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(MCStreamer *Streamer, MCContext &Context,
82 void EmitFrames(bool usingCFI);
85 virtual ~MCStreamer();
87 MCContext &getContext() const { return Context; }
89 unsigned getNumFrameInfos() {
90 return FrameInfos.size();
93 const MCDwarfFrameInfo &getFrameInfo(unsigned i) {
97 /// @name Assembly File Formatting.
100 /// isVerboseAsm - Return true if this streamer supports verbose assembly
101 /// and if it is enabled.
102 virtual bool isVerboseAsm() const { return false; }
104 /// hasRawTextSupport - Return true if this asm streamer supports emitting
105 /// unformatted text to the .s file with EmitRawText.
106 virtual bool hasRawTextSupport() const { return false; }
108 /// AddComment - Add a comment that can be emitted to the generated .s
109 /// file if applicable as a QoI issue to make the output of the compiler
110 /// more readable. This only affects the MCAsmStreamer, and only when
111 /// verbose assembly output is enabled.
113 /// If the comment includes embedded \n's, they will each get the comment
114 /// prefix as appropriate. The added comment should not end with a \n.
115 virtual void AddComment(const Twine &T) {}
117 /// GetCommentOS - Return a raw_ostream that comments can be written to.
118 /// Unlike AddComment, you are required to terminate comments with \n if you
120 virtual raw_ostream &GetCommentOS();
122 /// AddBlankLine - Emit a blank line to a .s file to pretty it up.
123 virtual void AddBlankLine() {}
127 /// @name Symbol & Section Management
130 /// getCurrentSection - Return the current section that the streamer is
131 /// emitting code to.
132 const MCSection *getCurrentSection() const {
133 if (!SectionStack.empty())
134 return SectionStack.back().first;
138 /// getPreviousSection - Return the previous section that the streamer is
139 /// emitting code to.
140 const MCSection *getPreviousSection() const {
141 if (!SectionStack.empty())
142 return SectionStack.back().second;
146 /// ChangeSection - Update streamer for a new active section.
148 /// This is called by PopSection and SwitchSection, if the current
150 virtual void ChangeSection(const MCSection *) = 0;
152 /// pushSection - Save the current and previous section on the
155 SectionStack.push_back(std::make_pair(getCurrentSection(),
156 getPreviousSection()));
159 /// popSection - Restore the current and previous section from
160 /// the section stack. Calls ChangeSection as needed.
162 /// Returns false if the stack was empty.
164 if (SectionStack.size() <= 1)
166 const MCSection *oldSection = SectionStack.pop_back_val().first;
167 const MCSection *curSection = SectionStack.back().first;
169 if (oldSection != curSection)
170 ChangeSection(curSection);
174 /// SwitchSection - Set the current section where code is being emitted to
175 /// @p Section. This is required to update CurSection.
177 /// This corresponds to assembler directives like .section, .text, etc.
178 void SwitchSection(const MCSection *Section) {
179 assert(Section && "Cannot switch to a null section!");
180 const MCSection *curSection = SectionStack.back().first;
181 SectionStack.back().second = curSection;
182 if (Section != curSection) {
183 SectionStack.back().first = Section;
184 ChangeSection(Section);
188 /// InitSections - Create the default sections and set the initial one.
189 virtual void InitSections() = 0;
191 /// EmitLabel - Emit a label for @p Symbol into the current section.
193 /// This corresponds to an assembler statement such as:
196 /// @param Symbol - The symbol to emit. A given symbol should only be
197 /// emitted as a label once, and symbols emitted as a label should never be
198 /// used in an assignment.
199 virtual void EmitLabel(MCSymbol *Symbol);
201 virtual void EmitEHSymAttributes(const MCSymbol *Symbol,
204 /// EmitAssemblerFlag - Note in the output the specified @p Flag
205 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) = 0;
207 /// EmitThumbFunc - Note in the output that the specified @p Func is
208 /// a Thumb mode function (ARM target only).
209 virtual void EmitThumbFunc(MCSymbol *Func) = 0;
211 /// EmitAssignment - Emit an assignment of @p Value to @p Symbol.
213 /// This corresponds to an assembler statement such as:
216 /// The assignment generates no code, but has the side effect of binding the
217 /// value in the current context. For the assembly streamer, this prints the
218 /// binding into the .s file.
220 /// @param Symbol - The symbol being assigned to.
221 /// @param Value - The value for the symbol.
222 virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) = 0;
224 /// EmitWeakReference - Emit an weak reference from @p Alias to @p Symbol.
226 /// This corresponds to an assembler statement such as:
227 /// .weakref alias, symbol
229 /// @param Alias - The alias that is being created.
