text: //===-- llvm/CodeGen/DwarfUnit.h - Dwarf Compile Unit ---*- C++ -*--===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  //
  // This file contains support for writing dwarf compile unit.
  //
  //===----------------------------------------------------------------------===//
  
  #ifndef CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H
  #define CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H
  
  #include "DIE.h"
  #include "DwarfDebug.h"
  #include "llvm/ADT/DenseMap.h"
  #include "llvm/ADT/Optional.h"
  #include "llvm/ADT/StringMap.h"
  #include "llvm/CodeGen/AsmPrinter.h"
  #include "llvm/IR/DIBuilder.h"
  #include "llvm/IR/DebugInfo.h"
  #include "llvm/MC/MCExpr.h"
  #include "llvm/MC/MCSection.h"
  #include "llvm/MC/MCDwarf.h"
  
  namespace llvm {
  
  class MachineLocation;
  class MachineOperand;
  class ConstantInt;
  class ConstantFP;
  class DbgVariable;
  class DwarfCompileUnit;
  
  // Data structure to hold a range for range lists.
  class RangeSpan {
  public:
    RangeSpan(MCSymbol *S, MCSymbol *E) : Start(S), End(E) {}
    const MCSymbol *getStart() const { return Start; }
    const MCSymbol *getEnd() const { return End; }
    void setEnd(const MCSymbol *E) { End = E; }
  
  private:
    const MCSymbol *Start, *End;
  };
  
  class RangeSpanList {
  private:
    // Index for locating within the debug_range section this particular span.
    MCSymbol *RangeSym;
    // List of ranges.
    SmallVector<RangeSpan, 2> Ranges;
  
  public:
    RangeSpanList(MCSymbol *Sym) : RangeSym(Sym) {}
    MCSymbol *getSym() const { return RangeSym; }
    const SmallVectorImpl<RangeSpan> &getRanges() const { return Ranges; }
    void addRange(RangeSpan Range) { Ranges.push_back(Range); }
  };
  
  //===----------------------------------------------------------------------===//
  /// Unit - This dwarf writer support class manages information associated
  /// with a source file.
  class DwarfUnit {
  protected:
    /// UniqueID - a numeric ID unique among all CUs in the module
    unsigned UniqueID;
  
    /// Node - MDNode for the compile unit.
    DICompileUnit CUNode;
  
    /// Unit debug information entry.
    DIE UnitDie;
  
    /// Offset of the UnitDie from beginning of debug info section.
    unsigned DebugInfoOffset;
  
    /// Asm - Target of Dwarf emission.
    AsmPrinter *Asm;
  
    // Holders for some common dwarf information.
    DwarfDebug *DD;
    DwarfFile *DU;
  
    /// IndexTyDie - An anonymous type for index type.  Owned by UnitDie.
    DIE *IndexTyDie;
  
    /// MDNodeToDieMap - Tracks the mapping of unit level debug information
    /// variables to debug information entries.
    DenseMap<const MDNode *, DIE *> MDNodeToDieMap;
  
    /// MDNodeToDIEEntryMap - Tracks the mapping of unit level debug information
    /// descriptors to debug information entries using a DIEEntry proxy.
    DenseMap<const MDNode *, DIEEntry *> MDNodeToDIEEntryMap;
  
    /// GlobalNames - A map of globally visible named entities for this unit.
    StringMap<const DIE *> GlobalNames;
  
    /// GlobalTypes - A map of globally visible types for this unit.
    StringMap<const DIE *> GlobalTypes;
  
    /// DIEBlocks - A list of all the DIEBlocks in use.
    std::vector<DIEBlock *> DIEBlocks;
    
    /// DIELocs - A list of all the DIELocs in use.
    std::vector<DIELoc *> DIELocs;
  
    /// ContainingTypeMap - This map is used to keep track of subprogram DIEs that
    /// need DW_AT_containing_type attribute. This attribute points to a DIE that
    /// corresponds to the MDNode mapped with the subprogram DIE.
    DenseMap<DIE *, const MDNode *> ContainingTypeMap;
  
    // List of ranges for a given compile unit.
    SmallVector<RangeSpan, 1> CURanges;
  
