MCStreamer.h revision dda1bdc962a314bf4fca86f4cd4802ff6c55b172 
1//===- MCStreamer.h - High-level Streaming Machine Code Output --*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file declares the MCStreamer class.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_MC_MCSTREAMER_H
15#define LLVM_MC_MCSTREAMER_H
16
17#include "llvm/Support/DataTypes.h"
18#include "llvm/MC/MCDirectives.h"
19#include "llvm/MC/MCDwarf.h"
20#include "llvm/MC/MCWin64EH.h"
21#include "llvm/ADT/ArrayRef.h"
22#include "llvm/ADT/SmallVector.h"
23
24namespace llvm {
25  class MCAsmInfo;
26  class MCCodeEmitter;
27  class MCContext;
28  class MCExpr;
29  class MCInst;
30  class MCInstPrinter;
31  class MCSection;
32  class MCSymbol;
33  class StringRef;
34  class TargetAsmBackend;
35  class TargetLoweringObjectFile;
36  class Twine;
37  class raw_ostream;
38  class formatted_raw_ostream;
39
40  /// MCStreamer - Streaming machine code generation interface.  This interface
41  /// is intended to provide a programatic interface that is very similar to the
42  /// level that an assembler .s file provides.  It has callbacks to emit bytes,
43  /// handle directives, etc.  The implementation of this interface retains
44  /// state to know what the current section is etc.
45  ///
46  /// There are multiple implementations of this interface: one for writing out
47  /// a .s file, and implementations that write out .o files of various formats.
48  ///
49  class MCStreamer {
50    MCContext &Context;
51
52    MCStreamer(const MCStreamer&); // DO NOT IMPLEMENT
53    MCStreamer &operator=(const MCStreamer&); // DO NOT IMPLEMENT
54
55    bool EmitEHFrame;
56    bool EmitDebugFrame;
57
58    std::vector<MCDwarfFrameInfo> FrameInfos;
59    MCDwarfFrameInfo *getCurrentFrameInfo();
60    void EnsureValidFrame();
61
62    std::vector<MCWin64EHUnwindInfo *> W64UnwindInfos;
63    MCWin64EHUnwindInfo *CurrentW64UnwindInfo;
64    void setCurrentW64UnwindInfo(MCWin64EHUnwindInfo *Frame);
65    void EnsureValidW64UnwindInfo();
66
67    const MCSymbol* LastNonPrivate;
68
69    /// SectionStack - This is stack of current and previous section
70    /// values saved by PushSection.
71    SmallVector<std::pair<const MCSection *,
72                const MCSection *>, 4> SectionStack;
73
74  protected:
75    MCStreamer(MCContext &Ctx);
76
77    const MCExpr *BuildSymbolDiff(MCContext &Context, const MCSymbol *A,
78                                  const MCSymbol *B);
79
80    const MCExpr *ForceExpAbs(const MCExpr* Expr);
81
82    void EmitFrames(bool usingCFI);
83
84    MCWin64EHUnwindInfo *getCurrentW64UnwindInfo(){return CurrentW64UnwindInfo;}
85    void EmitW64Tables();
86
87  public:
88    virtual ~MCStreamer();
89
90    MCContext &getContext() const { return Context; }
91
92    unsigned getNumFrameInfos() {
93      return FrameInfos.size();
94    }
95
96    const MCDwarfFrameInfo &getFrameInfo(unsigned i) {
97      return FrameInfos[i];
98    }
99
100    ArrayRef<MCDwarfFrameInfo> getFrameInfos() {
101      return FrameInfos;
102    }
103
104    unsigned getNumW64UnwindInfos() {
105      return W64UnwindInfos.size();
106    }
107
108    MCWin64EHUnwindInfo &getW64UnwindInfo(unsigned i) {
109      return *W64UnwindInfos[i];
110    }
111
112    /// @name Assembly File Formatting.
113    /// @{
114
115    /// isVerboseAsm - Return true if this streamer supports verbose assembly
116    /// and if it is enabled.
117    virtual bool isVerboseAsm() const { return false; }
118
119    /// hasRawTextSupport - Return true if this asm streamer supports emitting
120    /// unformatted text to the .s file with EmitRawText.
