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 void EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
54 bool isPCRel, unsigned AddrSpace);
56 std::vector<MCDwarfFrameInfo> FrameInfos;
57 MCDwarfFrameInfo *getCurrentFrameInfo();
58 void EnsureValidFrame();
60 /// SectionStack - This is stack of current and previous section
61 /// values saved by PushSection.
62 SmallVector<std::pair<const MCSection *,
63 const MCSection *>, 4> SectionStack;
66 MCStreamer(MCContext &Ctx);
69 virtual ~MCStreamer();
71 MCContext &getContext() const { return Context; }
73 unsigned getNumFrameInfos() {
74 return FrameInfos.size();
77 const MCDwarfFrameInfo &getFrameInfo(unsigned i) {
81 /// @name Assembly File Formatting.
84 /// isVerboseAsm - Return true if this streamer supports verbose assembly
85 /// and if it is enabled.
86 virtual bool isVerboseAsm() const { return false; }
88 /// hasRawTextSupport - Return true if this asm streamer supports emitting
89 /// unformatted text to the .s file with EmitRawText.
90 virtual bool hasRawTextSupport() const { return false; }
92 /// AddComment - Add a comment that can be emitted to the generated .s
93 /// file if applicable as a QoI issue to make the output of the compiler
94 /// more readable. This only affects the MCAsmStreamer, and only when
95 /// verbose assembly output is enabled.
97 /// If the comment includes embedded \n's, they will each get the comment
98 /// prefix as appropriate. The added comment should not end with a \n.
99 virtual void AddComment(const Twine &T) {}
101 /// GetCommentOS - Return a raw_ostream that comments can be written to.
102 /// Unlike AddComment, you are required to terminate comments with \n if you
104 virtual raw_ostream &GetCommentOS();
106 /// AddBlankLine - Emit a blank line to a .s file to pretty it up.
107 virtual void AddBlankLine() {}
111 /// @name Symbol & Section Management
114 /// getCurrentSection - Return the current section that the streamer is
115 /// emitting code to.
116 const MCSection *getCurrentSection() const {
117 if (!SectionStack.empty())
118 return SectionStack.back().first;
122 /// getPreviousSection - Return the previous section that the streamer is
123 /// emitting code to.
124 const MCSection *getPreviousSection() const {
125 if (!SectionStack.empty())
126 return SectionStack.back().second;
130 /// ChangeSection - Update streamer for a new active section.
132 /// This is called by PopSection and SwitchSection, if the current
134 virtual void ChangeSection(const MCSection *) = 0;
136 /// pushSection - Save the current and previous section on the
139 SectionStack.push_back(std::make_pair(getCurrentSection(),
140 getPreviousSection()));
143 /// popSection - Restore the current and previous section from
144 /// the section stack. Calls ChangeSection as needed.
146 /// Returns false if the stack was empty.
148 if (SectionStack.size() <= 1)
150 const MCSection *oldSection = SectionStack.pop_back_val().first;
151 const MCSection *curSection = SectionStack.back().first;
153 if (oldSection != curSection)
154 ChangeSection(curSection);
158 /// SwitchSection - Set the current section where code is being emitted to
159 /// @p Section. This is required to update CurSection.
161 /// This corresponds to assembler directives like .section, .text, etc.
162 void SwitchSection(const MCSection *Section) {
163 assert(Section && "Cannot switch to a null section!");
164 const MCSection *curSection = SectionStack.back().first;
165 SectionStack.back().second = curSection;
166 if (Section != curSection) {
167 SectionStack.back().first = Section;
168 ChangeSection(Section);
172 /// InitSections - Create the default sections and set the initial one.
173 virtual void InitSections() = 0;
175 /// EmitLabel - Emit a label for @p Symbol into the current section.
177 /// This corresponds to an assembler statement such as:
180 /// @param Symbol - The symbol to emit. A given symbol should only be
181 /// emitted as a label once, and symbols emitted as a label should never be
182 /// used in an assignment.
183 virtual void EmitLabel(MCSymbol *Symbol) = 0;
185 /// EmitAssemblerFlag - Note in the output the specified @p Flag
186 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) = 0;
188 /// EmitThumbFunc - Note in the output that the specified @p Func is
189 /// a Thumb mode function (ARM target only).
190 virtual void EmitThumbFunc(MCSymbol *Func) = 0;
192 /// EmitAssignment - Emit an assignment of @p Value to @p Symbol.
194 /// This corresponds to an assembler statement such as:
197 /// The assignment generates no code, but has the side effect of binding the
198 /// value in the current context. For the assembly streamer, this prints the
199 /// binding into the .s file.
201 /// @param Symbol - The symbol being assigned to.
202 /// @param Value - The value for the symbol.
203 virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) = 0;
205 /// EmitWeakReference - Emit an weak reference from @p Alias to @p Symbol.
207 /// This corresponds to an assembler statement such as:
208 /// .weakref alias, symbol
210 /// @param Alias - The alias that is being created.
