MCStreamer.h revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f
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/MCLinkerOptimizationHint.h" 23#include "llvm/MC/MCWin64EH.h" 24#include "llvm/Support/DataTypes.h" 25#include <string> 26 27namespace llvm { 28class MCAsmBackend; 29class MCCodeEmitter; 30class MCContext; 31class MCExpr; 32class MCInst; 33class MCInstPrinter; 34class MCSection; 35class MCStreamer; 36class MCSymbol; 37class MCSymbolRefExpr; 38class MCSubtargetInfo; 39class StringRef; 40class Twine; 41class raw_ostream; 42class formatted_raw_ostream; 43class AssemblerConstantPools; 44 45typedef std::pair<const MCSection *, const MCExpr *> MCSectionSubPair; 46 47/// Target specific streamer interface. This is used so that targets can 48/// implement support for target specific assembly directives. 49/// 50/// If target foo wants to use this, it should implement 3 classes: 51/// * FooTargetStreamer : public MCTargetStreamer 52/// * FooTargetAsmSreamer : public FooTargetStreamer 53/// * FooTargetELFStreamer : public FooTargetStreamer 54/// 55/// FooTargetStreamer should have a pure virtual method for each directive. For 56/// example, for a ".bar symbol_name" directive, it should have 57/// virtual emitBar(const MCSymbol &Symbol) = 0; 58/// 59/// The FooTargetAsmSreamer and FooTargetELFStreamer classes implement the 60/// method. The assembly streamer just prints ".bar symbol_name". The object 61/// streamer does whatever is needed to implement .bar in the object file. 62/// 63/// In the assembly printer and parser the target streamer can be used by 64/// calling getTargetStreamer and casting it to FooTargetStreamer: 65/// 66/// MCTargetStreamer &TS = OutStreamer.getTargetStreamer(); 67/// FooTargetStreamer &ATS = static_cast<FooTargetStreamer &>(TS); 68/// 69/// The base classes FooTargetAsmSreamer and FooTargetELFStreamer should *never* 70/// be treated differently. Callers should always talk to a FooTargetStreamer. 71class MCTargetStreamer { 72protected: 73 MCStreamer &Streamer; 74 75public: 76 MCTargetStreamer(MCStreamer &S); 77 virtual ~MCTargetStreamer(); 78 79 const MCStreamer &getStreamer() { return Streamer; } 80 81 // Allow a target to add behavior to the EmitLabel of MCStreamer. 82 virtual void emitLabel(MCSymbol *Symbol); 83 // Allow a target to add behavior to the emitAssignment of MCStreamer. 84 virtual void emitAssignment(MCSymbol *Symbol, const MCExpr *Value); 85 86 virtual void finish(); 87}; 88 89// FIXME: declared here because it is used from 90// lib/CodeGen/AsmPrinter/ARMException.cpp. 91class ARMTargetStreamer : public MCTargetStreamer { 92public: 93 ARMTargetStreamer(MCStreamer &S); 94 ~ARMTargetStreamer(); 95 96 virtual void emitFnStart(); 97 virtual void emitFnEnd(); 98 virtual void emitCantUnwind(); 99 virtual void emitPersonality(const MCSymbol *Personality); 100 virtual void emitPersonalityIndex(unsigned Index); 101 virtual void emitHandlerData(); 102 virtual void emitSetFP(unsigned FpReg, unsigned SpReg, 103 int64_t Offset = 0); 104 virtual void emitMovSP(unsigned Reg, int64_t Offset = 0); 105 virtual void emitPad(int64_t Offset); 106 virtual void emitRegSave(const SmallVectorImpl<unsigned> &RegList, 107 bool isVector); 108 virtual void emitUnwindRaw(int64_t StackOffset, 109 const SmallVectorImpl<uint8_t> &Opcodes); 110 111 virtual void switchVendor(StringRef Vendor); 112 virtual void emitAttribute(unsigned Attribute, unsigned Value); 113 virtual void emitTextAttribute(unsigned Attribute, StringRef String); 114 virtual void emitIntTextAttribute(unsigned Attribute, unsigned IntValue, 115 StringRef StringValue = ""); 116 virtual void emitFPU(unsigned FPU); 117 virtual void emitArch(unsigned Arch); 118 virtual void emitObjectArch(unsigned Arch); 119 virtual void finishAttributeSection(); 120 virtual void emitInst(uint32_t Inst, char Suffix = '\0'); 121 122 virtual void AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *SRE); 123 124 virtual void emitThumbSet(MCSymbol *Symbol, const MCExpr *Value); 125 126 void finish() override; 127 128 /// Callback used to implement the ldr= pseudo. 