121    virtual bool hasRawTextSupport() const { return false; }
122
123    /// AddComment - Add a comment that can be emitted to the generated .s
124    /// file if applicable as a QoI issue to make the output of the compiler
125    /// more readable.  This only affects the MCAsmStreamer, and only when
126    /// verbose assembly output is enabled.
127    ///
128    /// If the comment includes embedded \n's, they will each get the comment
129    /// prefix as appropriate.  The added comment should not end with a \n.
130    virtual void AddComment(const Twine &T) {}
131
132    /// GetCommentOS - Return a raw_ostream that comments can be written to.
133    /// Unlike AddComment, you are required to terminate comments with \n if you
134    /// use this method.
135    virtual raw_ostream &GetCommentOS();
136
137    /// AddBlankLine - Emit a blank line to a .s file to pretty it up.
138    virtual void AddBlankLine() {}
139
140    /// @}
141
142    /// @name Symbol & Section Management
143    /// @{
144
145    /// getCurrentSection - Return the current section that the streamer is
146    /// emitting code to.
147    const MCSection *getCurrentSection() const {
148      if (!SectionStack.empty())
149        return SectionStack.back().first;
150      return NULL;
151    }
152
153    /// getPreviousSection - Return the previous section that the streamer is
154    /// emitting code to.
155    const MCSection *getPreviousSection() const {
156      if (!SectionStack.empty())
157        return SectionStack.back().second;
158      return NULL;
159    }
160
161    /// ChangeSection - Update streamer for a new active section.
162    ///
163    /// This is called by PopSection and SwitchSection, if the current
164    /// section changes.
165    virtual void ChangeSection(const MCSection *) = 0;
166
167    /// pushSection - Save the current and previous section on the
168    /// section stack.
169    void PushSection() {
170      SectionStack.push_back(std::make_pair(getCurrentSection(),
171                                            getPreviousSection()));
172    }
173
174    /// popSection - Restore the current and previous section from
175    /// the section stack.  Calls ChangeSection as needed.
176    ///
177    /// Returns false if the stack was empty.
178    bool PopSection() {
179      if (SectionStack.size() <= 1)
180        return false;
181      const MCSection *oldSection = SectionStack.pop_back_val().first;
182      const MCSection *curSection = SectionStack.back().first;
183
184      if (oldSection != curSection)
185        ChangeSection(curSection);
186      return true;
187    }
188
189    /// SwitchSection - Set the current section where code is being emitted to
190    /// @p Section.  This is required to update CurSection.
191    ///
192    /// This corresponds to assembler directives like .section, .text, etc.
193    void SwitchSection(const MCSection *Section) {
194      assert(Section && "Cannot switch to a null section!");
195      const MCSection *curSection = SectionStack.back().first;
196      SectionStack.back().second = curSection;
197      if (Section != curSection) {
198        SectionStack.back().first = Section;
199        ChangeSection(Section);
200      }
201    }
202
203    /// SwitchSectionNoChange - Set the current section where code is being
204    /// emitted to @p Section.  This is required to update CurSection. This
205    /// version does not call ChangeSection.
206    void SwitchSectionNoChange(const MCSection *Section) {
207      assert(Section && "Cannot switch to a null section!");
208      const MCSection *curSection = SectionStack.back().first;
209      SectionStack.back().second = curSection;
210      if (Section != curSection)
211        SectionStack.back().first = Section;
212    }
213
214    /// InitSections - Create the default sections and set the initial one.
215    virtual void InitSections() = 0;
216
217    /// EmitLabel - Emit a label for @p Symbol into the current section.
218    ///
219    /// This corresponds to an assembler statement such as:
220    ///   foo:
221    ///
222    /// @param Symbol - The symbol to emit. A given symbol should only be
223    /// emitted as a label once, and symbols emitted as a label should never be
224    /// used in an assignment.
225    virtual void EmitLabel(MCSymbol *Symbol);
226
227    virtual void EmitEHSymAttributes(const MCSymbol *Symbol,
228                                     MCSymbol *EHSymbol);
229
230    /// EmitAssemblerFlag - Note in the output the specified @p Flag
231    virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) = 0;
232
233    /// EmitThumbFunc - Note in the output that the specified @p Func is
234    /// a Thumb mode function (ARM target only).
