MCStreamer.h revision f410608271b6318bfc9e26c0d199f185d5a89ccb
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 /// EmitCOFFSecRel32 - Emits a COFF section relative relocation. 243 /// 244 /// @param Symbol - Symbol the section relative realocation should point to. 245 virtual void EmitCOFFSecRel32(MCSymbol const *Symbol) = 0; 246 247 /// EmitELFSize - Emit an ELF .size directive. 248 /// 249 /// This corresponds to an assembler statement such as: 250 /// .size symbol, expression 251 /// 252 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) = 0; 253 254 /// EmitCommonSymbol - Emit a common symbol. 255 /// 256 /// @param Symbol - The common symbol to emit. 257 /// @param Size - The size of the common symbol. 258 /// @param ByteAlignment - The alignment of the symbol if 259 /// non-zero. This must be a power of 2. 260 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size, 261 unsigned ByteAlignment) = 0; 262 263 /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol. 264 /// 265 /// @param Symbol - The common symbol to emit. 266 /// @param Size - The size of the common symbol. 267 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) = 0; 268 269 /// EmitZerofill - Emit the zerofill section and an optional symbol. 270 /// 271 /// @param Section - The zerofill section to create and or to put the symbol 272 /// @param Symbol - The zerofill symbol to emit, if non-NULL. 273 /// @param Size - The size of the zerofill symbol. 274 /// @param ByteAlignment - The alignment of the zerofill symbol if 275 /// non-zero. This must be a power of 2 on some targets. 276 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0, 277 unsigned Size = 0,unsigned ByteAlignment = 0) = 0; 278 279 /// EmitTBSSSymbol - Emit a thread local bss (.tbss) symbol. 280 /// 281 /// @param Section - The thread local common section. 282 /// @param Symbol - The thread local common symbol to emit. 283 /// @param Size - The size of the symbol. 284 /// @param ByteAlignment - The alignment of the thread local common symbol 285 /// if non-zero. This must be a power of 2 on some targets. 286 virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol, 287 uint64_t Size, unsigned ByteAlignment = 0) = 0; 288 /// @} 289 /// @name Generating Data 290 /// @{ 291 292 /// EmitBytes - Emit the bytes in \arg Data into the output. 293 /// 294 /// This is used to implement assembler directives such as .byte, .ascii, 295 /// etc. 296 virtual void EmitBytes(StringRef Data, unsigned AddrSpace) = 0; 297 298 /// EmitValue - Emit the expression @p Value into the output as a native 299 /// integer of the given @p Size bytes. 300 /// 301 /// This is used to implement assembler directives such as .word, .quad, 302 /// etc. 303 /// 304 /// @param Value - The value to emit. 305 /// @param Size - The size of the integer (in bytes) to emit. This must 306 /// match a native machine width. 307 virtual void EmitValueImpl(const MCExpr *Value, unsigned Size, 308 bool isPCRel, unsigned AddrSpace) = 0; 309 310 void EmitValue(const MCExpr *Value, unsigned Size, unsigned AddrSpace = 0); 311 312 void EmitPCRelValue(const MCExpr *Value, unsigned Size, 313 unsigned AddrSpace = 0); 314 315 /// EmitIntValue - Special case of EmitValue that avoids the client having 316 /// to pass in a MCExpr for constant integers. 317 virtual void EmitIntValue(uint64_t Value, unsigned Size, 318 unsigned AddrSpace = 0); 319 320 /// EmitAbsValue - Emit the Value, but try to avoid relocations. On MachO 321 /// this is done by producing 322 /// foo = value 323 /// .long foo 324 void EmitAbsValue(const MCExpr *Value, unsigned Size, 325 unsigned AddrSpace = 0); 326 327 virtual void EmitULEB128Value(const MCExpr *Value, 328 unsigned AddrSpace = 0) = 0; 329 330 virtual void EmitSLEB128Value(const MCExpr *Value, 331 unsigned AddrSpace = 0) = 0; 332 333 /// EmitULEB128Value - Special case of EmitULEB128Value that avoids the 334 /// client having to pass in a MCExpr for constant integers. 335 void EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace = 0); 336 337 /// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the 338 /// client having to pass in a MCExpr for constant integers. 