1 //===- MCStreamer.h - High-level Streaming Machine Code Output --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file declares the MCStreamer class.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_MC_MCSTREAMER_H
15 #define LLVM_MC_MCSTREAMER_H
17 #include "llvm/ADT/SmallVector.h"
18 #include "llvm/Support/DataTypes.h"
19 #include "llvm/MC/MCDirectives.h"
20 #include "llvm/MC/MCDwarf.h"
21 #include "llvm/MC/MCWin64EH.h"
33 class TargetAsmBackend;
34 class TargetLoweringObjectFile;
37 class formatted_raw_ostream;
39 /// MCStreamer - Streaming machine code generation interface. This interface
40 /// is intended to provide a programatic interface that is very similar to the
41 /// level that an assembler .s file provides. It has callbacks to emit bytes,
42 /// handle directives, etc. The implementation of this interface retains
43 /// state to know what the current section is etc.
45 /// There are multiple implementations of this interface: one for writing out
46 /// a .s file, and implementations that write out .o files of various formats.
51 MCStreamer(const MCStreamer&); // DO NOT IMPLEMENT
52 MCStreamer &operator=(const MCStreamer&); // DO NOT IMPLEMENT
57 std::vector<MCDwarfFrameInfo> FrameInfos;
58 MCDwarfFrameInfo *getCurrentFrameInfo();
59 void EnsureValidFrame();
61 std::vector<MCWin64EHUnwindInfo> W64UnwindInfos;
62 MCWin64EHUnwindInfo *CurrentW64UnwindInfo;
63 void setCurrentW64UnwindInfo(MCWin64EHUnwindInfo *Frame);
64 void EnsureValidW64UnwindInfo();
66 const MCSymbol* LastNonPrivate;
68 /// SectionStack - This is stack of current and previous section
69 /// values saved by PushSection.
70 SmallVector<std::pair<const MCSection *,
71 const MCSection *>, 4> SectionStack;
74 MCStreamer(MCContext &Ctx);
76 const MCExpr *BuildSymbolDiff(MCContext &Context, const MCSymbol *A,
79 const MCExpr *ForceExpAbs(const MCExpr* Expr);
81 void EmitFrames(bool usingCFI);
83 MCWin64EHUnwindInfo *getCurrentW64UnwindInfo(){return CurrentW64UnwindInfo;}
86 virtual ~MCStreamer();
88 MCContext &getContext() const { return Context; }
90 unsigned getNumFrameInfos() {
91 return FrameInfos.size();
94 const MCDwarfFrameInfo &getFrameInfo(unsigned i) {
98 /// @name Assembly File Formatting.
101 /// isVerboseAsm - Return true if this streamer supports verbose assembly
102 /// and if it is enabled.
103 virtual bool isVerboseAsm() const { return false; }
105 /// hasRawTextSupport - Return true if this asm streamer supports emitting
106 /// unformatted text to the .s file with EmitRawText.
107 virtual bool hasRawTextSupport() const { return false; }
109 /// AddComment - Add a comment that can be emitted to the generated .s
110 /// file if applicable as a QoI issue to make the output of the compiler
111 /// more readable. This only affects the MCAsmStreamer, and only when
112 /// verbose assembly output is enabled.
114 /// If the comment includes embedded \n's, they will each get the comment
115 /// prefix as appropriate. The added comment should not end with a \n.
116 virtual void AddComment(const Twine &T) {}
118 /// GetCommentOS - Return a raw_ostream that comments can be written to.
119 /// Unlike AddComment, you are required to terminate comments with \n if you
121 virtual raw_ostream &GetCommentOS();
123 /// AddBlankLine - Emit a blank line to a .s file to pretty it up.
124 virtual void AddBlankLine() {}
128 /// @name Symbol & Section Management
131 /// getCurrentSection - Return the current section that the streamer is
132 /// emitting code to.
133 const MCSection *getCurrentSection() const {
134 if (!SectionStack.empty())
135 return SectionStack.back().first;
139 /// getPreviousSection - Return the previous section that the streamer is
140 /// emitting code to.
141 const MCSection *getPreviousSection() const {
142 if (!SectionStack.empty())
143 return SectionStack.back().second;
147 /// ChangeSection - Update streamer for a new active section.
