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/ADT/ArrayRef.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/MC/MCAssembler.h"
20#include "llvm/MC/MCDirectives.h"
21#include "llvm/MC/MCDwarf.h"
22#include "llvm/MC/MCWin64EH.h"
23#include "llvm/Support/DataTypes.h"
24#include <string>
25
26namespace llvm {
27  class MCAsmBackend;
28  class MCCodeEmitter;
29  class MCContext;
30  class MCExpr;
31  class MCInst;
32  class MCInstPrinter;
33  class MCSection;
34  class MCSymbol;
35  class StringRef;
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  public:
51    enum StreamerKind {
52      SK_AsmStreamer,
53      SK_NullStreamer,
54      SK_RecordStreamer,
55
56      // MCObjectStreamer subclasses.
57      SK_ELFStreamer,
58      SK_ARMELFStreamer,
59      SK_MachOStreamer,
60      SK_PureStreamer,
61      SK_MipsELFStreamer,
62      SK_WinCOFFStreamer
63    };
64
65  private:
66    const StreamerKind Kind;
67    MCContext &Context;
68
69    MCStreamer(const MCStreamer&) LLVM_DELETED_FUNCTION;
70    MCStreamer &operator=(const MCStreamer&) LLVM_DELETED_FUNCTION;
71
72    bool EmitEHFrame;
73    bool EmitDebugFrame;
74
75    std::vector<MCDwarfFrameInfo> FrameInfos;
76    MCDwarfFrameInfo *getCurrentFrameInfo();
77    MCSymbol *EmitCFICommon();
78    void EnsureValidFrame();
79
80    std::vector<MCWin64EHUnwindInfo *> W64UnwindInfos;
81    MCWin64EHUnwindInfo *CurrentW64UnwindInfo;
82    void setCurrentW64UnwindInfo(MCWin64EHUnwindInfo *Frame);
83    void EnsureValidW64UnwindInfo();
84
85    MCSymbol* LastSymbol;
86
87    /// SectionStack - This is stack of current and previous section
88    /// values saved by PushSection.
89    SmallVector<std::pair<const MCSection *,
90                const MCSection *>, 4> SectionStack;
91
92    bool AutoInitSections;
93
94  protected:
95    MCStreamer(StreamerKind Kind, MCContext &Ctx);
96
97    const MCExpr *BuildSymbolDiff(MCContext &Context, const MCSymbol *A,
98                                  const MCSymbol *B);
99
100    const MCExpr *ForceExpAbs(const MCExpr* Expr);
101
102    void RecordProcStart(MCDwarfFrameInfo &Frame);
103    virtual void EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame);
104    void RecordProcEnd(MCDwarfFrameInfo &Frame);
105    virtual void EmitCFIEndProcImpl(MCDwarfFrameInfo &CurFrame);
106    void EmitFrames(bool usingCFI);
107
108    MCWin64EHUnwindInfo *getCurrentW64UnwindInfo(){return CurrentW64UnwindInfo;}
109    void EmitW64Tables();
110
111  public:
112    virtual ~MCStreamer();
113
114    StreamerKind getKind() const { return Kind; }
115
116    /// State management
117    ///
118    virtual void reset();
119
120    MCContext &getContext() const { return Context; }
121
122    unsigned getNumFrameInfos() {
123      return FrameInfos.size();
124    }
125
126    const MCDwarfFrameInfo &getFrameInfo(unsigned i) {
127      return FrameInfos[i];
128    }
129
130    ArrayRef<MCDwarfFrameInfo> getFrameInfos() {
131      return FrameInfos;
132    }
133
134    unsigned getNumW64UnwindInfos() {
135      return W64UnwindInfos.size();
136    }
137
138    MCWin64EHUnwindInfo &getW64UnwindInfo(unsigned i) {
139      return *W64UnwindInfos[i];
140    }
141
142    /// @name Assembly File Formatting.
143    /// @{
144
145    /// isVerboseAsm - Return true if this streamer supports verbose assembly
146    /// and if it is enabled.