339 void EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace = 0); 340 341 /// EmitSymbolValue - Special case of EmitValue that avoids the client 342 /// having to pass in a MCExpr for MCSymbols. 343 void EmitSymbolValue(const MCSymbol *Sym, unsigned Size, 344 unsigned AddrSpace = 0); 345 346 void EmitPCRelSymbolValue(const MCSymbol *Sym, unsigned Size, 347 unsigned AddrSpace = 0); 348 349 /// EmitGPRel32Value - Emit the expression @p Value into the output as a 350 /// gprel32 (32-bit GP relative) value. 351 /// 352 /// This is used to implement assembler directives such as .gprel32 on 353 /// targets that support them. 354 virtual void EmitGPRel32Value(const MCExpr *Value); 355 356 /// EmitFill - Emit NumBytes bytes worth of the value specified by 357 /// FillValue. This implements directives such as '.space'. 358 virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue, 359 unsigned AddrSpace); 360 361 /// EmitZeros - Emit NumBytes worth of zeros. This is a convenience 362 /// function that just wraps EmitFill. 363 void EmitZeros(uint64_t NumBytes, unsigned AddrSpace) { 364 EmitFill(NumBytes, 0, AddrSpace); 365 } 366 367 368 /// EmitValueToAlignment - Emit some number of copies of @p Value until 369 /// the byte alignment @p ByteAlignment is reached. 370 /// 371 /// If the number of bytes need to emit for the alignment is not a multiple 372 /// of @p ValueSize, then the contents of the emitted fill bytes is 373 /// undefined. 374 /// 375 /// This used to implement the .align assembler directive. 376 /// 377 /// @param ByteAlignment - The alignment to reach. This must be a power of 378 /// two on some targets. 379 /// @param Value - The value to use when filling bytes. 380 /// @param ValueSize - The size of the integer (in bytes) to emit for 381 /// @p Value. This must match a native machine width. 382 /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If 383 /// the alignment cannot be reached in this many bytes, no bytes are 384 /// emitted. 385 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0, 386 unsigned ValueSize = 1, 387 unsigned MaxBytesToEmit = 0) = 0; 388 389 /// EmitCodeAlignment - Emit nops until the byte alignment @p ByteAlignment 390 /// is reached. 391 /// 392 /// This used to align code where the alignment bytes may be executed. This 393 /// can emit different bytes for different sizes to optimize execution. 394 /// 395 /// @param ByteAlignment - The alignment to reach. This must be a power of 396 /// two on some targets. 397 /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If 398 /// the alignment cannot be reached in this many bytes, no bytes are 399 /// emitted. 400 virtual void EmitCodeAlignment(unsigned ByteAlignment, 401 unsigned MaxBytesToEmit = 0) = 0; 402 403 /// EmitValueToOffset - Emit some number of copies of @p Value until the 404 /// byte offset @p Offset is reached. 405 /// 406 /// This is used to implement assembler directives such as .org. 407 /// 408 /// @param Offset - The offset to reach. This may be an expression, but the 409 /// expression must be associated with the current section. 410 /// @param Value - The value to use when filling bytes. 411 virtual void EmitValueToOffset(const MCExpr *Offset, 412 unsigned char Value = 0) = 0; 413 414 /// @} 415 416 /// EmitFileDirective - Switch to a new logical file. This is used to 417 /// implement the '.file "foo.c"' assembler directive. 418 virtual void EmitFileDirective(StringRef Filename) = 0; 419 420 /// EmitDwarfFileDirective - Associate a filename with a specified logical 421 /// file number. This implements the DWARF2 '.file 4 "foo.c"' assembler 422 /// directive. 423 virtual bool EmitDwarfFileDirective(unsigned FileNo,StringRef Filename); 424 425 /// EmitDwarfLocDirective - This implements the DWARF2 426 // '.loc fileno lineno ...' assembler directive. 