text: //===-- llvm/CodeGen/AsmPrinter.h - AsmPrinter 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 a class to be used as the base class for target specific
  // asm writers.  This class primarily handles common functionality used by
  // all asm writers.
  //
  //===----------------------------------------------------------------------===//
  
  #ifndef LLVM_CODEGEN_ASMPRINTER_H
  #define LLVM_CODEGEN_ASMPRINTER_H
  
  #include "llvm/CodeGen/MachineFunctionPass.h"
  #include "llvm/Support/DataTypes.h"
  
  namespace llvm {
    class BlockAddress;
    class GCStrategy;
    class Constant;
    class ConstantArray;
    class ConstantFP;
    class ConstantInt;
    class ConstantStruct;
    class ConstantVector;
    class GCMetadataPrinter;
    class GlobalValue;
    class GlobalVariable;
    class MachineBasicBlock;
    class MachineFunction;
    class MachineInstr;
    class MachineLocation;
    class MachineLoopInfo;
    class MachineLoop;
    class MachineConstantPool;
    class MachineConstantPoolEntry;
    class MachineConstantPoolValue;
    class MachineJumpTableInfo;
    class MachineModuleInfo;
    class MachineMove;
    class MCAsmInfo;
    class MCInst;
    class MCContext;
    class MCSection;
    class MCStreamer;
    class MCSymbol;
    class MDNode;
    class DwarfDebug;
    class DwarfException;
    class Mangler;
    class TargetLoweringObjectFile;
    class TargetData;
    class TargetMachine;
    class Twine;
    class Type;
  
    /// AsmPrinter - This class is intended to be used as a driving class for all
    /// asm writers.
    class AsmPrinter : public MachineFunctionPass {
    public:
      /// Target machine description.
      ///
      TargetMachine &TM;
  
      /// Target Asm Printer information.
      ///
      const MCAsmInfo *MAI;
  
      /// OutContext - This is the context for the output file that we are
      /// streaming.  This owns all of the global MC-related objects for the
      /// generated translation unit.
      MCContext &OutContext;
  
      /// OutStreamer - This is the MCStreamer object for the file we are
      /// generating.  This contains the transient state for the current
      /// translation unit that we are generating (such as the current section
      /// etc).
      MCStreamer &OutStreamer;
  
      /// The current machine function.
      const MachineFunction *MF;
  
      /// MMI - This is a pointer to the current MachineModuleInfo.
      MachineModuleInfo *MMI;
  
      /// Name-mangler for global names.
      ///
      Mangler *Mang;
  
      /// The symbol for the current function. This is recalculated at the
      /// beginning of each call to runOnMachineFunction().
      ///
      MCSymbol *CurrentFnSym;
  
    private:
      // GCMetadataPrinters - The garbage collection metadata printer table.
      void *GCMetadataPrinters;  // Really a DenseMap.
  
      /// VerboseAsm - Emit comments in assembly output if this is true.
      ///
      bool VerboseAsm;
      static char ID;
  
      /// If VerboseAsm is set, a pointer to the loop info for this
      /// function.
      MachineLoopInfo *LI;
  
      /// DD - If the target supports dwarf debug info, this pointer is non-null.
      DwarfDebug *DD;
  
      /// DE - If the target supports dwarf exception info, this pointer is
      /// non-null.
      DwarfException *DE;
  
    protected:
      explicit AsmPrinter(TargetMachine &TM, MCStreamer &Streamer);
  
    public:
      virtual ~AsmPrinter();
  
      /// isVerbose - Return true if assembly output should contain comments.
      ///
      bool isVerbose() const { return VerboseAsm; }
  
      /// getFunctionNumber - Return a unique ID for the current function.
      ///
      unsigned getFunctionNumber() const;
  
      /// getObjFileLowering - Return information about object file lowering.
      const TargetLoweringObjectFile &getObjFileLowering() const;
  
      /// getTargetData - Return information about data layout.
      const TargetData &getTargetData() const;
  
      /// getCurrentSection() - Return the current section we are emitting to.
      const MCSection *getCurrentSection() const;
  
  
      //===------------------------------------------------------------------===//
      // MachineFunctionPass Implementation.
      //===------------------------------------------------------------------===//
  