129 /// Add a new entry to the constant pool for the current section and return an 130 /// MCExpr that can be used to refer to the constant pool location. 131 const MCExpr *addConstantPoolEntry(const MCExpr *); 132 133 /// Callback used to implemnt the .ltorg directive. 134 /// Emit contents of constant pool for the current section. 135 void emitCurrentConstantPool(); 136 137private: 138 std::unique_ptr<AssemblerConstantPools> ConstantPools; 139}; 140 141/// MCStreamer - Streaming machine code generation interface. This interface 142/// is intended to provide a programatic interface that is very similar to the 143/// level that an assembler .s file provides. It has callbacks to emit bytes, 144/// handle directives, etc. The implementation of this interface retains 145/// state to know what the current section is etc. 146/// 147/// There are multiple implementations of this interface: one for writing out 148/// a .s file, and implementations that write out .o files of various formats. 149/// 150class MCStreamer { 151 MCContext &Context; 152 std::unique_ptr<MCTargetStreamer> TargetStreamer; 153 154 MCStreamer(const MCStreamer &) LLVM_DELETED_FUNCTION; 155 MCStreamer &operator=(const MCStreamer &) LLVM_DELETED_FUNCTION; 156 157 std::vector<MCDwarfFrameInfo> FrameInfos; 158 MCDwarfFrameInfo *getCurrentFrameInfo(); 159 MCSymbol *EmitCFICommon(); 160 void EnsureValidFrame(); 161 162 std::vector<MCWin64EHUnwindInfo *> W64UnwindInfos; 163 MCWin64EHUnwindInfo *CurrentW64UnwindInfo; 164 void setCurrentW64UnwindInfo(MCWin64EHUnwindInfo *Frame); 165 void EnsureValidW64UnwindInfo(); 166 167 MCSymbol *LastSymbol; 168 169 // SymbolOrdering - Tracks an index to represent the order 170 // a symbol was emitted in. Zero means we did not emit that symbol. 171 DenseMap<const MCSymbol *, unsigned> SymbolOrdering; 172 173 /// SectionStack - This is stack of current and previous section 174 /// values saved by PushSection. 175 SmallVector<std::pair<MCSectionSubPair, MCSectionSubPair>, 4> SectionStack; 176 177protected: 178 MCStreamer(MCContext &Ctx); 179 180 const MCExpr *BuildSymbolDiff(MCContext &Context, const MCSymbol *A, 181 const MCSymbol *B); 182 183 const MCExpr *ForceExpAbs(const MCExpr *Expr); 184 185 void RecordProcStart(MCDwarfFrameInfo &Frame); 186 virtual void EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame); 187 void RecordProcEnd(MCDwarfFrameInfo &Frame); 188 virtual void EmitCFIEndProcImpl(MCDwarfFrameInfo &CurFrame); 189 190 MCWin64EHUnwindInfo *getCurrentW64UnwindInfo() { 191 return CurrentW64UnwindInfo; 192 } 193 void EmitW64Tables(); 194 195 virtual void EmitRawTextImpl(StringRef String); 196 197public: 198 virtual ~MCStreamer(); 199 200 void setTargetStreamer(MCTargetStreamer *TS) { 201 TargetStreamer.reset(TS); 202 } 203 204 /// State management 205 /// 206 virtual void reset(); 207 208 MCContext &getContext() const { return Context; } 209 210 MCTargetStreamer *getTargetStreamer() { 211 return TargetStreamer.get(); 212 } 213 214 unsigned getNumFrameInfos() { return FrameInfos.size(); } 215 216 const MCDwarfFrameInfo &getFrameInfo(unsigned i) { return FrameInfos[i]; } 217 218 ArrayRef<MCDwarfFrameInfo> getFrameInfos() const { return FrameInfos; } 219 220 unsigned getNumW64UnwindInfos() { return W64UnwindInfos.size(); } 221 222 MCWin64EHUnwindInfo &getW64UnwindInfo(unsigned i) { 223 return *W64UnwindInfos[i]; 224 } 225 226 void generateCompactUnwindEncodings(MCAsmBackend *MAB); 227 228 /// @name Assembly File Formatting. 