text: //===-- llvm/CodeGen/DwarfDebug.h - Dwarf Debug Framework ------*- 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 debug info into asm files.
  //
  //===----------------------------------------------------------------------===//
  
  #ifndef CODEGEN_ASMPRINTER_DWARFDEBUG_H__
  #define CODEGEN_ASMPRINTER_DWARFDEBUG_H__
  
  #include "llvm/CodeGen/AsmPrinter.h"
  #include "llvm/CodeGen/LexicalScopes.h"
  #include "llvm/MC/MachineLocation.h"
  #include "llvm/Analysis/DebugInfo.h"
  #include "DIE.h"
  #include "llvm/ADT/DenseMap.h"
  #include "llvm/ADT/FoldingSet.h"
  #include "llvm/ADT/SmallPtrSet.h"
  #include "llvm/ADT/StringMap.h"
  #include "llvm/ADT/UniqueVector.h"
  #include "llvm/Support/Allocator.h"
  #include "llvm/Support/DebugLoc.h"
  
  namespace llvm {
  
  class CompileUnit;
  class DbgConcreteScope;
  class DbgVariable;
  class MachineFrameInfo;
  class MachineModuleInfo;
  class MachineOperand;
  class MCAsmInfo;
  class DIEAbbrev;
  class DIE;
  class DIEBlock;
  class DIEEntry;
  
  //===----------------------------------------------------------------------===//
  /// SrcLineInfo - This class is used to record source line correspondence.
  ///
  class SrcLineInfo {
    unsigned Line;                     // Source line number.
    unsigned Column;                   // Source column.
    unsigned SourceID;                 // Source ID number.
    MCSymbol *Label;                   // Label in code ID number.
  public:
    SrcLineInfo(unsigned L, unsigned C, unsigned S, MCSymbol *label)
      : Line(L), Column(C), SourceID(S), Label(label) {}
  
    // Accessors
    unsigned getLine() const { return Line; }
    unsigned getColumn() const { return Column; }
    unsigned getSourceID() const { return SourceID; }
    MCSymbol *getLabel() const { return Label; }
  };
  
  /// DotDebugLocEntry - This struct describes location entries emitted in
  /// .debug_loc section.
  typedef struct DotDebugLocEntry {
    const MCSymbol *Begin;
    const MCSymbol *End;
    MachineLocation Loc;
    const MDNode *Variable;
    bool Merged;
    bool Constant;
    enum EntryType {
      E_Location,
      E_Integer,
      E_ConstantFP,
      E_ConstantInt
    };
    enum EntryType EntryKind;
  
    union {
      int64_t Int;
      const ConstantFP *CFP;
      const ConstantInt *CIP;
    } Constants;
    DotDebugLocEntry() 
      : Begin(0), End(0), Variable(0), Merged(false), 
        Constant(false) { Constants.Int = 0;}
    DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E, MachineLocation &L,
                     const MDNode *V) 
      : Begin(B), End(E), Loc(L), Variable(V), Merged(false), 
        Constant(false) { Constants.Int = 0; EntryKind = E_Location; }
    DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E, int64_t i)
      : Begin(B), End(E), Variable(0), Merged(false), 
        Constant(true) { Constants.Int = i; EntryKind = E_Integer; }
    DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E, const ConstantFP *FPtr)
      : Begin(B), End(E), Variable(0), Merged(false), 
        Constant(true) { Constants.CFP = FPtr; EntryKind = E_ConstantFP; }
    DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E, const ConstantInt *IPtr)
      : Begin(B), End(E), Variable(0), Merged(false), 
        Constant(true) { Constants.CIP = IPtr; EntryKind = E_ConstantInt; }
  
    /// Empty entries are also used as a trigger to emit temp label. Such
    /// labels are referenced is used to find debug_loc offset for a given DIE.
    bool isEmpty() { return Begin == 0 && End == 0; }
    bool isMerged() { return Merged; }
    void Merge(DotDebugLocEntry *Next) {
      if (!(Begin && Loc == Next->Loc && End == Next->Begin))
        return;
      Next->Begin = Begin;
      Merged = true;
    }
    bool isLocation() const    { return EntryKind == E_Location; }
    bool isInt() const         { return EntryKind == E_Integer; }
    bool isConstantFP() const  { return EntryKind == E_ConstantFP; }
    bool isConstantInt() const { return EntryKind == E_ConstantInt; }
    int64_t getInt()                    { return Constants.Int; }
    const ConstantFP *getConstantFP()   { return Constants.CFP; }
    const ConstantInt *getConstantInt() { return Constants.CIP; }
  } DotDebugLocEntry;
  