235    virtual void EmitThumbFunc(MCSymbol *Func) = 0;
236
237    /// EmitAssignment - Emit an assignment of @p Value to @p Symbol.
238    ///
239    /// This corresponds to an assembler statement such as:
240    ///  symbol = value
241    ///
242    /// The assignment generates no code, but has the side effect of binding the
243    /// value in the current context. For the assembly streamer, this prints the
244    /// binding into the .s file.
245    ///
246    /// @param Symbol - The symbol being assigned to.
247    /// @param Value - The value for the symbol.
248    virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) = 0;
249
250    /// EmitWeakReference - Emit an weak reference from @p Alias to @p Symbol.
251    ///
252    /// This corresponds to an assembler statement such as:
253    ///  .weakref alias, symbol
254    ///
255    /// @param Alias - The alias that is being created.
256    /// @param Symbol - The symbol being aliased.
257    virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) = 0;
258
259    /// EmitSymbolAttribute - Add the given @p Attribute to @p Symbol.
260    virtual void EmitSymbolAttribute(MCSymbol *Symbol,
261                                     MCSymbolAttr Attribute) = 0;
262
263    /// EmitSymbolDesc - Set the @p DescValue for the @p Symbol.
264    ///
265    /// @param Symbol - The symbol to have its n_desc field set.
266    /// @param DescValue - The value to set into the n_desc field.
267    virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) = 0;
268
269    /// BeginCOFFSymbolDef - Start emitting COFF symbol definition
270    ///
271    /// @param Symbol - The symbol to have its External & Type fields set.
272    virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) = 0;
273
274    /// EmitCOFFSymbolStorageClass - Emit the storage class of the symbol.
275    ///
276    /// @param StorageClass - The storage class the symbol should have.
277    virtual void EmitCOFFSymbolStorageClass(int StorageClass) = 0;
278
279    /// EmitCOFFSymbolType - Emit the type of the symbol.
280    ///
281    /// @param Type - A COFF type identifier (see COFF::SymbolType in X86COFF.h)
282    virtual void EmitCOFFSymbolType(int Type) = 0;
283
284    /// EndCOFFSymbolDef - Marks the end of the symbol definition.
285    virtual void EndCOFFSymbolDef() = 0;
286
287    /// EmitELFSize - Emit an ELF .size directive.
288    ///
289    /// This corresponds to an assembler statement such as:
290    ///  .size symbol, expression
291    ///
292    virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) = 0;
293
294    /// EmitCommonSymbol - Emit a common symbol.
295    ///
296    /// @param Symbol - The common symbol to emit.
297    /// @param Size - The size of the common symbol.
298    /// @param ByteAlignment - The alignment of the symbol if
299    /// non-zero. This must be a power of 2.
300    virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
301                                  unsigned ByteAlignment) = 0;
302
303    /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
304    ///
305    /// @param Symbol - The common symbol to emit.
306    /// @param Size - The size of the common symbol.
307    virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) = 0;
308
309    /// EmitZerofill - Emit the zerofill section and an optional symbol.
310    ///
311    /// @param Section - The zerofill section to create and or to put the symbol
312    /// @param Symbol - The zerofill symbol to emit, if non-NULL.
313    /// @param Size - The size of the zerofill symbol.
314    /// @param ByteAlignment - The alignment of the zerofill symbol if
315    /// non-zero. This must be a power of 2 on some targets.
316    virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
317                              unsigned Size = 0,unsigned ByteAlignment = 0) = 0;
318
319    /// EmitTBSSSymbol - Emit a thread local bss (.tbss) symbol.
320    ///
321    /// @param Section - The thread local common section.
322    /// @param Symbol - The thread local common symbol to emit.
323    /// @param Size - The size of the symbol.
324    /// @param ByteAlignment - The alignment of the thread local common symbol
325    /// if non-zero.  This must be a power of 2 on some targets.
326    virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
327                                uint64_t Size, unsigned ByteAlignment = 0) = 0;
328
329    /// @}
330    /// @name Generating Data
331    /// @{
332
333    /// EmitBytes - Emit the bytes in \arg Data into the output.