    // List of range lists for a given compile unit, separate from the ranges for
    // the CU itself.
    SmallVector<RangeSpanList, 1> CURangeLists;
  
    // DIEValueAllocator - All DIEValues are allocated through this allocator.
    BumpPtrAllocator DIEValueAllocator;
  
    // DIEIntegerOne - A preallocated DIEValue because 1 is used frequently.
    DIEInteger *DIEIntegerOne;
  
    /// The section this unit will be emitted in.
    const MCSection *Section;
  
    /// A label at the start of the non-dwo section related to this unit.
    MCSymbol *SectionSym;
  
    /// The start of the unit within its section.
    MCSymbol *LabelBegin;
  
    /// The end of the unit within its section.
    MCSymbol *LabelEnd;
  
    /// Skeleton unit associated with this unit.
    DwarfUnit *Skeleton;
  
    DwarfUnit(unsigned UID, dwarf::Tag, DICompileUnit CU, AsmPrinter *A,
              DwarfDebug *DW, DwarfFile *DWU);
  
  public:
    virtual ~DwarfUnit();
  
    /// Set the skeleton unit associated with this unit.
    void setSkeleton(DwarfUnit &Skel) { Skeleton = &Skel; }
  
    /// Get the skeleton unit associated with this unit.
    DwarfUnit *getSkeleton() const { return Skeleton; }
  
    /// Pass in the SectionSym even though we could recreate it in every compile
    /// unit (type units will have actually distinct symbols once they're in
    /// comdat sections).
    void initSection(const MCSection *Section, MCSymbol *SectionSym) {
      assert(!this->Section);
      this->Section = Section;
      this->SectionSym = SectionSym;
      this->LabelBegin =
          Asm->GetTempSymbol(Section->getLabelBeginName(), getUniqueID());
      this->LabelEnd =
          Asm->GetTempSymbol(Section->getLabelEndName(), getUniqueID());
    }
  
    const MCSection *getSection() const {
      assert(Section);
      return Section;
    }
  
    /// If there's a skeleton then return the section symbol for the skeleton
    /// unit, otherwise return the section symbol for this unit.
    MCSymbol *getLocalSectionSym() const {
      if (Skeleton)
        return Skeleton->getSectionSym();
      return getSectionSym();
    }
  
    MCSymbol *getSectionSym() const {
      assert(Section);
      return SectionSym;
    }
  
    /// If there's a skeleton then return the begin label for the skeleton unit,
    /// otherwise return the local label for this unit.
    MCSymbol *getLocalLabelBegin() const {
      if (Skeleton)
        return Skeleton->getLabelBegin();
      return getLabelBegin();
    }
  
    MCSymbol *getLabelBegin() const {
      assert(Section);
      return LabelBegin;
    }
  
    MCSymbol *getLabelEnd() const {
      assert(Section);
      return LabelEnd;
    }
  
    // Accessors.
    unsigned getUniqueID() const { return UniqueID; }
    uint16_t getLanguage() const { return CUNode.getLanguage(); }
    DICompileUnit getCUNode() const { return CUNode; }
    DIE &getUnitDie() { return UnitDie; }
    const StringMap<const DIE *> &getGlobalNames() const { return GlobalNames; }
    const StringMap<const DIE *> &getGlobalTypes() const { return GlobalTypes; }
  
    unsigned getDebugInfoOffset() const { return DebugInfoOffset; }
    void setDebugInfoOffset(unsigned DbgInfoOff) { DebugInfoOffset = DbgInfoOff; }
  
    /// hasContent - Return true if this compile unit has something to write out.
    bool hasContent() const { return !UnitDie.getChildren().empty(); }
  
    /// addRange - Add an address range to the list of ranges for this unit.
    void addRange(RangeSpan Range);
  
    /// getRanges - Get the list of ranges for this unit.
    const SmallVectorImpl<RangeSpan> &getRanges() const { return CURanges; }
    SmallVectorImpl<RangeSpan> &getRanges() { return CURanges; }
  
    /// addRangeList - Add an address range list to the list of range lists.
    void addRangeList(RangeSpanList Ranges) { CURangeLists.push_back(Ranges); }
  
