MCStreamer.h revision e8cfbd843d737e1f95c3032c7670c2be3838a6f6
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 /// 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; 64 65 protected: 66 MCStreamer(MCContext &Ctx); 67 68 public: 69 virtual ~MCStreamer(); 70 71 MCContext &getContext() const { return Context; } 72 73 unsigned getNumFrameInfos() { 74 return FrameInfos.size(); 75 } 76 77 const MCDwarfFrameInfo &getFrameInfo(unsigned i) { 78 return FrameInfos[i]; 79 } 80 81 /// @name Assembly File Formatting. 82 /// @{ 83 84 /// isVerboseAsm - Return true if this streamer supports verbose assembly 85 /// and if it is enabled. 86 virtual bool isVerboseAsm() const { return false; } 87 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; } 91 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. 96 /// 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) {} 100 101 /// GetCommentOS - Return a raw_ostream that comments can be written to. 102 /// Unlike AddComment, you are required to terminate comments with \n if you 103 /// use this method. 104 virtual raw_ostream &GetCommentOS(); 105 106 /// AddBlankLine - Emit a blank line to a .s file to pretty it up. 107 virtual void AddBlankLine() {} 108 109 /// @} 110 111 /// @name Symbol & Section Management 112 /// @{ 113 114 /// 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; 119 return NULL; 120 } 121 122 /// 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; 127 return NULL; 128 } 129 130 /// ChangeSection - Update streamer for a new active section. 131 /// 132 /// This is called by PopSection and SwitchSection, if the current 133 /// section changes. 134 virtual void ChangeSection(const MCSection *) = 0; 135 136 /// pushSection - Save the current and previous section on the 137 /// section stack. 138 void PushSection() { 139 SectionStack.push_back(std::make_pair(getCurrentSection(), 140 getPreviousSection())); 141 } 142 143 /// popSection - Restore the current and previous section from 144 /// the section stack. Calls ChangeSection as needed. 145 /// 146 /// Returns false if the stack was empty. 147 bool PopSection() { 148 if (SectionStack.size() <= 1) 149 return false; 150 const MCSection *oldSection = SectionStack.pop_back_val().first; 151 const MCSection *curSection = SectionStack.back().first; 152 153 if (oldSection != curSection) 154 ChangeSection(curSection); 155 return true; 156 } 157 158 /// SwitchSection - Set the current section where code is being emitted to 159 /// @p Section. This is required to update CurSection. 160 /// 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); 169 } 170 } 171 172 /// InitSections - Create the default sections and set the initial one. 173 virtual void InitSections() = 0; 174 175 /// EmitLabel - Emit a label for @p Symbol into the current section. 176 /// 177 /// This corresponds to an assembler statement such as: 178 /// foo: 179 /// 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; 184 185 /// EmitAssemblerFlag - Note in the output the specified @p Flag 186 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) = 0; 187 188 /// 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; 191 192 /// EmitAssignment - Emit an assignment of @p Value to @p Symbol. 193 /// 194 /// This corresponds to an assembler statement such as: 195 /// symbol = value 196 /// 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. 200 /// 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; 204 205 /// EmitWeakReference - Emit an weak reference from @p Alias to @p Symbol. 206 /// 207 /// This corresponds to an assembler statement such as: 208 /// .weakref alias, symbol 209 /// 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; 213 214 /// EmitSymbolAttribute - Add the given @p Attribute to @p Symbol. 215 virtual void EmitSymbolAttribute(MCSymbol *Symbol, 216 MCSymbolAttr Attribute) = 0; 217 218 /// EmitSymbolDesc - Set the @p DescValue for the @p Symbol. 