229 /// @{ 230 231 /// isVerboseAsm - Return true if this streamer supports verbose assembly 232 /// and if it is enabled. 233 virtual bool isVerboseAsm() const { return false; } 234 235 /// hasRawTextSupport - Return true if this asm streamer supports emitting 236 /// unformatted text to the .s file with EmitRawText. 237 virtual bool hasRawTextSupport() const { return false; } 238 239 /// Is the integrated assembler required for this streamer to function 240 /// correctly? 241 virtual bool isIntegratedAssemblerRequired() const { return false; } 242 243 /// AddComment - Add a comment that can be emitted to the generated .s 244 /// file if applicable as a QoI issue to make the output of the compiler 245 /// more readable. This only affects the MCAsmStreamer, and only when 246 /// verbose assembly output is enabled. 247 /// 248 /// If the comment includes embedded \n's, they will each get the comment 249 /// prefix as appropriate. The added comment should not end with a \n. 250 virtual void AddComment(const Twine &T) {} 251 252 /// GetCommentOS - Return a raw_ostream that comments can be written to. 253 /// Unlike AddComment, you are required to terminate comments with \n if you 254 /// use this method. 255 virtual raw_ostream &GetCommentOS(); 256 257 /// Print T and prefix it with the comment string (normally #) and optionally 258 /// a tab. This prints the comment immediately, not at the end of the 259 /// current line. It is basically a safe version of EmitRawText: since it 260 /// only prints comments, the object streamer ignores it instead of asserting. 261 virtual void emitRawComment(const Twine &T, bool TabPrefix = true); 262 263 /// AddBlankLine - Emit a blank line to a .s file to pretty it up. 264 virtual void AddBlankLine() {} 265 266 /// @} 267 268 /// @name Symbol & Section Management 269 /// @{ 270 271 /// getCurrentSection - Return the current section that the streamer is 272 /// emitting code to. 273 MCSectionSubPair getCurrentSection() const { 274 if (!SectionStack.empty()) 275 return SectionStack.back().first; 276 return MCSectionSubPair(); 277 } 278 279 /// getPreviousSection - Return the previous section that the streamer is 280 /// emitting code to. 281 MCSectionSubPair getPreviousSection() const { 282 if (!SectionStack.empty()) 283 return SectionStack.back().second; 284 return MCSectionSubPair(); 285 } 286 287 /// GetSymbolOrder - Returns an index to represent the order 288 /// a symbol was emitted in. (zero if we did not emit that symbol) 289 unsigned GetSymbolOrder(const MCSymbol *Sym) const { 290 return SymbolOrdering.lookup(Sym); 291 } 292 293 /// ChangeSection - Update streamer for a new active section. 294 /// 295 /// This is called by PopSection and SwitchSection, if the current 296 /// section changes. 297 virtual void ChangeSection(const MCSection *, const MCExpr *) = 0; 298 299 /// pushSection - Save the current and previous section on the 300 /// section stack. 301 void PushSection() { 302 SectionStack.push_back( 303 std::make_pair(getCurrentSection(), getPreviousSection())); 304 } 305 306 /// popSection - Restore the current and previous section from 307 /// the section stack. Calls ChangeSection as needed. 308 /// 309 /// Returns false if the stack was empty. 310 bool PopSection() { 311 if (SectionStack.size() <= 1) 312 return false; 313 MCSectionSubPair oldSection = SectionStack.pop_back_val().first; 314 MCSectionSubPair curSection = SectionStack.back().first; 315 316 if (oldSection != curSection) 317 ChangeSection(curSection.first, curSection.second); 318 return true; 319 } 320 321 bool SubSection(const MCExpr *Subsection) { 322 if (SectionStack.empty()) 323 return false; 324 325 SwitchSection(SectionStack.back().first.first, Subsection); 326 return true; 327 } 328 329 /// SwitchSection - Set the current section where code is being emitted to 330 /// @p Section. This is required to update CurSection. 