230 /// @param Symbol - The symbol being aliased.
231 virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) = 0;
233 /// EmitSymbolAttribute - Add the given @p Attribute to @p Symbol.
234 virtual void EmitSymbolAttribute(MCSymbol *Symbol,
235 MCSymbolAttr Attribute) = 0;
237 /// EmitSymbolDesc - Set the @p DescValue for the @p Symbol.
239 /// @param Symbol - The symbol to have its n_desc field set.
240 /// @param DescValue - The value to set into the n_desc field.
241 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) = 0;
243 /// BeginCOFFSymbolDef - Start emitting COFF symbol definition
245 /// @param Symbol - The symbol to have its External & Type fields set.
246 virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) = 0;
248 /// EmitCOFFSymbolStorageClass - Emit the storage class of the symbol.
250 /// @param StorageClass - The storage class the symbol should have.
251 virtual void EmitCOFFSymbolStorageClass(int StorageClass) = 0;
253 /// EmitCOFFSymbolType - Emit the type of the symbol.
255 /// @param Type - A COFF type identifier (see COFF::SymbolType in X86COFF.h)
256 virtual void EmitCOFFSymbolType(int Type) = 0;
258 /// EndCOFFSymbolDef - Marks the end of the symbol definition.
259 virtual void EndCOFFSymbolDef() = 0;
261 /// EmitELFSize - Emit an ELF .size directive.
263 /// This corresponds to an assembler statement such as:
264 /// .size symbol, expression
266 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) = 0;
268 /// EmitCommonSymbol - Emit a common symbol.
270 /// @param Symbol - The common symbol to emit.
271 /// @param Size - The size of the common symbol.
272 /// @param ByteAlignment - The alignment of the symbol if
273 /// non-zero. This must be a power of 2.
274 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
275 unsigned ByteAlignment) = 0;
277 /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
279 /// @param Symbol - The common symbol to emit.
280 /// @param Size - The size of the common symbol.
281 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) = 0;
283 /// EmitZerofill - Emit the zerofill section and an optional symbol.
285 /// @param Section - The zerofill section to create and or to put the symbol
286 /// @param Symbol - The zerofill symbol to emit, if non-NULL.
287 /// @param Size - The size of the zerofill symbol.
288 /// @param ByteAlignment - The alignment of the zerofill symbol if
289 /// non-zero. This must be a power of 2 on some targets.
290 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
291 unsigned Size = 0,unsigned ByteAlignment = 0) = 0;
293 /// EmitTBSSSymbol - Emit a thread local bss (.tbss) symbol.
295 /// @param Section - The thread local common section.
296 /// @param Symbol - The thread local common symbol to emit.
297 /// @param Size - The size of the symbol.
298 /// @param ByteAlignment - The alignment of the thread local common symbol
299 /// if non-zero. This must be a power of 2 on some targets.
300 virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
301 uint64_t Size, unsigned ByteAlignment = 0) = 0;
304 /// @name Generating Data
307 /// EmitBytes - Emit the bytes in \arg Data into the output.
309 /// This is used to implement assembler directives such as .byte, .ascii,
311 virtual void EmitBytes(StringRef Data, unsigned AddrSpace) = 0;
313 /// EmitValue - Emit the expression @p Value into the output as a native
314 /// integer of the given @p Size bytes.
316 /// This is used to implement assembler directives such as .word, .quad,
319 /// @param Value - The value to emit.
320 /// @param Size - The size of the integer (in bytes) to emit. This must
321 /// match a native machine width.
322 virtual void EmitValueImpl(const MCExpr *Value, unsigned Size,
323 unsigned AddrSpace) = 0;
325 void EmitValue(const MCExpr *Value, unsigned Size, unsigned AddrSpace = 0);
327 /// EmitIntValue - Special case of EmitValue that avoids the client having
328 /// to pass in a MCExpr for constant integers.
329 virtual void EmitIntValue(uint64_t Value, unsigned Size,
330 unsigned AddrSpace = 0);
332 /// EmitAbsValue - Emit the Value, but try to avoid relocations. On MachO
333 /// this is done by producing
336 void EmitAbsValue(const MCExpr *Value, unsigned Size,
337 unsigned AddrSpace = 0);
339 virtual void EmitULEB128Value(const MCExpr *Value) = 0;
341 virtual void EmitSLEB128Value(const MCExpr *Value) = 0;
343 /// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
344 /// client having to pass in a MCExpr for constant integers.
345 void EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace = 0);
347 /// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
348 /// client having to pass in a MCExpr for constant integers.
349 void EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace = 0);
351 /// EmitSymbolValue - Special case of EmitValue that avoids the client
352 /// having to pass in a MCExpr for MCSymbols.