147    virtual bool isVerboseAsm() const { return false; }
148
149    /// hasRawTextSupport - Return true if this asm streamer supports emitting
150    /// unformatted text to the .s file with EmitRawText.
151    virtual bool hasRawTextSupport() const { return false; }
152
153    /// AddComment - Add a comment that can be emitted to the generated .s
154    /// file if applicable as a QoI issue to make the output of the compiler
155    /// more readable.  This only affects the MCAsmStreamer, and only when
156    /// verbose assembly output is enabled.
157    ///
158    /// If the comment includes embedded \n's, they will each get the comment
159    /// prefix as appropriate.  The added comment should not end with a \n.
160    virtual void AddComment(const Twine &T) {}
161
162    /// GetCommentOS - Return a raw_ostream that comments can be written to.
163    /// Unlike AddComment, you are required to terminate comments with \n if you
164    /// use this method.
165    virtual raw_ostream &GetCommentOS();
166
167    /// AddBlankLine - Emit a blank line to a .s file to pretty it up.
168    virtual void AddBlankLine() {}
169
170    /// @}
171
172    /// @name Symbol & Section Management
173    /// @{
174
175    /// getCurrentSection - Return the current section that the streamer is
176    /// emitting code to.
177    const MCSection *getCurrentSection() const {
178      if (!SectionStack.empty())
179        return SectionStack.back().first;
180      return NULL;
181    }
182
183    /// getPreviousSection - Return the previous section that the streamer is
184    /// emitting code to.
185    const MCSection *getPreviousSection() const {
186      if (!SectionStack.empty())
187        return SectionStack.back().second;
188      return NULL;
189    }
190
191    /// ChangeSection - Update streamer for a new active section.
192    ///
193    /// This is called by PopSection and SwitchSection, if the current
194    /// section changes.
195    virtual void ChangeSection(const MCSection *) = 0;
196
197    /// pushSection - Save the current and previous section on the
198    /// section stack.
199    void PushSection() {
200      SectionStack.push_back(std::make_pair(getCurrentSection(),
201                                            getPreviousSection()));
202    }
203
204    /// popSection - Restore the current and previous section from
205    /// the section stack.  Calls ChangeSection as needed.
206    ///
207    /// Returns false if the stack was empty.
208    bool PopSection() {
209      if (SectionStack.size() <= 1)
210        return false;
211      const MCSection *oldSection = SectionStack.pop_back_val().first;
212      const MCSection *curSection = SectionStack.back().first;
213
214      if (oldSection != curSection)
215        ChangeSection(curSection);
216      return true;
217    }
218
219    /// SwitchSection - Set the current section where code is being emitted to
220    /// @p Section.  This is required to update CurSection.
221    ///
222    /// This corresponds to assembler directives like .section, .text, etc.
223    void SwitchSection(const MCSection *Section) {
224      assert(Section && "Cannot switch to a null section!");
225      const MCSection *curSection = SectionStack.back().first;
226      SectionStack.back().second = curSection;
227      if (Section != curSection) {
228        SectionStack.back().first = Section;
229        ChangeSection(Section);
230      }
231    }
232
233    /// SwitchSectionNoChange - Set the current section where code is being
234    /// emitted to @p Section.  This is required to update CurSection. This
235    /// version does not call ChangeSection.
236    void SwitchSectionNoChange(const MCSection *Section) {
237      assert(Section && "Cannot switch to a null section!");
238      const MCSection *curSection = SectionStack.back().first;
239      SectionStack.back().second = curSection;
240      if (Section != curSection)
241        SectionStack.back().first = Section;
242    }
243
244    /// Initialize the streamer.
245    void InitStreamer() {
246      if (AutoInitSections)
247        InitSections();
248    }
249
250    /// Tell this MCStreamer to call InitSections upon initialization.
251    void setAutoInitSections(bool AutoInitSections) {
252      this->AutoInitSections = AutoInitSections;
253    }
254
255    /// InitSections - Create the default sections and set the initial one.