331 /// 332 /// This corresponds to assembler directives like .section, .text, etc. 333 void SwitchSection(const MCSection *Section, 334 const MCExpr *Subsection = nullptr) { 335 assert(Section && "Cannot switch to a null section!"); 336 MCSectionSubPair curSection = SectionStack.back().first; 337 SectionStack.back().second = curSection; 338 if (MCSectionSubPair(Section, Subsection) != curSection) { 339 SectionStack.back().first = MCSectionSubPair(Section, Subsection); 340 ChangeSection(Section, Subsection); 341 } 342 } 343 344 /// SwitchSectionNoChange - Set the current section where code is being 345 /// emitted to @p Section. This is required to update CurSection. This 346 /// version does not call ChangeSection. 347 void SwitchSectionNoChange(const MCSection *Section, 348 const MCExpr *Subsection = nullptr) { 349 assert(Section && "Cannot switch to a null section!"); 350 MCSectionSubPair curSection = SectionStack.back().first; 351 SectionStack.back().second = curSection; 352 if (MCSectionSubPair(Section, Subsection) != curSection) 353 SectionStack.back().first = MCSectionSubPair(Section, Subsection); 354 } 355 356 /// Create the default sections and set the initial one. 357 virtual void InitSections(); 358 359 /// AssignSection - Sets the symbol's section. 360 /// 361 /// Each emitted symbol will be tracked in the ordering table, 362 /// so we can sort on them later. 363 void AssignSection(MCSymbol *Symbol, const MCSection *Section); 364 365 /// EmitLabel - Emit a label for @p Symbol into the current section. 366 /// 367 /// This corresponds to an assembler statement such as: 368 /// foo: 369 /// 370 /// @param Symbol - The symbol to emit. A given symbol should only be 371 /// emitted as a label once, and symbols emitted as a label should never be 372 /// used in an assignment. 373 // FIXME: These emission are non-const because we mutate the symbol to 374 // add the section we're emitting it to later. 375 virtual void EmitLabel(MCSymbol *Symbol); 376 377 virtual void EmitDebugLabel(MCSymbol *Symbol); 378 379 virtual void EmitEHSymAttributes(const MCSymbol *Symbol, MCSymbol *EHSymbol); 380 381 /// EmitAssemblerFlag - Note in the output the specified @p Flag. 382 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) = 0; 383 384 /// EmitLinkerOptions - Emit the given list @p Options of strings as linker 385 /// options into the output. 386 virtual void EmitLinkerOptions(ArrayRef<std::string> Kind) {} 387 388 /// EmitDataRegion - Note in the output the specified region @p Kind. 389 virtual void EmitDataRegion(MCDataRegionType Kind) {} 390 391 /// EmitVersionMin - Specify the MachO minimum deployment target version. 392 virtual void EmitVersionMin(MCVersionMinType, unsigned Major, unsigned Minor, 393 unsigned Update) {} 394 395 /// EmitThumbFunc - Note in the output that the specified @p Func is 396 /// a Thumb mode function (ARM target only). 397 virtual void EmitThumbFunc(MCSymbol *Func) = 0; 398 399 /// EmitAssignment - Emit an assignment of @p Value to @p Symbol. 400 /// 401 /// This corresponds to an assembler statement such as: 402 /// symbol = value 403 /// 404 /// The assignment generates no code, but has the side effect of binding the 405 /// value in the current context. For the assembly streamer, this prints the 406 /// binding into the .s file. 407 /// 408 /// @param Symbol - The symbol being assigned to. 409 /// @param Value - The value for the symbol. 410 virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value); 411 412 /// EmitWeakReference - Emit an weak reference from @p Alias to @p Symbol. 413 /// 414 /// This corresponds to an assembler statement such as: 415 /// .weakref alias, symbol 416 /// 417 /// @param Alias - The alias that is being created. 418 /// @param Symbol - The symbol being aliased. 