Commit d54883f0 authored by Paul Robinson's avatar Paul Robinson
Browse files

[DWARFv5] Emit file 0 to the line table. 

DWARF v5 specifies that the root file (also given in the DW_AT_name
attribute of the compilation unit DIE) should be emitted explicitly to
the line table's list of files.  This makes the line table more
independent of the .debug_info section.

Differential Revision: https://reviews.llvm.org/D44054
parent 6405f2f9

llvm/include/llvm/MC/MCContext.h

+7 −2
Original line number Diff line number Diff line
@@ -537,8 +537,13 @@ namespace llvm { 
      DwarfCompileUnitID = CUIndex;

    }



    void setMCLineTableCompilationDir(unsigned CUID, StringRef CompilationDir) {

      getMCDwarfLineTable(CUID).setCompilationDir(CompilationDir);

    /// Specifies the "root" file and directory of the compilation unit.

    /// These are "file 0" and "directory 0" in DWARF v5.

    void setMCLineTableRootFile(unsigned CUID, StringRef CompilationDir,

                                StringRef Filename, MD5::MD5Result *Checksum,

                                Optional<StringRef> Source) {

      getMCDwarfLineTable(CUID).setRootFile(CompilationDir, Filename, Checksum,

                                            Source);

    }



    /// Saves the information from the currently parsed dwarf .loc directive

llvm/include/llvm/MC/MCDwarf.h

+23 −6
Original line number Diff line number Diff line
@@ -214,6 +214,7 @@ struct MCDwarfLineTableHeader { 
  SmallVector<MCDwarfFile, 3> MCDwarfFiles;

  StringMap<unsigned> SourceIdMap;

  StringRef CompilationDir;

  MCDwarfFile RootFile;

  bool HasMD5 = false;

  bool HasSource = false;
@@ -241,8 +242,17 @@ class MCDwarfDwoLineTable { 
  MCDwarfLineTableHeader Header;



public:

  void setCompilationDir(StringRef CompilationDir) {

    Header.CompilationDir = CompilationDir;

  void maybeSetRootFile(StringRef Directory, StringRef FileName,

                        MD5::MD5Result *Checksum, Optional<StringRef> Source) {

    if (!Header.RootFile.Name.empty())

      return;

    Header.CompilationDir = Directory;

    Header.RootFile.Name = FileName;

    Header.RootFile.DirIndex = 0;

    Header.RootFile.Checksum = Checksum;

    Header.RootFile.Source = Source;

    Header.HasMD5 = (Checksum != nullptr);

    Header.HasSource = Source.hasValue();

  }



  unsigned getFile(StringRef Directory, StringRef FileName,
@@ -276,6 +286,17 @@ public: 
                               FileNumber));

  }



  void setRootFile(StringRef Directory, StringRef FileName,

                   MD5::MD5Result *Checksum, Optional<StringRef> Source) {

    Header.CompilationDir = Directory;

    Header.RootFile.Name = FileName;

    Header.RootFile.DirIndex = 0;

    Header.RootFile.Checksum = Checksum;

    Header.RootFile.Source = Source;

    Header.HasMD5 = (Checksum != nullptr);

    Header.HasSource = Source.hasValue();

  }



  MCSymbol *getLabel() const {

    return Header.Label;

  }
@@ -284,10 +305,6 @@ public: 
    Header.Label = Label;

  }



  void setCompilationDir(StringRef CompilationDir) {

    Header.CompilationDir = CompilationDir;

  }



  const SmallVectorImpl<std::string> &getMCDwarfDirs() const {

    return Header.MCDwarfDirs;

  }

llvm/include/llvm/MC/MCStreamer.h

+6 −0
Original line number Diff line number Diff line
@@ -774,6 +774,12 @@ public: 
      MD5::MD5Result *Checksum = nullptr, Optional<StringRef> Source = None,

      unsigned CUID = 0);



  /// Specify the "root" file of the compilation, using the ".file 0" extension.

  virtual void emitDwarfFile0Directive(StringRef Directory, StringRef Filename,

                                       MD5::MD5Result *Checksum,

                                       Optional<StringRef> Source,

                                       unsigned CUID = 0);



  /// \brief This implements the DWARF2 '.loc fileno lineno ...' assembler

  /// directive.

  virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

+7 −4
Original line number Diff line number Diff line
@@ -476,8 +476,9 @@ DwarfDebug::getOrCreateDwarfCompileUnit(const DICompileUnit *DIUnit) { 
  // explicitly describe the directory of all files, never relying on the

  // compilation directory.

  if (!Asm->OutStreamer->hasRawTextSupport() || SingleCU)

    Asm->OutStreamer->getContext().setMCLineTableCompilationDir(

        NewCU.getUniqueID(), CompilationDir);

    Asm->OutStreamer->emitDwarfFile0Directive(

        CompilationDir, FN, NewCU.getMD5AsBytes(DIUnit->getFile()),

        DIUnit->getSource(), NewCU.getUniqueID());



  StringRef Producer = DIUnit->getProducer();

  StringRef Flags = DIUnit->getFlags();
@@ -2110,8 +2111,10 @@ void DwarfDebug::emitDebugStrDWO() { 
MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {

  if (!useSplitDwarf())

    return nullptr;

  if (SingleCU)

    SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode()->getDirectory());

  const DICompileUnit *DIUnit = CU.getCUNode();

  SplitTypeUnitFileTable.maybeSetRootFile(

      DIUnit->getDirectory(), DIUnit->getFilename(),

      CU.getMD5AsBytes(DIUnit->getFile()), DIUnit->getSource());

  return &SplitTypeUnitFileTable;

}

llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp

+1 −1
Original line number Diff line number Diff line
@@ -284,7 +284,7 @@ void DwarfUnit::addSectionOffset(DIE &Die, dwarf::Attribute Attribute, 
    addUInt(Die, Attribute, dwarf::DW_FORM_data4, Integer);

}



MD5::MD5Result *DwarfUnit::getMD5AsBytes(const DIFile *File) {

MD5::MD5Result *DwarfUnit::getMD5AsBytes(const DIFile *File) const {

  assert(File);

  Optional<DIFile::ChecksumInfo<StringRef>> Checksum = File->getChecksum();

  if (!Checksum || Checksum->Kind != DIFile::CSK_MD5)