256    virtual void InitSections() = 0;
257
258    /// InitToTextSection - Create a text section and switch the streamer to it.
259    virtual void InitToTextSection() = 0;
260
261    /// EmitLabel - Emit a label for @p Symbol into the current section.
262    ///
263    /// This corresponds to an assembler statement such as:
264    ///   foo:
265    ///
266    /// @param Symbol - The symbol to emit. A given symbol should only be
267    /// emitted as a label once, and symbols emitted as a label should never be
268    /// used in an assignment.
269    virtual void EmitLabel(MCSymbol *Symbol);
270
271    virtual void EmitDebugLabel(MCSymbol *Symbol);
272
273    virtual void EmitEHSymAttributes(const MCSymbol *Symbol,
274                                     MCSymbol *EHSymbol);
275
276    /// EmitAssemblerFlag - Note in the output the specified @p Flag.
277    virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) = 0;
278
279    /// EmitLinkerOptions - Emit the given list @p Options of strings as linker
280    /// options into the output.
281    virtual void EmitLinkerOptions(ArrayRef<std::string> Kind) {}
282
283    /// EmitDataRegion - Note in the output the specified region @p Kind.
284    virtual void EmitDataRegion(MCDataRegionType Kind) {}
285
286    /// EmitThumbFunc - Note in the output that the specified @p Func is
287    /// a Thumb mode function (ARM target only).
288    virtual void EmitThumbFunc(MCSymbol *Func) = 0;
289
290    /// getOrCreateSymbolData - Get symbol data for given symbol.
291    virtual MCSymbolData &getOrCreateSymbolData(MCSymbol *Symbol);
292
293    /// EmitAssignment - Emit an assignment of @p Value to @p Symbol.
294    ///
295    /// This corresponds to an assembler statement such as:
296    ///  symbol = value
297    ///
298    /// The assignment generates no code, but has the side effect of binding the
299    /// value in the current context. For the assembly streamer, this prints the
300    /// binding into the .s file.
301    ///
302    /// @param Symbol - The symbol being assigned to.
303    /// @param Value - The value for the symbol.
304    virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) = 0;
305
306    /// EmitWeakReference - Emit an weak reference from @p Alias to @p Symbol.
307    ///
308    /// This corresponds to an assembler statement such as:
309    ///  .weakref alias, symbol
310    ///
311    /// @param Alias - The alias that is being created.
312    /// @param Symbol - The symbol being aliased.
313    virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) = 0;
314
315    /// EmitSymbolAttribute - Add the given @p Attribute to @p Symbol.
316    virtual void EmitSymbolAttribute(MCSymbol *Symbol,
317                                     MCSymbolAttr Attribute) = 0;
318
319    /// EmitSymbolDesc - Set the @p DescValue for the @p Symbol.
320    ///
321    /// @param Symbol - The symbol to have its n_desc field set.
322    /// @param DescValue - The value to set into the n_desc field.
323    virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) = 0;
324
325    /// BeginCOFFSymbolDef - Start emitting COFF symbol definition
326    ///
327    /// @param Symbol - The symbol to have its External & Type fields set.
328    virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) = 0;
329
330    /// EmitCOFFSymbolStorageClass - Emit the storage class of the symbol.
331    ///
332    /// @param StorageClass - The storage class the symbol should have.
333    virtual void EmitCOFFSymbolStorageClass(int StorageClass) = 0;
334
335    /// EmitCOFFSymbolType - Emit the type of the symbol.
336    ///
337    /// @param Type - A COFF type identifier (see COFF::SymbolType in X86COFF.h)
338    virtual void EmitCOFFSymbolType(int Type) = 0;
339
340    /// EndCOFFSymbolDef - Marks the end of the symbol definition.
341    virtual void EndCOFFSymbolDef() = 0;
342
343    /// EmitCOFFSecRel32 - Emits a COFF section relative relocation.
