MCStreamer.h revision ed708f9c1facb9928ef2f79503e7030c8f25b00d
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/SmallVector.h" 18#include "llvm/Support/DataTypes.h" 19#include "llvm/MC/MCDirectives.h" 20#include "llvm/MC/MCDwarf.h" 21 22namespace llvm { 23 class MCAsmInfo; 24 class MCCodeEmitter; 25 class MCContext; 26 class MCExpr; 27 class MCInst; 28 class MCInstPrinter; 29 class MCSection; 30 class MCSymbol; 31 class StringRef; 32 class TargetAsmBackend; 33 class TargetLoweringObjectFile; 34 class Twine; 35 class raw_ostream; 36 class formatted_raw_ostream; 37 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. 43 /// 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. 46 /// 47 class MCStreamer { 48 MCContext &Context; 49 50 MCStreamer(const MCStreamer&); // DO NOT IMPLEMENT 51 MCStreamer &operator=(const MCStreamer&); // DO NOT IMPLEMENT 52 53 void EmitSymbolValue(const MCSymbol *Sym, unsigned Size, 54 bool isPCRel, unsigned AddrSpace); 55 56 std::vector<MCDwarfFrameInfo> FrameInfos; 57 MCDwarfFrameInfo *getCurrentFrameInfo(); 58 void EnsureValidFrame(); 59 60 const MCSymbol* LastNonPrivate; 61 62 /// SectionStack - This is stack of current and previous section 63 /// values saved by PushSection. 64 SmallVector<std::pair<const MCSection *, 65 const MCSection *>, 4> SectionStack; 66 67 protected: 68 MCStreamer(MCContext &Ctx); 69 70 public: 71 virtual ~MCStreamer(); 72 73 MCContext &getContext() const { return Context; } 74 75 unsigned getNumFrameInfos() { 76 return FrameInfos.size(); 77 } 78 79 const MCDwarfFrameInfo &getFrameInfo(unsigned i) { 80 return FrameInfos[i]; 81 } 82 83 /// @name Assembly File Formatting. 84 /// @{ 85 86 /// isVerboseAsm - Return true if this streamer supports verbose assembly 87 /// and if it is enabled. 88 virtual bool isVerboseAsm() const { return false; } 89 90 /// hasRawTextSupport - Return true if this asm streamer supports emitting 91 /// unformatted text to the .s file with EmitRawText. 92 virtual bool hasRawTextSupport() const { return false; } 93 94 /// AddComment - Add a comment that can be emitted to the generated .s 95 /// file if applicable as a QoI issue to make the output of the compiler 96 /// more readable. This only affects the MCAsmStreamer, and only when 97 /// verbose assembly output is enabled. 98 /// 99 /// If the comment includes embedded \n's, they will each get the comment 100 /// prefix as appropriate. The added comment should not end with a \n. 101 virtual void AddComment(const Twine &T) {} 102 103 /// GetCommentOS - Return a raw_ostream that comments can be written to. 104 /// Unlike AddComment, you are required to terminate comments with \n if you 105 /// use this method. 106 virtual raw_ostream &GetCommentOS(); 107 108 /// AddBlankLine - Emit a blank line to a .s file to pretty it up. 109 virtual void AddBlankLine() {} 110 111 /// @} 112 113 /// @name Symbol & Section Management 114 /// @{ 115 116 /// getCurrentSection - Return the current section that the streamer is 117 /// emitting code to. 118 const MCSection *getCurrentSection() const { 119 if (!SectionStack.empty()) 120 return SectionStack.back().first; 121 return NULL; 122 } 123 124 /// getPreviousSection - Return the previous section that the streamer is 125 /// emitting code to. 126 const MCSection *getPreviousSection() const { 127 if (!SectionStack.empty()) 128 return SectionStack.back().second; 129 return NULL; 130 } 131 132 /// ChangeSection - Update streamer for a new active section. 133 /// 134 /// This is called by PopSection and SwitchSection, if the current 135 /// section changes. 136 virtual void ChangeSection(const MCSection *) = 0; 137 138 /// pushSection - Save the current and previous section on the 139 /// section stack. 140 void PushSection() { 141 SectionStack.push_back(std::make_pair(getCurrentSection(), 142 getPreviousSection())); 143 } 144 145 /// popSection - Restore the current and previous section from 146 /// the section stack. Calls ChangeSection as needed. 147 /// 148 /// Returns false if the stack was empty. 