      /// getAnalysisUsage - Record analysis usage.
      ///
      void getAnalysisUsage(AnalysisUsage &AU) const;
  
      /// doInitialization - Set up the AsmPrinter when we are working on a new
      /// module.  If your pass overrides this, it must make sure to explicitly
      /// call this implementation.
      bool doInitialization(Module &M);
  
      /// doFinalization - Shut down the asmprinter.  If you override this in your
      /// pass, you must make sure to call it explicitly.
      bool doFinalization(Module &M);
  
      /// runOnMachineFunction - Emit the specified function out to the
      /// OutStreamer.
      virtual bool runOnMachineFunction(MachineFunction &MF) {
        SetupMachineFunction(MF);
        EmitFunctionHeader();
        EmitFunctionBody();
        return false;
      }
  
      //===------------------------------------------------------------------===//
      // Coarse grained IR lowering routines.
      //===------------------------------------------------------------------===//
  
      /// SetupMachineFunction - This should be called when a new MachineFunction
      /// is being processed from runOnMachineFunction.
      void SetupMachineFunction(MachineFunction &MF);
  
      /// EmitFunctionHeader - This method emits the header for the current
      /// function.
      void EmitFunctionHeader();
  
      /// EmitFunctionBody - This method emits the body and trailer for a
      /// function.
      void EmitFunctionBody();
  
      /// EmitConstantPool - Print to the current output stream assembly
      /// representations of the constants in the constant pool MCP. This is
      /// used to print out constants which have been "spilled to memory" by
      /// the code generator.
      ///
      virtual void EmitConstantPool();
  
      /// EmitJumpTableInfo - Print assembly representations of the jump tables
      /// used by the current function to the current output stream.
      ///
      void EmitJumpTableInfo();
  
      /// EmitGlobalVariable - Emit the specified global variable to the .s file.
      virtual void EmitGlobalVariable(const GlobalVariable *GV);
  
      /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
      /// special global used by LLVM.  If so, emit it and return true, otherwise
      /// do nothing and return false.
      bool EmitSpecialLLVMGlobal(const GlobalVariable *GV);
  
      /// EmitAlignment - Emit an alignment directive to the specified power of
      /// two boundary.  For example, if you pass in 3 here, you will get an 8
      /// byte alignment.  If a global value is specified, and if that global has
      /// an explicit alignment requested, it will override the alignment request
      /// if required for correctness.
      ///
      void EmitAlignment(unsigned NumBits, const GlobalValue *GV = 0) const;
  
      /// EmitBasicBlockStart - This method prints the label for the specified
      /// MachineBasicBlock, an alignment (if present) and a comment describing
      /// it if appropriate.
      void EmitBasicBlockStart(const MachineBasicBlock *MBB) const;
  
      /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
      void EmitGlobalConstant(const Constant *CV, unsigned AddrSpace = 0);
  
  
      //===------------------------------------------------------------------===//
      // Overridable Hooks
      //===------------------------------------------------------------------===//
  
      // Targets can, or in the case of EmitInstruction, must implement these to
      // customize output.
  
      /// EmitStartOfAsmFile - This virtual method can be overridden by targets
      /// that want to emit something at the start of their file.
      virtual void EmitStartOfAsmFile(Module &) {}
  
      /// EmitEndOfAsmFile - This virtual method can be overridden by targets that
      /// want to emit something at the end of their file.
      virtual void EmitEndOfAsmFile(Module &) {}
  
      /// EmitFunctionBodyStart - Targets can override this to emit stuff before
      /// the first basic block in the function.
      virtual void EmitFunctionBodyStart() {}
  
      /// EmitFunctionBodyEnd - Targets can override this to emit stuff after
      /// the last basic block in the function.
      virtual void EmitFunctionBodyEnd() {}
  
      /// EmitInstruction - Targets should implement this to emit instructions.
      virtual void EmitInstruction(const MachineInstr *) {
        assert(0 && "EmitInstruction not implemented");
      }
  
      virtual void EmitFunctionEntryLabel();
  
      virtual void EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV);
  
      /// isBlockOnlyReachableByFallthough - Return true if the basic block has
      /// exactly one predecessor and the control transfer mechanism between
      /// the predecessor and this block is a fall-through.
      virtual bool
      isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const;
  