344    ///
345    /// @param Symbol - Symbol the section relative realocation should point to.
346    virtual void EmitCOFFSecRel32(MCSymbol const *Symbol);
347
348    /// EmitELFSize - Emit an ELF .size directive.
349    ///
350    /// This corresponds to an assembler statement such as:
351    ///  .size symbol, expression
352    ///
353    virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) = 0;
354
355    /// EmitCommonSymbol - Emit a common symbol.
356    ///
357    /// @param Symbol - The common symbol to emit.
358    /// @param Size - The size of the common symbol.
359    /// @param ByteAlignment - The alignment of the symbol if
360    /// non-zero. This must be a power of 2.
361    virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
362                                  unsigned ByteAlignment) = 0;
363
364    /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
365    ///
366    /// @param Symbol - The common symbol to emit.
367    /// @param Size - The size of the common symbol.
368    /// @param ByteAlignment - The alignment of the common symbol in bytes.
369    virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
370                                       unsigned ByteAlignment) = 0;
371
372    /// EmitZerofill - Emit the zerofill section and an optional symbol.
373    ///
374    /// @param Section - The zerofill section to create and or to put the symbol
375    /// @param Symbol - The zerofill symbol to emit, if non-NULL.
376    /// @param Size - The size of the zerofill symbol.
377    /// @param ByteAlignment - The alignment of the zerofill symbol if
378    /// non-zero. This must be a power of 2 on some targets.
379    virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
380                              uint64_t Size = 0,unsigned ByteAlignment = 0) = 0;
381
382    /// EmitTBSSSymbol - Emit a thread local bss (.tbss) symbol.
383    ///
384    /// @param Section - The thread local common section.
385    /// @param Symbol - The thread local common symbol to emit.
386    /// @param Size - The size of the symbol.
387    /// @param ByteAlignment - The alignment of the thread local common symbol
388    /// if non-zero.  This must be a power of 2 on some targets.
389    virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
390                                uint64_t Size, unsigned ByteAlignment = 0) = 0;
391
392    /// @}
393    /// @name Generating Data
394    /// @{
395
396    /// EmitBytes - Emit the bytes in \p Data into the output.
397    ///
398    /// This is used to implement assembler directives such as .byte, .ascii,
399    /// etc.
400    virtual void EmitBytes(StringRef Data, unsigned AddrSpace = 0) = 0;
401
402    /// EmitValue - Emit the expression @p Value into the output as a native
403    /// integer of the given @p Size bytes.
404    ///
405    /// This is used to implement assembler directives such as .word, .quad,
406    /// etc.
407    ///
408    /// @param Value - The value to emit.
409    /// @param Size - The size of the integer (in bytes) to emit. This must
410    /// match a native machine width.
411    virtual void EmitValueImpl(const MCExpr *Value, unsigned Size,
412                               unsigned AddrSpace) = 0;
413
414    void EmitValue(const MCExpr *Value, unsigned Size, unsigned AddrSpace = 0);
415
416    /// EmitIntValue - Special case of EmitValue that avoids the client having
417    /// to pass in a MCExpr for constant integers.
418    virtual void EmitIntValue(uint64_t Value, unsigned Size,
419                              unsigned AddrSpace = 0);
420
421    /// EmitAbsValue - Emit the Value, but try to avoid relocations. On MachO
422    /// this is done by producing
423    /// foo = value
424    /// .long foo
425    void EmitAbsValue(const MCExpr *Value, unsigned Size,
426                      unsigned AddrSpace = 0);
427
428    virtual void EmitULEB128Value(const MCExpr *Value) = 0;
429
430    virtual void EmitSLEB128Value(const MCExpr *Value) = 0;
431
432    /// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
433    /// client having to pass in a MCExpr for constant integers.
434    void EmitULEB128IntValue(uint64_t Value, unsigned Padding = 0,
435                             unsigned AddrSpace = 0);
436
437    /// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
438    /// client having to pass in a MCExpr for constant integers.
