CodeGen, Driver: Start using direct split dwarf emission in clang.

Fixes PR37466.

Differential Revision: https://reviews.llvm.org/D47093

llvm-svn: 332885

clang/include/clang/Driver/CC1Options.td

@@ -619,6 +619,8 @@ def version : Flag<["-"], "version">,
   HelpText<"Print the compiler version">;
 def main_file_name : Separate<["-"], "main-file-name">,
   HelpText<"Main file name to use for debug info">;
+def split_dwarf_file : Separate<["-"], "split-dwarf-file">,
+  HelpText<"File name to use for split dwarf debug info output">;
 
 }
 
@@ -628,8 +630,6 @@ 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 split dwarf/Fission">;
-def split_dwarf_file : Separate<["-"], "split-dwarf-file">,
-  HelpText<"File name to use for split dwarf debug info output">;
 def fno_wchar : Flag<["-"], "fno-wchar">,
   HelpText<"Disable C++ builtin type wchar_t">;
 def fconstant_string_class : Separate<["-"], "fconstant-string-class">,

clang/lib/CodeGen/BackendUtil.cpp

@@ -104,7 +104,17 @@ class EmitAssemblyHelper {
   ///
   /// \return True on success.
   bool AddEmitPasses(legacy::PassManager &CodeGenPasses, BackendAction Action,
-                     raw_pwrite_stream &OS);
+                     raw_pwrite_stream &OS, raw_pwrite_stream *DwoOS);
+
+  std::unique_ptr<llvm::ToolOutputFile> openOutputFile(StringRef Path) {
+    std::error_code EC;
+    auto F = make_unique<llvm::ToolOutputFile>(Path, EC, llvm::sys::fs::F_None);
+    if (EC) {
+      Diags.Report(diag::err_fe_unable_to_open_output) << Path << EC.message();
+      F.reset();
+    }
+    return F;
+  }
 
 public:
   EmitAssemblyHelper(DiagnosticsEngine &_Diags,
@@ -701,7 +711,8 @@ void EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
 
 bool EmitAssemblyHelper::AddEmitPasses(legacy::PassManager &CodeGenPasses,
                                        BackendAction Action,
-                                       raw_pwrite_stream &OS) {
+                                       raw_pwrite_stream &OS,
+                                       raw_pwrite_stream *DwoOS) {
   // Add LibraryInfo.
   llvm::Triple TargetTriple(TheModule->getTargetTriple());
   std::unique_ptr<TargetLibraryInfoImpl> TLII(
@@ -718,7 +729,7 @@ bool EmitAssemblyHelper::AddEmitPasses(legacy::PassManager &CodeGenPasses,
   if (CodeGenOpts.OptimizationLevel > 0)
     CodeGenPasses.add(createObjCARCContractPass());
 
-  if (TM->addPassesToEmitFile(CodeGenPasses, OS, nullptr, CGFT,
+  if (TM->addPassesToEmitFile(CodeGenPasses, OS, DwoOS, CGFT,
                               /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
     Diags.Report(diag::err_fe_unable_to_interface_with_target);
     return false;
@@ -757,7 +768,7 @@ void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
   CodeGenPasses.add(
       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
 
-  std::unique_ptr<raw_fd_ostream> ThinLinkOS;
+  std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
 
   switch (Action) {
   case Backend_EmitNothing:
@@ -766,18 +777,12 @@ void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
   case Backend_EmitBC:
     if (CodeGenOpts.EmitSummaryIndex) {
       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
-        std::error_code EC;
-        ThinLinkOS.reset(new llvm::raw_fd_ostream(
-            CodeGenOpts.ThinLinkBitcodeFile, EC,
-            llvm::sys::fs::F_None));
-        if (EC) {
-          Diags.Report(diag::err_fe_unable_to_open_output) << CodeGenOpts.ThinLinkBitcodeFile
-                                                           << EC.message();
+        ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
+        if (!ThinLinkOS)
           return;
-        }
       }
-      PerModulePasses.add(
-          createWriteThinLTOBitcodePass(*OS, ThinLinkOS.get()));
+      PerModulePasses.add(createWriteThinLTOBitcodePass(
+          *OS, ThinLinkOS ? &ThinLinkOS->os() : nullptr));
     }
     else
       PerModulePasses.add(
@@ -790,7 +795,13 @@ void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
     break;
 
   default:
-    if (!AddEmitPasses(CodeGenPasses, Action, *OS))
+    if (!CodeGenOpts.SplitDwarfFile.empty()) {
+      DwoOS = openOutputFile(CodeGenOpts.SplitDwarfFile);
+      if (!DwoOS)
+        return;
+    }
+    if (!AddEmitPasses(CodeGenPasses, Action, *OS,
+                       DwoOS ? &DwoOS->os() : nullptr))
       return;
   }
 
