MCStreamer.h revision f9efd83166401bca542c6702ea329f9901c4e04b
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 bool EmitEHFrame; 54 bool EmitDebugFrame; 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 const MCExpr *BuildSymbolDiff(MCContext &Context, const MCSymbol *A, 71 const MCSymbol *B); 72 73 const MCExpr *ForceExpAbs(MCStreamer *Streamer, MCContext &Context, 74 const MCExpr* Expr); 75 76 public: 77 virtual ~MCStreamer(); 78 79 MCContext &getContext() const { return Context; } 80 81 unsigned getNumFrameInfos() { 82 return FrameInfos.size(); 83 } 84 85 const MCDwarfFrameInfo &getFrameInfo(unsigned i) { 86 return FrameInfos[i]; 87 } 88 89 /// @name Assembly File Formatting. 90 /// @{ 91 92 /// isVerboseAsm - Return true if this streamer supports verbose assembly 93 /// and if it is enabled. 94 virtual bool isVerboseAsm() const { return false; } 95 96 /// hasRawTextSupport - Return true if this asm streamer supports emitting 97 /// unformatted text to the .s file with EmitRawText. 98 virtual bool hasRawTextSupport() const { return false; } 99 100 /// AddComment - Add a comment that can be emitted to the generated .s 101 /// file if applicable as a QoI issue to make the output of the compiler 102 /// more readable. This only affects the MCAsmStreamer, and only when 103 /// verbose assembly output is enabled. 104 /// 105 /// If the comment includes embedded \n's, they will each get the comment 106 /// prefix as appropriate. The added comment should not end with a \n. 107 virtual void AddComment(const Twine &T) {} 108 109 /// GetCommentOS - Return a raw_ostream that comments can be written to. 110 /// Unlike AddComment, you are required to terminate comments with \n if you 111 /// use this method. 112 virtual raw_ostream &GetCommentOS(); 113 114 /// AddBlankLine - Emit a blank line to a .s file to pretty it up. 115 virtual void AddBlankLine() {} 116 117 /// @} 118 119 /// @name Symbol & Section Management 120 /// @{ 121 122 /// getCurrentSection - Return the current section that the streamer is 123 /// emitting code to. 124 const MCSection *getCurrentSection() const { 125 if (!SectionStack.empty()) 126 return SectionStack.back().first; 127 return NULL; 128 } 129 130 /// getPreviousSection - Return the previous section that the streamer is 131 /// emitting code to. 132 const MCSection *getPreviousSection() const { 133 if (!SectionStack.empty()) 134 return SectionStack.back().second; 135 return NULL; 136 } 137 138 /// ChangeSection - Update streamer for a new active section. 139 /// 140 /// This is called by PopSection and SwitchSection, if the current 141 /// section changes. 142 virtual void ChangeSection(const MCSection *) = 0; 143 144 /// pushSection - Save the current and previous section on the 145 /// section stack. 146 void PushSection() { 147 SectionStack.push_back(std::make_pair(getCurrentSection(), 148 getPreviousSection())); 149 } 150 151 /// popSection - Restore the current and previous section from 152 /// the section stack. Calls ChangeSection as needed. 153 /// 154 /// Returns false if the stack was empty. 155 bool PopSection() { 156 if (SectionStack.size() <= 1) 157 return false; 158 const MCSection *oldSection = SectionStack.pop_back_val().first; 159 const MCSection *curSection = SectionStack.back().first; 160 161 if (oldSection != curSection) 162 ChangeSection(curSection); 163 return true; 164 } 165 166 /// SwitchSection - Set the current section where code is being emitted to 167 /// @p Section. This is required to update CurSection. 168 /// 169 /// This corresponds to assembler directives like .section, .text, etc. 170 void SwitchSection(const MCSection *Section) { 171 assert(Section && "Cannot switch to a null section!"); 172 const MCSection *curSection = SectionStack.back().first; 173 SectionStack.back().second = curSection; 174 if (Section != curSection) { 175 SectionStack.back().first = Section; 176 ChangeSection(Section); 177 } 178 } 179 180 /// InitSections - Create the default sections and set the initial one. 181 virtual void InitSections() = 0; 182 183 /// EmitLabel - Emit a label for @p Symbol into the current section. 