439    void EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace = 0);
440
441    /// EmitSymbolValue - Special case of EmitValue that avoids the client
442    /// having to pass in a MCExpr for MCSymbols.
443    void EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
444                         unsigned AddrSpace = 0);
445
446    /// EmitGPRel64Value - Emit the expression @p Value into the output as a
447    /// gprel64 (64-bit GP relative) value.
448    ///
449    /// This is used to implement assembler directives such as .gpdword on
450    /// targets that support them.
451    virtual void EmitGPRel64Value(const MCExpr *Value);
452
453    /// EmitGPRel32Value - Emit the expression @p Value into the output as a
454    /// gprel32 (32-bit GP relative) value.
455    ///
456    /// This is used to implement assembler directives such as .gprel32 on
457    /// targets that support them.
458    virtual void EmitGPRel32Value(const MCExpr *Value);
459
460    /// EmitFill - Emit NumBytes bytes worth of the value specified by
461    /// FillValue.  This implements directives such as '.space'.
462    virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue,
463                          unsigned AddrSpace = 0);
464
465    /// EmitZeros - Emit NumBytes worth of zeros.  This is a convenience
466    /// function that just wraps EmitFill.
467    void EmitZeros(uint64_t NumBytes, unsigned AddrSpace = 0) {
468      EmitFill(NumBytes, 0, AddrSpace);
469    }
470
471    /// EmitValueToAlignment - Emit some number of copies of @p Value until
472    /// the byte alignment @p ByteAlignment is reached.
473    ///
474    /// If the number of bytes need to emit for the alignment is not a multiple
475    /// of @p ValueSize, then the contents of the emitted fill bytes is
476    /// undefined.
477    ///
478    /// This used to implement the .align assembler directive.
479    ///
480    /// @param ByteAlignment - The alignment to reach. This must be a power of
481    /// two on some targets.
482    /// @param Value - The value to use when filling bytes.
483    /// @param ValueSize - The size of the integer (in bytes) to emit for
484    /// @p Value. This must match a native machine width.
485    /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If
486    /// the alignment cannot be reached in this many bytes, no bytes are
487    /// emitted.
488    virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
489                                      unsigned ValueSize = 1,
490                                      unsigned MaxBytesToEmit = 0) = 0;
491
492    /// EmitCodeAlignment - Emit nops until the byte alignment @p ByteAlignment
493    /// is reached.
494    ///
495    /// This used to align code where the alignment bytes may be executed.  This
496    /// can emit different bytes for different sizes to optimize execution.
497    ///
498    /// @param ByteAlignment - The alignment to reach. This must be a power of
499    /// two on some targets.
500    /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If
501    /// the alignment cannot be reached in this many bytes, no bytes are
502    /// emitted.
503    virtual void EmitCodeAlignment(unsigned ByteAlignment,
504                                   unsigned MaxBytesToEmit = 0) = 0;
505
506    /// EmitValueToOffset - Emit some number of copies of @p Value until the
507    /// byte offset @p Offset is reached.
508    ///
509    /// This is used to implement assembler directives such as .org.
510    ///
511    /// @param Offset - The offset to reach. This may be an expression, but the
512    /// expression must be associated with the current section.
513    /// @param Value - The value to use when filling bytes.
514    /// @return false on success, true if the offset was invalid.
515    virtual bool EmitValueToOffset(const MCExpr *Offset,
516                                   unsigned char Value = 0) = 0;
517
518    /// @}
519
520    /// EmitFileDirective - Switch to a new logical file.  This is used to
521    /// implement the '.file "foo.c"' assembler directive.
522    virtual void EmitFileDirective(StringRef Filename) = 0;
523
524    /// EmitDwarfFileDirective - Associate a filename with a specified logical
525    /// file number.  This implements the DWARF2 '.file 4 "foo.c"' assembler
526    /// directive.
527    virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
528                                        StringRef Filename, unsigned CUID = 0);
529
530    /// EmitDwarfLocDirective - This implements the DWARF2
531    // '.loc fileno lineno ...' assembler directive.