149 /// This is called by PopSection and SwitchSection, if the current
151 virtual void ChangeSection(const MCSection *) = 0;
153 /// pushSection - Save the current and previous section on the
156 SectionStack.push_back(std::make_pair(getCurrentSection(),
157 getPreviousSection()));
160 /// popSection - Restore the current and previous section from
161 /// the section stack. Calls ChangeSection as needed.
163 /// Returns false if the stack was empty.
165 if (SectionStack.size() <= 1)
167 const MCSection *oldSection = SectionStack.pop_back_val().first;
168 const MCSection *curSection = SectionStack.back().first;
170 if (oldSection != curSection)
171 ChangeSection(curSection);
175 /// SwitchSection - Set the current section where code is being emitted to
176 /// @p Section. This is required to update CurSection.
178 /// This corresponds to assembler directives like .section, .text, etc.
179 void SwitchSection(const MCSection *Section) {
180 assert(Section && "Cannot switch to a null section!");
181 const MCSection *curSection = SectionStack.back().first;
182 SectionStack.back().second = curSection;
183 if (Section != curSection) {
184 SectionStack.back().first = Section;
185 ChangeSection(Section);
189 /// InitSections - Create the default sections and set the initial one.
190 virtual void InitSections() = 0;
192 /// EmitLabel - Emit a label for @p Symbol into the current section.
194 /// This corresponds to an assembler statement such as:
197 /// @param Symbol - The symbol to emit. A given symbol should only be
198 /// emitted as a label once, and symbols emitted as a label should never be
199 /// used in an assignment.
200 virtual void EmitLabel(MCSymbol *Symbol);
202 virtual void EmitEHSymAttributes(const MCSymbol *Symbol,
205 /// EmitAssemblerFlag - Note in the output the specified @p Flag
206 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) = 0;
208 /// EmitThumbFunc - Note in the output that the specified @p Func is
209 /// a Thumb mode function (ARM target only).
210 virtual void EmitThumbFunc(MCSymbol *Func) = 0;
212 /// EmitAssignment - Emit an assignment of @p Value to @p Symbol.
214 /// This corresponds to an assembler statement such as:
217 /// The assignment generates no code, but has the side effect of binding the
218 /// value in the current context. For the assembly streamer, this prints the
219 /// binding into the .s file.
221 /// @param Symbol - The symbol being assigned to.
222 /// @param Value - The value for the symbol.
223 virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) = 0;
225 /// EmitWeakReference - Emit an weak reference from @p Alias to @p Symbol.
227 /// This corresponds to an assembler statement such as:
228 /// .weakref alias, symbol
230 /// @param Alias - The alias that is being created.
231 /// @param Symbol - The symbol being aliased.
232 virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) = 0;
234 /// EmitSymbolAttribute - Add the given @p Attribute to @p Symbol.
235 virtual void EmitSymbolAttribute(MCSymbol *Symbol,
236 MCSymbolAttr Attribute) = 0;
238 /// EmitSymbolDesc - Set the @p DescValue for the @p Symbol.
240 /// @param Symbol - The symbol to have its n_desc field set.
241 /// @param DescValue - The value to set into the n_desc field.
242 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) = 0;
244 /// BeginCOFFSymbolDef - Start emitting COFF symbol definition
246 /// @param Symbol - The symbol to have its External & Type fields set.
247 virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) = 0;
249 /// EmitCOFFSymbolStorageClass - Emit the storage class of the symbol.
251 /// @param StorageClass - The storage class the symbol should have.
252 virtual void EmitCOFFSymbolStorageClass(int StorageClass) = 0;
254 /// EmitCOFFSymbolType - Emit the type of the symbol.
256 /// @param Type - A COFF type identifier (see COFF::SymbolType in X86COFF.h)
257 virtual void EmitCOFFSymbolType(int Type) = 0;
259 /// EndCOFFSymbolDef - Marks the end of the symbol definition.
260 virtual void EndCOFFSymbolDef() = 0;
262 /// EmitELFSize - Emit an ELF .size directive.
264 /// This corresponds to an assembler statement such as:
265 /// .size symbol, expression
267 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) = 0;
269 /// EmitCommonSymbol - Emit a common symbol.