    /// getRangeLists - Get the vector of range lists.
    const SmallVectorImpl<RangeSpanList> &getRangeLists() const {
      return CURangeLists;
    }
    SmallVectorImpl<RangeSpanList> &getRangeLists() { return CURangeLists; }
  
    /// getParentContextString - Get a string containing the language specific
    /// context for a global name.
    std::string getParentContextString(DIScope Context) const;
  
    /// addGlobalName - Add a new global entity to the compile unit.
    ///
    void addGlobalName(StringRef Name, DIE &Die, DIScope Context);
  
    /// addAccelNamespace - Add a new name to the namespace accelerator table.
    void addAccelNamespace(StringRef Name, const DIE &Die);
  
    /// getDIE - Returns the debug information entry map slot for the
    /// specified debug variable. We delegate the request to DwarfDebug
    /// when the MDNode can be part of the type system, since DIEs for
    /// the type system can be shared across CUs and the mappings are
    /// kept in DwarfDebug.
    DIE *getDIE(DIDescriptor D) const;
  
    /// getDIELoc - Returns a fresh newly allocated DIELoc.
    DIELoc *getDIELoc() { return new (DIEValueAllocator) DIELoc(); }
  
    /// insertDIE - Insert DIE into the map. We delegate the request to DwarfDebug
    /// when the MDNode can be part of the type system, since DIEs for
    /// the type system can be shared across CUs and the mappings are
    /// kept in DwarfDebug.
    void insertDIE(DIDescriptor Desc, DIE *D);
  
    /// addFlag - Add a flag that is true to the DIE.
    void addFlag(DIE &Die, dwarf::Attribute Attribute);
  
    /// addUInt - Add an unsigned integer attribute data and value.
    void addUInt(DIE &Die, dwarf::Attribute Attribute, Optional<dwarf::Form> Form,
                 uint64_t Integer);
  
    void addUInt(DIE &Block, dwarf::Form Form, uint64_t Integer);
  
    /// addSInt - Add an signed integer attribute data and value.
    void addSInt(DIE &Die, dwarf::Attribute Attribute, Optional<dwarf::Form> Form,
                 int64_t Integer);
  
    void addSInt(DIELoc &Die, Optional<dwarf::Form> Form, int64_t Integer);
  
    /// addString - Add a string attribute data and value.
    void addString(DIE &Die, dwarf::Attribute Attribute, const StringRef Str);
  
    /// addLocalString - Add a string attribute data and value.
    void addLocalString(DIE &Die, dwarf::Attribute Attribute,
                        const StringRef Str);
  
    /// addExpr - Add a Dwarf expression attribute data and value.
    void addExpr(DIELoc &Die, dwarf::Form Form, const MCExpr *Expr);
  
    /// addLabel - Add a Dwarf label attribute data and value.
    void addLabel(DIE &Die, dwarf::Attribute Attribute, dwarf::Form Form,
                  const MCSymbol *Label);
  
    void addLabel(DIELoc &Die, dwarf::Form Form, const MCSymbol *Label);
  
    /// addLocationList - Add a Dwarf loclistptr attribute data and value.
    void addLocationList(DIE &Die, dwarf::Attribute Attribute, unsigned Index);
  
    /// addSectionLabel - Add a Dwarf section label attribute data and value.
    ///
    void addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
                         const MCSymbol *Label);
  
    /// addSectionOffset - Add an offset into a section attribute data and value.
    ///
    void addSectionOffset(DIE &Die, dwarf::Attribute Attribute, uint64_t Integer);
  
    /// addOpAddress - Add a dwarf op address data and value using the
    /// form given and an op of either DW_FORM_addr or DW_FORM_GNU_addr_index.
    void addOpAddress(DIELoc &Die, const MCSymbol *Label);
  
    /// addSectionDelta - Add a label delta attribute data and value.
    void addSectionDelta(DIE &Die, dwarf::Attribute Attribute, const MCSymbol *Hi,
                         const MCSymbol *Lo);
  
    /// addLabelDelta - Add a label delta attribute data and value.
    void addLabelDelta(DIE &Die, dwarf::Attribute Attribute, const MCSymbol *Hi,
                       const MCSymbol *Lo);
  
    /// addDIEEntry - Add a DIE attribute data and value.
    void addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIE &Entry);
  