  //===----------------------------------------------------------------------===//
  /// DbgVariable - This class is used to track local variable information.
  ///
  class DbgVariable {
    DIVariable Var;                    // Variable Descriptor.
    DIE *TheDIE;                       // Variable DIE.
    unsigned DotDebugLocOffset;        // Offset in DotDebugLocEntries.
    DbgVariable *AbsVar;               // Corresponding Abstract variable, if any.
    const MachineInstr *MInsn;         // DBG_VALUE instruction of the variable.
    int FrameIndex;
  public:
    // AbsVar may be NULL.
    DbgVariable(DIVariable V, DbgVariable *AV) 
      : Var(V), TheDIE(0), DotDebugLocOffset(~0U), AbsVar(AV), MInsn(0),
        FrameIndex(~0) {}
  
    // Accessors.
    DIVariable getVariable()           const { return Var; }
    void setDIE(DIE *D)                      { TheDIE = D; }
    DIE *getDIE()                      const { return TheDIE; }
    void setDotDebugLocOffset(unsigned O)    { DotDebugLocOffset = O; }
    unsigned getDotDebugLocOffset()    const { return DotDebugLocOffset; }
    StringRef getName()                const { return Var.getName(); }
    DbgVariable *getAbstractVariable() const { return AbsVar; }
    const MachineInstr *getMInsn()     const { return MInsn; }
    void setMInsn(const MachineInstr *M)     { MInsn = M; }
    int getFrameIndex()                const { return FrameIndex; }
    void setFrameIndex(int FI)               { FrameIndex = FI; }
    // Translate tag to proper Dwarf tag.  
    unsigned getTag()                  const { 
      if (Var.getTag() == dwarf::DW_TAG_arg_variable)
        return dwarf::DW_TAG_formal_parameter;
      
      return dwarf::DW_TAG_variable;
    }
    /// isArtificial - Return true if DbgVariable is artificial.
    bool isArtificial()                const {
      if (Var.isArtificial())
        return true;
      if (Var.getTag() == dwarf::DW_TAG_arg_variable
          && getType().isArtificial())
        return true;
      return false;
    }
    bool variableHasComplexAddress()   const {
      assert(Var.Verify() && "Invalid complex DbgVariable!");
      return Var.hasComplexAddress();
    }
    bool isBlockByrefVariable()        const {
      assert(Var.Verify() && "Invalid complex DbgVariable!");
      return Var.isBlockByrefVariable();
    }
    unsigned getNumAddrElements()      const { 
      assert(Var.Verify() && "Invalid complex DbgVariable!");
      return Var.getNumAddrElements();
    }
    uint64_t getAddrElement(unsigned i) const {
      return Var.getAddrElement(i);
    }
    DIType getType() const;
  };
  
  class DwarfDebug {
    /// Asm - Target of Dwarf emission.
    AsmPrinter *Asm;
  
    /// MMI - Collected machine module information.
    MachineModuleInfo *MMI;
  
    //===--------------------------------------------------------------------===//
    // Attributes used to construct specific Dwarf sections.
    //
  
    CompileUnit *FirstCU;
  
    /// Maps MDNode with its corresponding CompileUnit.
    DenseMap <const MDNode *, CompileUnit *> CUMap;
  
    /// Maps subprogram MDNode with its corresponding CompileUnit.
    DenseMap <const MDNode *, CompileUnit *> SPMap;
  
    /// AbbreviationsSet - Used to uniquely define abbreviations.
    ///
    FoldingSet<DIEAbbrev> AbbreviationsSet;
  
    /// Abbreviations - A list of all the unique abbreviations in use.
    ///
    std::vector<DIEAbbrev *> Abbreviations;
  