271 /// @param Symbol - The common symbol to emit.
272 /// @param Size - The size of the common symbol.
273 /// @param ByteAlignment - The alignment of the symbol if
274 /// non-zero. This must be a power of 2.
275 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
276 unsigned ByteAlignment) = 0;
278 /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
280 /// @param Symbol - The common symbol to emit.
281 /// @param Size - The size of the common symbol.
282 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) = 0;
284 /// EmitZerofill - Emit the zerofill section and an optional symbol.
286 /// @param Section - The zerofill section to create and or to put the symbol
287 /// @param Symbol - The zerofill symbol to emit, if non-NULL.
288 /// @param Size - The size of the zerofill symbol.
289 /// @param ByteAlignment - The alignment of the zerofill symbol if
290 /// non-zero. This must be a power of 2 on some targets.
291 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
292 unsigned Size = 0,unsigned ByteAlignment = 0) = 0;
294 /// EmitTBSSSymbol - Emit a thread local bss (.tbss) symbol.
296 /// @param Section - The thread local common section.
297 /// @param Symbol - The thread local common symbol to emit.
298 /// @param Size - The size of the symbol.
299 /// @param ByteAlignment - The alignment of the thread local common symbol
300 /// if non-zero. This must be a power of 2 on some targets.
301 virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
302 uint64_t Size, unsigned ByteAlignment = 0) = 0;
305 /// @name Generating Data
308 /// EmitBytes - Emit the bytes in \arg Data into the output.
310 /// This is used to implement assembler directives such as .byte, .ascii,
312 virtual void EmitBytes(StringRef Data, unsigned AddrSpace) = 0;
314 /// EmitValue - Emit the expression @p Value into the output as a native
315 /// integer of the given @p Size bytes.
317 /// This is used to implement assembler directives such as .word, .quad,
320 /// @param Value - The value to emit.
321 /// @param Size - The size of the integer (in bytes) to emit. This must
322 /// match a native machine width.
323 virtual void EmitValueImpl(const MCExpr *Value, unsigned Size,
324 unsigned AddrSpace) = 0;
326 void EmitValue(const MCExpr *Value, unsigned Size, unsigned AddrSpace = 0);
328 /// EmitIntValue - Special case of EmitValue that avoids the client having
329 /// to pass in a MCExpr for constant integers.
330 virtual void EmitIntValue(uint64_t Value, unsigned Size,
331 unsigned AddrSpace = 0);
333 /// EmitAbsValue - Emit the Value, but try to avoid relocations. On MachO
334 /// this is done by producing
337 void EmitAbsValue(const MCExpr *Value, unsigned Size,
338 unsigned AddrSpace = 0);
340 virtual void EmitULEB128Value(const MCExpr *Value) = 0;
342 virtual void EmitSLEB128Value(const MCExpr *Value) = 0;
344 /// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
345 /// client having to pass in a MCExpr for constant integers.
346 void EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace = 0);
348 /// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
349 /// client having to pass in a MCExpr for constant integers.
350 void EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace = 0);
352 /// EmitSymbolValue - Special case of EmitValue that avoids the client
353 /// having to pass in a MCExpr for MCSymbols.
354 void EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
355 unsigned AddrSpace = 0);
357 /// EmitGPRel32Value - Emit the expression @p Value into the output as a
358 /// gprel32 (32-bit GP relative) value.
360 /// This is used to implement assembler directives such as .gprel32 on
361 /// targets that support them.
362 virtual void EmitGPRel32Value(const MCExpr *Value);
364 /// EmitFill - Emit NumBytes bytes worth of the value specified by
365 /// FillValue. This implements directives such as '.space'.
366 virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue,
369 /// EmitZeros - Emit NumBytes worth of zeros. This is a convenience
370 /// function that just wraps EmitFill.
371 void EmitZeros(uint64_t NumBytes, unsigned AddrSpace) {
372 EmitFill(NumBytes, 0, AddrSpace);
376 /// EmitValueToAlignment - Emit some number of copies of @p Value until
377 /// the byte alignment @p ByteAlignment is reached.