219 /// 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; 223 224 /// BeginCOFFSymbolDef - Start emitting COFF symbol definition 225 /// 226 /// @param Symbol - The symbol to have its External & Type fields set. 227 virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) = 0; 228 229 /// EmitCOFFSymbolStorageClass - Emit the storage class of the symbol. 230 /// 231 /// @param StorageClass - The storage class the symbol should have. 232 virtual void EmitCOFFSymbolStorageClass(int StorageClass) = 0; 233 234 /// EmitCOFFSymbolType - Emit the type of the symbol. 235 /// 236 /// @param Type - A COFF type identifier (see COFF::SymbolType in X86COFF.h) 237 virtual void EmitCOFFSymbolType(int Type) = 0; 238 239 /// EndCOFFSymbolDef - Marks the end of the symbol definition. 240 virtual void EndCOFFSymbolDef() = 0; 241 242 /// EmitELFSize - Emit an ELF .size directive. 243 /// 244 /// This corresponds to an assembler statement such as: 245 /// .size symbol, expression 246 /// 247 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) = 0; 248 249 /// EmitCommonSymbol - Emit a common symbol. 250 /// 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; 257 258 /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol. 259 /// 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; 263 264 /// EmitZerofill - Emit the zerofill section and an optional symbol. 265 /// 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; 273 274 /// EmitTBSSSymbol - Emit a thread local bss (.tbss) symbol. 275 /// 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; 283 /// @} 284 /// @name Generating Data 285 /// @{ 286 287 /// EmitBytes - Emit the bytes in \arg Data into the output. 288 /// 289 /// This is used to implement assembler directives such as .byte, .ascii, 290 /// etc. 291 virtual void EmitBytes(StringRef Data, unsigned AddrSpace) = 0; 292 293 /// EmitValue - Emit the expression @p Value into the output as a native 294 /// integer of the given @p Size bytes. 295 /// 296 /// This is used to implement assembler directives such as .word, .quad, 297 /// etc. 298 /// 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; 304 305 void EmitValue(const MCExpr *Value, unsigned Size, unsigned AddrSpace = 0); 306 307 void EmitPCRelValue(const MCExpr *Value, unsigned Size, 308 unsigned AddrSpace = 0); 309 310 /// 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); 314 315 /// EmitAbsValue - Emit the Value, but try to avoid relocations. On MachO 316 /// this is done by producing 317 /// foo = value 318 /// .long foo 319 void EmitAbsValue(const MCExpr *Value, unsigned Size, 320 unsigned AddrSpace = 0); 321 322 virtual void EmitULEB128Value(const MCExpr *Value) = 0; 323 324 virtual void EmitSLEB128Value(const MCExpr *Value) = 0; 325 326 /// EmitULEB128Value - Special case of EmitULEB128Value that avoids the 327 /// client having to pass in a MCExpr for constant integers. 328 void EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace = 0); 329 330 /// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the 331 /// client having to pass in a MCExpr for constant integers. 332 void EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace = 0); 333 334 /// EmitSymbolValue - Special case of EmitValue that avoids the client 335 /// having to pass in a MCExpr for MCSymbols. 336 void EmitSymbolValue(const MCSymbol *Sym, unsigned Size, 337 unsigned AddrSpace = 0); 338 339 void EmitPCRelSymbolValue(const MCSymbol *Sym, unsigned Size, 340 unsigned AddrSpace = 0); 341 342 /// EmitGPRel32Value - Emit the expression @p Value into the output as a 343 /// gprel32 (32-bit GP relative) value. 344 /// 345 /// This is used to implement assembler directives such as .gprel32 on 346 /// targets that support them. 347 virtual void EmitGPRel32Value(const MCExpr *Value); 348 349 /// EmitFill - Emit NumBytes bytes worth of the value specified by 350 /// FillValue. This implements directives such as '.space'. 351 virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue, 352 unsigned AddrSpace); 353 354 /// EmitZeros - Emit NumBytes worth of zeros. This is a convenience 355 /// function that just wraps EmitFill. 