184 /// 185 /// This corresponds to an assembler statement such as: 186 /// foo: 187 /// 188 /// @param Symbol - The symbol to emit. A given symbol should only be 189 /// emitted as a label once, and symbols emitted as a label should never be 190 /// used in an assignment. 191 virtual void EmitLabel(MCSymbol *Symbol); 192 193 virtual void EmitEHSymAttributes(const MCSymbol *Symbol, 194 MCSymbol *EHSymbol); 195 196 /// EmitAssemblerFlag - Note in the output the specified @p Flag 197 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) = 0; 198 199 /// EmitThumbFunc - Note in the output that the specified @p Func is 200 /// a Thumb mode function (ARM target only). 201 virtual void EmitThumbFunc(MCSymbol *Func) = 0; 202 203 /// EmitAssignment - Emit an assignment of @p Value to @p Symbol. 204 /// 205 /// This corresponds to an assembler statement such as: 206 /// symbol = value 207 /// 208 /// The assignment generates no code, but has the side effect of binding the 209 /// value in the current context. For the assembly streamer, this prints the 210 /// binding into the .s file. 211 /// 212 /// @param Symbol - The symbol being assigned to. 213 /// @param Value - The value for the symbol. 214 virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) = 0; 215 216 /// EmitWeakReference - Emit an weak reference from @p Alias to @p Symbol. 217 /// 218 /// This corresponds to an assembler statement such as: 219 /// .weakref alias, symbol 220 /// 221 /// @param Alias - The alias that is being created. 222 /// @param Symbol - The symbol being aliased. 223 virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) = 0; 224 225 /// EmitSymbolAttribute - Add the given @p Attribute to @p Symbol. 226 virtual void EmitSymbolAttribute(MCSymbol *Symbol, 227 MCSymbolAttr Attribute) = 0; 228 229 /// EmitSymbolDesc - Set the @p DescValue for the @p Symbol. 230 /// 231 /// @param Symbol - The symbol to have its n_desc field set. 232 /// @param DescValue - The value to set into the n_desc field. 233 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) = 0; 234 235 /// BeginCOFFSymbolDef - Start emitting COFF symbol definition 236 /// 237 /// @param Symbol - The symbol to have its External & Type fields set. 238 virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) = 0; 239 240 /// EmitCOFFSymbolStorageClass - Emit the storage class of the symbol. 241 /// 242 /// @param StorageClass - The storage class the symbol should have. 243 virtual void EmitCOFFSymbolStorageClass(int StorageClass) = 0; 244 245 /// EmitCOFFSymbolType - Emit the type of the symbol. 246 /// 247 /// @param Type - A COFF type identifier (see COFF::SymbolType in X86COFF.h) 248 virtual void EmitCOFFSymbolType(int Type) = 0; 249 250 /// EndCOFFSymbolDef - Marks the end of the symbol definition. 251 virtual void EndCOFFSymbolDef() = 0; 252 253 /// EmitELFSize - Emit an ELF .size directive. 254 /// 255 /// This corresponds to an assembler statement such as: 256 /// .size symbol, expression 257 /// 258 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) = 0; 259 260 /// EmitCommonSymbol - Emit a common symbol. 261 /// 262 /// @param Symbol - The common symbol to emit. 263 /// @param Size - The size of the common symbol. 264 /// @param ByteAlignment - The alignment of the symbol if 265 /// non-zero. This must be a power of 2. 266 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size, 267 unsigned ByteAlignment) = 0; 268 269 /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol. 270 /// 271 /// @param Symbol - The common symbol to emit. 272 /// @param Size - The size of the common symbol. 273 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) = 0; 274 275 /// EmitZerofill - Emit the zerofill section and an optional symbol. 