path: root/lib/MC/MCAsmStreamer.cpp

//===- lib/MC/MCAsmStreamer.cpp - Text Assembly Output --------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCFixupKindInfo.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstPrinter.h"
#include "llvm/MC/MCSectionMachO.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Target/TargetAsmBackend.h"
#include "llvm/Target/TargetAsmInfo.h"
#include "llvm/Target/TargetLoweringObjectFile.h"
#include <cctype>
using namespace llvm;

namespace {

class MCAsmStreamer : public MCStreamer {
  formatted_raw_ostream &OS;
  const MCAsmInfo &MAI;
  OwningPtr<MCInstPrinter> InstPrinter;
  OwningPtr<MCCodeEmitter> Emitter;
  OwningPtr<TargetAsmBackend> AsmBackend;

  SmallString<128> CommentToEmit;
  raw_svector_ostream CommentStream;

  unsigned IsVerboseAsm : 1;
  unsigned ShowInst : 1;
  unsigned UseLoc : 1;

  bool needsSet(const MCExpr *Value);

public:
  MCAsmStreamer(MCContext &Context, formatted_raw_ostream &os,
                bool isVerboseAsm,
                bool useLoc,
                MCInstPrinter *printer, MCCodeEmitter *emitter,
                TargetAsmBackend *asmbackend,
                bool showInst)
    : MCStreamer(Context), OS(os), MAI(Context.getAsmInfo()),
      InstPrinter(printer), Emitter(emitter), AsmBackend(asmbackend),
      CommentStream(CommentToEmit), IsVerboseAsm(isVerboseAsm),
      ShowInst(showInst), UseLoc(useLoc) {
    if (InstPrinter && IsVerboseAsm)
      InstPrinter->setCommentStream(CommentStream);
  }
  ~MCAsmStreamer() {}

  inline void EmitEOL() {
    // If we don't have any comments, just emit a \n.
    if (!IsVerboseAsm) {
      OS << '\n';
      return;
    }
    EmitCommentsAndEOL();
  }
  void EmitCommentsAndEOL();

  /// isVerboseAsm - Return true if this streamer supports verbose assembly at
  /// all.
  virtual bool isVerboseAsm() const { return IsVerboseAsm; }

  /// hasRawTextSupport - We support EmitRawText.
  virtual bool hasRawTextSupport() const { return true; }

  /// AddComment - Add a comment that can be emitted to the generated .s
  /// file if applicable as a QoI issue to make the output of the compiler
  /// more readable.  This only affects the MCAsmStreamer, and only when
  /// verbose assembly output is enabled.
  virtual void AddComment(const Twine &T);

  /// AddEncodingComment - Add a comment showing the encoding of an instruction.
  virtual void AddEncodingComment(const MCInst &Inst);

  /// GetCommentOS - Return a raw_ostream that comments can be written to.
  /// Unlike AddComment, you are required to terminate comments with \n if you
  /// use this method.
  virtual raw_ostream &GetCommentOS() {
    if (!IsVerboseAsm)
      return nulls();  // Discard comments unless in verbose asm mode.
    return CommentStream;
  }

  /// AddBlankLine - Emit a blank line to a .s file to pretty it up.
  virtual void AddBlankLine() {
    EmitEOL();
  }

  /// @name MCStreamer Interface
  /// @{

  virtual void ChangeSection(const MCSection *Section);

  virtual void InitSections() {
    // FIXME, this is MachO specific, but the testsuite
    // expects this.
    SwitchSection(getContext().getMachOSection("__TEXT", "__text",
                         MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
                         0, SectionKind::getText()));
  }

  virtual void EmitLabel(MCSymbol *Symbol);

  virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
  virtual void EmitThumbFunc(MCSymbol *Func);

  virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
  virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol);
  virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
                                        const MCSymbol *LastLabel,
                                        const MCSymbol *Label);

  virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);

  virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
  virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol);
  virtual void EmitCOFFSymbolStorageClass(int StorageClass);
  virtual void EmitCOFFSymbolType(int Type);
  virtual void EndCOFFSymbolDef();
  virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value);
  virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                                unsigned ByteAlignment);