379 /// If the number of bytes need to emit for the alignment is not a multiple
380 /// of @p ValueSize, then the contents of the emitted fill bytes is
383 /// This used to implement the .align assembler directive.
385 /// @param ByteAlignment - The alignment to reach. This must be a power of
386 /// two on some targets.
387 /// @param Value - The value to use when filling bytes.
388 /// @param ValueSize - The size of the integer (in bytes) to emit for
389 /// @p Value. This must match a native machine width.
390 /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If
391 /// the alignment cannot be reached in this many bytes, no bytes are
393 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
394 unsigned ValueSize = 1,
395 unsigned MaxBytesToEmit = 0) = 0;
397 /// EmitCodeAlignment - Emit nops until the byte alignment @p ByteAlignment
400 /// This used to align code where the alignment bytes may be executed. This
401 /// can emit different bytes for different sizes to optimize execution.
403 /// @param ByteAlignment - The alignment to reach. This must be a power of
404 /// two on some targets.
405 /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If
406 /// the alignment cannot be reached in this many bytes, no bytes are
408 virtual void EmitCodeAlignment(unsigned ByteAlignment,
409 unsigned MaxBytesToEmit = 0) = 0;
411 /// EmitValueToOffset - Emit some number of copies of @p Value until the
412 /// byte offset @p Offset is reached.
414 /// This is used to implement assembler directives such as .org.
416 /// @param Offset - The offset to reach. This may be an expression, but the
417 /// expression must be associated with the current section.
418 /// @param Value - The value to use when filling bytes.
419 virtual void EmitValueToOffset(const MCExpr *Offset,
420 unsigned char Value = 0) = 0;
424 /// EmitFileDirective - Switch to a new logical file. This is used to
425 /// implement the '.file "foo.c"' assembler directive.
426 virtual void EmitFileDirective(StringRef Filename) = 0;
428 /// EmitDwarfFileDirective - Associate a filename with a specified logical
429 /// file number. This implements the DWARF2 '.file 4 "foo.c"' assembler
431 virtual bool EmitDwarfFileDirective(unsigned FileNo,StringRef Filename);
433 /// EmitDwarfLocDirective - This implements the DWARF2
434 // '.loc fileno lineno ...' assembler directive.
435 virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
436 unsigned Column, unsigned Flags,
438 unsigned Discriminator,
441 virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
442 const MCSymbol *LastLabel,
443 const MCSymbol *Label) = 0;
445 virtual void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
446 const MCSymbol *Label) {
449 void EmitDwarfSetLineAddr(int64_t LineDelta, const MCSymbol *Label,
452 virtual void EmitCFISections(bool EH, bool Debug);
453 virtual void EmitCFIStartProc();
454 virtual void EmitCFIEndProc();
455 virtual void EmitCFIDefCfa(int64_t Register, int64_t Offset);
456 virtual void EmitCFIDefCfaOffset(int64_t Offset);
457 virtual void EmitCFIDefCfaRegister(int64_t Register);
458 virtual void EmitCFIOffset(int64_t Register, int64_t Offset);
459 virtual void EmitCFIPersonality(const MCSymbol *Sym, unsigned Encoding);
460 virtual void EmitCFILsda(const MCSymbol *Sym, unsigned Encoding);
461 virtual void EmitCFIRememberState();
462 virtual void EmitCFIRestoreState();
463 virtual void EmitCFISameValue(int64_t Register);
464 virtual void EmitCFIRelOffset(int64_t Register, int64_t Offset);
465 virtual void EmitCFIAdjustCfaOffset(int64_t Adjustment);
467 virtual void EmitWin64EHStartProc(MCSymbol *Symbol);
468 virtual void EmitWin64EHEndProc();
469 virtual void EmitWin64EHStartChained();
470 virtual void EmitWin64EHEndChained();
471 virtual void EmitWin64EHHandler(const MCSymbol *Sym, bool Unwind,
473 virtual void EmitWin64EHHandlerData();
474 virtual void EmitWin64EHPushReg(unsigned Register);
475 virtual void EmitWin64EHSetFrame(unsigned Register, unsigned Offset);
476 virtual void EmitWin64EHAllocStack(unsigned Size);
477 virtual void EmitWin64EHSaveReg(unsigned Register, unsigned Offset);
478 virtual void EmitWin64EHSaveXMM(unsigned Register, unsigned Offset);
479 virtual void EmitWin64EHPushFrame(bool Code);
480 virtual void EmitWin64EHEndProlog();
482 /// EmitInstruction - Emit the given @p Instruction into the current
484 virtual void EmitInstruction(const MCInst &Inst) = 0;
486 /// EmitRawText - If this file is backed by a assembly streamer, this dumps
487 /// the specified string in the output .s file. This capability is
488 /// indicated by the hasRawTextSupport() predicate. By default this aborts.