276 /// 277 /// @param Section - The zerofill section to create and or to put the symbol 278 /// @param Symbol - The zerofill symbol to emit, if non-NULL. 279 /// @param Size - The size of the zerofill symbol. 280 /// @param ByteAlignment - The alignment of the zerofill symbol if 281 /// non-zero. This must be a power of 2 on some targets. 282 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0, 283 unsigned Size = 0,unsigned ByteAlignment = 0) = 0; 284 285 /// EmitTBSSSymbol - Emit a thread local bss (.tbss) symbol. 286 /// 287 /// @param Section - The thread local common section. 288 /// @param Symbol - The thread local common symbol to emit. 289 /// @param Size - The size of the symbol. 290 /// @param ByteAlignment - The alignment of the thread local common symbol 291 /// if non-zero. This must be a power of 2 on some targets. 292 virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol, 293 uint64_t Size, unsigned ByteAlignment = 0) = 0; 294 /// @} 295 /// @name Generating Data 296 /// @{ 297 298 /// EmitBytes - Emit the bytes in \arg Data into the output. 299 /// 300 /// This is used to implement assembler directives such as .byte, .ascii, 301 /// etc. 302 virtual void EmitBytes(StringRef Data, unsigned AddrSpace) = 0; 303 304 /// EmitValue - Emit the expression @p Value into the output as a native 305 /// integer of the given @p Size bytes. 306 /// 307 /// This is used to implement assembler directives such as .word, .quad, 308 /// etc. 309 /// 310 /// @param Value - The value to emit. 311 /// @param Size - The size of the integer (in bytes) to emit. This must 312 /// match a native machine width. 313 virtual void EmitValueImpl(const MCExpr *Value, unsigned Size, 314 unsigned AddrSpace) = 0; 315 316 void EmitValue(const MCExpr *Value, unsigned Size, unsigned AddrSpace = 0); 317 318 /// EmitIntValue - Special case of EmitValue that avoids the client having 319 /// to pass in a MCExpr for constant integers. 320 virtual void EmitIntValue(uint64_t Value, unsigned Size, 321 unsigned AddrSpace = 0); 322 323 /// EmitAbsValue - Emit the Value, but try to avoid relocations. On MachO 324 /// this is done by producing 325 /// foo = value 326 /// .long foo 327 void EmitAbsValue(const MCExpr *Value, unsigned Size, 328 unsigned AddrSpace = 0); 329 330 virtual void EmitULEB128Value(const MCExpr *Value) = 0; 331 332 virtual void EmitSLEB128Value(const MCExpr *Value) = 0; 333 334 /// EmitULEB128Value - Special case of EmitULEB128Value that avoids the 335 /// client having to pass in a MCExpr for constant integers. 336 void EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace = 0); 337 338 /// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the 339 /// client having to pass in a MCExpr for constant integers. 340 void EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace = 0); 341 342 /// EmitSymbolValue - Special case of EmitValue that avoids the client 343 /// having to pass in a MCExpr for MCSymbols. 344 void EmitSymbolValue(const MCSymbol *Sym, unsigned Size, 345 unsigned AddrSpace = 0); 346 347 /// EmitGPRel32Value - Emit the expression @p Value into the output as a 348 /// gprel32 (32-bit GP relative) value. 349 /// 350 /// This is used to implement assembler directives such as .gprel32 on 351 /// targets that support them. 352 virtual void EmitGPRel32Value(const MCExpr *Value); 353 354 /// EmitFill - Emit NumBytes bytes worth of the value specified by 355 /// FillValue. This implements directives such as '.space'. 356 virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue, 357 unsigned AddrSpace); 358 359 /// EmitZeros - Emit NumBytes worth of zeros. This is a convenience 360 /// function that just wraps EmitFill. 361 void EmitZeros(uint64_t NumBytes, unsigned AddrSpace) { 362 EmitFill(NumBytes, 0, AddrSpace); 363 } 364 365 366 /// EmitValueToAlignment - Emit some number of copies of @p Value until 367 /// the byte alignment @p ByteAlignment is reached. 