419 virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) = 0; 420 421 /// EmitSymbolAttribute - Add the given @p Attribute to @p Symbol. 422 virtual bool EmitSymbolAttribute(MCSymbol *Symbol, 423 MCSymbolAttr Attribute) = 0; 424 425 /// EmitSymbolDesc - Set the @p DescValue for the @p Symbol. 426 /// 427 /// @param Symbol - The symbol to have its n_desc field set. 428 /// @param DescValue - The value to set into the n_desc field. 429 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) = 0; 430 431 /// BeginCOFFSymbolDef - Start emitting COFF symbol definition 432 /// 433 /// @param Symbol - The symbol to have its External & Type fields set. 434 virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) = 0; 435 436 /// EmitCOFFSymbolStorageClass - Emit the storage class of the symbol. 437 /// 438 /// @param StorageClass - The storage class the symbol should have. 439 virtual void EmitCOFFSymbolStorageClass(int StorageClass) = 0; 440 441 /// EmitCOFFSymbolType - Emit the type of the symbol. 442 /// 443 /// @param Type - A COFF type identifier (see COFF::SymbolType in X86COFF.h) 444 virtual void EmitCOFFSymbolType(int Type) = 0; 445 446 /// EndCOFFSymbolDef - Marks the end of the symbol definition. 447 virtual void EndCOFFSymbolDef() = 0; 448 449 /// EmitCOFFSectionIndex - Emits a COFF section index. 450 /// 451 /// @param Symbol - Symbol the section number relocation should point to. 452 virtual void EmitCOFFSectionIndex(MCSymbol const *Symbol); 453 454 /// EmitCOFFSecRel32 - Emits a COFF section relative relocation. 455 /// 456 /// @param Symbol - Symbol the section relative relocation should point to. 457 virtual void EmitCOFFSecRel32(MCSymbol const *Symbol); 458 459 /// EmitELFSize - Emit an ELF .size directive. 460 /// 461 /// This corresponds to an assembler statement such as: 462 /// .size symbol, expression 463 /// 464 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) = 0; 465 466 /// \brief Emit a Linker Optimization Hint (LOH) directive. 467 /// \param Args - Arguments of the LOH. 468 virtual void EmitLOHDirective(MCLOHType Kind, const MCLOHArgs &Args) {} 469 470 /// EmitCommonSymbol - Emit a common symbol. 471 /// 472 /// @param Symbol - The common symbol to emit. 473 /// @param Size - The size of the common symbol. 474 /// @param ByteAlignment - The alignment of the symbol if 475 /// non-zero. This must be a power of 2. 476 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size, 477 unsigned ByteAlignment) = 0; 478 479 /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol. 480 /// 481 /// @param Symbol - The common symbol to emit. 482 /// @param Size - The size of the common symbol. 483 /// @param ByteAlignment - The alignment of the common symbol in bytes. 484 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size, 485 unsigned ByteAlignment) = 0; 486 487 /// EmitZerofill - Emit the zerofill section and an optional symbol. 488 /// 489 /// @param Section - The zerofill section to create and or to put the symbol 490 /// @param Symbol - The zerofill symbol to emit, if non-NULL. 491 /// @param Size - The size of the zerofill symbol. 492 /// @param ByteAlignment - The alignment of the zerofill symbol if 493 /// non-zero. This must be a power of 2 on some targets. 494 virtual void EmitZerofill(const MCSection *Section, 495 MCSymbol *Symbol = nullptr, uint64_t Size = 0, 496 unsigned ByteAlignment = 0) = 0; 497 498 /// EmitTBSSSymbol - Emit a thread local bss (.tbss) symbol. 499 /// 500 /// @param Section - The thread local common section. 501 /// @param Symbol - The thread local common symbol to emit. 502 /// @param Size - The size of the symbol. 503 /// @param ByteAlignment - The alignment of the thread local common symbol 504 /// if non-zero. This must be a power of 2 on some targets. 