MCStreamer.h revision d7c8ccae8e48dce3ab7c3e9b4d8a309998c47961
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/Support/DataTypes.h" 18#include "llvm/MC/MCDirectives.h" 19#include "llvm/MC/MCDwarf.h" 20 21namespace llvm { 22 class MCAsmInfo; 23 class MCCodeEmitter; 24 class MCContext; 25 class MCExpr; 26 class MCInst; 27 class MCInstPrinter; 28 class MCSection; 29 class MCSymbol; 30 class StringRef; 31 class TargetAsmBackend; 32 class TargetLoweringObjectFile; 33 class Twine; 34 class raw_ostream; 35 class formatted_raw_ostream; 36 37 /// MCStreamer - Streaming machine code generation interface. This interface 38 /// is intended to provide a programatic interface that is very similar to the 39 /// level that an assembler .s file provides. It has callbacks to emit bytes, 40 /// handle directives, etc. The implementation of this interface retains 41 /// state to know what the current section is etc. 42 /// 43 /// There are multiple implementations of this interface: one for writing out 44 /// a .s file, and implementations that write out .o files of various formats. 45 /// 46 class MCStreamer { 47 MCContext &Context; 48 49 MCStreamer(const MCStreamer&); // DO NOT IMPLEMENT 50 MCStreamer &operator=(const MCStreamer&); // DO NOT IMPLEMENT 51 52 void EmitSymbolValue(const MCSymbol *Sym, unsigned Size, 53 bool isPCRel, unsigned AddrSpace); 54 55 std::vector<MCDwarfFrameInfo> FrameInfos; 56 MCDwarfFrameInfo *getCurrentFrameInfo(); 57 void EnsureValidFrame(); 58 59 protected: 60 MCStreamer(MCContext &Ctx); 61 62 /// CurSection - This is the current section code is being emitted to, it is 63 /// kept up to date by SwitchSection. 64 const MCSection *CurSection; 65 66 /// PrevSection - This is the previous section code is being emitted to, it 67 /// is kept up to date by SwitchSection. 68 const MCSection *PrevSection; 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 { return CurSection; } 119 120 /// getPreviousSection - Return the previous section that the streamer is 121 /// emitting code to. 122 const MCSection *getPreviousSection() const { return PrevSection; } 123 124 /// SwitchSection - Set the current section where code is being emitted to 125 /// @p Section. This is required to update CurSection. 126 /// 127 /// This corresponds to assembler directives like .section, .text, etc. 128 virtual void SwitchSection(const MCSection *Section) = 0; 129 130 /// InitSections - Create the default sections and set the initial one. 131 virtual void InitSections() = 0; 132 133 /// EmitLabel - Emit a label for @p Symbol into the current section. 134 /// 135 /// This corresponds to an assembler statement such as: 136 /// foo: 137 /// 138 /// @param Symbol - The symbol to emit. A given symbol should only be 139 /// emitted as a label once, and symbols emitted as a label should never be 140 /// used in an assignment. 141 virtual void EmitLabel(MCSymbol *Symbol) = 0; 142 143 /// EmitAssemblerFlag - Note in the output the specified @p Flag 144 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) = 0; 145 146 /// EmitThumbFunc - Note in the output that the specified @p Func is 147 /// a Thumb mode function (ARM target only). 148 virtual void EmitThumbFunc(MCSymbol *Func) = 0; 149 150 /// EmitAssignment - Emit an assignment of @p Value to @p Symbol. 151 /// 152 /// This corresponds to an assembler statement such as: 153 /// symbol = value 154 /// 155 /// The assignment generates no code, but has the side effect of binding the 156 /// value in the current context. For the assembly streamer, this prints the 157 /// binding into the .s file. 158 /// 159 /// @param Symbol - The symbol being assigned to. 160 /// @param Value - The value for the symbol. 161 virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) = 0; 162 163 /// EmitWeakReference - Emit an weak reference from @p Alias to @p Symbol. 164 /// 165 /// This corresponds to an assembler statement such as: 166 /// .weakref alias, symbol 167 /// 168 /// @param Alias - The alias that is being created. 169 /// @param Symbol - The symbol being aliased. 170 virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) = 0; 171 172 /// EmitSymbolAttribute - Add the given @p Attribute to @p Symbol. 173 virtual void EmitSymbolAttribute(MCSymbol *Symbol, 174 MCSymbolAttr Attribute) = 0; 175 176 /// EmitSymbolDesc - Set the @p DescValue for the @p Symbol. 177 /// 178 /// @param Symbol - The symbol to have its n_desc field set. 179 /// @param DescValue - The value to set into the n_desc field. 180 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) = 0; 181 182 /// BeginCOFFSymbolDef - Start emitting COFF symbol definition 183 /// 184 /// @param Symbol - The symbol to have its External & Type fields set. 185 virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) = 0; 186 187 /// EmitCOFFSymbolStorageClass - Emit the storage class of the symbol. 188 /// 189 /// @param StorageClass - The storage class the symbol should have. 190 virtual void EmitCOFFSymbolStorageClass(int StorageClass) = 0; 191 192 /// EmitCOFFSymbolType - Emit the type of the symbol. 