.dwo -S -emit-llvm -o - %s | FileCheck %s
// RUN: %clang_cc1 -debug-info-kind=limited -enable-split-dwarf -split-dwarf-file foo.dwo -S -emit-llvm -o - %s | FileCheck --check-prefix=VANILLA %s
// ...

// Testing to ensure that the dwo name gets output into the compile unit.
// CHECK: !DICompileUnit({{.*}}, splitDebugFilename: "foo.dwo"

// Testing to ensure that the dwo name is not output into the compile unit if
// it's for vanilla split-dwarf rather than split-dwarf for implicit modules.
// VANILLA-NOT: splitDebugFilename

This seems intentional.

[aaronpuchert]

include/clang/Basic/CodeGenOptions.def

263 ↗

(On Diff #204162)

Although if that's up to change, I think we can drop it. If I'm not overlooking anything, -enable-split-dwarf does nothing when -emit-llvm is also given. So I'm not sure we lose anything by treating it the same way as -emit-llvm -split-dwarf-file ... without -enable-split-dwarf.

Actually llc has exactly that behavior (inferring whether to enable Split DWARF depending on whether there was a -split-dwarf-file argument), as I remarked in D59673#1457720, but it doesn't emit IR and doesn't have to deal with implicit modules...

[aaronpuchert]

Remove -enable-split-dwarf completely, adapting the test case accordingly. Also remove -split-dwarf which wasn't used at all.

[aaronpuchert]

clang/lib/CodeGen/BackendUtil.cpp

864

Perhaps I should also check whether SplitDwarfFile is empty.

1276

Dito here.

clang/test/CodeGen/split-debug-filename.c

14–16

We lose that when we remove -enable-split-dwarf.

[aaronpuchert]

clang/lib/CodeGen/BackendUtil.cpp

864

Maybe not. As it is, we just create an empty (but valid) debug info file when we have -split-dwarf-output but no -split-dwarf-file. This is exactly what llc does as well.

$ clang -c -g -o clang.o -Xclang -split-dwarf-output -Xclang clang.dwo test.cpp
$ clang -c -S -emit-llvm -g -o test.ll test.cpp
$ llc -filetype=obj -o llc.o -split-dwarf-output llc.dwo test.ll
$ diff <(llvm-dwarfdump clang.o) <(llvm-dwarfdump llc.o)
1c1
< clang.o:      file format ELF64-x86-64
---
> llc.o:        file format ELF64-x86-64
$ diff clang.dwo llc.dwo

[dblaikie]

Sounds alright :)

[aaronpuchert]

Thanks for the reviews!

clang/include/clang/Basic/CodeGenOptions.h

public:
 
   enum TLSModel {
     GeneralDynamicTLSModel,
     LocalDynamicTLSModel,
     InitialExecTLSModel,
     LocalExecTLSModel
   };
 
-  enum DwarfFissionKind { NoFission, SplitFileFission, SingleFileFission };
-
   /// Clang versions with different platform ABI conformance.
   enum class ClangABI {
     /// Attempt to be ABI-compatible with code generated by Clang 3.8.x
     /// (SVN r257626). This causes <1 x long long> to be passed in an
     /// integer register instead of an SSE register on x64_64.
     Ver3_8,
 
     /// Attempt to be ABI-compatible with code generated by Clang 4.0.x

clang/include/clang/Basic/CodeGenOptions.def

 
 CODEGENOPT(DebugTypeExtRefs, 1, 0) ///< Whether or not debug info should contain
                                    ///< external references to a PCH or module.
 
 CODEGENOPT(DebugExplicitImport, 1, 0)  ///< Whether or not debug info should
                                        ///< contain explicit imports for
                                        ///< anonymous namespaces
 
-ENUM_CODEGENOPT(SplitDwarfMode, DwarfFissionKind, 2, NoFission) ///< DWARF fission mode to use.
-
 CODEGENOPT(SplitDwarfInlining, 1, 1) ///< Whether to include inlining info in the
                                      ///< skeleton CU to allow for symbolication
                                      ///< of inline stack frames without .dwo files.
 CODEGENOPT(DebugFwdTemplateParams, 1, 0) ///< Whether to emit complete
                                          ///< template parameter descriptions in
                                          ///< forward declarations (versus just
                                          ///< including them in the name).
 