    /// addDIEEntry - Add a DIE attribute data and value.
    void addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIEEntry *Entry);
  
    void addDIETypeSignature(DIE &Die, const DwarfTypeUnit &Type);
  
    /// addBlock - Add block data.
    void addBlock(DIE &Die, dwarf::Attribute Attribute, DIELoc *Block);
  
    /// addBlock - Add block data.
    void addBlock(DIE &Die, dwarf::Attribute Attribute, DIEBlock *Block);
  
    /// addSourceLine - Add location information to specified debug information
    /// entry.
    void addSourceLine(DIE &Die, unsigned Line, StringRef File,
                       StringRef Directory);
    void addSourceLine(DIE &Die, DIVariable V);
    void addSourceLine(DIE &Die, DIGlobalVariable G);
    void addSourceLine(DIE &Die, DISubprogram SP);
    void addSourceLine(DIE &Die, DIType Ty);
    void addSourceLine(DIE &Die, DINameSpace NS);
    void addSourceLine(DIE &Die, DIObjCProperty Ty);
  
    /// addAddress - Add an address attribute to a die based on the location
    /// provided.
    void addAddress(DIE &Die, dwarf::Attribute Attribute,
                    const MachineLocation &Location, bool Indirect = false);
  
    /// addConstantValue - Add constant value entry in variable DIE.
    void addConstantValue(DIE &Die, const MachineOperand &MO, DIType Ty);
    void addConstantValue(DIE &Die, const ConstantInt *CI, DIType Ty);
    void addConstantValue(DIE &Die, const APInt &Val, DIType Ty);
    void addConstantValue(DIE &Die, const APInt &Val, bool Unsigned);
    void addConstantValue(DIE &Die, bool Unsigned, uint64_t Val);
  
    /// addConstantFPValue - Add constant value entry in variable DIE.
    void addConstantFPValue(DIE &Die, const MachineOperand &MO);
    void addConstantFPValue(DIE &Die, const ConstantFP *CFP);
  
    /// addTemplateParams - Add template parameters in buffer.
    void addTemplateParams(DIE &Buffer, DIArray TParams);
  
    /// addRegisterOp - Add register operand.
    void addRegisterOp(DIELoc &TheDie, unsigned Reg);
  
    /// addRegisterOffset - Add register offset.
    void addRegisterOffset(DIELoc &TheDie, unsigned Reg, int64_t Offset);
  
    /// addComplexAddress - Start with the address based on the location provided,
    /// and generate the DWARF information necessary to find the actual variable
    /// (navigating the extra location information encoded in the type) based on
    /// the starting location.  Add the DWARF information to the die.
    void addComplexAddress(const DbgVariable &DV, DIE &Die,
                           dwarf::Attribute Attribute,
                           const MachineLocation &Location);
  
    // FIXME: Should be reformulated in terms of addComplexAddress.
    /// addBlockByrefAddress - Start with the address based on the location
    /// provided, and generate the DWARF information necessary to find the
    /// actual Block variable (navigating the Block struct) based on the
    /// starting location.  Add the DWARF information to the die.  Obsolete,
    /// please use addComplexAddress instead.
    void addBlockByrefAddress(const DbgVariable &DV, DIE &Die,
                              dwarf::Attribute Attribute,
                              const MachineLocation &Location);
  
    /// addVariableAddress - Add DW_AT_location attribute for a
    /// DbgVariable based on provided MachineLocation.
    void addVariableAddress(const DbgVariable &DV, DIE &Die,
                            MachineLocation Location);
  
    /// addType - Add a new type attribute to the specified entity. This takes
    /// and attribute parameter because DW_AT_friend attributes are also
    /// type references.
    void addType(DIE &Entity, DIType Ty,
                 dwarf::Attribute Attribute = dwarf::DW_AT_type);
  
    /// getOrCreateNameSpace - Create a DIE for DINameSpace.
    DIE *getOrCreateNameSpace(DINameSpace NS);
  
    /// getOrCreateSubprogramDIE - Create new DIE using SP.
    DIE *getOrCreateSubprogramDIE(DISubprogram SP);
  
    void applySubprogramAttributes(DISubprogram SP, DIE &SPDie);
    void applySubprogramAttributesToDefinition(DISubprogram SP, DIE &SPDie);
    void applyVariableAttributes(const DbgVariable &Var, DIE &VariableDie);
  