505 virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol, 506 uint64_t Size, unsigned ByteAlignment = 0) = 0; 507 508 /// @} 509 /// @name Generating Data 510 /// @{ 511 512 /// EmitBytes - Emit the bytes in \p Data into the output. 513 /// 514 /// This is used to implement assembler directives such as .byte, .ascii, 515 /// etc. 516 virtual void EmitBytes(StringRef Data) = 0; 517 518 /// EmitValue - Emit the expression @p Value into the output as a native 519 /// integer of the given @p Size bytes. 520 /// 521 /// This is used to implement assembler directives such as .word, .quad, 522 /// etc. 523 /// 524 /// @param Value - The value to emit. 525 /// @param Size - The size of the integer (in bytes) to emit. This must 526 /// match a native machine width. 527 /// @param Loc - The location of the expression for error reporting. 528 virtual void EmitValueImpl(const MCExpr *Value, unsigned Size, 529 const SMLoc &Loc = SMLoc()) = 0; 530 531 void EmitValue(const MCExpr *Value, unsigned Size, 532 const SMLoc &Loc = SMLoc()); 533 534 /// EmitIntValue - Special case of EmitValue that avoids the client having 535 /// to pass in a MCExpr for constant integers. 536 virtual void EmitIntValue(uint64_t Value, unsigned Size); 537 538 /// EmitAbsValue - Emit the Value, but try to avoid relocations. On MachO 539 /// this is done by producing 540 /// foo = value 541 /// .long foo 542 void EmitAbsValue(const MCExpr *Value, unsigned Size); 543 544 virtual void EmitULEB128Value(const MCExpr *Value) = 0; 545 546 virtual void EmitSLEB128Value(const MCExpr *Value) = 0; 547 548 /// EmitULEB128Value - Special case of EmitULEB128Value that avoids the 549 /// client having to pass in a MCExpr for constant integers. 550 void EmitULEB128IntValue(uint64_t Value, unsigned Padding = 0); 551 552 /// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the 553 /// client having to pass in a MCExpr for constant integers. 554 void EmitSLEB128IntValue(int64_t Value); 555 556 /// EmitSymbolValue - Special case of EmitValue that avoids the client 557 /// having to pass in a MCExpr for MCSymbols. 558 void EmitSymbolValue(const MCSymbol *Sym, unsigned Size); 559 560 /// EmitGPRel64Value - Emit the expression @p Value into the output as a 561 /// gprel64 (64-bit GP relative) value. 562 /// 563 /// This is used to implement assembler directives such as .gpdword on 564 /// targets that support them. 565 virtual void EmitGPRel64Value(const MCExpr *Value); 566 567 /// EmitGPRel32Value - Emit the expression @p Value into the output as a 568 /// gprel32 (32-bit GP relative) value. 569 /// 570 /// This is used to implement assembler directives such as .gprel32 on 571 /// targets that support them. 572 virtual void EmitGPRel32Value(const MCExpr *Value); 573 574 /// EmitFill - Emit NumBytes bytes worth of the value specified by 575 /// FillValue. This implements directives such as '.space'. 576 virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue); 577 578 /// \brief Emit NumBytes worth of zeros. 579 /// This function properly handles data in virtual sections. 580 virtual void EmitZeros(uint64_t NumBytes); 581 582 /// EmitValueToAlignment - Emit some number of copies of @p Value until 583 /// the byte alignment @p ByteAlignment is reached. 584 /// 585 /// If the number of bytes need to emit for the alignment is not a multiple 586 /// of @p ValueSize, then the contents of the emitted fill bytes is 587 /// undefined. 588 /// 589 /// This used to implement the .align assembler directive. 590 /// 591 /// @param ByteAlignment - The alignment to reach. This must be a power of 592 /// two on some targets. 593 /// @param Value - The value to use when filling bytes. 594 /// @param ValueSize - The size of the integer (in bytes) to emit for 595 /// @p Value. This must match a native machine width. 