353 void EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
354 unsigned AddrSpace = 0);
356 /// EmitGPRel32Value - Emit the expression @p Value into the output as a
357 /// gprel32 (32-bit GP relative) value.
359 /// This is used to implement assembler directives such as .gprel32 on
360 /// targets that support them.
361 virtual void EmitGPRel32Value(const MCExpr *Value);
363 /// EmitFill - Emit NumBytes bytes worth of the value specified by
364 /// FillValue. This implements directives such as '.space'.
365 virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue,
368 /// EmitZeros - Emit NumBytes worth of zeros. This is a convenience
369 /// function that just wraps EmitFill.
370 void EmitZeros(uint64_t NumBytes, unsigned AddrSpace) {
371 EmitFill(NumBytes, 0, AddrSpace);
375 /// EmitValueToAlignment - Emit some number of copies of @p Value until
376 /// the byte alignment @p ByteAlignment is reached.
378 /// If the number of bytes need to emit for the alignment is not a multiple
379 /// of @p ValueSize, then the contents of the emitted fill bytes is
382 /// This used to implement the .align assembler directive.
384 /// @param ByteAlignment - The alignment to reach. This must be a power of
385 /// two on some targets.
386 /// @param Value - The value to use when filling bytes.
387 /// @param ValueSize - The size of the integer (in bytes) to emit for
388 /// @p Value. This must match a native machine width.
389 /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If
390 /// the alignment cannot be reached in this many bytes, no bytes are
392 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
393 unsigned ValueSize = 1,
394 unsigned MaxBytesToEmit = 0) = 0;
396 /// EmitCodeAlignment - Emit nops until the byte alignment @p ByteAlignment
399 /// This used to align code where the alignment bytes may be executed. This
400 /// can emit different bytes for different sizes to optimize execution.
402 /// @param ByteAlignment - The alignment to reach. This must be a power of
403 /// two on some targets.
404 /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If
405 /// the alignment cannot be reached in this many bytes, no bytes are
407 virtual void EmitCodeAlignment(unsigned ByteAlignment,
408 unsigned MaxBytesToEmit = 0) = 0;
410 /// EmitValueToOffset - Emit some number of copies of @p Value until the
411 /// byte offset @p Offset is reached.
413 /// This is used to implement assembler directives such as .org.
415 /// @param Offset - The offset to reach. This may be an expression, but the
416 /// expression must be associated with the current section.
417 /// @param Value - The value to use when filling bytes.
418 virtual void EmitValueToOffset(const MCExpr *Offset,
419 unsigned char Value = 0) = 0;
423 /// EmitFileDirective - Switch to a new logical file. This is used to
424 /// implement the '.file "foo.c"' assembler directive.
425 virtual void EmitFileDirective(StringRef Filename) = 0;
427 /// EmitDwarfFileDirective - Associate a filename with a specified logical
428 /// file number. This implements the DWARF2 '.file 4 "foo.c"' assembler
430 virtual bool EmitDwarfFileDirective(unsigned FileNo,StringRef Filename);
432 /// EmitDwarfLocDirective - This implements the DWARF2
433 // '.loc fileno lineno ...' assembler directive.
434 virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
435 unsigned Column, unsigned Flags,
437 unsigned Discriminator,
440 virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
441 const MCSymbol *LastLabel,
442 const MCSymbol *Label) = 0;
444 virtual void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
445 const MCSymbol *Label) {
448 void EmitDwarfSetLineAddr(int64_t LineDelta, const MCSymbol *Label,
451 virtual void EmitCFISections(bool EH, bool Debug);
452 virtual void EmitCFIStartProc();
453 virtual void EmitCFIEndProc();
454 virtual void EmitCFIDefCfa(int64_t Register, int64_t Offset);
455 virtual void EmitCFIDefCfaOffset(int64_t Offset);
456 virtual void EmitCFIDefCfaRegister(int64_t Register);
457 virtual void EmitCFIOffset(int64_t Register, int64_t Offset);
458 virtual void EmitCFIPersonality(const MCSymbol *Sym, unsigned Encoding);
459 virtual void EmitCFILsda(const MCSymbol *Sym, unsigned Encoding);
460 virtual void EmitCFIRememberState();
461 virtual void EmitCFIRestoreState();
462 virtual void EmitCFISameValue(int64_t Register);
463 virtual void EmitCFIRelOffset(int64_t Register, int64_t Offset);
464 virtual void EmitCFIAdjustCfaOffset(int64_t Adjustment);
466 virtual void EmitWin64EHStartProc(MCSymbol *Symbol);
467 virtual void EmitWin64EHEndProc();
468 virtual void EmitWin64EHStartChained();
469 virtual void EmitWin64EHEndChained();
470 virtual void EmitWin64EHHandler(const MCSymbol *Sym, bool Unwind,
472 virtual void EmitWin64EHHandlerData();
473 virtual void EmitWin64EHPushReg(unsigned Register);
474 virtual void EmitWin64EHSetFrame(unsigned Register, unsigned Offset);
475 virtual void EmitWin64EHAllocStack(unsigned Size);
476 virtual void EmitWin64EHSaveReg(unsigned Register, unsigned Offset);
477 virtual void EmitWin64EHSaveXMM(unsigned Register, unsigned Offset);
478 virtual void EmitWin64EHPushFrame(bool Code);
479 virtual void EmitWin64EHEndProlog();
481 /// EmitInstruction - Emit the given @p Instruction into the current
483 virtual void EmitInstruction(const MCInst &Inst) = 0;
485 /// EmitRawText - If this file is backed by a assembly streamer, this dumps
486 /// the specified string in the output .s file. This capability is
487 /// indicated by the hasRawTextSupport() predicate. By default this aborts.