    /// getOrCreateTypeDIE - Find existing DIE or create new DIE for the
    /// given DIType.
    DIE *getOrCreateTypeDIE(const MDNode *N);
  
    /// getOrCreateContextDIE - Get context owner's DIE.
    DIE *createTypeDIE(DICompositeType Ty);
  
    /// getOrCreateContextDIE - Get context owner's DIE.
    DIE *getOrCreateContextDIE(DIScope Context);
  
    /// constructContainingTypeDIEs - Construct DIEs for types that contain
    /// vtables.
    void constructContainingTypeDIEs();
  
    /// constructVariableDIE - Construct a DIE for the given DbgVariable.
    std::unique_ptr<DIE> constructVariableDIE(DbgVariable &DV,
                                              bool Abstract = false);
  
    /// constructSubprogramArguments - Construct function argument DIEs.
    void constructSubprogramArguments(DIE &Buffer, DIArray Args);
  
    /// Create a DIE with the given Tag, add the DIE to its parent, and
    /// call insertDIE if MD is not null.
    DIE &createAndAddDIE(unsigned Tag, DIE &Parent,
                         DIDescriptor N = DIDescriptor());
  
    /// Compute the size of a header for this unit, not including the initial
    /// length field.
    virtual unsigned getHeaderSize() const {
      return sizeof(int16_t) + // DWARF version number
             sizeof(int32_t) + // Offset Into Abbrev. Section
             sizeof(int8_t);   // Pointer Size (in bytes)
    }
  
    /// Emit the header for this unit, not including the initial length field.
    virtual void emitHeader(const MCSymbol *ASectionSym) const;
  
    virtual DwarfCompileUnit &getCU() = 0;
  
    /// constructTypeDIE - Construct type DIE from DICompositeType.
    void constructTypeDIE(DIE &Buffer, DICompositeType CTy);
  
  protected:
    /// getOrCreateStaticMemberDIE - Create new static data member DIE.
    DIE *getOrCreateStaticMemberDIE(DIDerivedType DT);
  
    /// Look up the source ID with the given directory and source file names. If
    /// none currently exists, create a new ID and insert it in the line table.
    virtual unsigned getOrCreateSourceID(StringRef File, StringRef Directory) = 0;
  
  private:
    /// \brief Construct a DIE for the given DbgVariable without initializing the
    /// DbgVariable's DIE reference.
    std::unique_ptr<DIE> constructVariableDIEImpl(const DbgVariable &DV,
                                                  bool Abstract);
  
    /// constructTypeDIE - Construct basic type die from DIBasicType.
    void constructTypeDIE(DIE &Buffer, DIBasicType BTy);
  
    /// constructTypeDIE - Construct derived type die from DIDerivedType.
    void constructTypeDIE(DIE &Buffer, DIDerivedType DTy);
  
    /// constructSubrangeDIE - Construct subrange DIE from DISubrange.
    void constructSubrangeDIE(DIE &Buffer, DISubrange SR, DIE *IndexTy);
  
    /// constructArrayTypeDIE - Construct array type DIE from DICompositeType.
    void constructArrayTypeDIE(DIE &Buffer, DICompositeType CTy);
  
    /// constructEnumTypeDIE - Construct enum type DIE from DIEnumerator.
    void constructEnumTypeDIE(DIE &Buffer, DICompositeType CTy);
  
    /// constructMemberDIE - Construct member DIE from DIDerivedType.
    void constructMemberDIE(DIE &Buffer, DIDerivedType DT);
  
    /// constructTemplateTypeParameterDIE - Construct new DIE for the given
    /// DITemplateTypeParameter.
    void constructTemplateTypeParameterDIE(DIE &Buffer,
                                           DITemplateTypeParameter TP);
  
    /// constructTemplateValueParameterDIE - Construct new DIE for the given
    /// DITemplateValueParameter.
    void constructTemplateValueParameterDIE(DIE &Buffer,
                                            DITemplateValueParameter TVP);
  