clang/include/clang/Driver/CC1Options.td

def disable_lifetimemarkers : Flag<["-"], "disable-lifetime-markers">,
   HelpText<"Disable lifetime-markers emission even when optimizations are "
            "enabled">;
 def disable_O0_optnone : Flag<["-"], "disable-O0-optnone">,
   HelpText<"Disable adding the optnone attribute to functions at O0">;
 def disable_red_zone : Flag<["-"], "disable-red-zone">,
   HelpText<"Do not emit code that uses the red zone.">;
 def dwarf_column_info : Flag<["-"], "dwarf-column-info">,
   HelpText<"Turn on column location information.">;
-def split_dwarf : Flag<["-"], "split-dwarf">,
-  HelpText<"Split out the dwarf .dwo sections">;
 def dwarf_ext_refs : Flag<["-"], "dwarf-ext-refs">,
   HelpText<"Generate debug info with external references to clang modules"
            " or precompiled headers">;
 def dwarf_explicit_import : Flag<["-"], "dwarf-explicit-import">,
   HelpText<"Generate explicit import from anonymous namespace to containing"
            " scope">;
 def debug_forward_template_params : Flag<["-"], "debug-forward-template-params">,
   HelpText<"Emit complete descriptions of template parameters in forward"
def split_dwarf_output : Separate<["-"], "split-dwarf-output">,
   HelpText<"File name to use for split dwarf debug info output">;
 
 }
 
 def fblocks_runtime_optional : Flag<["-"], "fblocks-runtime-optional">,
   HelpText<"Weakly link in the blocks runtime">;
 def fexternc_nounwind : Flag<["-"], "fexternc-nounwind">,
   HelpText<"Assume all functions with C linkage do not unwind">;
-def enable_split_dwarf : Flag<["-"], "enable-split-dwarf">,
-  HelpText<"Use DWARF fission in 'split' mode">;
-def enable_split_dwarf_EQ : Joined<["-"], "enable-split-dwarf=">,
-  HelpText<"Set DWARF fission mode to either 'split' or 'single'">, Values<"split,single">;
 def split_dwarf_file : Separate<["-"], "split-dwarf-file">,
   HelpText<"Name of the split dwarf debug info file to encode in the object file">;
 def fno_wchar : Flag<["-"], "fno-wchar">,
   HelpText<"Disable C++ builtin type wchar_t">;
 def fconstant_string_class : Separate<["-"], "fconstant-string-class">,
   MetaVarName<"<class name>">,
   HelpText<"Specify the class to use for constant Objective-C string objects.">;
 def fobjc_arc_cxxlib_EQ : Joined<["-"], "fobjc-arc-cxxlib=">,

clang/lib/CodeGen/BackendUtil.cpp

static void initTargetOptions(llvm::TargetOptions &Options,
   Options.DataSections = CodeGenOpts.DataSections;
   Options.UniqueSectionNames = CodeGenOpts.UniqueSectionNames;
   Options.EmulatedTLS = CodeGenOpts.EmulatedTLS;
   Options.ExplicitEmulatedTLS = CodeGenOpts.ExplicitEmulatedTLS;
   Options.DebuggerTuning = CodeGenOpts.getDebuggerTuning();
   Options.EmitStackSizeSection = CodeGenOpts.StackSizeSection;
   Options.EmitAddrsig = CodeGenOpts.Addrsig;
 
-  if (CodeGenOpts.getSplitDwarfMode() != CodeGenOptions::NoFission)
-    Options.MCOptions.SplitDwarfFile = CodeGenOpts.SplitDwarfFile;
   Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll;
   Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels;
   Options.MCOptions.MCUseDwarfDirectory = !CodeGenOpts.NoDwarfDirectoryAsm;
   Options.MCOptions.MCNoExecStack = CodeGenOpts.NoExecStack;
   Options.MCOptions.MCIncrementalLinkerCompatible =
       CodeGenOpts.IncrementalLinkerCompatible;
   Options.MCOptions.MCPIECopyRelocations = CodeGenOpts.PIECopyRelocations;
   Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
case Backend_EmitBC:
     break;
 
   case Backend_EmitLL:
     PerModulePasses.add(
         createPrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
     break;
 