596 /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If 597 /// the alignment cannot be reached in this many bytes, no bytes are 598 /// emitted. 599 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0, 600 unsigned ValueSize = 1, 601 unsigned MaxBytesToEmit = 0) = 0; 602 603 /// EmitCodeAlignment - Emit nops until the byte alignment @p ByteAlignment 604 /// is reached. 605 /// 606 /// This used to align code where the alignment bytes may be executed. This 607 /// can emit different bytes for different sizes to optimize execution. 608 /// 609 /// @param ByteAlignment - The alignment to reach. This must be a power of 610 /// two on some targets. 611 /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If 612 /// the alignment cannot be reached in this many bytes, no bytes are 613 /// emitted. 614 virtual void EmitCodeAlignment(unsigned ByteAlignment, 615 unsigned MaxBytesToEmit = 0) = 0; 616 617 /// EmitValueToOffset - Emit some number of copies of @p Value until the 618 /// byte offset @p Offset is reached. 619 /// 620 /// This is used to implement assembler directives such as .org. 621 /// 622 /// @param Offset - The offset to reach. This may be an expression, but the 623 /// expression must be associated with the current section. 624 /// @param Value - The value to use when filling bytes. 625 /// @return false on success, true if the offset was invalid. 626 virtual bool EmitValueToOffset(const MCExpr *Offset, 627 unsigned char Value = 0) = 0; 628 629 /// @} 630 631 /// EmitFileDirective - Switch to a new logical file. This is used to 632 /// implement the '.file "foo.c"' assembler directive. 633 virtual void EmitFileDirective(StringRef Filename) = 0; 634 635 /// Emit the "identifiers" directive. This implements the 636 /// '.ident "version foo"' assembler directive. 637 virtual void EmitIdent(StringRef IdentString) {} 638 639 /// EmitDwarfFileDirective - Associate a filename with a specified logical 640 /// file number. This implements the DWARF2 '.file 4 "foo.c"' assembler 641 /// directive. 642 virtual unsigned EmitDwarfFileDirective(unsigned FileNo, StringRef Directory, 643 StringRef Filename, 644 unsigned CUID = 0); 645 646 /// EmitDwarfLocDirective - This implements the DWARF2 647 // '.loc fileno lineno ...' assembler directive. 648 virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line, 649 unsigned Column, unsigned Flags, 650 unsigned Isa, unsigned Discriminator, 651 StringRef FileName); 652 653 virtual MCSymbol *getDwarfLineTableSymbol(unsigned CUID); 654 655 void EmitDwarfSetLineAddr(int64_t LineDelta, const MCSymbol *Label, 656 int PointerSize); 657 658 virtual void EmitCompactUnwindEncoding(uint32_t CompactUnwindEncoding); 659 virtual void EmitCFISections(bool EH, bool Debug); 660 void EmitCFIStartProc(bool IsSimple); 661 void EmitCFIEndProc(); 662 virtual void EmitCFIDefCfa(int64_t Register, int64_t Offset); 663 virtual void EmitCFIDefCfaOffset(int64_t Offset); 664 virtual void EmitCFIDefCfaRegister(int64_t Register); 665 virtual void EmitCFIOffset(int64_t Register, int64_t Offset); 666 virtual void EmitCFIPersonality(const MCSymbol *Sym, unsigned Encoding); 667 virtual void EmitCFILsda(const MCSymbol *Sym, unsigned Encoding); 668 virtual void EmitCFIRememberState(); 669 virtual void EmitCFIRestoreState(); 670 virtual void EmitCFISameValue(int64_t Register); 671 virtual void EmitCFIRestore(int64_t Register); 672 virtual void EmitCFIRelOffset(int64_t Register, int64_t Offset); 673 virtual void EmitCFIAdjustCfaOffset(int64_t Adjustment); 674 virtual void EmitCFIEscape(StringRef Values); 675 virtual void EmitCFISignalFrame(); 676 virtual void EmitCFIUndefined(int64_t Register); 677 virtual void EmitCFIRegister(int64_t Register1, int64_t Register2); 678 virtual void EmitCFIWindowSave(); 679 680 virtual void EmitWin64EHStartProc(const MCSymbol *Symbol); 681 virtual void EmitWin64EHEndProc(); 