356 void EmitZeros(uint64_t NumBytes, unsigned AddrSpace) { 357 EmitFill(NumBytes, 0, AddrSpace); 358 } 359 360 361 /// EmitValueToAlignment - Emit some number of copies of @p Value until 362 /// the byte alignment @p ByteAlignment is reached. 363 /// 364 /// If the number of bytes need to emit for the alignment is not a multiple 365 /// of @p ValueSize, then the contents of the emitted fill bytes is 366 /// undefined. 367 /// 368 /// This used to implement the .align assembler directive. 369 /// 370 /// @param ByteAlignment - The alignment to reach. This must be a power of 371 /// two on some targets. 372 /// @param Value - The value to use when filling bytes. 373 /// @param ValueSize - The size of the integer (in bytes) to emit for 374 /// @p Value. This must match a native machine width. 375 /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If 376 /// the alignment cannot be reached in this many bytes, no bytes are 377 /// emitted. 378 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0, 379 unsigned ValueSize = 1, 380 unsigned MaxBytesToEmit = 0) = 0; 381 382 /// EmitCodeAlignment - Emit nops until the byte alignment @p ByteAlignment 383 /// is reached. 384 /// 385 /// This used to align code where the alignment bytes may be executed. This 386 /// can emit different bytes for different sizes to optimize execution. 387 /// 388 /// @param ByteAlignment - The alignment to reach. This must be a power of 389 /// two on some targets. 390 /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If 391 /// the alignment cannot be reached in this many bytes, no bytes are 392 /// emitted. 393 virtual void EmitCodeAlignment(unsigned ByteAlignment, 394 unsigned MaxBytesToEmit = 0) = 0; 395 396 /// EmitValueToOffset - Emit some number of copies of @p Value until the 397 /// byte offset @p Offset is reached. 398 /// 399 /// This is used to implement assembler directives such as .org. 400 /// 401 /// @param Offset - The offset to reach. This may be an expression, but the 402 /// expression must be associated with the current section. 403 /// @param Value - The value to use when filling bytes. 404 virtual void EmitValueToOffset(const MCExpr *Offset, 405 unsigned char Value = 0) = 0; 406 407 /// @} 408 409 /// EmitFileDirective - Switch to a new logical file. This is used to 410 /// implement the '.file "foo.c"' assembler directive. 411 virtual void EmitFileDirective(StringRef Filename) = 0; 412 413 /// EmitDwarfFileDirective - Associate a filename with a specified logical 414 /// file number. This implements the DWARF2 '.file 4 "foo.c"' assembler 415 /// directive. 416 virtual bool EmitDwarfFileDirective(unsigned FileNo,StringRef Filename); 417 418 /// EmitDwarfLocDirective - This implements the DWARF2 419 // '.loc fileno lineno ...' assembler directive. 420 virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line, 421 unsigned Column, unsigned Flags, 422 unsigned Isa, 423 unsigned Discriminator, 424 StringRef FileName); 425 426 virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta, 427 const MCSymbol *LastLabel, 428 const MCSymbol *Label) = 0; 429 430 virtual void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel, 431 const MCSymbol *Label) { 432 } 433 434 void EmitDwarfSetLineAddr(int64_t LineDelta, const MCSymbol *Label, 435 int PointerSize); 436 437 virtual void EmitCFIStartProc(); 438 virtual void EmitCFIEndProc(); 439 virtual void EmitCFIDefCfa(int64_t Register, int64_t Offset); 440 virtual void EmitCFIDefCfaOffset(int64_t Offset); 441 virtual void EmitCFIDefCfaRegister(int64_t Register); 442 virtual void EmitCFIOffset(int64_t Register, int64_t Offset); 443 virtual void EmitCFIPersonality(const MCSymbol *Sym, unsigned Encoding); 444 virtual void EmitCFILsda(const MCSymbol *Sym, unsigned Encoding); 445 virtual void EmitCFIRememberState(); 446 virtual void EmitCFIRestoreState(); 447 virtual void EmitCFISameValue(int64_t Register); 448 virtual void EmitCFIRelOffset(int64_t Register, int64_t Offset); 449 virtual void EmitCFIAdjustCfaOffset(int64_t Adjustment); 450 451 /// EmitInstruction - Emit the given @p Instruction into the current 452 /// section. 