    /// getLowerBoundDefault - Return the default lower bound for an array. If the
    /// DWARF version doesn't handle the language, return -1.
    int64_t getDefaultLowerBound() const;
  
    /// getDIEEntry - Returns the debug information entry for the specified
    /// debug variable.
    DIEEntry *getDIEEntry(const MDNode *N) const {
      return MDNodeToDIEEntryMap.lookup(N);
    }
  
    /// insertDIEEntry - Insert debug information entry into the map.
    void insertDIEEntry(const MDNode *N, DIEEntry *E) {
      MDNodeToDIEEntryMap.insert(std::make_pair(N, E));
    }
  
    // getIndexTyDie - Get an anonymous type for index type.
    DIE *getIndexTyDie() { return IndexTyDie; }
  
    // setIndexTyDie - Set D as anonymous type for index which can be reused
    // later.
    void setIndexTyDie(DIE *D) { IndexTyDie = D; }
  
    /// createDIEEntry - Creates a new DIEEntry to be a proxy for a debug
    /// information entry.
    DIEEntry *createDIEEntry(DIE &Entry);
  
    /// resolve - Look in the DwarfDebug map for the MDNode that
    /// corresponds to the reference.
    template <typename T> T resolve(DIRef<T> Ref) const {
      return DD->resolve(Ref);
    }
  
    /// If this is a named finished type then include it in the list of types for
    /// the accelerator tables.
    void updateAcceleratorTables(DIScope Context, DIType Ty, const DIE &TyDIE);
  };
  
  class DwarfCompileUnit : public DwarfUnit {
    /// The attribute index of DW_AT_stmt_list in the compile unit DIE, avoiding
    /// the need to search for it in applyStmtList.
    unsigned stmtListIndex;
  
  public:
    DwarfCompileUnit(unsigned UID, DICompileUnit Node, AsmPrinter *A,
                     DwarfDebug *DW, DwarfFile *DWU);
  
    void initStmtList(MCSymbol *DwarfLineSectionSym);
  
    /// Apply the DW_AT_stmt_list from this compile unit to the specified DIE.
    void applyStmtList(DIE &D);
  
    /// createGlobalVariableDIE - create global variable DIE.
    void createGlobalVariableDIE(DIGlobalVariable GV);
  
    /// addLabelAddress - Add a dwarf label attribute data and value using
    /// either DW_FORM_addr or DW_FORM_GNU_addr_index.
    void addLabelAddress(DIE &Die, dwarf::Attribute Attribute,
                         const MCSymbol *Label);
  
    /// addLocalLabelAddress - Add a dwarf label attribute data and value using
    /// DW_FORM_addr only.
    void addLocalLabelAddress(DIE &Die, dwarf::Attribute Attribute,
                              const MCSymbol *Label);
  
    DwarfCompileUnit &getCU() override { return *this; }
  
    unsigned getOrCreateSourceID(StringRef FileName, StringRef DirName) override;
  };
  
  class DwarfTypeUnit : public DwarfUnit {
  private:
    uint64_t TypeSignature;
    const DIE *Ty;
    DwarfCompileUnit &CU;
    MCDwarfDwoLineTable *SplitLineTable;
  
  public:
    DwarfTypeUnit(unsigned UID, DwarfCompileUnit &CU, AsmPrinter *A,
                  DwarfDebug *DW, DwarfFile *DWU,
                  MCDwarfDwoLineTable *SplitLineTable = nullptr);
  
    void setTypeSignature(uint64_t Signature) { TypeSignature = Signature; }
    uint64_t getTypeSignature() const { return TypeSignature; }
    void setType(const DIE *Ty) { this->Ty = Ty; }
  
    /// Emit the header for this unit, not including the initial length field.
    void emitHeader(const MCSymbol *ASectionSym) const override;
    unsigned getHeaderSize() const override {
      return DwarfUnit::getHeaderSize() + sizeof(uint64_t) + // Type Signature
             sizeof(uint32_t);                               // Type DIE Offset
    }
    void initSection(const MCSection *Section);
    DwarfCompileUnit &getCU() override { return CU; }
  
  protected:
    unsigned getOrCreateSourceID(StringRef File, StringRef Directory) override;
  };
  } // end llvm namespace
  #endif
  