@@ -819,6 +830,11 @@ void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
     PrettyStackTraceString CrashInfo("Code generation");
     CodeGenPasses.run(*TheModule);
   }
+
+  if (ThinLinkOS)
+    ThinLinkOS->keep();
+  if (DwoOS)
+    DwoOS->keep();
 }
 
 static PassBuilder::OptimizationLevel mapToLevel(const CodeGenOptions &Opts) {
@@ -971,7 +987,7 @@ void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
   // create that pass manager here and use it as needed below.
   legacy::PassManager CodeGenPasses;
   bool NeedCodeGen = false;
-  Optional<raw_fd_ostream> ThinLinkOS;
+  std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
 
   // Append any output we need to the pass manager.
   switch (Action) {
@@ -981,17 +997,12 @@ void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
   case Backend_EmitBC:
     if (CodeGenOpts.EmitSummaryIndex) {
       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
-        std::error_code EC;
-        ThinLinkOS.emplace(CodeGenOpts.ThinLinkBitcodeFile, EC,
-                           llvm::sys::fs::F_None);
-        if (EC) {
-          Diags.Report(diag::err_fe_unable_to_open_output)
-              << CodeGenOpts.ThinLinkBitcodeFile << EC.message();
+        ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
+        if (!ThinLinkOS)
           return;
-        }
       }
-      MPM.addPass(
-          ThinLTOBitcodeWriterPass(*OS, ThinLinkOS ? &*ThinLinkOS : nullptr));
+      MPM.addPass(ThinLTOBitcodeWriterPass(*OS, ThinLinkOS ? &ThinLinkOS->os()
+                                                           : nullptr));
     } else {
       MPM.addPass(BitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists,
                                     CodeGenOpts.EmitSummaryIndex,
@@ -1009,7 +1020,13 @@ void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
     NeedCodeGen = true;
     CodeGenPasses.add(
         createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
-    if (!AddEmitPasses(CodeGenPasses, Action, *OS))
+    if (!CodeGenOpts.SplitDwarfFile.empty()) {
+      DwoOS = openOutputFile(CodeGenOpts.SplitDwarfFile);
+      if (!DwoOS)
+        return;
+    }
+    if (!AddEmitPasses(CodeGenPasses, Action, *OS,
+                       DwoOS ? &DwoOS->os() : nullptr))
       // FIXME: Should we handle this error differently?
       return;
     break;
@@ -1029,6 +1046,11 @@ void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
     PrettyStackTraceString CrashInfo("Code generation");
     CodeGenPasses.run(*TheModule);
   }
+
+  if (ThinLinkOS)
+    ThinLinkOS->keep();
+  if (DwoOS)
+    DwoOS->keep();
 }
 
 Expected<BitcodeModule> clang::FindThinLTOModule(MemoryBufferRef MBRef) {

clang/lib/Driver/ToolChains/Clang.cpp

@@ -4802,12 +4802,6 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
   }
 
-  // Handle the debug info splitting at object creation time if we're
-  // creating an object.
-  // TODO: Currently only works on linux with newer objcopy.
-  if (SplitDWARF && Output.getType() == types::TY_Object)
-    SplitDebugInfo(getToolChain(), C, *this, JA, Args, Output, SplitDWARFOut);
-
   if (Arg *A = Args.getLastArg(options::OPT_pg))
     if (Args.hasArg(options::OPT_fomit_frame_pointer))
       D.Diag(diag::err_drv_argument_not_allowed_with) << "-fomit-frame-pointer"
@@ -5464,19 +5458,17 @@ void ClangAs::ConstructJob(Compilation &C, const JobAction &JA,
   CmdArgs.push_back("-o");
   CmdArgs.push_back(Output.getFilename());
 