368 /// 369 /// If the number of bytes need to emit for the alignment is not a multiple 370 /// of @p ValueSize, then the contents of the emitted fill bytes is 371 /// undefined. 372 /// 373 /// This used to implement the .align assembler directive. 374 /// 375 /// @param ByteAlignment - The alignment to reach. This must be a power of 376 /// two on some targets. 377 /// @param Value - The value to use when filling bytes. 378 /// @param ValueSize - The size of the integer (in bytes) to emit for 379 /// @p Value. This must match a native machine width. 380 /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If 381 /// the alignment cannot be reached in this many bytes, no bytes are 382 /// emitted. 383 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0, 384 unsigned ValueSize = 1, 385 unsigned MaxBytesToEmit = 0) = 0; 386 387 /// EmitCodeAlignment - Emit nops until the byte alignment @p ByteAlignment 388 /// is reached. 389 /// 390 /// This used to align code where the alignment bytes may be executed. This 391 /// can emit different bytes for different sizes to optimize execution. 392 /// 393 /// @param ByteAlignment - The alignment to reach. This must be a power of 394 /// two on some targets. 395 /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If 396 /// the alignment cannot be reached in this many bytes, no bytes are 397 /// emitted. 398 virtual void EmitCodeAlignment(unsigned ByteAlignment, 399 unsigned MaxBytesToEmit = 0) = 0; 400 401 /// EmitValueToOffset - Emit some number of copies of @p Value until the 402 /// byte offset @p Offset is reached. 403 /// 404 /// This is used to implement assembler directives such as .org. 405 /// 406 /// @param Offset - The offset to reach. This may be an expression, but the 407 /// expression must be associated with the current section. 408 /// @param Value - The value to use when filling bytes. 409 virtual void EmitValueToOffset(const MCExpr *Offset, 410 unsigned char Value = 0) = 0; 411 412 /// @} 413 414 /// EmitFileDirective - Switch to a new logical file. This is used to 415 /// implement the '.file "foo.c"' assembler directive. 416 virtual void EmitFileDirective(StringRef Filename) = 0; 417 418 /// EmitDwarfFileDirective - Associate a filename with a specified logical 419 /// file number. This implements the DWARF2 '.file 4 "foo.c"' assembler 420 /// directive. 421 virtual bool EmitDwarfFileDirective(unsigned FileNo,StringRef Filename); 422 423 /// EmitDwarfLocDirective - This implements the DWARF2 424 // '.loc fileno lineno ...' assembler directive. 425 virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line, 426 unsigned Column, unsigned Flags, 427 unsigned Isa, 428 unsigned Discriminator, 429 StringRef FileName); 430 431 virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta, 432 const MCSymbol *LastLabel, 433 const MCSymbol *Label) = 0; 434 435 virtual void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel, 436 const MCSymbol *Label) { 437 } 438 439 void EmitDwarfSetLineAddr(int64_t LineDelta, const MCSymbol *Label, 440 int PointerSize); 441 442 virtual void EmitCFISections(bool EH, bool Debug); 443 virtual void EmitCFIStartProc(); 444 virtual void EmitCFIEndProc(); 445 virtual void EmitCFIDefCfa(int64_t Register, int64_t Offset); 446 virtual void EmitCFIDefCfaOffset(int64_t Offset); 447 virtual void EmitCFIDefCfaRegister(int64_t Register); 448 virtual void EmitCFIOffset(int64_t Register, int64_t Offset); 449 virtual void EmitCFIPersonality(const MCSymbol *Sym, unsigned Encoding); 450 virtual void EmitCFILsda(const MCSymbol *Sym, unsigned Encoding); 451 virtual void EmitCFIRememberState(); 452 virtual void EmitCFIRestoreState(); 453 virtual void EmitCFISameValue(int64_t Register); 454 virtual void EmitCFIRelOffset(int64_t Register, int64_t Offset); 455 virtual void EmitCFIAdjustCfaOffset(int64_t Adjustment); 456 457 /// EmitInstruction - Emit the given @p Instruction into the current 458 /// section. 