334    ///
335    /// This is used to implement assembler directives such as .byte, .ascii,
336    /// etc.
337    virtual void EmitBytes(StringRef Data, unsigned AddrSpace) = 0;
338
339    /// EmitValue - Emit the expression @p Value into the output as a native
340    /// integer of the given @p Size bytes.
341    ///
342    /// This is used to implement assembler directives such as .word, .quad,
343    /// etc.
344    ///
345    /// @param Value - The value to emit.
346    /// @param Size - The size of the integer (in bytes) to emit. This must
347    /// match a native machine width.
348    virtual void EmitValueImpl(const MCExpr *Value, unsigned Size,
349                               unsigned AddrSpace) = 0;
350
351    void EmitValue(const MCExpr *Value, unsigned Size, unsigned AddrSpace = 0);
352
353    /// EmitIntValue - Special case of EmitValue that avoids the client having
354    /// to pass in a MCExpr for constant integers.
355    virtual void EmitIntValue(uint64_t Value, unsigned Size,
356                              unsigned AddrSpace = 0);
357
358    /// EmitAbsValue - Emit the Value, but try to avoid relocations. On MachO
359    /// this is done by producing
360    /// foo = value
361    /// .long foo
362    void EmitAbsValue(const MCExpr *Value, unsigned Size,
363                      unsigned AddrSpace = 0);
364
365    virtual void EmitULEB128Value(const MCExpr *Value) = 0;
366
367    virtual void EmitSLEB128Value(const MCExpr *Value) = 0;
368
369    /// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
370    /// client having to pass in a MCExpr for constant integers.
371    void EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace = 0);
372
373    /// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
374    /// client having to pass in a MCExpr for constant integers.
375    void EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace = 0);
376
377    /// EmitSymbolValue - Special case of EmitValue that avoids the client
378    /// having to pass in a MCExpr for MCSymbols.
379    void EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
380                         unsigned AddrSpace = 0);
381
382    /// EmitGPRel32Value - Emit the expression @p Value into the output as a
383    /// gprel32 (32-bit GP relative) value.
384    ///
385    /// This is used to implement assembler directives such as .gprel32 on
386    /// targets that support them.
387    virtual void EmitGPRel32Value(const MCExpr *Value);
388
389    /// EmitFill - Emit NumBytes bytes worth of the value specified by
390    /// FillValue.  This implements directives such as '.space'.
391    virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue,
392                          unsigned AddrSpace);
393
394    /// EmitZeros - Emit NumBytes worth of zeros.  This is a convenience
395    /// function that just wraps EmitFill.
396    void EmitZeros(uint64_t NumBytes, unsigned AddrSpace) {
397      EmitFill(NumBytes, 0, AddrSpace);
398    }
399
400
401    /// EmitValueToAlignment - Emit some number of copies of @p Value until
402    /// the byte alignment @p ByteAlignment is reached.
403    ///
404    /// If the number of bytes need to emit for the alignment is not a multiple
405    /// of @p ValueSize, then the contents of the emitted fill bytes is
406    /// undefined.
407    ///
408    /// This used to implement the .align assembler directive.
409    ///
410    /// @param ByteAlignment - The alignment to reach. This must be a power of
411    /// two on some targets.
412    /// @param Value - The value to use when filling bytes.
413    /// @param ValueSize - The size of the integer (in bytes) to emit for
414    /// @p Value. This must match a native machine width.
415    /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If
416    /// the alignment cannot be reached in this many bytes, no bytes are
417    /// emitted.
418    virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
419                                      unsigned ValueSize = 1,
420                                      unsigned MaxBytesToEmit = 0) = 0;
421
422    /// EmitCodeAlignment - Emit nops until the byte alignment @p ByteAlignment
423    /// is reached.
424    ///
425    /// This used to align code where the alignment bytes may be executed.  This
426    /// can emit different bytes for different sizes to optimize execution.
427    ///
428    /// @param ByteAlignment - The alignment to reach. This must be a power of
429    /// two on some targets.
430    /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If
431    /// the alignment cannot be reached in this many bytes, no bytes are
432    /// emitted.