      //===------------------------------------------------------------------===//
      // Symbol Lowering Routines.
      //===------------------------------------------------------------------===//
    public:
  
      /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
      /// temporary label with the specified stem and unique ID.
      MCSymbol *GetTempSymbol(StringRef Name, unsigned ID) const;
  
      /// GetTempSymbol - Return an assembler temporary label with the specified
      /// stem.
      MCSymbol *GetTempSymbol(StringRef Name) const;
  
  
      /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
      /// global value name as its base, with the specified suffix, and where the
      /// symbol is forced to have private linkage if ForcePrivate is true.
      MCSymbol *GetSymbolWithGlobalValueBase(const GlobalValue *GV,
                                             StringRef Suffix,
                                             bool ForcePrivate = true) const;
  
      /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
      /// ExternalSymbol.
      MCSymbol *GetExternalSymbolSymbol(StringRef Sym) const;
  
      /// GetCPISymbol - Return the symbol for the specified constant pool entry.
      MCSymbol *GetCPISymbol(unsigned CPID) const;
  
      /// GetJTISymbol - Return the symbol for the specified jump table entry.
      MCSymbol *GetJTISymbol(unsigned JTID, bool isLinkerPrivate = false) const;
  
      /// GetJTSetSymbol - Return the symbol for the specified jump table .set
      /// FIXME: privatize to AsmPrinter.
      MCSymbol *GetJTSetSymbol(unsigned UID, unsigned MBBID) const;
  
      /// GetBlockAddressSymbol - Return the MCSymbol used to satisfy BlockAddress
      /// uses of the specified basic block.
      MCSymbol *GetBlockAddressSymbol(const BlockAddress *BA) const;
      MCSymbol *GetBlockAddressSymbol(const BasicBlock *BB) const;
  
      //===------------------------------------------------------------------===//
      // Emission Helper Routines.
      //===------------------------------------------------------------------===//
    public:
      /// printOffset - This is just convenient handler for printing offsets.
      void printOffset(int64_t Offset, raw_ostream &OS) const;
  
      /// EmitInt8 - Emit a byte directive and value.
      ///
      void EmitInt8(int Value) const;
  
      /// EmitInt16 - Emit a short directive and value.
      ///
      void EmitInt16(int Value) const;
  
      /// EmitInt32 - Emit a long directive and value.
      ///
      void EmitInt32(int Value) const;
  
      /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
      /// in bytes of the directive is specified by Size and Hi/Lo specify the
      /// labels.  This implicitly uses .set if it is available.
      void EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
                               unsigned Size) const;
  
      /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
      /// where the size in bytes of the directive is specified by Size and Hi/Lo
      /// specify the labels.  This implicitly uses .set if it is available.
      void EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
                                     const MCSymbol *Lo, unsigned Size) const;
  
      /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
      /// where the size in bytes of the directive is specified by Size and Label
      /// specifies the label.  This implicitly uses .set if it is available.
      void EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
                                     unsigned Size) const;
  
      //===------------------------------------------------------------------===//
      // Dwarf Emission Helper Routines
      //===------------------------------------------------------------------===//
  
      /// EmitSLEB128 - emit the specified signed leb128 value.
      void EmitSLEB128(int Value, const char *Desc = 0) const;
  
      /// EmitULEB128 - emit the specified unsigned leb128 value.
      void EmitULEB128(unsigned Value, const char *Desc = 0,
                       unsigned PadTo = 0) const;
  
      /// EmitCFAByte - Emit a .byte 42 directive for a DW_CFA_xxx value.
      void EmitCFAByte(unsigned Val) const;
  
      /// EmitEncodingByte - Emit a .byte 42 directive that corresponds to an
      /// encoding.  If verbose assembly output is enabled, we output comments
      /// describing the encoding.  Desc is a string saying what the encoding is
      /// specifying (e.g. "LSDA").
      void EmitEncodingByte(unsigned Val, const char *Desc = 0) const;
  
      /// GetSizeOfEncodedValue - Return the size of the encoding in bytes.
      unsigned GetSizeOfEncodedValue(unsigned Encoding) const;
  