211 /// @param Symbol - The symbol being aliased.
212 virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) = 0;
214 /// EmitSymbolAttribute - Add the given @p Attribute to @p Symbol.
215 virtual void EmitSymbolAttribute(MCSymbol *Symbol,
216 MCSymbolAttr Attribute) = 0;
218 /// EmitSymbolDesc - Set the @p DescValue for the @p Symbol.
220 /// @param Symbol - The symbol to have its n_desc field set.
221 /// @param DescValue - The value to set into the n_desc field.
222 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) = 0;
224 /// BeginCOFFSymbolDef - Start emitting COFF symbol definition
226 /// @param Symbol - The symbol to have its External & Type fields set.
227 virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) = 0;
229 /// EmitCOFFSymbolStorageClass - Emit the storage class of the symbol.
231 /// @param StorageClass - The storage class the symbol should have.
232 virtual void EmitCOFFSymbolStorageClass(int StorageClass) = 0;
234 /// EmitCOFFSymbolType - Emit the type of the symbol.
236 /// @param Type - A COFF type identifier (see COFF::SymbolType in X86COFF.h)
237 virtual void EmitCOFFSymbolType(int Type) = 0;
239 /// EndCOFFSymbolDef - Marks the end of the symbol definition.
240 virtual void EndCOFFSymbolDef() = 0;
242 /// EmitELFSize - Emit an ELF .size directive.
244 /// This corresponds to an assembler statement such as:
245 /// .size symbol, expression
247 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) = 0;
249 /// EmitCommonSymbol - Emit a common symbol.
251 /// @param Symbol - The common symbol to emit.
252 /// @param Size - The size of the common symbol.
253 /// @param ByteAlignment - The alignment of the symbol if
254 /// non-zero. This must be a power of 2.
255 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
256 unsigned ByteAlignment) = 0;
258 /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
260 /// @param Symbol - The common symbol to emit.
261 /// @param Size - The size of the common symbol.
262 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) = 0;
264 /// EmitZerofill - Emit the zerofill section and an optional symbol.
266 /// @param Section - The zerofill section to create and or to put the symbol
267 /// @param Symbol - The zerofill symbol to emit, if non-NULL.
268 /// @param Size - The size of the zerofill symbol.
269 /// @param ByteAlignment - The alignment of the zerofill symbol if
270 /// non-zero. This must be a power of 2 on some targets.
271 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
272 unsigned Size = 0,unsigned ByteAlignment = 0) = 0;
274 /// EmitTBSSSymbol - Emit a thread local bss (.tbss) symbol.
276 /// @param Section - The thread local common section.
277 /// @param Symbol - The thread local common symbol to emit.
278 /// @param Size - The size of the symbol.
279 /// @param ByteAlignment - The alignment of the thread local common symbol
280 /// if non-zero. This must be a power of 2 on some targets.
281 virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
282 uint64_t Size, unsigned ByteAlignment = 0) = 0;
284 /// @name Generating Data
287 /// EmitBytes - Emit the bytes in \arg Data into the output.
289 /// This is used to implement assembler directives such as .byte, .ascii,
291 virtual void EmitBytes(StringRef Data, unsigned AddrSpace) = 0;
293 /// EmitValue - Emit the expression @p Value into the output as a native
294 /// integer of the given @p Size bytes.
296 /// This is used to implement assembler directives such as .word, .quad,
299 /// @param Value - The value to emit.
300 /// @param Size - The size of the integer (in bytes) to emit. This must
301 /// match a native machine width.
302 virtual void EmitValueImpl(const MCExpr *Value, unsigned Size,
303 bool isPCRel, unsigned AddrSpace) = 0;
305 void EmitValue(const MCExpr *Value, unsigned Size, unsigned AddrSpace = 0);
307 void EmitPCRelValue(const MCExpr *Value, unsigned Size,
308 unsigned AddrSpace = 0);
310 /// EmitIntValue - Special case of EmitValue that avoids the client having
311 /// to pass in a MCExpr for constant integers.
312 virtual void EmitIntValue(uint64_t Value, unsigned Size,
313 unsigned AddrSpace = 0);
315 /// EmitAbsValue - Emit the Value, but try to avoid relocations. On MachO
316 /// this is done by producing
319 void EmitAbsValue(const MCExpr *Value, unsigned Size,
320 unsigned AddrSpace = 0);
322 virtual void EmitULEB128Value(const MCExpr *Value,
323 unsigned AddrSpace = 0) = 0;
325 virtual void EmitSLEB128Value(const MCExpr *Value,
326 unsigned AddrSpace = 0) = 0;
328 /// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
329 /// client having to pass in a MCExpr for constant integers.
330 void EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace = 0);
332 /// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
333 /// client having to pass in a MCExpr for constant integers.
334 void EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace = 0);
336 /// EmitSymbolValue - Special case of EmitValue that avoids the client
337 /// having to pass in a MCExpr for MCSymbols.