149 bool PopSection() { 150 if (SectionStack.size() <= 1) 151 return false; 152 const MCSection *oldSection = SectionStack.pop_back_val().first; 153 const MCSection *curSection = SectionStack.back().first; 154 155 if (oldSection != curSection) 156 ChangeSection(curSection); 157 return true; 158 } 159 160 /// SwitchSection - Set the current section where code is being emitted to 161 /// @p Section. This is required to update CurSection. 162 /// 163 /// This corresponds to assembler directives like .section, .text, etc. 164 void SwitchSection(const MCSection *Section) { 165 assert(Section && "Cannot switch to a null section!"); 166 const MCSection *curSection = SectionStack.back().first; 167 SectionStack.back().second = curSection; 168 if (Section != curSection) { 169 SectionStack.back().first = Section; 170 ChangeSection(Section); 171 } 172 } 173 174 /// InitSections - Create the default sections and set the initial one. 175 virtual void InitSections() = 0; 176 177 /// EmitLabel - Emit a label for @p Symbol into the current section. 178 /// 179 /// This corresponds to an assembler statement such as: 180 /// foo: 181 /// 182 /// @param Symbol - The symbol to emit. A given symbol should only be 183 /// emitted as a label once, and symbols emitted as a label should never be 184 /// used in an assignment. 185 virtual void EmitLabel(MCSymbol *Symbol); 186 187 /// EmitAssemblerFlag - Note in the output the specified @p Flag 188 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) = 0; 189 190 /// EmitThumbFunc - Note in the output that the specified @p Func is 191 /// a Thumb mode function (ARM target only). 192 virtual void EmitThumbFunc(MCSymbol *Func) = 0; 193 194 /// EmitAssignment - Emit an assignment of @p Value to @p Symbol. 195 /// 196 /// This corresponds to an assembler statement such as: 197 /// symbol = value 198 /// 199 /// The assignment generates no code, but has the side effect of binding the 200 /// value in the current context. For the assembly streamer, this prints the 201 /// binding into the .s file. 202 /// 203 /// @param Symbol - The symbol being assigned to. 204 /// @param Value - The value for the symbol. 205 virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) = 0; 206 207 /// EmitWeakReference - Emit an weak reference from @p Alias to @p Symbol. 208 /// 209 /// This corresponds to an assembler statement such as: 210 /// .weakref alias, symbol 211 /// 212 /// @param Alias - The alias that is being created. 213 /// @param Symbol - The symbol being aliased. 214 virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) = 0; 215 216 /// EmitSymbolAttribute - Add the given @p Attribute to @p Symbol. 217 virtual void EmitSymbolAttribute(MCSymbol *Symbol, 218 MCSymbolAttr Attribute) = 0; 219 220 /// EmitSymbolDesc - Set the @p DescValue for the @p Symbol. 221 /// 222 /// @param Symbol - The symbol to have its n_desc field set. 223 /// @param DescValue - The value to set into the n_desc field. 224 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) = 0; 225 226 /// BeginCOFFSymbolDef - Start emitting COFF symbol definition 227 /// 228 /// @param Symbol - The symbol to have its External & Type fields set. 229 virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) = 0; 230 231 /// EmitCOFFSymbolStorageClass - Emit the storage class of the symbol. 232 /// 233 /// @param StorageClass - The storage class the symbol should have. 234 virtual void EmitCOFFSymbolStorageClass(int StorageClass) = 0; 235 236 /// EmitCOFFSymbolType - Emit the type of the symbol. 237 /// 238 /// @param Type - A COFF type identifier (see COFF::SymbolType in X86COFF.h) 239 virtual void EmitCOFFSymbolType(int Type) = 0; 240 241 /// EndCOFFSymbolDef - Marks the end of the symbol definition. 242 virtual void EndCOFFSymbolDef() = 0; 243 244 /// EmitELFSize - Emit an ELF .size directive. 245 /// 246 /// This corresponds to an assembler statement such as: 247 /// .size symbol, expression 248 /// 249 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) = 0; 250 251 /// EmitCommonSymbol - Emit a common symbol. 252 /// 253 /// @param Symbol - The common symbol to emit. 254 /// @param Size - The size of the common symbol. 255 /// @param ByteAlignment - The alignment of the symbol if 256 /// non-zero. This must be a power of 2. 257 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size, 258 unsigned ByteAlignment) = 0; 259 260 /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol. 261 /// 262 /// @param Symbol - The common symbol to emit. 263 /// @param Size - The size of the common symbol. 