   default:
-    if (!CodeGenOpts.SplitDwarfOutput.empty() &&
-        (CodeGenOpts.getSplitDwarfMode() == CodeGenOptions::SplitFileFission)) {
+    if (!CodeGenOpts.SplitDwarfOutput.empty()) {
       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
       if (!DwoOS)
         return;
     }
     if (!AddEmitPasses(CodeGenPasses, Action, *OS,
                        DwoOS ? &DwoOS->os() : nullptr))
       return;
   }
case Backend_EmitLL:
     break;
 
   case Backend_EmitAssembly:
   case Backend_EmitMCNull:
   case Backend_EmitObj:
     NeedCodeGen = true;
     CodeGenPasses.add(
         createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
-    if (!CodeGenOpts.SplitDwarfOutput.empty() &&
-        CodeGenOpts.getSplitDwarfMode() == CodeGenOptions::SplitFileFission) {
+    if (!CodeGenOpts.SplitDwarfOutput.empty()) {
       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
       if (!DwoOS)
         return;
     }
     if (!AddEmitPasses(CodeGenPasses, Action, *OS,
                        DwoOS ? &DwoOS->os() : nullptr))
       // FIXME: Should we handle this error differently?
       return;

clang/lib/CodeGen/CGDebugInfo.cpp

llvm::DIFile *CUFile = DBuilder.createFile(
       remapDIPath(MainFileName), remapDIPath(getCurrentDirname()), CSInfo,
       getSource(SM, SM.getMainFileID()));
 
   // Create new compile unit.
   TheCU = DBuilder.createCompileUnit(
       LangTag, CUFile, CGOpts.EmitVersionIdentMetadata ? Producer : "",
       LO.Optimize || CGOpts.PrepareForLTO || CGOpts.PrepareForThinLTO,
       CGOpts.DwarfDebugFlags, RuntimeVers,
-      (CGOpts.getSplitDwarfMode() != CodeGenOptions::NoFission)
-          ? ""
-          : CGOpts.SplitDwarfFile,
+      CGOpts.SplitDwarfFile,
       EmissionKind, DwoId, CGOpts.SplitDwarfInlining,
       CGOpts.DebugInfoForProfiling,
       CGM.getTarget().getTriple().isNVPTX()
           ? llvm::DICompileUnit::DebugNameTableKind::None
           : static_cast<llvm::DICompileUnit::DebugNameTableKind>(
                 CGOpts.DebugNameTable),
       CGOpts.DebugRangesBaseAddress);
 }

clang/lib/Driver/ToolChains/Clang.cpp

if (checkDebugInfoOption(A, Args, D, TC)) {
       if (DebugInfoKind != codegenoptions::DebugLineTablesOnly &&
           DebugInfoKind != codegenoptions::DebugDirectivesOnly) {
         DebugInfoKind = codegenoptions::LimitedDebugInfo;
         CmdArgs.push_back("-dwarf-ext-refs");
         CmdArgs.push_back("-fmodule-format=obj");
       }
     }
 
-  // -gsplit-dwarf enables the backend dwarf splitting and extraction.
-  if (T.isOSBinFormatELF()) {
-    if (!SplitDWARFInlining)
-      CmdArgs.push_back("-fno-split-dwarf-inlining");
+  if (T.isOSBinFormatELF() && !SplitDWARFInlining)
 
-    if (DwarfFission != DwarfFissionKind::None) {
-      if (DwarfFission == DwarfFissionKind::Single)
-        CmdArgs.push_back("-enable-split-dwarf=single");
-      else
-        CmdArgs.push_back("-enable-split-dwarf");
-    }
-  }
-
   // After we've dealt with all combinations of things that could
   // make DebugInfoKind be other than None or DebugLineTablesOnly,
   // figure out if we need to "upgrade" it to standalone debug info.
   // We parse these two '-f' options whether or not they will be used,
   // to claim them even if you wrote "-fstandalone-debug -gline-tables-only"
   bool NeedFullDebug = Args.hasFlag(
       options::OPT_fstandalone_debug, options::OPT_fno_standalone_debug,
       DebuggerTuning == llvm::DebuggerKind::LLDB ||