    /// SourceIdMap - Source id map, i.e. pair of directory id and source file
    /// id mapped to a unique id.
    StringMap<unsigned> SourceIdMap;
  
    /// StringPool - A String->Symbol mapping of strings used by indirect
    /// references.
    StringMap<std::pair<MCSymbol*, unsigned> > StringPool;
    unsigned NextStringPoolNumber;
    
    MCSymbol *getStringPoolEntry(StringRef Str);
  
    /// SectionMap - Provides a unique id per text section.
    ///
    UniqueVector<const MCSection*> SectionMap;
  
    /// CurrentFnArguments - List of Arguments (DbgValues) for current function.
    SmallVector<DbgVariable *, 8> CurrentFnArguments;
  
    LexicalScopes LScopes;
  
    /// AbstractSPDies - Collection of abstract subprogram DIEs.
    DenseMap<const MDNode *, DIE *> AbstractSPDies;
  
    /// ScopeVariables - Collection of dbg variables of a scope.
    DenseMap<LexicalScope *, SmallVector<DbgVariable *, 8> > ScopeVariables;
  
    /// AbstractVariables - Collection on abstract variables.
    DenseMap<const MDNode *, DbgVariable *> AbstractVariables;
  
    /// DotDebugLocEntries - Collection of DotDebugLocEntry.
    SmallVector<DotDebugLocEntry, 4> DotDebugLocEntries;
  
    /// InliendSubprogramDIEs - Collection of subprgram DIEs that are marked
    /// (at the end of the module) as DW_AT_inline.
    SmallPtrSet<DIE *, 4> InlinedSubprogramDIEs;
  
    /// InlineInfo - Keep track of inlined functions and their location.  This
    /// information is used to populate debug_inlined section.
    typedef std::pair<const MCSymbol *, DIE *> InlineInfoLabels;
    DenseMap<const MDNode *, SmallVector<InlineInfoLabels, 4> > InlineInfo;
    SmallVector<const MDNode *, 4> InlinedSPNodes;
  
    // ProcessedSPNodes - This is a collection of subprogram MDNodes that
    // are processed to create DIEs.
    SmallPtrSet<const MDNode *, 16> ProcessedSPNodes;
  
    /// LabelsBeforeInsn - Maps instruction with label emitted before 
    /// instruction.
    DenseMap<const MachineInstr *, MCSymbol *> LabelsBeforeInsn;
  
    /// LabelsAfterInsn - Maps instruction with label emitted after
    /// instruction.
    DenseMap<const MachineInstr *, MCSymbol *> LabelsAfterInsn;
  
    /// UserVariables - Every user variable mentioned by a DBG_VALUE instruction
    /// in order of appearance.
    SmallVector<const MDNode*, 8> UserVariables;
  
    /// DbgValues - For each user variable, keep a list of DBG_VALUE
    /// instructions in order. The list can also contain normal instructions that
    /// clobber the previous DBG_VALUE.
    typedef DenseMap<const MDNode*, SmallVector<const MachineInstr*, 4> >
      DbgValueHistoryMap;
    DbgValueHistoryMap DbgValues;
  
    SmallVector<const MCSymbol *, 8> DebugRangeSymbols;
  
    /// Previous instruction's location information. This is used to determine
    /// label location to indicate scope boundries in dwarf debug info.
    DebugLoc PrevInstLoc;
    MCSymbol *PrevLabel;
  
    /// PrologEndLoc - This location indicates end of function prologue and
    /// beginning of function body.
    DebugLoc PrologEndLoc;
  
    struct FunctionDebugFrameInfo {
      unsigned Number;
      std::vector<MachineMove> Moves;
  
      FunctionDebugFrameInfo(unsigned Num, const std::vector<MachineMove> &M)
        : Number(Num), Moves(M) {}
    };
  
    std::vector<FunctionDebugFrameInfo> DebugFrames;
  
    // DIEValueAllocator - All DIEValues are allocated through this allocator.
    BumpPtrAllocator DIEValueAllocator;
  