433    virtual void EmitCodeAlignment(unsigned ByteAlignment,
434                                   unsigned MaxBytesToEmit = 0) = 0;
435
436    /// EmitValueToOffset - Emit some number of copies of @p Value until the
437    /// byte offset @p Offset is reached.
438    ///
439    /// This is used to implement assembler directives such as .org.
440    ///
441    /// @param Offset - The offset to reach. This may be an expression, but the
442    /// expression must be associated with the current section.
443    /// @param Value - The value to use when filling bytes.
444    virtual void EmitValueToOffset(const MCExpr *Offset,
445                                   unsigned char Value = 0) = 0;
446
447    /// @}
448
449    /// EmitFileDirective - Switch to a new logical file.  This is used to
450    /// implement the '.file "foo.c"' assembler directive.
451    virtual void EmitFileDirective(StringRef Filename) = 0;
452
453    /// EmitDwarfFileDirective - Associate a filename with a specified logical
454    /// file number.  This implements the DWARF2 '.file 4 "foo.c"' assembler
455    /// directive.
456    virtual bool EmitDwarfFileDirective(unsigned FileNo,StringRef Filename);
457
458    /// EmitDwarfLocDirective - This implements the DWARF2
459    // '.loc fileno lineno ...' assembler directive.
460    virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
461                                       unsigned Column, unsigned Flags,
462                                       unsigned Isa,
463                                       unsigned Discriminator,
464                                       StringRef FileName);
465
466    virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
467                                          const MCSymbol *LastLabel,
468                                          const MCSymbol *Label,
469                                          unsigned PointerSize) = 0;
470
471    virtual void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
472                                           const MCSymbol *Label) {
473    }
474
475    void EmitDwarfSetLineAddr(int64_t LineDelta, const MCSymbol *Label,
476                              int PointerSize);
477
478    virtual void EmitCompactUnwindEncoding(uint32_t CompactUnwindEncoding);
479    virtual void EmitCFISections(bool EH, bool Debug);
480    virtual void EmitCFIStartProc();
481    virtual void EmitCFIEndProc();
482    virtual void EmitCFIDefCfa(int64_t Register, int64_t Offset);
483    virtual void EmitCFIDefCfaOffset(int64_t Offset);
484    virtual void EmitCFIDefCfaRegister(int64_t Register);
485    virtual void EmitCFIOffset(int64_t Register, int64_t Offset);
486    virtual void EmitCFIPersonality(const MCSymbol *Sym, unsigned Encoding);
487    virtual void EmitCFILsda(const MCSymbol *Sym, unsigned Encoding);
488    virtual void EmitCFIRememberState();
489    virtual void EmitCFIRestoreState();
490    virtual void EmitCFISameValue(int64_t Register);
491    virtual void EmitCFIRelOffset(int64_t Register, int64_t Offset);
492    virtual void EmitCFIAdjustCfaOffset(int64_t Adjustment);
493
494    virtual void EmitWin64EHStartProc(const MCSymbol *Symbol);
495    virtual void EmitWin64EHEndProc();
496    virtual void EmitWin64EHStartChained();
497    virtual void EmitWin64EHEndChained();
498    virtual void EmitWin64EHHandler(const MCSymbol *Sym, bool Unwind,
499                                    bool Except);
500    virtual void EmitWin64EHHandlerData();
501    virtual void EmitWin64EHPushReg(unsigned Register);
502    virtual void EmitWin64EHSetFrame(unsigned Register, unsigned Offset);
503    virtual void EmitWin64EHAllocStack(unsigned Size);
504    virtual void EmitWin64EHSaveReg(unsigned Register, unsigned Offset);
505    virtual void EmitWin64EHSaveXMM(unsigned Register, unsigned Offset);
506    virtual void EmitWin64EHPushFrame(bool Code);
507    virtual void EmitWin64EHEndProlog();
508
509    /// EmitInstruction - Emit the given @p Instruction into the current
510    /// section.
511    virtual void EmitInstruction(const MCInst &Inst) = 0;
512
513    /// EmitRawText - If this file is backed by a assembly streamer, this dumps
514    /// the specified string in the output .s file.  This capability is
515    /// indicated by the hasRawTextSupport() predicate.  By default this aborts.