427 virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line, 428 unsigned Column, unsigned Flags, 429 unsigned Isa, 430 unsigned Discriminator); 431 432 virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta, 433 const MCSymbol *LastLabel, 434 const MCSymbol *Label) = 0; 435 436 virtual void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel, 437 const MCSymbol *Label) { 438 } 439 440 void EmitDwarfSetLineAddr(int64_t LineDelta, const MCSymbol *Label, 441 int PointerSize); 442 443 virtual bool EmitCFIStartProc(); 444 virtual bool EmitCFIEndProc(); 445 virtual bool EmitCFIDefCfa(int64_t Register, int64_t Offset); 446 virtual bool EmitCFIDefCfaOffset(int64_t Offset); 447 virtual bool EmitCFIDefCfaRegister(int64_t Register); 448 virtual bool EmitCFIOffset(int64_t Register, int64_t Offset); 449 virtual bool EmitCFIPersonality(const MCSymbol *Sym, 450 unsigned Encoding); 451 virtual bool EmitCFILsda(const MCSymbol *Sym, unsigned Encoding); 452 virtual bool EmitCFIRememberState(); 453 virtual bool EmitCFIRestoreState(); 454 455 /// EmitInstruction - Emit the given @p Instruction into the current 456 /// section. 457 virtual void EmitInstruction(const MCInst &Inst) = 0; 458 459 /// EmitRawText - If this file is backed by a assembly streamer, this dumps 460 /// the specified string in the output .s file. This capability is 461 /// indicated by the hasRawTextSupport() predicate. By default this aborts. 462 virtual void EmitRawText(StringRef String); 463 void EmitRawText(const Twine &String); 464 465 /// Finish - Finish emission of machine code. 466 virtual void Finish() = 0; 467 }; 468 469 /// createNullStreamer - Create a dummy machine code streamer, which does 470 /// nothing. This is useful for timing the assembler front end. 471 MCStreamer *createNullStreamer(MCContext &Ctx); 472 473 /// createAsmStreamer - Create a machine code streamer which will print out 474 /// assembly for the native target, suitable for compiling with a native 475 /// assembler. 476 /// 477 /// \param InstPrint - If given, the instruction printer to use. If not given 478 /// the MCInst representation will be printed. This method takes ownership of 479 /// InstPrint. 480 /// 481 /// \param CE - If given, a code emitter to use to show the instruction 482 /// encoding inline with the assembly. This method takes ownership of \arg CE. 483 /// 484 /// \param TAB - If given, a target asm backend to use to show the fixup 485 /// information in conjunction with encoding information. This method takes 486 /// ownership of \arg TAB. 487 /// 488 /// \param ShowInst - Whether to show the MCInst representation inline with 489 /// the assembly. 490 MCStreamer *createAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS, 491 bool isVerboseAsm, 492 bool useLoc, 493 MCInstPrinter *InstPrint = 0, 494 MCCodeEmitter *CE = 0, 495 TargetAsmBackend *TAB = 0, 496 bool ShowInst = false); 497 498 /// createMachOStreamer - Create a machine code streamer which will generate 499 /// Mach-O format object files. 500 /// 501 /// Takes ownership of \arg TAB and \arg CE. 502 MCStreamer *createMachOStreamer(MCContext &Ctx, TargetAsmBackend &TAB, 503 raw_ostream &OS, MCCodeEmitter *CE, 504 bool RelaxAll = false); 505 506 /// createWinCOFFStreamer - Create a machine code streamer which will 507 /// generate Microsoft COFF format object files. 508 /// 509 /// Takes ownership of \arg TAB and \arg CE. 510 MCStreamer *createWinCOFFStreamer(MCContext &Ctx, 511 TargetAsmBackend &TAB, 512 MCCodeEmitter &CE, raw_ostream &OS, 513 bool RelaxAll = false); 514 515 /// createELFStreamer - Create a machine code streamer which will generate 516 /// ELF format object files. 517 MCStreamer *createELFStreamer(MCContext &Ctx, TargetAsmBackend &TAB, 518 raw_ostream &OS, MCCodeEmitter *CE, 519 bool RelaxAll, bool NoExecStack); 520 521 /// createLoggingStreamer - Create a machine code streamer which just logs the 522 /// API calls and then dispatches to another streamer. 523 /// 524 /// The new streamer takes ownership of the \arg Child. 525 MCStreamer *createLoggingStreamer(MCStreamer *Child, raw_ostream &OS); 526 527 /// createPureStreamer - Create a machine code streamer which will generate 528 /// "pure" MC object files, for use with MC-JIT and testing tools. 529 /// 530 /// Takes ownership of \arg TAB and \arg CE. 531 MCStreamer *createPureStreamer(MCContext &Ctx, TargetAsmBackend &TAB, 532 raw_ostream &OS, MCCodeEmitter *CE); 533 534} // end namespace llvm 535 536#endif 537