682 virtual void EmitWin64EHStartChained(); 683 virtual void EmitWin64EHEndChained(); 684 virtual void EmitWin64EHHandler(const MCSymbol *Sym, bool Unwind, 685 bool Except); 686 virtual void EmitWin64EHHandlerData(); 687 virtual void EmitWin64EHPushReg(unsigned Register); 688 virtual void EmitWin64EHSetFrame(unsigned Register, unsigned Offset); 689 virtual void EmitWin64EHAllocStack(unsigned Size); 690 virtual void EmitWin64EHSaveReg(unsigned Register, unsigned Offset); 691 virtual void EmitWin64EHSaveXMM(unsigned Register, unsigned Offset); 692 virtual void EmitWin64EHPushFrame(bool Code); 693 virtual void EmitWin64EHEndProlog(); 694 695 /// EmitInstruction - Emit the given @p Instruction into the current 696 /// section. 697 virtual void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI) = 0; 698 699 /// \brief Set the bundle alignment mode from now on in the section. 700 /// The argument is the power of 2 to which the alignment is set. The 701 /// value 0 means turn the bundle alignment off. 702 virtual void EmitBundleAlignMode(unsigned AlignPow2) = 0; 703 704 /// \brief The following instructions are a bundle-locked group. 705 /// 706 /// \param AlignToEnd - If true, the bundle-locked group will be aligned to 707 /// the end of a bundle. 708 virtual void EmitBundleLock(bool AlignToEnd) = 0; 709 710 /// \brief Ends a bundle-locked group. 711 virtual void EmitBundleUnlock() = 0; 712 713 /// EmitRawText - If this file is backed by a assembly streamer, this dumps 714 /// the specified string in the output .s file. This capability is 715 /// indicated by the hasRawTextSupport() predicate. By default this aborts. 716 void EmitRawText(const Twine &String); 717 718 /// Flush - Causes any cached state to be written out. 719 virtual void Flush() {} 720 721 /// FinishImpl - Streamer specific finalization. 722 virtual void FinishImpl() = 0; 723 /// Finish - Finish emission of machine code. 724 void Finish(); 725}; 726 727/// createNullStreamer - Create a dummy machine code streamer, which does 728/// nothing. This is useful for timing the assembler front end. 729MCStreamer *createNullStreamer(MCContext &Ctx); 730 731/// createAsmStreamer - Create a machine code streamer which will print out 732/// assembly for the native target, suitable for compiling with a native 733/// assembler. 734/// 735/// \param InstPrint - If given, the instruction printer to use. If not given 736/// the MCInst representation will be printed. This method takes ownership of 737/// InstPrint. 738/// 739/// \param CE - If given, a code emitter to use to show the instruction 740/// encoding inline with the assembly. This method takes ownership of \p CE. 741/// 742/// \param TAB - If given, a target asm backend to use to show the fixup 743/// information in conjunction with encoding information. This method takes 744/// ownership of \p TAB. 745/// 746/// \param ShowInst - Whether to show the MCInst representation inline with 747/// the assembly. 748MCStreamer *createAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS, 749 bool isVerboseAsm, bool useDwarfDirectory, 750 MCInstPrinter *InstPrint, MCCodeEmitter *CE, 751 MCAsmBackend *TAB, bool ShowInst); 752 753/// createMachOStreamer - Create a machine code streamer which will generate 754/// Mach-O format object files. 755/// 756/// Takes ownership of \p TAB and \p CE. 757MCStreamer *createMachOStreamer(MCContext &Ctx, MCAsmBackend &TAB, 758 raw_ostream &OS, MCCodeEmitter *CE, 759 bool RelaxAll = false, 760 bool LabelSections = false); 761 762/// createELFStreamer - Create a machine code streamer which will generate 763/// ELF format object files. 764MCStreamer *createELFStreamer(MCContext &Ctx, MCAsmBackend &TAB, 765 raw_ostream &OS, MCCodeEmitter *CE, bool RelaxAll, 766 bool NoExecStack); 767 768} // end namespace llvm 769 770#endif 771