264 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) = 0; 265 266 /// EmitZerofill - Emit the zerofill section and an optional symbol. 267 /// 268 /// @param Section - The zerofill section to create and or to put the symbol 269 /// @param Symbol - The zerofill symbol to emit, if non-NULL. 270 /// @param Size - The size of the zerofill symbol. 271 /// @param ByteAlignment - The alignment of the zerofill symbol if 272 /// non-zero. This must be a power of 2 on some targets. 273 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0, 274 unsigned Size = 0,unsigned ByteAlignment = 0) = 0; 275 276 /// EmitTBSSSymbol - Emit a thread local bss (.tbss) symbol. 277 /// 278 /// @param Section - The thread local common section. 279 /// @param Symbol - The thread local common symbol to emit. 280 /// @param Size - The size of the symbol. 281 /// @param ByteAlignment - The alignment of the thread local common symbol 282 /// if non-zero. This must be a power of 2 on some targets. 283 virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol, 284 uint64_t Size, unsigned ByteAlignment = 0) = 0; 285 /// @} 286 /// @name Generating Data 287 /// @{ 288 289 /// EmitBytes - Emit the bytes in \arg Data into the output. 290 /// 291 /// This is used to implement assembler directives such as .byte, .ascii, 292 /// etc. 293 virtual void EmitBytes(StringRef Data, unsigned AddrSpace) = 0; 294 295 /// EmitValue - Emit the expression @p Value into the output as a native 296 /// integer of the given @p Size bytes. 297 /// 298 /// This is used to implement assembler directives such as .word, .quad, 299 /// etc. 300 /// 301 /// @param Value - The value to emit. 302 /// @param Size - The size of the integer (in bytes) to emit. This must 303 /// match a native machine width. 304 virtual void EmitValueImpl(const MCExpr *Value, unsigned Size, 305 bool isPCRel, unsigned AddrSpace) = 0; 306 307 void EmitValue(const MCExpr *Value, unsigned Size, unsigned AddrSpace = 0); 308 309 void EmitPCRelValue(const MCExpr *Value, unsigned Size, 310 unsigned AddrSpace = 0); 311 312 /// EmitIntValue - Special case of EmitValue that avoids the client having 313 /// to pass in a MCExpr for constant integers. 314 virtual void EmitIntValue(uint64_t Value, unsigned Size, 315 unsigned AddrSpace = 0); 316 317 /// EmitAbsValue - Emit the Value, but try to avoid relocations. On MachO 318 /// this is done by producing 319 /// foo = value 320 /// .long foo 321 void EmitAbsValue(const MCExpr *Value, unsigned Size, 322 unsigned AddrSpace = 0); 323 324 virtual void EmitULEB128Value(const MCExpr *Value) = 0; 325 326 virtual void EmitSLEB128Value(const MCExpr *Value) = 0; 327 328 /// 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); 331 332 /// 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); 335 336 /// 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); 340 341 void EmitPCRelSymbolValue(const MCSymbol *Sym, unsigned Size, 342 unsigned AddrSpace = 0); 343 344 /// EmitGPRel32Value - Emit the expression @p Value into the output as a 345 /// gprel32 (32-bit GP relative) value. 346 /// 347 /// This is used to implement assembler directives such as .gprel32 on 348 /// targets that support them. 349 virtual void EmitGPRel32Value(const MCExpr *Value); 350 351 /// 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, 354 unsigned AddrSpace); 355 356 /// 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); 360 } 361 362 363 /// EmitValueToAlignment - Emit some number of copies of @p Value until 364 /// the byte alignment @p ByteAlignment is reached. 365 /// 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 368 /// undefined. 369 /// 370 /// This used to implement the .align assembler directive. 371 /// 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 379 /// emitted. 380 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0, 381 unsigned ValueSize = 1, 382 unsigned MaxBytesToEmit = 0) = 0; 383 384 /// EmitCodeAlignment - Emit nops until the byte alignment @p ByteAlignment 385 /// is reached. 386 /// 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. 