532    virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
533                                       unsigned Column, unsigned Flags,
534                                       unsigned Isa,
535                                       unsigned Discriminator,
536                                       StringRef FileName);
537
538    virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
539                                          const MCSymbol *LastLabel,
540                                          const MCSymbol *Label,
541                                          unsigned PointerSize) = 0;
542
543    virtual void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
544                                           const MCSymbol *Label) {
545    }
546
547    void EmitDwarfSetLineAddr(int64_t LineDelta, const MCSymbol *Label,
548                              int PointerSize);
549
550    virtual void EmitCompactUnwindEncoding(uint32_t CompactUnwindEncoding);
551    virtual void EmitCFISections(bool EH, bool Debug);
552    void EmitCFIStartProc();
553    void EmitCFIEndProc();
554    virtual void EmitCFIDefCfa(int64_t Register, int64_t Offset);
555    virtual void EmitCFIDefCfaOffset(int64_t Offset);
556    virtual void EmitCFIDefCfaRegister(int64_t Register);
557    virtual void EmitCFIOffset(int64_t Register, int64_t Offset);
558    virtual void EmitCFIPersonality(const MCSymbol *Sym, unsigned Encoding);
559    virtual void EmitCFILsda(const MCSymbol *Sym, unsigned Encoding);
560    virtual void EmitCFIRememberState();
561    virtual void EmitCFIRestoreState();
562    virtual void EmitCFISameValue(int64_t Register);
563    virtual void EmitCFIRestore(int64_t Register);
564    virtual void EmitCFIRelOffset(int64_t Register, int64_t Offset);
565    virtual void EmitCFIAdjustCfaOffset(int64_t Adjustment);
566    virtual void EmitCFIEscape(StringRef Values);
567    virtual void EmitCFISignalFrame();
568    virtual void EmitCFIUndefined(int64_t Register);
569    virtual void EmitCFIRegister(int64_t Register1, int64_t Register2);
570
571    virtual void EmitWin64EHStartProc(const MCSymbol *Symbol);
572    virtual void EmitWin64EHEndProc();
573    virtual void EmitWin64EHStartChained();
574    virtual void EmitWin64EHEndChained();
575    virtual void EmitWin64EHHandler(const MCSymbol *Sym, bool Unwind,
576                                    bool Except);
577    virtual void EmitWin64EHHandlerData();
578    virtual void EmitWin64EHPushReg(unsigned Register);
579    virtual void EmitWin64EHSetFrame(unsigned Register, unsigned Offset);
580    virtual void EmitWin64EHAllocStack(unsigned Size);
581    virtual void EmitWin64EHSaveReg(unsigned Register, unsigned Offset);
582    virtual void EmitWin64EHSaveXMM(unsigned Register, unsigned Offset);
583    virtual void EmitWin64EHPushFrame(bool Code);
584    virtual void EmitWin64EHEndProlog();
585
586    /// EmitInstruction - Emit the given @p Instruction into the current
587    /// section.
588    virtual void EmitInstruction(const MCInst &Inst) = 0;
589
590    /// \brief Set the bundle alignment mode from now on in the section.
591    /// The argument is the power of 2 to which the alignment is set. The
592    /// value 0 means turn the bundle alignment off.
593    virtual void EmitBundleAlignMode(unsigned AlignPow2) = 0;
594
595    /// \brief The following instructions are a bundle-locked group.
596    ///
597    /// \param AlignToEnd - If true, the bundle-locked group will be aligned to
598    ///                     the end of a bundle.
599    virtual void EmitBundleLock(bool AlignToEnd) = 0;
600
601    /// \brief Ends a bundle-locked group.
602    virtual void EmitBundleUnlock() = 0;
603
604    /// EmitRawText - If this file is backed by a assembly streamer, this dumps
605    /// the specified string in the output .s file.  This capability is
606    /// indicated by the hasRawTextSupport() predicate.  By default this aborts.