clang/lib/Frontend/CompilerInvocation.cpp

static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   Opts.EmitCodeView = Args.hasArg(OPT_gcodeview);
   Opts.CodeViewGHash = Args.hasArg(OPT_gcodeview_ghash);
   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.SplitDwarfFile = Args.getLastArgValue(OPT_split_dwarf_file);
   Opts.SplitDwarfOutput = Args.getLastArgValue(OPT_split_dwarf_output);
   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);
   Opts.EmbedSource = Args.hasArg(OPT_gembed_source);
 
   for (const auto &Arg : Args.getAllArgValues(OPT_fdebug_prefix_map_EQ))
     Opts.DebugPrefixMap.insert(StringRef(Arg).split('='));
 

clang/test/CodeGen/split-debug-filename.c

 // REQUIRES: x86-registered-target
 // RUN: %clang_cc1 -debug-info-kind=limited -split-dwarf-file foo.dwo -S -emit-llvm -o - %s | FileCheck %s
-// RUN: %clang_cc1 -debug-info-kind=limited -enable-split-dwarf -split-dwarf-file foo.dwo -S -emit-llvm -o - %s | FileCheck --check-prefix=VANILLA %s
-// RUN: %clang_cc1 -triple x86_64-unknown-linux -debug-info-kind=limited -enable-split-dwarf -split-dwarf-file %t.dwo -split-dwarf-output %t.dwo -emit-obj -o - %s | llvm-readobj -S - | FileCheck --check-prefix=O %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux -debug-info-kind=limited -split-dwarf-file %t.dwo -split-dwarf-output %t.dwo -emit-obj -o - %s | llvm-readobj -S - | FileCheck --check-prefix=O %s
 // RUN: llvm-readobj -S %t.dwo | FileCheck --check-prefix=DWO %s
 
 int main (void) {
   return 0;
 }
 
 // Testing to ensure that the dwo name gets output into the compile unit.
 // CHECK: !DICompileUnit({{.*}}, splitDebugFilename: "foo.dwo"
 
-// Testing to ensure that the dwo name is not output into the compile unit if
-// it's for vanilla split-dwarf rather than split-dwarf for implicit modules.
-// VANILLA-NOT: splitDebugFilename
-
 // O-NOT: .dwo
 // DWO: .dwo

clang/test/CodeGen/split-debug-output.c

 // REQUIRES: x86-registered-target
-// RUN: %clang_cc1 -triple x86_64-unknown-linux -debug-info-kind=limited -enable-split-dwarf -split-dwarf-file foo.dwo -split-dwarf-output %t -emit-obj -o - %s | llvm-dwarfdump -debug-info - | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux -debug-info-kind=limited -split-dwarf-file foo.dwo -split-dwarf-output %t -emit-obj -o - %s | llvm-dwarfdump -debug-info - | FileCheck %s
 // RUN: llvm-dwarfdump -debug-info %t | FileCheck %s
 
 int f() { return 0; }
 
 // CHECK: DW_AT_GNU_dwo_name ("foo.dwo")

clang/test/CodeGen/split-debug-single-file.c

 // REQUIRES: x86-registered-target
 
-// Testing to ensure -enable-split-dwarf=single allows to place .dwo sections into regular output object.
+// Testing to ensure that setting only -split-dwarf-file allows to place .dwo sections into regular output object.
 //  RUN: %clang_cc1 -debug-info-kind=limited -triple x86_64-unknown-linux \
-//  RUN:   -enable-split-dwarf=single -split-dwarf-file %t.o -emit-obj -o %t.o %s -fno-experimental-new-pass-manager
+//  RUN:   -split-dwarf-file %t.o -emit-obj -o %t.o %s -fno-experimental-new-pass-manager
 //  RUN: llvm-readobj -S %t.o | FileCheck --check-prefix=MODE-SINGLE %s
 //  RUN: %clang_cc1 -debug-info-kind=limited -triple x86_64-unknown-linux \
-//  RUN:   -enable-split-dwarf=single -split-dwarf-file %t.o -emit-obj -o %t.o %s -fexperimental-new-pass-manager
+//  RUN:   -split-dwarf-file %t.o -emit-obj -o %t.o %s -fexperimental-new-pass-manager
 //  RUN: llvm-readobj -S %t.o | FileCheck --check-prefix=MODE-SINGLE %s
 //  MODE-SINGLE: .dwo
 