+  if (Args.hasArg(options::OPT_gsplit_dwarf) &&
+      getToolChain().getTriple().isOSLinux()) {
+    CmdArgs.push_back("-split-dwarf-file");
+    CmdArgs.push_back(SplitDebugName(Args, Input));
+  }
+
   assert(Input.isFilename() && "Invalid input.");
   CmdArgs.push_back(Input.getFilename());
 
   const char *Exec = getToolChain().getDriver().getClangProgramPath();
   C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
-
-  // Handle the debug info splitting at object creation time if we're
-  // creating an object.
-  // TODO: Currently only works on linux with newer objcopy.
-  if (Args.hasArg(options::OPT_gsplit_dwarf) &&
-      getToolChain().getTriple().isOSLinux())
-    SplitDebugInfo(getToolChain(), C, *this, JA, Args, Output,
-                   SplitDebugName(Args, Input));
 }
 
 // Begin OffloadBundler

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

@@ -1,5 +1,8 @@
 // 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 -debug-info-kind=limited -enable-split-dwarf -split-dwarf-file %t.dwo -emit-obj -o - %s | llvm-objdump -section-headers - | FileCheck --check-prefix=O %s
+// RUN: llvm-objdump -section-headers %t.dwo | FileCheck --check-prefix=DWO %s
+
 int main (void) {
   return 0;
 }
@@ -10,3 +13,6 @@ int main (void) {
 // 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/Driver/split-debug.c

@@ -3,8 +3,7 @@
 // RUN: %clang -target x86_64-unknown-linux-gnu -gsplit-dwarf -c -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-ACTIONS < %t %s
 //
-// CHECK-ACTIONS: objcopy{{.*}}--extract-dwo{{.*}}"split-debug.dwo"
-// CHECK-ACTIONS: objcopy{{.*}}--strip-dwo{{.*}}"split-debug.o"
+// CHECK-ACTIONS: "-split-dwarf-file" "split-debug.dwo"
 
 
 // RUN: %clang -target x86_64-macosx -gsplit-dwarf -c -### %s 2> %t

clang/test/Driver/split-debug.s

@@ -3,8 +3,7 @@
 // RUN: %clang -target x86_64-unknown-linux-gnu -gsplit-dwarf -c -### %s 2> %t
 // RUN: FileCheck -check-prefix=CHECK-ACTIONS < %t %s
 //
-// CHECK-ACTIONS: objcopy{{.*}}--extract-dwo{{.*}}"split-debug.dwo"
-// CHECK-ACTIONS: objcopy{{.*}}--strip-dwo{{.*}}"split-debug.o"
+// CHECK-ACTIONS: "-split-dwarf-file" "split-debug.dwo"
 
 
 // RUN: %clang -target x86_64-macosx -gsplit-dwarf -c -### %s 2> %t

clang/test/Misc/cc1as-split-dwarf.s

@@ -0,0 +1,25 @@
+// RUN: %clang -cc1as -triple x86_64-pc-linux-gnu %s -filetype obj -o %t1 -split-dwarf-file %t2
+// RUN: llvm-objdump -s %t1 | FileCheck --check-prefix=O %s
+// RUN: llvm-objdump -s %t2 | FileCheck --check-prefix=DWO %s
+
+// O-NOT: Contents of section
+// O: Contents of section .strtab:
+// O-NOT: Contents of section
+// O: Contents of section .text:
+// O-NEXT: 0000 c3
+// O-NEXT: Contents of section .symtab:
+// O-NOT: Contents of section
+.globl main
+main:
+.Ltmp1:
+ret
+.Ltmp2:
+
+// DWO-NOT: Contents of section
+// DWO: Contents of section .strtab:
+// DWO-NOT: Contents of section
+// DWO: Contents of section .foo.dwo:
+// DWO-NEXT: 0000 01000000
+// DWO-NOT: Contents of section
+.section .foo.dwo
+.long .Ltmp2-.Ltmp1

clang/tools/driver/cc1as_main.cpp

@@ -97,6 +97,7 @@ struct AssemblerInvocation {
   llvm::DebugCompressionType CompressDebugSections =
       llvm::DebugCompressionType::None;
   std::string MainFileName;
+  std::string SplitDwarfFile;
 
