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"
32 class TargetAsmBackend;
33 class TargetLoweringObjectFile;
36 class formatted_raw_ostream;
38 /// MCStreamer - Streaming machine code generation interface. This interface
39 /// is intended to provide a programatic interface that is very similar to the
40 /// level that an assembler .s file provides. It has callbacks to emit bytes,
41 /// handle directives, etc. The implementation of this interface retains
42 /// state to know what the current section is etc.
44 /// There are multiple implementations of this interface: one for writing out
45 /// a .s file, and implementations that write out .o files of various formats.
50 MCStreamer(const MCStreamer&); // DO NOT IMPLEMENT
51 MCStreamer &operator=(const MCStreamer&); // DO NOT IMPLEMENT
53 std::vector<MCDwarfFrameInfo> FrameInfos;
54 MCDwarfFrameInfo *getCurrentFrameInfo();
55 void EnsureValidFrame();
57 const MCSymbol* LastNonPrivate;
59 /// SectionStack - This is stack of current and previous section
60 /// values saved by PushSection.
61 SmallVector<std::pair<const MCSection *,
62 const MCSection *>, 4> SectionStack;
65 MCStreamer(MCContext &Ctx);
67 const MCExpr *BuildSymbolDiff(MCContext &Context, const MCSymbol *A,
70 const MCExpr *ForceExpAbs(MCStreamer *Streamer, MCContext &Context,
74 virtual ~MCStreamer();
76 MCContext &getContext() const { return Context; }
78 unsigned getNumFrameInfos() {
79 return FrameInfos.size();
82 const MCDwarfFrameInfo &getFrameInfo(unsigned i) {
86 /// @name Assembly File Formatting.
89 /// isVerboseAsm - Return true if this streamer supports verbose assembly
90 /// and if it is enabled.
91 virtual bool isVerboseAsm() const { return false; }
93 /// hasRawTextSupport - Return true if this asm streamer supports emitting
94 /// unformatted text to the .s file with EmitRawText.
95 virtual bool hasRawTextSupport() const { return false; }
97 /// AddComment - Add a comment that can be emitted to the generated .s
98 /// file if applicable as a QoI issue to make the output of the compiler
99 /// more readable. This only affects the MCAsmStreamer, and only when
100 /// verbose assembly output is enabled.
102 /// If the comment includes embedded \n's, they will each get the comment
103 /// prefix as appropriate. The added comment should not end with a \n.
104 virtual void AddComment(const Twine &T) {}
106 /// GetCommentOS - Return a raw_ostream that comments can be written to.
107 /// Unlike AddComment, you are required to terminate comments with \n if you
109 virtual raw_ostream &GetCommentOS();
111 /// AddBlankLine - Emit a blank line to a .s file to pretty it up.
112 virtual void AddBlankLine() {}
116 /// @name Symbol & Section Management
119 /// getCurrentSection - Return the current section that the streamer is
120 /// emitting code to.
121 const MCSection *getCurrentSection() const {
122 if (!SectionStack.empty())
123 return SectionStack.back().first;
127 /// getPreviousSection - Return the previous section that the streamer is
128 /// emitting code to.
129 const MCSection *getPreviousSection() const {
130 if (!SectionStack.empty())
131 return SectionStack.back().second;
135 /// ChangeSection - Update streamer for a new active section.
137 /// This is called by PopSection and SwitchSection, if the current
139 virtual void ChangeSection(const MCSection *) = 0;
141 /// pushSection - Save the current and previous section on the
144 SectionStack.push_back(std::make_pair(getCurrentSection(),
145 getPreviousSection()));
148 /// popSection - Restore the current and previous section from
149 /// the section stack. Calls ChangeSection as needed.
151 /// Returns false if the stack was empty.
153 if (SectionStack.size() <= 1)
155 const MCSection *oldSection = SectionStack.pop_back_val().first;
156 const MCSection *curSection = SectionStack.back().first;
158 if (oldSection != curSection)
159 ChangeSection(curSection);
163 /// SwitchSection - Set the current section where code is being emitted to
164 /// @p Section. This is required to update CurSection.
166 /// This corresponds to assembler directives like .section, .text, etc.
167 void SwitchSection(const MCSection *Section) {
168 assert(Section && "Cannot switch to a null section!");
169 const MCSection *curSection = SectionStack.back().first;
170 SectionStack.back().second = curSection;
171 if (Section != curSection) {
172 SectionStack.back().first = Section;
173 ChangeSection(Section);
177 /// InitSections - Create the default sections and set the initial one.
178 virtual void InitSections() = 0;
180 /// EmitLabel - Emit a label for @p Symbol into the current section.