-// Testing to ensure -enable-split-dwarf=split does not place .dwo sections into regular output object.
+// Testing to ensure that setting both -split-dwarf-file and -split-dwarf-output
+// does not place .dwo sections into regular output object.
 //  RUN: %clang_cc1 -debug-info-kind=limited -triple x86_64-unknown-linux \
-//  RUN:   -enable-split-dwarf=split -split-dwarf-file %t.dwo -split-dwarf-output %t.dwo -emit-obj -o %t.o %s -fno-experimental-new-pass-manager
+//  RUN:   -split-dwarf-file %t.dwo -split-dwarf-output %t.dwo -emit-obj -o %t.o %s -fno-experimental-new-pass-manager
 //  RUN: llvm-readobj -S %t.o | FileCheck --check-prefix=MODE-SPLIT %s
 //  RUN: %clang_cc1 -debug-info-kind=limited -triple x86_64-unknown-linux \
-//  RUN:   -enable-split-dwarf=split -split-dwarf-file %t.dwo -split-dwarf-output %t.dwo -emit-obj -o %t.o %s -fexperimental-new-pass-manager
+//  RUN:   -split-dwarf-file %t.dwo -split-dwarf-output %t.dwo -emit-obj -o %t.o %s -fexperimental-new-pass-manager
 //  RUN: llvm-readobj -S %t.o | FileCheck --check-prefix=MODE-SPLIT %s
 //  MODE-SPLIT-NOT: .dwo
 
 int main (void) {
   return 0;
 }

clang/test/Driver/split-debug.c

 // Check that we split debug output properly
 //
 // RUN: %clang -target x86_64-unknown-linux-gnu -gsplit-dwarf -c -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-ACTIONS < %t %s
 //
 // CHECK-ACTIONS: "-split-dwarf-file" "split-debug.dwo" "-split-dwarf-output" "split-debug.dwo"
 
 // RUN: %clang -target x86_64-unknown-linux-gnu -gsplit-dwarf -c -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-ACTIONS < %t %s
 // RUN: %clang -target x86_64-unknown-linux-gnu -gsplit-dwarf=split -c -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-ACTIONS < %t %s
 
 // RUN: %clang -target x86_64-unknown-linux-gnu -gsplit-dwarf=single -c -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-ACTIONS-SINGLE-SPLIT < %t %s
 //
-// CHECK-ACTIONS-SINGLE-SPLIT: "-enable-split-dwarf=single"
 // CHECK-ACTIONS-SINGLE-SPLIT: "-split-dwarf-file" "split-debug.o"
 // CHECK-ACTIONS-SINGLE-SPLIT-NOT: "-split-dwarf-output"
 
 // RUN: %clang -target x86_64-unknown-linux-gnu -gsplit-dwarf=single -c -### -o %tfoo.o %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-SINGLE-SPLIT-FILENAME < %t %s
 //
 // CHECK-SINGLE-SPLIT-FILENAME: "-split-dwarf-file" "{{.*}}foo.o"
 // CHECK-SINGLE-SPLIT-FILENAME-NOT: "-split-dwarf-output"

 // RUN: %clang -target x86_64-unknown-linux-gnu -no-integrated-as -gsplit-dwarf -c -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-IAS < %t %s
 //
 // CHECK-IAS: objcopy
 
 // RUN: %clang -target x86_64-unknown-linux-gnu -gsplit-dwarf -gmlt -fno-split-dwarf-inlining -S -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-GMLT-WITH-SPLIT < %t %s
 //
-// CHECK-GMLT-WITH-SPLIT: "-enable-split-dwarf"
 // CHECK-GMLT-WITH-SPLIT: "-debug-info-kind=line-tables-only"
 // CHECK-GMLT-WITH-SPLIT: "-split-dwarf-file"
 // CHECK-GMLT-WITH-SPLIT: "-split-dwarf-output"
 
 // RUN: %clang -target x86_64-unknown-linux-gnu -g -fno-split-dwarf-inlining -S -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-NOINLINE-WITHOUT-SPLIT < %t %s
 //
-// CHECK-NOINLINE-WITHOUT-SPLIT-NOT: "-enable-split-dwarf"
 // CHECK-NOINLINE-WITHOUT-SPLIT: "-fno-split-dwarf-inlining"
 // CHECK-NOINLINE-WITHOUT-SPLIT: "-debug-info-kind=limited"
 