338 void EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
339 unsigned AddrSpace = 0);
341 void EmitPCRelSymbolValue(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);
427 virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
428 const MCSymbol *LastLabel,
429 const MCSymbol *Label) = 0;
431 virtual void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
432 const MCSymbol *Label) {
435 void EmitDwarfSetLineAddr(int64_t LineDelta, const MCSymbol *Label,
438 virtual bool EmitCFIStartProc();
439 virtual bool EmitCFIEndProc();
440 virtual bool EmitCFIDefCfa(int64_t Register, int64_t Offset);
441 virtual bool EmitCFIDefCfaOffset(int64_t Offset);
442 virtual bool EmitCFIDefCfaRegister(int64_t Register);
443 virtual bool EmitCFIOffset(int64_t Register, int64_t Offset);
444 virtual bool EmitCFIPersonality(const MCSymbol *Sym,
446 virtual bool EmitCFILsda(const MCSymbol *Sym, unsigned Encoding);
447 virtual bool EmitCFIRememberState();
448 virtual bool EmitCFIRestoreState();
450 /// EmitInstruction - Emit the given @p Instruction into the current
452 virtual void EmitInstruction(const MCInst &Inst) = 0;
454 /// EmitRawText - If this file is backed by a assembly streamer, this dumps
455 /// the specified string in the output .s file. This capability is
456 /// indicated by the hasRawTextSupport() predicate. By default this aborts.
457 virtual void EmitRawText(StringRef String);
458 void EmitRawText(const Twine &String);
460 /// ARM-related methods.
461 /// FIXME: Eventually we should have some "target MC streamer" and move
462 /// these methods there.
463 virtual void EmitFnStart();
464 virtual void EmitFnEnd();
465 virtual void EmitCantUnwind();
466 virtual void EmitPersonality(const MCSymbol *Personality);
467 virtual void EmitHandlerData();
468 virtual void EmitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0);
469 virtual void EmitPad(int64_t Offset);
470 virtual void EmitRegSave(const SmallVectorImpl<unsigned> &RegList,
473 /// Finish - Finish emission of machine code.
474 virtual void Finish() = 0;
477 /// createNullStreamer - Create a dummy machine code streamer, which does
478 /// nothing. This is useful for timing the assembler front end.
479 MCStreamer *createNullStreamer(MCContext &Ctx);
481 /// createAsmStreamer - Create a machine code streamer which will print out
482 /// assembly for the native target, suitable for compiling with a native
485 /// \param InstPrint - If given, the instruction printer to use. If not given
486 /// the MCInst representation will be printed. This method takes ownership of
489 /// \param CE - If given, a code emitter to use to show the instruction
490 /// encoding inline with the assembly. This method takes ownership of \arg CE.
492 /// \param TAB - If given, a target asm backend to use to show the fixup
493 /// information in conjunction with encoding information. This method takes
494 /// ownership of \arg TAB.
496 /// \param ShowInst - Whether to show the MCInst representation inline with
498 MCStreamer *createAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS,
501 MCInstPrinter *InstPrint = 0,
502 MCCodeEmitter *CE = 0,
503 TargetAsmBackend *TAB = 0,
504 bool ShowInst = false);
506 /// createMachOStreamer - Create a machine code streamer which will generate
507 /// Mach-O format object files.
509 /// Takes ownership of \arg TAB and \arg CE.
510 MCStreamer *createMachOStreamer(MCContext &Ctx, TargetAsmBackend &TAB,
511 raw_ostream &OS, MCCodeEmitter *CE,
512 bool RelaxAll = false);
514 /// createWinCOFFStreamer - Create a machine code streamer which will
515 /// generate Microsoft COFF format object files.
517 /// Takes ownership of \arg TAB and \arg CE.
518 MCStreamer *createWinCOFFStreamer(MCContext &Ctx,
519 TargetAsmBackend &TAB,
520 MCCodeEmitter &CE, raw_ostream &OS,
521 bool RelaxAll = false);
523 /// createELFStreamer - Create a machine code streamer which will generate
524 /// ELF format object files.
525 MCStreamer *createELFStreamer(MCContext &Ctx, TargetAsmBackend &TAB,
526 raw_ostream &OS, MCCodeEmitter *CE,
527 bool RelaxAll, bool NoExecStack);
529 /// createLoggingStreamer - Create a machine code streamer which just logs the
530 /// API calls and then dispatches to another streamer.
532 /// The new streamer takes ownership of the \arg Child.
533 MCStreamer *createLoggingStreamer(MCStreamer *Child, raw_ostream &OS);
535 /// createPureStreamer - Create a machine code streamer which will generate
536 /// "pure" MC object files, for use with MC-JIT and testing tools.
538 /// Takes ownership of \arg TAB and \arg CE.
539 MCStreamer *createPureStreamer(MCContext &Ctx, TargetAsmBackend &TAB,
540 raw_ostream &OS, MCCodeEmitter *CE);
542 } // end namespace llvm