182 /// This corresponds to an assembler statement such as:
185 /// @param Symbol - The symbol to emit. A given symbol should only be
186 /// emitted as a label once, and symbols emitted as a label should never be
187 /// used in an assignment.
188 virtual void EmitLabel(MCSymbol *Symbol);
190 virtual void EmitEHSymAttributes(const MCSymbol *Symbol,
193 /// EmitAssemblerFlag - Note in the output the specified @p Flag
194 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) = 0;
196 /// EmitThumbFunc - Note in the output that the specified @p Func is
197 /// a Thumb mode function (ARM target only).
198 virtual void EmitThumbFunc(MCSymbol *Func) = 0;
200 /// EmitAssignment - Emit an assignment of @p Value to @p Symbol.
202 /// This corresponds to an assembler statement such as:
205 /// The assignment generates no code, but has the side effect of binding the
206 /// value in the current context. For the assembly streamer, this prints the
207 /// binding into the .s file.
209 /// @param Symbol - The symbol being assigned to.
210 /// @param Value - The value for the symbol.
211 virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) = 0;
213 /// EmitWeakReference - Emit an weak reference from @p Alias to @p Symbol.
215 /// This corresponds to an assembler statement such as:
216 /// .weakref alias, symbol
218 /// @param Alias - The alias that is being created.
219 /// @param Symbol - The symbol being aliased.
220 virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) = 0;
222 /// EmitSymbolAttribute - Add the given @p Attribute to @p Symbol.
223 virtual void EmitSymbolAttribute(MCSymbol *Symbol,
224 MCSymbolAttr Attribute) = 0;
226 /// EmitSymbolDesc - Set the @p DescValue for the @p Symbol.
228 /// @param Symbol - The symbol to have its n_desc field set.
229 /// @param DescValue - The value to set into the n_desc field.
230 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) = 0;
232 /// BeginCOFFSymbolDef - Start emitting COFF symbol definition
234 /// @param Symbol - The symbol to have its External & Type fields set.
235 virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) = 0;
237 /// EmitCOFFSymbolStorageClass - Emit the storage class of the symbol.
239 /// @param StorageClass - The storage class the symbol should have.
240 virtual void EmitCOFFSymbolStorageClass(int StorageClass) = 0;
242 /// EmitCOFFSymbolType - Emit the type of the symbol.
244 /// @param Type - A COFF type identifier (see COFF::SymbolType in X86COFF.h)
245 virtual void EmitCOFFSymbolType(int Type) = 0;
247 /// EndCOFFSymbolDef - Marks the end of the symbol definition.
248 virtual void EndCOFFSymbolDef() = 0;
250 /// EmitELFSize - Emit an ELF .size directive.
252 /// This corresponds to an assembler statement such as:
253 /// .size symbol, expression
255 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) = 0;
257 /// EmitCommonSymbol - Emit a common symbol.
259 /// @param Symbol - The common symbol to emit.
260 /// @param Size - The size of the common symbol.
261 /// @param ByteAlignment - The alignment of the symbol if
262 /// non-zero. This must be a power of 2.
263 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
264 unsigned ByteAlignment) = 0;
266 /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
268 /// @param Symbol - The common symbol to emit.
269 /// @param Size - The size of the common symbol.
270 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) = 0;
272 /// EmitZerofill - Emit the zerofill section and an optional symbol.
274 /// @param Section - The zerofill section to create and or to put the symbol
275 /// @param Symbol - The zerofill symbol to emit, if non-NULL.
276 /// @param Size - The size of the zerofill symbol.
277 /// @param ByteAlignment - The alignment of the zerofill symbol if
278 /// non-zero. This must be a power of 2 on some targets.
279 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
280 unsigned Size = 0,unsigned ByteAlignment = 0) = 0;
282 /// EmitTBSSSymbol - Emit a thread local bss (.tbss) symbol.
284 /// @param Section - The thread local common section.
285 /// @param Symbol - The thread local common symbol to emit.
286 /// @param Size - The size of the symbol.
287 /// @param ByteAlignment - The alignment of the thread local common symbol
288 /// if non-zero. This must be a power of 2 on some targets.
289 virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
290 uint64_t Size, unsigned ByteAlignment = 0) = 0;
292 /// @name Generating Data
295 /// EmitBytes - Emit the bytes in \arg Data into the output.
297 /// This is used to implement assembler directives such as .byte, .ascii,
299 virtual void EmitBytes(StringRef Data, unsigned AddrSpace) = 0;
301 /// EmitValue - Emit the expression @p Value into the output as a native
302 /// integer of the given @p Size bytes.
304 /// This is used to implement assembler directives such as .word, .quad,
307 /// @param Value - The value to emit.
308 /// @param Size - The size of the integer (in bytes) to emit. This must
309 /// match a native machine width.