 // RUN: %clang -target x86_64-unknown-linux-gnu -gmlt -gsplit-dwarf -fno-split-dwarf-inlining -S -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-SPLIT-WITH-GMLT < %t %s
 //
-// CHECK-SPLIT-WITH-GMLT: "-enable-split-dwarf"
 // CHECK-SPLIT-WITH-GMLT: "-debug-info-kind=limited"
 // CHECK-SPLIT-WITH-GMLT: "-split-dwarf-output"
 
 // RUN: %clang -target x86_64-unknown-linux-gnu -gsplit-dwarf -fno-split-dwarf-inlining -S -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-SPLIT-WITH-NOINL < %t %s
 //
-// CHECK-SPLIT-WITH-NOINL: "-enable-split-dwarf"
 // CHECK-SPLIT-WITH-NOINL: "-debug-info-kind=limited"
 // CHECK-SPLIT-WITH-NOINL: "-split-dwarf-output"
 
 // RUN: %clang -target x86_64-unknown-linux-gnu -gsplit-dwarf -gmlt -S -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-GMLT-OVER-SPLIT < %t %s
 //
-// CHECK-GMLT-OVER-SPLIT-NOT: "-enable-split-dwarf"
 // CHECK-GMLT-OVER-SPLIT: "-debug-info-kind=line-tables-only"
 // CHECK-GMLT-OVER-SPLIT-NOT: "-split-dwarf-file"
 // CHECK-GMLT-OVER-SPLIT-NOT: "-split-dwarf-output"
 
 // RUN: %clang -target x86_64-unknown-linux-gnu -gmlt -gsplit-dwarf -S -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-SPLIT-OVER-GMLT < %t %s
 //
-// CHECK-SPLIT-OVER-GMLT: "-enable-split-dwarf" "-debug-info-kind=limited"
+// CHECK-SPLIT-OVER-GMLT: "-debug-info-kind=limited"
 // CHECK-SPLIT-OVER-GMLT: "-split-dwarf-file"
 // CHECK-SPLIT-OVER-GMLT: "-split-dwarf-output"
 
 // RUN: %clang -target x86_64-unknown-linux-gnu -gsplit-dwarf -g0 -fno-split-dwarf-inlining -S -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-G0-OVER-SPLIT < %t %s
 //
-// CHECK-G0-OVER-SPLIT-NOT: "-enable-split-dwarf"
 // CHECK-G0-OVER-SPLIT-NOT: "-debug-info-kind
 // CHECK-G0-OVER-SPLIT-NOT: "-split-dwarf-file"
 // CHECK-G0-OVER-SPLIT-NOT: "-split-dwarf-output"
 
 // RUN: %clang -target x86_64-unknown-linux-gnu -gsplit-dwarf -g0 -S -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-G0-OVER-SPLIT < %t %s
 // RUN: %clang -target x86_64-unknown-linux-gnu -gsplit-dwarf=split -g0 -S -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-G0-OVER-SPLIT < %t %s
 //
-// CHECK-G0-OVER-SPLIT-NOT: "-enable-split-dwarf"
 // CHECK-G0-OVER-SPLIT-NOT: "-debug-info-kind
 // CHECK-G0-OVER-SPLIT-NOT: "-split-dwarf-file"
 // CHECK-G0-OVER-SPLIT-NOT: "-split-dwarf-output"
 
 // RUN: %clang -target x86_64-unknown-linux-gnu -g0 -gsplit-dwarf -S -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-SPLIT-OVER-G0 < %t %s
 // RUN: %clang -target x86_64-unknown-linux-gnu -g0 -gsplit-dwarf=split -S -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-SPLIT-OVER-G0 < %t %s
 //
-// CHECK-SPLIT-OVER-G0: "-enable-split-dwarf" "-debug-info-kind=limited"
+// CHECK-SPLIT-OVER-G0: "-debug-info-kind=limited"
 // CHECK-SPLIT-OVER-G0: "-split-dwarf-file"
 // CHECK-SPLIT-OVER-G0: "-split-dwarf-output"