389 /// 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 394 /// emitted. 395 virtual void EmitCodeAlignment(unsigned ByteAlignment, 396 unsigned MaxBytesToEmit = 0) = 0; 397 398 /// EmitValueToOffset - Emit some number of copies of @p Value until the 399 /// byte offset @p Offset is reached. 400 /// 401 /// This is used to implement assembler directives such as .org. 402 /// 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; 408 409 /// @} 410 411 /// 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; 414 415 /// EmitDwarfFileDirective - Associate a filename with a specified logical 416 /// file number. This implements the DWARF2 '.file 4 "foo.c"' assembler 417 /// directive. 418 virtual bool EmitDwarfFileDirective(unsigned FileNo,StringRef Filename); 419 420 /// EmitDwarfLocDirective - This implements the DWARF2 421 // '.loc fileno lineno ...' assembler directive. 422 virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line, 423 unsigned Column, unsigned Flags, 424 unsigned Isa, 425 unsigned Discriminator, 426 StringRef FileName); 427 428 virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta, 429 const MCSymbol *LastLabel, 430 const MCSymbol *Label) = 0; 431 432 virtual void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel, 433 const MCSymbol *Label) { 434 } 435 436 void EmitDwarfSetLineAddr(int64_t LineDelta, const MCSymbol *Label, 437 int PointerSize); 438 439 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); 452 453 /// EmitInstruction - Emit the given @p Instruction into the current 454 /// section. 455 virtual void EmitInstruction(const MCInst &Inst) = 0; 456 457 /// 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); 462 463 /// 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, 474 bool isVector); 475 476 /// Finish - Finish emission of machine code. 477 virtual void Finish() = 0; 478 }; 479 480 /// 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); 483 484 /// createAsmStreamer - Create a machine code streamer which will print out 485 /// assembly for the native target, suitable for compiling with a native 486 /// assembler. 487 /// 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 490 /// InstPrint. 491 /// 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. 494 /// 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. 498 /// 499 /// \param ShowInst - Whether to show the MCInst representation inline with 500 /// the assembly. 501 MCStreamer *createAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS, 502 bool isVerboseAsm, 503 bool useLoc, 504 MCInstPrinter *InstPrint = 0, 505 MCCodeEmitter *CE = 0, 506 TargetAsmBackend *TAB = 0, 507 bool ShowInst = false); 508 509 /// createMachOStreamer - Create a machine code streamer which will generate 510 /// Mach-O format object files. 511 /// 512 /// Takes ownership of \arg TAB and \arg CE. 513 MCStreamer *createMachOStreamer(MCContext &Ctx, TargetAsmBackend &TAB, 514 raw_ostream &OS, MCCodeEmitter *CE, 515 bool RelaxAll = false); 516 517 /// createWinCOFFStreamer - Create a machine code streamer which will 518 /// generate Microsoft COFF format object files. 519 /// 520 /// Takes ownership of \arg TAB and \arg CE. 521 MCStreamer *createWinCOFFStreamer(MCContext &Ctx, 522 TargetAsmBackend &TAB, 523 MCCodeEmitter &CE, raw_ostream &OS, 524 bool RelaxAll = false); 525 526 /// createELFStreamer - Create a machine code streamer which will generate 527 /// ELF format object files. 528 MCStreamer *createELFStreamer(MCContext &Ctx, TargetAsmBackend &TAB, 529 raw_ostream &OS, MCCodeEmitter *CE, 530 bool RelaxAll, bool NoExecStack); 531 532 /// createLoggingStreamer - Create a machine code streamer which just logs the 533 /// API calls and then dispatches to another streamer. 534 /// 535 /// The new streamer takes ownership of the \arg Child. 536 MCStreamer *createLoggingStreamer(MCStreamer *Child, raw_ostream &OS); 537 538 /// createPureStreamer - Create a machine code streamer which will generate 539 /// "pure" MC object files, for use with MC-JIT and testing tools. 540 /// 541 /// Takes ownership of \arg TAB and \arg CE. 542 MCStreamer *createPureStreamer(MCContext &Ctx, TargetAsmBackend &TAB, 543 raw_ostream &OS, MCCodeEmitter *CE); 544 545} // end namespace llvm 546 547#endif 548