488 virtual void EmitRawText(StringRef String);
489 void EmitRawText(const Twine &String);
491 /// ARM-related methods.
492 /// FIXME: Eventually we should have some "target MC streamer" and move
493 /// these methods there.
494 virtual void EmitFnStart();
495 virtual void EmitFnEnd();
496 virtual void EmitCantUnwind();
497 virtual void EmitPersonality(const MCSymbol *Personality);
498 virtual void EmitHandlerData();
499 virtual void EmitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0);
500 virtual void EmitPad(int64_t Offset);
501 virtual void EmitRegSave(const SmallVectorImpl<unsigned> &RegList,
504 /// Finish - Finish emission of machine code.
505 virtual void Finish() = 0;
508 /// createNullStreamer - Create a dummy machine code streamer, which does
509 /// nothing. This is useful for timing the assembler front end.
510 MCStreamer *createNullStreamer(MCContext &Ctx);
512 /// createAsmStreamer - Create a machine code streamer which will print out
513 /// assembly for the native target, suitable for compiling with a native
516 /// \param InstPrint - If given, the instruction printer to use. If not given
517 /// the MCInst representation will be printed. This method takes ownership of
520 /// \param CE - If given, a code emitter to use to show the instruction
521 /// encoding inline with the assembly. This method takes ownership of \arg CE.
523 /// \param TAB - If given, a target asm backend to use to show the fixup
524 /// information in conjunction with encoding information. This method takes
525 /// ownership of \arg TAB.
527 /// \param ShowInst - Whether to show the MCInst representation inline with
529 MCStreamer *createAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS,
533 MCInstPrinter *InstPrint = 0,
534 MCCodeEmitter *CE = 0,
535 TargetAsmBackend *TAB = 0,
536 bool ShowInst = false);
538 /// createMachOStreamer - Create a machine code streamer which will generate
539 /// Mach-O format object files.
541 /// Takes ownership of \arg TAB and \arg CE.
542 MCStreamer *createMachOStreamer(MCContext &Ctx, TargetAsmBackend &TAB,
543 raw_ostream &OS, MCCodeEmitter *CE,
544 bool RelaxAll = false);
546 /// createWinCOFFStreamer - Create a machine code streamer which will
547 /// generate Microsoft COFF format object files.
549 /// Takes ownership of \arg TAB and \arg CE.
550 MCStreamer *createWinCOFFStreamer(MCContext &Ctx,
551 TargetAsmBackend &TAB,
552 MCCodeEmitter &CE, raw_ostream &OS,
553 bool RelaxAll = false);
555 /// createELFStreamer - Create a machine code streamer which will generate
556 /// ELF format object files.
557 MCStreamer *createELFStreamer(MCContext &Ctx, TargetAsmBackend &TAB,
558 raw_ostream &OS, MCCodeEmitter *CE,
559 bool RelaxAll, bool NoExecStack);
561 /// createLoggingStreamer - Create a machine code streamer which just logs the
562 /// API calls and then dispatches to another streamer.
564 /// The new streamer takes ownership of the \arg Child.
565 MCStreamer *createLoggingStreamer(MCStreamer *Child, raw_ostream &OS);
567 /// createPureStreamer - Create a machine code streamer which will generate
568 /// "pure" MC object files, for use with MC-JIT and testing tools.
570 /// Takes ownership of \arg TAB and \arg CE.
571 MCStreamer *createPureStreamer(MCContext &Ctx, TargetAsmBackend &TAB,
572 raw_ostream &OS, MCCodeEmitter *CE);
574 } // end namespace llvm