453 virtual void EmitInstruction(const MCInst &Inst) = 0; 454 455 /// EmitRawText - If this file is backed by a assembly streamer, this dumps 456 /// the specified string in the output .s file. This capability is 457 /// indicated by the hasRawTextSupport() predicate. By default this aborts. 458 virtual void EmitRawText(StringRef String); 459 void EmitRawText(const Twine &String); 460 461 /// ARM-related methods. 462 /// FIXME: Eventually we should have some "target MC streamer" and move 463 /// these methods there. 464 virtual void EmitFnStart(); 465 virtual void EmitFnEnd(); 466 virtual void EmitCantUnwind(); 467 virtual void EmitPersonality(const MCSymbol *Personality); 468 virtual void EmitHandlerData(); 469 virtual void EmitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0); 470 virtual void EmitPad(int64_t Offset); 471 virtual void EmitRegSave(const SmallVectorImpl<unsigned> &RegList, 472 bool isVector); 473 474 /// Finish - Finish emission of machine code. 475 virtual void Finish() = 0; 476 }; 477 478 /// createNullStreamer - Create a dummy machine code streamer, which does 479 /// nothing. This is useful for timing the assembler front end. 480 MCStreamer *createNullStreamer(MCContext &Ctx); 481 482 /// createAsmStreamer - Create a machine code streamer which will print out 483 /// assembly for the native target, suitable for compiling with a native 484 /// assembler. 485 /// 486 /// \param InstPrint - If given, the instruction printer to use. If not given 487 /// the MCInst representation will be printed. This method takes ownership of 488 /// InstPrint. 489 /// 490 /// \param CE - If given, a code emitter to use to show the instruction 491 /// encoding inline with the assembly. This method takes ownership of \arg CE. 492 /// 493 /// \param TAB - If given, a target asm backend to use to show the fixup 494 /// information in conjunction with encoding information. This method takes 495 /// ownership of \arg TAB. 496 /// 497 /// \param ShowInst - Whether to show the MCInst representation inline with 498 /// the assembly. 499 MCStreamer *createAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS, 500 bool isVerboseAsm, 501 bool useLoc, 502 MCInstPrinter *InstPrint = 0, 503 MCCodeEmitter *CE = 0, 504 TargetAsmBackend *TAB = 0, 505 bool ShowInst = false); 506 507 /// createMachOStreamer - Create a machine code streamer which will generate 508 /// Mach-O format object files. 509 /// 510 /// Takes ownership of \arg TAB and \arg CE. 511 MCStreamer *createMachOStreamer(MCContext &Ctx, TargetAsmBackend &TAB, 512 raw_ostream &OS, MCCodeEmitter *CE, 513 bool RelaxAll = false); 514 515 /// createWinCOFFStreamer - Create a machine code streamer which will 516 /// generate Microsoft COFF format object files. 517 /// 518 /// Takes ownership of \arg TAB and \arg CE. 519 MCStreamer *createWinCOFFStreamer(MCContext &Ctx, 520 TargetAsmBackend &TAB, 521 MCCodeEmitter &CE, raw_ostream &OS, 522 bool RelaxAll = false); 523 524 /// createELFStreamer - Create a machine code streamer which will generate 525 /// ELF format object files. 526 MCStreamer *createELFStreamer(MCContext &Ctx, TargetAsmBackend &TAB, 527 raw_ostream &OS, MCCodeEmitter *CE, 528 bool RelaxAll, bool NoExecStack); 529 530 /// createLoggingStreamer - Create a machine code streamer which just logs the 531 /// API calls and then dispatches to another streamer. 532 /// 533 /// The new streamer takes ownership of the \arg Child. 534 MCStreamer *createLoggingStreamer(MCStreamer *Child, raw_ostream &OS); 535 536 /// createPureStreamer - Create a machine code streamer which will generate 537 /// "pure" MC object files, for use with MC-JIT and testing tools. 538 /// 539 /// Takes ownership of \arg TAB and \arg CE. 540 MCStreamer *createPureStreamer(MCContext &Ctx, TargetAsmBackend &TAB, 541 raw_ostream &OS, MCCodeEmitter *CE); 542 543} // end namespace llvm 544 545#endif 546