516    virtual void EmitRawText(StringRef String);
517    void EmitRawText(const Twine &String);
518
519    /// ARM-related methods.
520    /// FIXME: Eventually we should have some "target MC streamer" and move
521    /// these methods there.
522    virtual void EmitFnStart();
523    virtual void EmitFnEnd();
524    virtual void EmitCantUnwind();
525    virtual void EmitPersonality(const MCSymbol *Personality);
526    virtual void EmitHandlerData();
527    virtual void EmitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0);
528    virtual void EmitPad(int64_t Offset);
529    virtual void EmitRegSave(const SmallVectorImpl<unsigned> &RegList,
530                             bool isVector);
531
532    /// Finish - Finish emission of machine code.
533    virtual void Finish() = 0;
534  };
535
536  /// createNullStreamer - Create a dummy machine code streamer, which does
537  /// nothing. This is useful for timing the assembler front end.
538  MCStreamer *createNullStreamer(MCContext &Ctx);
539
540  /// createAsmStreamer - Create a machine code streamer which will print out
541  /// assembly for the native target, suitable for compiling with a native
542  /// assembler.
543  ///
544  /// \param InstPrint - If given, the instruction printer to use. If not given
545  /// the MCInst representation will be printed.  This method takes ownership of
546  /// InstPrint.
547  ///
548  /// \param CE - If given, a code emitter to use to show the instruction
549  /// encoding inline with the assembly. This method takes ownership of \arg CE.
550  ///
551  /// \param TAB - If given, a target asm backend to use to show the fixup
552  /// information in conjunction with encoding information. This method takes
553  /// ownership of \arg TAB.
554  ///
555  /// \param ShowInst - Whether to show the MCInst representation inline with
556  /// the assembly.
557  ///
558  /// \param DecodeLSDA - If true, emit comments that translates the LSDA into a
559  /// human readable format. Only usable with CFI.
560  MCStreamer *createAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS,
561                                bool isVerboseAsm,
562                                bool useLoc,
563                                bool useCFI,
564                                MCInstPrinter *InstPrint = 0,
565                                MCCodeEmitter *CE = 0,
566                                TargetAsmBackend *TAB = 0,
567                                bool ShowInst = false);
568
569  /// createMachOStreamer - Create a machine code streamer which will generate
570  /// Mach-O format object files.
571  ///
572  /// Takes ownership of \arg TAB and \arg CE.
573  MCStreamer *createMachOStreamer(MCContext &Ctx, TargetAsmBackend &TAB,
574                                  raw_ostream &OS, MCCodeEmitter *CE,
575                                  bool RelaxAll = false);
576
577  /// createWinCOFFStreamer - Create a machine code streamer which will
578  /// generate Microsoft COFF format object files.
579  ///
580  /// Takes ownership of \arg TAB and \arg CE.
581  MCStreamer *createWinCOFFStreamer(MCContext &Ctx,
582                                    TargetAsmBackend &TAB,
583                                    MCCodeEmitter &CE, raw_ostream &OS,
584                                    bool RelaxAll = false);
585
586  /// createELFStreamer - Create a machine code streamer which will generate
587  /// ELF format object files.
588  MCStreamer *createELFStreamer(MCContext &Ctx, TargetAsmBackend &TAB,
589				raw_ostream &OS, MCCodeEmitter *CE,
590				bool RelaxAll, bool NoExecStack);
591
592  /// createLoggingStreamer - Create a machine code streamer which just logs the
593  /// API calls and then dispatches to another streamer.
594  ///
595  /// The new streamer takes ownership of the \arg Child.
596  MCStreamer *createLoggingStreamer(MCStreamer *Child, raw_ostream &OS);
597
598  /// createPureStreamer - Create a machine code streamer which will generate
599  /// "pure" MC object files, for use with MC-JIT and testing tools.
600  ///
601  /// Takes ownership of \arg TAB and \arg CE.
602  MCStreamer *createPureStreamer(MCContext &Ctx, TargetAsmBackend &TAB,
603                                 raw_ostream &OS, MCCodeEmitter *CE);
604
605} // end namespace llvm
606
607#endif
608