310 virtual void EmitValueImpl(const MCExpr *Value, unsigned Size,
311 unsigned AddrSpace) = 0;
313 void EmitValue(const MCExpr *Value, unsigned Size, unsigned AddrSpace = 0);
315 /// EmitIntValue - Special case of EmitValue that avoids the client having
316 /// to pass in a MCExpr for constant integers.
317 virtual void EmitIntValue(uint64_t Value, unsigned Size,
318 unsigned AddrSpace = 0);
320 /// EmitAbsValue - Emit the Value, but try to avoid relocations. On MachO
321 /// this is done by producing
324 void EmitAbsValue(const MCExpr *Value, unsigned Size,
325 unsigned AddrSpace = 0);
327 virtual void EmitULEB128Value(const MCExpr *Value) = 0;
329 virtual void EmitSLEB128Value(const MCExpr *Value) = 0;
331 /// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
332 /// client having to pass in a MCExpr for constant integers.
333 void EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace = 0);
335 /// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
336 /// client having to pass in a MCExpr for constant integers.
337 void EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace = 0);
339 /// EmitSymbolValue - Special case of EmitValue that avoids the client
340 /// having to pass in a MCExpr for MCSymbols.
341 void EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
342 unsigned AddrSpace = 0);
344 /// EmitGPRel32Value - Emit the expression @p Value into the output as a
345 /// gprel32 (32-bit GP relative) value.
347 /// This is used to implement assembler directives such as .gprel32 on
348 /// targets that support them.
349 virtual void EmitGPRel32Value(const MCExpr *Value);
351 /// EmitFill - Emit NumBytes bytes worth of the value specified by
352 /// FillValue. This implements directives such as '.space'.
353 virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue,
356 /// EmitZeros - Emit NumBytes worth of zeros. This is a convenience
357 /// function that just wraps EmitFill.
358 void EmitZeros(uint64_t NumBytes, unsigned AddrSpace) {
359 EmitFill(NumBytes, 0, AddrSpace);
363 /// EmitValueToAlignment - Emit some number of copies of @p Value until
364 /// the byte alignment @p ByteAlignment is reached.
366 /// If the number of bytes need to emit for the alignment is not a multiple
367 /// of @p ValueSize, then the contents of the emitted fill bytes is
370 /// This used to implement the .align assembler directive.
372 /// @param ByteAlignment - The alignment to reach. This must be a power of
373 /// two on some targets.
374 /// @param Value - The value to use when filling bytes.
375 /// @param ValueSize - The size of the integer (in bytes) to emit for
376 /// @p Value. This must match a native machine width.
377 /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If
378 /// the alignment cannot be reached in this many bytes, no bytes are
380 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
381 unsigned ValueSize = 1,
382 unsigned MaxBytesToEmit = 0) = 0;
384 /// EmitCodeAlignment - Emit nops until the byte alignment @p ByteAlignment
387 /// This used to align code where the alignment bytes may be executed. This
388 /// can emit different bytes for different sizes to optimize execution.
390 /// @param ByteAlignment - The alignment to reach. This must be a power of
391 /// two on some targets.
392 /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If
393 /// the alignment cannot be reached in this many bytes, no bytes are
395 virtual void EmitCodeAlignment(unsigned ByteAlignment,
396 unsigned MaxBytesToEmit = 0) = 0;
398 /// EmitValueToOffset - Emit some number of copies of @p Value until the
399 /// byte offset @p Offset is reached.
401 /// This is used to implement assembler directives such as .org.
403 /// @param Offset - The offset to reach. This may be an expression, but the
404 /// expression must be associated with the current section.
405 /// @param Value - The value to use when filling bytes.
406 virtual void EmitValueToOffset(const MCExpr *Offset,
407 unsigned char Value = 0) = 0;
411 /// EmitFileDirective - Switch to a new logical file. This is used to
412 /// implement the '.file "foo.c"' assembler directive.
413 virtual void EmitFileDirective(StringRef Filename) = 0;
415 /// EmitDwarfFileDirective - Associate a filename with a specified logical
416 /// file number. This implements the DWARF2 '.file 4 "foo.c"' assembler
418 virtual bool EmitDwarfFileDirective(unsigned FileNo,StringRef Filename);
420 /// EmitDwarfLocDirective - This implements the DWARF2
421 // '.loc fileno lineno ...' assembler directive.