    // Section Symbols: these are assembler temporary labels that are emitted at
    // the beginning of each supported dwarf section.  These are used to form
    // section offsets and are created by EmitSectionLabels.
    MCSymbol *DwarfInfoSectionSym, *DwarfAbbrevSectionSym;
    MCSymbol *DwarfStrSectionSym, *TextSectionSym, *DwarfDebugRangeSectionSym;
    MCSymbol *DwarfDebugLocSectionSym;
    MCSymbol *FunctionBeginSym, *FunctionEndSym;
  
  private:
  
    /// assignAbbrevNumber - Define a unique number for the abbreviation.
    ///
    void assignAbbrevNumber(DIEAbbrev &Abbrev);
  
    void addScopeVariable(LexicalScope *LS, DbgVariable *Var);
  
    /// findAbstractVariable - Find abstract variable associated with Var.
    DbgVariable *findAbstractVariable(DIVariable &Var, DebugLoc Loc);
  
    /// updateSubprogramScopeDIE - Find DIE for the given subprogram and 
    /// attach appropriate DW_AT_low_pc and DW_AT_high_pc attributes.
    /// If there are global variables in this scope then create and insert
    /// DIEs for these variables.
    DIE *updateSubprogramScopeDIE(CompileUnit *SPCU, const MDNode *SPNode);
  
    /// constructLexicalScope - Construct new DW_TAG_lexical_block 
    /// for this scope and attach DW_AT_low_pc/DW_AT_high_pc labels.
    DIE *constructLexicalScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
  
    /// constructInlinedScopeDIE - This scope represents inlined body of
    /// a function. Construct DIE to represent this concrete inlined copy
    /// of the function.
    DIE *constructInlinedScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
  
    /// constructVariableDIE - Construct a DIE for the given DbgVariable.
    DIE *constructVariableDIE(DbgVariable *DV, LexicalScope *S);
  
    /// constructScopeDIE - Construct a DIE for this scope.
    DIE *constructScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
  
    /// EmitSectionLabels - Emit initial Dwarf sections with a label at
    /// the start of each one.
    void EmitSectionLabels();
  
    /// emitDIE - Recusively Emits a debug information entry.
    ///
    void emitDIE(DIE *Die);
  
    /// computeSizeAndOffset - Compute the size and offset of a DIE.
    ///
    unsigned computeSizeAndOffset(DIE *Die, unsigned Offset, bool Last);
  
    /// computeSizeAndOffsets - Compute the size and offset of all the DIEs.
    ///
    void computeSizeAndOffsets();
  
    /// EmitDebugInfo - Emit the debug info section.
    ///
    void emitDebugInfo();
  
    /// emitAbbreviations - Emit the abbreviation section.
    ///
    void emitAbbreviations() const;
  
    /// emitEndOfLineMatrix - Emit the last address of the section and the end of
    /// the line matrix.
    ///
    void emitEndOfLineMatrix(unsigned SectionEnd);
  
    /// emitDebugPubNames - Emit visible names into a debug pubnames section.
    ///
    void emitDebugPubNames();
  
    /// emitDebugPubTypes - Emit visible types into a debug pubtypes section.
    ///
    void emitDebugPubTypes();
  
    /// emitDebugStr - Emit visible names into a debug str section.
    ///
    void emitDebugStr();
  
    /// emitDebugLoc - Emit visible names into a debug loc section.
    ///
    void emitDebugLoc();
  
    /// EmitDebugARanges - Emit visible names into a debug aranges section.
    ///
    void EmitDebugARanges();
  
    /// emitDebugRanges - Emit visible names into a debug ranges section.
    ///
    void emitDebugRanges();
  
    /// emitDebugMacInfo - Emit visible names into a debug macinfo section.
    ///
    void emitDebugMacInfo();
  
    /// emitDebugInlineInfo - Emit inline info using following format.
    /// Section Header:
    /// 1. length of section
    /// 2. Dwarf version number
    /// 3. address size.
    ///
    /// Entries (one "entry" for each function that was inlined):
    ///
    /// 1. offset into __debug_str section for MIPS linkage name, if exists; 
    ///   otherwise offset into __debug_str for regular function name.
    /// 2. offset into __debug_str section for regular function name.
    /// 3. an unsigned LEB128 number indicating the number of distinct inlining 
    /// instances for the function.
    /// 
    /// The rest of the entry consists of a {die_offset, low_pc}  pair for each 
    /// inlined instance; the die_offset points to the inlined_subroutine die in
    /// the __debug_info section, and the low_pc is the starting address  for the
    ///  inlining instance.
    void emitDebugInlineInfo();
  