   /// @}
   /// @name Frontend Options
@@ -247,6 +248,7 @@ bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
   }
   Opts.LLVMArgs = Args.getAllArgValues(OPT_mllvm);
   Opts.OutputPath = Args.getLastArgValue(OPT_o);
+  Opts.SplitDwarfFile = Args.getLastArgValue(OPT_split_dwarf_file);
   if (Arg *A = Args.getLastArg(OPT_filetype)) {
     StringRef Name = A->getValue();
     unsigned OutputType = StringSwitch<unsigned>(Name)
@@ -282,22 +284,17 @@ bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
 }
 
 static std::unique_ptr<raw_fd_ostream>
-getOutputStream(AssemblerInvocation &Opts, DiagnosticsEngine &Diags,
-                bool Binary) {
-  if (Opts.OutputPath.empty())
-    Opts.OutputPath = "-";
-
+getOutputStream(StringRef Path, DiagnosticsEngine &Diags, bool Binary) {
   // Make sure that the Out file gets unlinked from the disk if we get a
   // SIGINT.
-  if (Opts.OutputPath != "-")
-    sys::RemoveFileOnSignal(Opts.OutputPath);
+  if (Path != "-")
+    sys::RemoveFileOnSignal(Path);
 
   std::error_code EC;
   auto Out = llvm::make_unique<raw_fd_ostream>(
-      Opts.OutputPath, EC, (Binary ? sys::fs::F_None : sys::fs::F_Text));
+      Path, EC, (Binary ? sys::fs::F_None : sys::fs::F_Text));
   if (EC) {
-    Diags.Report(diag::err_fe_unable_to_open_output) << Opts.OutputPath
-                                                     << EC.message();
+    Diags.Report(diag::err_fe_unable_to_open_output) << Path << EC.message();
     return nullptr;
   }
 
@@ -342,9 +339,15 @@ static bool ExecuteAssembler(AssemblerInvocation &Opts,
   MAI->setRelaxELFRelocations(Opts.RelaxELFRelocations);
 
   bool IsBinary = Opts.OutputType == AssemblerInvocation::FT_Obj;
-  std::unique_ptr<raw_fd_ostream> FDOS = getOutputStream(Opts, Diags, IsBinary);
+  if (Opts.OutputPath.empty())
+    Opts.OutputPath = "-";
+  std::unique_ptr<raw_fd_ostream> FDOS =
+      getOutputStream(Opts.OutputPath, Diags, IsBinary);
   if (!FDOS)
     return true;
+  std::unique_ptr<raw_fd_ostream> DwoOS;
+  if (!Opts.SplitDwarfFile.empty())
+    DwoOS = getOutputStream(Opts.SplitDwarfFile, Diags, IsBinary);
 
   // FIXME: This is not pretty. MCContext has a ptr to MCObjectFileInfo and
   // MCObjectFileInfo needs a MCContext reference in order to initialize itself.
@@ -427,7 +430,9 @@ static bool ExecuteAssembler(AssemblerInvocation &Opts,
     MCTargetOptions MCOptions;
     std::unique_ptr<MCAsmBackend> MAB(
         TheTarget->createMCAsmBackend(*STI, *MRI, MCOptions));
-    std::unique_ptr<MCObjectWriter> OW = MAB->createObjectWriter(*Out);
+    std::unique_ptr<MCObjectWriter> OW =
+        DwoOS ? MAB->createDwoObjectWriter(*Out, *DwoOS)
+              : MAB->createObjectWriter(*Out);
 
     Triple T(Opts.Triple);
     Str.reset(TheTarget->createMCObjectStreamer(
@@ -476,8 +481,12 @@ static bool ExecuteAssembler(AssemblerInvocation &Opts,
   FDOS.reset();
 
   // Delete output file if there were errors.
-  if (Failed && Opts.OutputPath != "-")
-    sys::fs::remove(Opts.OutputPath);
+  if (Failed) {
+    if (Opts.OutputPath != "-")
+      sys::fs::remove(Opts.OutputPath);
+    if (!Opts.SplitDwarfFile.empty() && Opts.SplitDwarfFile != "-")
+      sys::fs::remove(Opts.SplitDwarfFile);
+  }
 
   return Failed;
 }