607    virtual void EmitRawText(StringRef String);
608    void EmitRawText(const Twine &String);
609
610    /// ARM-related methods.
611    /// FIXME: Eventually we should have some "target MC streamer" and move
612    /// these methods there.
613    virtual void EmitFnStart();
614    virtual void EmitFnEnd();
615    virtual void EmitCantUnwind();
616    virtual void EmitPersonality(const MCSymbol *Personality);
617    virtual void EmitHandlerData();
618    virtual void EmitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0);
619    virtual void EmitPad(int64_t Offset);
620    virtual void EmitRegSave(const SmallVectorImpl<unsigned> &RegList,
621                             bool isVector);
622
623    /// PPC-related methods.
624    /// FIXME: Eventually replace it with some "target MC streamer" and move
625    /// these methods there.
626    virtual void EmitTCEntry(const MCSymbol &S);
627
628    /// FinishImpl - Streamer specific finalization.
629    virtual void FinishImpl() = 0;
630    /// Finish - Finish emission of machine code.
631    void Finish();
632  };
633
634  /// createNullStreamer - Create a dummy machine code streamer, which does
635  /// nothing. This is useful for timing the assembler front end.
636  MCStreamer *createNullStreamer(MCContext &Ctx);
637
638  /// createAsmStreamer - Create a machine code streamer which will print out
639  /// assembly for the native target, suitable for compiling with a native
640  /// assembler.
641  ///
642  /// \param InstPrint - If given, the instruction printer to use. If not given
643  /// the MCInst representation will be printed.  This method takes ownership of
644  /// InstPrint.
645  ///
646  /// \param CE - If given, a code emitter to use to show the instruction
647  /// encoding inline with the assembly. This method takes ownership of \p CE.
648  ///
649  /// \param TAB - If given, a target asm backend to use to show the fixup
650  /// information in conjunction with encoding information. This method takes
651  /// ownership of \p TAB.
652  ///
653  /// \param ShowInst - Whether to show the MCInst representation inline with
654  /// the assembly.
655  MCStreamer *createAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS,
656                                bool isVerboseAsm,
657                                bool useLoc,
658                                bool useCFI,
659                                bool useDwarfDirectory,
660                                MCInstPrinter *InstPrint = 0,
661                                MCCodeEmitter *CE = 0,
662                                MCAsmBackend *TAB = 0,
663                                bool ShowInst = false);
664
665  /// createMachOStreamer - Create a machine code streamer which will generate
666  /// Mach-O format object files.
667  ///
668  /// Takes ownership of \p TAB and \p CE.
669  MCStreamer *createMachOStreamer(MCContext &Ctx, MCAsmBackend &TAB,
670                                  raw_ostream &OS, MCCodeEmitter *CE,
671                                  bool RelaxAll = false);
672
673  /// createWinCOFFStreamer - Create a machine code streamer which will
674  /// generate Microsoft COFF format object files.
675  ///
676  /// Takes ownership of \p TAB and \p CE.
677  MCStreamer *createWinCOFFStreamer(MCContext &Ctx,
678                                    MCAsmBackend &TAB,
679                                    MCCodeEmitter &CE, raw_ostream &OS,
680                                    bool RelaxAll = false);
681
682  /// createELFStreamer - Create a machine code streamer which will generate
683  /// ELF format object files.
684  MCStreamer *createELFStreamer(MCContext &Ctx, MCAsmBackend &TAB,
685                                raw_ostream &OS, MCCodeEmitter *CE,
686                                bool RelaxAll, bool NoExecStack);
687
688  /// createPureStreamer - Create a machine code streamer which will generate
689  /// "pure" MC object files, for use with MC-JIT and testing tools.
690  ///
691  /// Takes ownership of \p TAB and \p CE.
692  MCStreamer *createPureStreamer(MCContext &Ctx, MCAsmBackend &TAB,
693                                 raw_ostream &OS, MCCodeEmitter *CE);
694
695} // end namespace llvm
696
697#endif
698