422 virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
423 unsigned Column, unsigned Flags,
425 unsigned Discriminator,
428 virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
429 const MCSymbol *LastLabel,
430 const MCSymbol *Label) = 0;
432 virtual void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
433 const MCSymbol *Label) {
436 void EmitDwarfSetLineAddr(int64_t LineDelta, const MCSymbol *Label,
439 virtual void EmitCFIStartProc();
440 virtual void EmitCFIEndProc();
441 virtual void EmitCFIDefCfa(int64_t Register, int64_t Offset);
442 virtual void EmitCFIDefCfaOffset(int64_t Offset);
443 virtual void EmitCFIDefCfaRegister(int64_t Register);
444 virtual void EmitCFIOffset(int64_t Register, int64_t Offset);
445 virtual void EmitCFIPersonality(const MCSymbol *Sym, unsigned Encoding);
446 virtual void EmitCFILsda(const MCSymbol *Sym, unsigned Encoding);
447 virtual void EmitCFIRememberState();
448 virtual void EmitCFIRestoreState();
449 virtual void EmitCFISameValue(int64_t Register);
450 virtual void EmitCFIRelOffset(int64_t Register, int64_t Offset);
451 virtual void EmitCFIAdjustCfaOffset(int64_t Adjustment);
453 /// EmitInstruction - Emit the given @p Instruction into the current
455 virtual void EmitInstruction(const MCInst &Inst) = 0;
457 /// EmitRawText - If this file is backed by a assembly streamer, this dumps
458 /// the specified string in the output .s file. This capability is
459 /// indicated by the hasRawTextSupport() predicate. By default this aborts.
460 virtual void EmitRawText(StringRef String);
461 void EmitRawText(const Twine &String);
463 /// ARM-related methods.
464 /// FIXME: Eventually we should have some "target MC streamer" and move
465 /// these methods there.
466 virtual void EmitFnStart();
467 virtual void EmitFnEnd();
468 virtual void EmitCantUnwind();
469 virtual void EmitPersonality(const MCSymbol *Personality);
470 virtual void EmitHandlerData();
471 virtual void EmitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0);
472 virtual void EmitPad(int64_t Offset);
473 virtual void EmitRegSave(const SmallVectorImpl<unsigned> &RegList,
476 /// Finish - Finish emission of machine code.
477 virtual void Finish() = 0;
480 /// createNullStreamer - Create a dummy machine code streamer, which does
481 /// nothing. This is useful for timing the assembler front end.
482 MCStreamer *createNullStreamer(MCContext &Ctx);
484 /// createAsmStreamer - Create a machine code streamer which will print out
485 /// assembly for the native target, suitable for compiling with a native
488 /// \param InstPrint - If given, the instruction printer to use. If not given
489 /// the MCInst representation will be printed. This method takes ownership of
492 /// \param CE - If given, a code emitter to use to show the instruction
493 /// encoding inline with the assembly. This method takes ownership of \arg CE.
495 /// \param TAB - If given, a target asm backend to use to show the fixup
496 /// information in conjunction with encoding information. This method takes
497 /// ownership of \arg TAB.
499 /// \param ShowInst - Whether to show the MCInst representation inline with
501 MCStreamer *createAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS,
505 MCInstPrinter *InstPrint = 0,
506 MCCodeEmitter *CE = 0,
507 TargetAsmBackend *TAB = 0,
508 bool ShowInst = false);
510 /// createMachOStreamer - Create a machine code streamer which will generate
511 /// Mach-O format object files.
513 /// Takes ownership of \arg TAB and \arg CE.
514 MCStreamer *createMachOStreamer(MCContext &Ctx, TargetAsmBackend &TAB,
515 raw_ostream &OS, MCCodeEmitter *CE,
516 bool RelaxAll = false);
518 /// createWinCOFFStreamer - Create a machine code streamer which will
519 /// generate Microsoft COFF format object files.
521 /// Takes ownership of \arg TAB and \arg CE.
522 MCStreamer *createWinCOFFStreamer(MCContext &Ctx,
523 TargetAsmBackend &TAB,
524 MCCodeEmitter &CE, raw_ostream &OS,
525 bool RelaxAll = false);
527 /// createELFStreamer - Create a machine code streamer which will generate
528 /// ELF format object files.
529 MCStreamer *createELFStreamer(MCContext &Ctx, TargetAsmBackend &TAB,
530 raw_ostream &OS, MCCodeEmitter *CE,
531 bool RelaxAll, bool NoExecStack);
533 /// createLoggingStreamer - Create a machine code streamer which just logs the
534 /// API calls and then dispatches to another streamer.
536 /// The new streamer takes ownership of the \arg Child.
537 MCStreamer *createLoggingStreamer(MCStreamer *Child, raw_ostream &OS);
539 /// createPureStreamer - Create a machine code streamer which will generate
540 /// "pure" MC object files, for use with MC-JIT and testing tools.
542 /// Takes ownership of \arg TAB and \arg CE.
543 MCStreamer *createPureStreamer(MCContext &Ctx, TargetAsmBackend &TAB,
544 raw_ostream &OS, MCCodeEmitter *CE);
546 } // end namespace llvm