459 virtual void EmitInstruction(const MCInst &Inst) = 0; 460 461 /// EmitRawText - If this file is backed by a assembly streamer, this dumps 462 /// the specified string in the output .s file. This capability is 463 /// indicated by the hasRawTextSupport() predicate. By default this aborts. 464 virtual void EmitRawText(StringRef String); 465 void EmitRawText(const Twine &String); 466 467 /// ARM-related methods. 468 /// FIXME: Eventually we should have some "target MC streamer" and move 469 /// these methods there. 470 virtual void EmitFnStart(); 471 virtual void EmitFnEnd(); 472 virtual void EmitCantUnwind(); 473 virtual void EmitPersonality(const MCSymbol *Personality); 474 virtual void EmitHandlerData(); 475 virtual void EmitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0); 476 virtual void EmitPad(int64_t Offset); 477 virtual void EmitRegSave(const SmallVectorImpl<unsigned> &RegList, 478 bool isVector); 479 480 /// Finish - Finish emission of machine code. 481 virtual void Finish() = 0; 482 }; 483 484 /// createNullStreamer - Create a dummy machine code streamer, which does 485 /// nothing. This is useful for timing the assembler front end. 486 MCStreamer *createNullStreamer(MCContext &Ctx); 487 488 /// createAsmStreamer - Create a machine code streamer which will print out 489 /// assembly for the native target, suitable for compiling with a native 490 /// assembler. 491 /// 492 /// \param InstPrint - If given, the instruction printer to use. If not given 493 /// the MCInst representation will be printed. This method takes ownership of 494 /// InstPrint. 495 /// 496 /// \param CE - If given, a code emitter to use to show the instruction 497 /// encoding inline with the assembly. This method takes ownership of \arg CE. 498 /// 499 /// \param TAB - If given, a target asm backend to use to show the fixup 500 /// information in conjunction with encoding information. This method takes 501 /// ownership of \arg TAB. 502 /// 503 /// \param ShowInst - Whether to show the MCInst representation inline with 504 /// the assembly. 505 MCStreamer *createAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS, 506 bool isVerboseAsm, 507 bool useLoc, 508 bool useCFI, 509 MCInstPrinter *InstPrint = 0, 510 MCCodeEmitter *CE = 0, 511 TargetAsmBackend *TAB = 0, 512 bool ShowInst = false); 513 514 /// createMachOStreamer - Create a machine code streamer which will generate 515 /// Mach-O format object files. 516 /// 517 /// Takes ownership of \arg TAB and \arg CE. 518 MCStreamer *createMachOStreamer(MCContext &Ctx, TargetAsmBackend &TAB, 519 raw_ostream &OS, MCCodeEmitter *CE, 520 bool RelaxAll = false); 521 522 /// createWinCOFFStreamer - Create a machine code streamer which will 523 /// generate Microsoft COFF format object files. 524 /// 525 /// Takes ownership of \arg TAB and \arg CE. 526 MCStreamer *createWinCOFFStreamer(MCContext &Ctx, 527 TargetAsmBackend &TAB, 528 MCCodeEmitter &CE, raw_ostream &OS, 529 bool RelaxAll = false); 530 531 /// createELFStreamer - Create a machine code streamer which will generate 532 /// ELF format object files. 533 MCStreamer *createELFStreamer(MCContext &Ctx, TargetAsmBackend &TAB, 534 raw_ostream &OS, MCCodeEmitter *CE, 535 bool RelaxAll, bool NoExecStack); 536 537 /// createLoggingStreamer - Create a machine code streamer which just logs the 538 /// API calls and then dispatches to another streamer. 539 /// 540 /// The new streamer takes ownership of the \arg Child. 541 MCStreamer *createLoggingStreamer(MCStreamer *Child, raw_ostream &OS); 542 543 /// createPureStreamer - Create a machine code streamer which will generate 544 /// "pure" MC object files, for use with MC-JIT and testing tools. 545 /// 546 /// Takes ownership of \arg TAB and \arg CE. 547 MCStreamer *createPureStreamer(MCContext &Ctx, TargetAsmBackend &TAB, 548 raw_ostream &OS, MCCodeEmitter *CE); 549 550} // end namespace llvm 551 552#endif 553