    /// constructCompileUnit - Create new CompileUnit for the given 
    /// metadata node with tag DW_TAG_compile_unit.
    CompileUnit *constructCompileUnit(const MDNode *N);
  
    /// construct SubprogramDIE - Construct subprogram DIE.
    void constructSubprogramDIE(CompileUnit *TheCU, const MDNode *N);
  
    /// recordSourceLine - Register a source line with debug info. Returns the
    /// unique label that was emitted and which provides correspondence to
    /// the source line list.
    void recordSourceLine(unsigned Line, unsigned Col, const MDNode *Scope,
                          unsigned Flags);
    
    /// identifyScopeMarkers() - Indentify instructions that are marking
    /// beginning of or end of a scope.
    void identifyScopeMarkers();
  
    /// addCurrentFnArgument - If Var is an current function argument that add
    /// it in CurrentFnArguments list.
    bool addCurrentFnArgument(const MachineFunction *MF,
                              DbgVariable *Var, LexicalScope *Scope);
  
    /// collectVariableInfo - Populate LexicalScope entries with variables' info.
    void collectVariableInfo(const MachineFunction *,
                             SmallPtrSet<const MDNode *, 16> &ProcessedVars);
    
    /// collectVariableInfoFromMMITable - Collect variable information from
    /// side table maintained by MMI.
    void collectVariableInfoFromMMITable(const MachineFunction * MF,
                                         SmallPtrSet<const MDNode *, 16> &P);
  
    /// requestLabelBeforeInsn - Ensure that a label will be emitted before MI.
    void requestLabelBeforeInsn(const MachineInstr *MI) {
      LabelsBeforeInsn.insert(std::make_pair(MI, (MCSymbol*)0));
    }
  
    /// getLabelBeforeInsn - Return Label preceding the instruction.
    const MCSymbol *getLabelBeforeInsn(const MachineInstr *MI);
  
    /// requestLabelAfterInsn - Ensure that a label will be emitted after MI.
    void requestLabelAfterInsn(const MachineInstr *MI) {
      LabelsAfterInsn.insert(std::make_pair(MI, (MCSymbol*)0));
    }
  
    /// getLabelAfterInsn - Return Label immediately following the instruction.
    const MCSymbol *getLabelAfterInsn(const MachineInstr *MI);
  
  public:
    //===--------------------------------------------------------------------===//
    // Main entry points.
    //
    DwarfDebug(AsmPrinter *A, Module *M);
    ~DwarfDebug();
  
    /// collectInfoFromNamedMDNodes - Collect debug info from named mdnodes such
    /// as llvm.dbg.enum and llvm.dbg.ty
    void collectInfoFromNamedMDNodes(Module *M);
  
    /// collectLegacyDebugInfo - Collect debug info using DebugInfoFinder.
    /// FIXME - Remove this when dragon-egg and llvm-gcc switch to DIBuilder.
    bool collectLegacyDebugInfo(Module *M);
  
    /// beginModule - Emit all Dwarf sections that should come prior to the
    /// content.
    void beginModule(Module *M);
  
    /// endModule - Emit all Dwarf sections that should come after the content.
    ///
    void endModule();
  
    /// beginFunction - Gather pre-function debug information.  Assumes being
    /// emitted immediately after the function entry point.
    void beginFunction(const MachineFunction *MF);
  
    /// endFunction - Gather and emit post-function debug information.
    ///
    void endFunction(const MachineFunction *MF);
  
    /// beginInstruction - Process beginning of an instruction.
    void beginInstruction(const MachineInstr *MI);
  
    /// endInstruction - Prcess end of an instruction.
    void endInstruction(const MachineInstr *MI);
  
    /// GetOrCreateSourceID - 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 SourceIds map.
    unsigned GetOrCreateSourceID(StringRef DirName, StringRef FullName);
  
    /// createSubprogramDIE - Create new DIE using SP.
    DIE *createSubprogramDIE(DISubprogram SP);
  };
  } // End of namespace llvm
  
  #endif
  