489 virtual void EmitRawText(StringRef String);
490 void EmitRawText(const Twine &String);
492 /// ARM-related methods.
493 /// FIXME: Eventually we should have some "target MC streamer" and move
494 /// these methods there.
495 virtual void EmitFnStart();
496 virtual void EmitFnEnd();
497 virtual void EmitCantUnwind();
498 virtual void EmitPersonality(const MCSymbol *Personality);
499 virtual void EmitHandlerData();
500 virtual void EmitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0);
501 virtual void EmitPad(int64_t Offset);
502 virtual void EmitRegSave(const SmallVectorImpl<unsigned> &RegList,
505 /// Finish - Finish emission of machine code.
506 virtual void Finish() = 0;
509 /// createNullStreamer - Create a dummy machine code streamer, which does
510 /// nothing. This is useful for timing the assembler front end.
511 MCStreamer *createNullStreamer(MCContext &Ctx);
513 /// createAsmStreamer - Create a machine code streamer which will print out
514 /// assembly for the native target, suitable for compiling with a native
517 /// \param InstPrint - If given, the instruction printer to use. If not given
518 /// the MCInst representation will be printed. This method takes ownership of
521 /// \param CE - If given, a code emitter to use to show the instruction
522 /// encoding inline with the assembly. This method takes ownership of \arg CE.
524 /// \param TAB - If given, a target asm backend to use to show the fixup
525 /// information in conjunction with encoding information. This method takes
526 /// ownership of \arg TAB.
528 /// \param ShowInst - Whether to show the MCInst representation inline with
530 MCStreamer *createAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS,
534 MCInstPrinter *InstPrint = 0,
535 MCCodeEmitter *CE = 0,
536 TargetAsmBackend *TAB = 0,
537 bool ShowInst = false);
539 /// createMachOStreamer - Create a machine code streamer which will generate
540 /// Mach-O format object files.
542 /// Takes ownership of \arg TAB and \arg CE.
543 MCStreamer *createMachOStreamer(MCContext &Ctx, TargetAsmBackend &TAB,
544 raw_ostream &OS, MCCodeEmitter *CE,
545 bool RelaxAll = false);
547 /// createWinCOFFStreamer - Create a machine code streamer which will
548 /// generate Microsoft COFF format object files.
550 /// Takes ownership of \arg TAB and \arg CE.
551 MCStreamer *createWinCOFFStreamer(MCContext &Ctx,
552 TargetAsmBackend &TAB,
553 MCCodeEmitter &CE, raw_ostream &OS,
554 bool RelaxAll = false);
556 /// createELFStreamer - Create a machine code streamer which will generate
557 /// ELF format object files.
558 MCStreamer *createELFStreamer(MCContext &Ctx, TargetAsmBackend &TAB,
559 raw_ostream &OS, MCCodeEmitter *CE,
560 bool RelaxAll, bool NoExecStack);
562 /// createLoggingStreamer - Create a machine code streamer which just logs the
563 /// API calls and then dispatches to another streamer.
565 /// The new streamer takes ownership of the \arg Child.
566 MCStreamer *createLoggingStreamer(MCStreamer *Child, raw_ostream &OS);
568 /// createPureStreamer - Create a machine code streamer which will generate
569 /// "pure" MC object files, for use with MC-JIT and testing tools.
571 /// Takes ownership of \arg TAB and \arg CE.
572 MCStreamer *createPureStreamer(MCContext &Ctx, TargetAsmBackend &TAB,
573 raw_ostream &OS, MCCodeEmitter *CE);
575 } // end namespace llvm