      /// EmitReference - Emit a reference to a label with a specified encoding.
      ///
      void EmitReference(const MCSymbol *Sym, unsigned Encoding) const;
      void EmitReference(const GlobalValue *GV, unsigned Encoding) const;
  
      /// EmitSectionOffset - Emit the 4-byte offset of Label from the start of
      /// its section.  This can be done with a special directive if the target
      /// supports it (e.g. cygwin) or by emitting it as an offset from a label at
      /// the start of the section.
      ///
      /// SectionLabel is a temporary label emitted at the start of the section
      /// that Label lives in.
      void EmitSectionOffset(const MCSymbol *Label,
                             const MCSymbol *SectionLabel) const;
  
      /// getDebugValueLocation - Get location information encoded by DBG_VALUE
      /// operands.
      virtual MachineLocation getDebugValueLocation(const MachineInstr *MI) const;
  
      /// getISAEncoding - Get the value for DW_AT_APPLE_isa. Zero if no isa
      /// encoding specified.
      virtual unsigned getISAEncoding() { return 0; }
  
      // AVM2 specific
        virtual void EmitInlineAsmProlog(const MachineInstr *MI) const { };
      // AVM2 specific
  
      //===------------------------------------------------------------------===//
      // Dwarf Lowering Routines
      //===------------------------------------------------------------------===//
  
      /// EmitFrameMoves - Emit frame instructions to describe the layout of the
      /// frame.
      void EmitFrameMoves(const std::vector<MachineMove> &Moves,
                          MCSymbol *BaseLabel, bool isEH) const;
      void EmitCFIFrameMoves(const std::vector<MachineMove> &Moves) const;
  
      //===------------------------------------------------------------------===//
      // Inline Asm Support
      //===------------------------------------------------------------------===//
    public:
      // These are hooks that targets can override to implement inline asm
      // support.  These should probably be moved out of AsmPrinter someday.
  
      /// PrintSpecial - Print information related to the specified machine instr
      /// that is independent of the operand, and may be independent of the instr
      /// itself.  This can be useful for portably encoding the comment character
      /// or other bits of target-specific knowledge into the asmstrings.  The
      /// syntax used is ${:comment}.  Targets can override this to add support
      /// for their own strange codes.
      virtual void PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
                                const char *Code) const;
  
      /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
      /// instruction, using the specified assembler variant.  Targets should
      /// override this to format as appropriate.  This method can return true if
      /// the operand is erroneous.
      virtual bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
                                   unsigned AsmVariant, const char *ExtraCode,
                                   raw_ostream &OS);
  
      /// PrintAsmMemoryOperand - Print the specified operand of MI, an INLINEASM
      /// instruction, using the specified assembler variant as an address.
      /// Targets should override this to format as appropriate.  This method can
      /// return true if the operand is erroneous.
      virtual bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
                                         unsigned AsmVariant,
                                         const char *ExtraCode,
                                         raw_ostream &OS);
  
    private:
      /// Private state for PrintSpecial()
      // Assign a unique ID to this machine instruction.
      mutable const MachineInstr *LastMI;
      mutable unsigned LastFn;
      mutable unsigned Counter;
      mutable unsigned SetCounter;
  
      /// EmitInlineAsm - Emit a blob of inline asm to the output streamer.
      void EmitInlineAsm(StringRef Str, const MDNode *LocMDNode = 0) const;
  
      /// EmitInlineAsm - This method formats and emits the specified machine
      /// instruction that is an inline asm.
      void EmitInlineAsm(const MachineInstr *MI) const;
  
      //===------------------------------------------------------------------===//
      // Internal Implementation Details
      //===------------------------------------------------------------------===//
  
      /// EmitVisibility - This emits visibility information about symbol, if
      /// this is suported by the target.
      void EmitVisibility(MCSymbol *Sym, unsigned Visibility,
                          bool IsDefinition = true) const;
  
      void EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const;
  
      void EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
                              const MachineBasicBlock *MBB,
                              unsigned uid) const;
      void EmitLLVMUsedList(Constant *List);
      void EmitXXStructorList(Constant *List);
      GCMetadataPrinter *GetOrCreateGCPrinter(GCStrategy *C);
    };
  }
  
  #endif
  