193 /// 194 /// @param Type - A COFF type identifier (see COFF::SymbolType in X86COFF.h) 195 virtual void EmitCOFFSymbolType(int Type) = 0; 196 197 /// EndCOFFSymbolDef - Marks the end of the symbol definition. 198 virtual void EndCOFFSymbolDef() = 0; 199 200 /// EmitELFSize - Emit an ELF .size directive. 201 /// 202 /// This corresponds to an assembler statement such as: 203 /// .size symbol, expression 204 /// 205 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) = 0; 206 207 /// EmitCommonSymbol - Emit a common symbol. 208 /// 209 /// @param Symbol - The common symbol to emit. 210 /// @param Size - The size of the common symbol. 211 /// @param ByteAlignment - The alignment of the symbol if 212 /// non-zero. This must be a power of 2. 213 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size, 214 unsigned ByteAlignment) = 0; 215 216 /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol. 217 /// 218 /// @param Symbol - The common symbol to emit. 219 /// @param Size - The size of the common symbol. 220 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) = 0; 221 222 /// EmitZerofill - Emit the zerofill section and an optional symbol. 223 /// 224 /// @param Section - The zerofill section to create and or to put the symbol 225 /// @param Symbol - The zerofill symbol to emit, if non-NULL. 226 /// @param Size - The size of the zerofill symbol. 227 /// @param ByteAlignment - The alignment of the zerofill symbol if 228 /// non-zero. This must be a power of 2 on some targets. 229 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0, 230 unsigned Size = 0,unsigned ByteAlignment = 0) = 0; 231 232 /// EmitTBSSSymbol - Emit a thread local bss (.tbss) symbol. 233 /// 234 /// @param Section - The thread local common section. 235 /// @param Symbol - The thread local common symbol to emit. 236 /// @param Size - The size of the symbol. 237 /// @param ByteAlignment - The alignment of the thread local common symbol 238 /// if non-zero. This must be a power of 2 on some targets. 239 virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol, 240 uint64_t Size, unsigned ByteAlignment = 0) = 0; 241 /// @} 242 /// @name Generating Data 243 /// @{ 244 245 /// EmitBytes - Emit the bytes in \arg Data into the output. 246 /// 247 /// This is used to implement assembler directives such as .byte, .ascii, 248 /// etc. 249 virtual void EmitBytes(StringRef Data, unsigned AddrSpace) = 0; 250 251 /// EmitValue - Emit the expression @p Value into the output as a native 252 /// integer of the given @p Size bytes. 253 /// 254 /// This is used to implement assembler directives such as .word, .quad, 255 /// etc. 256 /// 257 /// @param Value - The value to emit. 258 /// @param Size - The size of the integer (in bytes) to emit. This must 259 /// match a native machine width. 260 virtual void EmitValueImpl(const MCExpr *Value, unsigned Size, 261 bool isPCRel, unsigned AddrSpace) = 0; 262 263 void EmitValue(const MCExpr *Value, unsigned Size, unsigned AddrSpace = 0); 264 265 void EmitPCRelValue(const MCExpr *Value, unsigned Size, 266 unsigned AddrSpace = 0); 267 268 /// EmitIntValue - Special case of EmitValue that avoids the client having 269 /// to pass in a MCExpr for constant integers. 270 virtual void EmitIntValue(uint64_t Value, unsigned Size, 271 unsigned AddrSpace = 0); 272 273 /// EmitAbsValue - Emit the Value, but try to avoid relocations. On MachO 274 /// this is done by producing 275 /// foo = value 276 /// .long foo 277 void EmitAbsValue(const MCExpr *Value, unsigned Size, 278 unsigned AddrSpace = 0); 279 280 virtual void EmitULEB128Value(const MCExpr *Value, 281 unsigned AddrSpace = 0) = 0; 282 283 virtual void EmitSLEB128Value(const MCExpr *Value, 284 unsigned AddrSpace = 0) = 0; 285 286 /// EmitULEB128Value - Special case of EmitULEB128Value that avoids the 287 /// client having to pass in a MCExpr for constant integers. 288 void EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace = 0); 289 290 /// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the 291 /// client having to pass in a MCExpr for constant integers. 292 void EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace = 0); 293 294 /// EmitSymbolValue - Special case of EmitValue that avoids the client 295 /// having to pass in a MCExpr for MCSymbols. 296 void EmitSymbolValue(const MCSymbol *Sym, unsigned Size, 297 unsigned AddrSpace = 0); 298 299 void EmitPCRelSymbolValue(const MCSymbol *Sym, unsigned Size, 300 unsigned AddrSpace = 0); 301 302 /// EmitGPRel32Value - Emit the expression @p Value into the output as a 303 /// gprel32 (32-bit GP relative) value. 304 /// 305 /// This is used to implement assembler directives such as .gprel32 on 306 /// targets that support them. 307 virtual void EmitGPRel32Value(const MCExpr *Value); 308 309 /// EmitFill - Emit NumBytes bytes worth of the value specified by 310 /// FillValue. This implements directives such as '.space'. 311 virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue, 312 unsigned AddrSpace); 313 314 /// EmitZeros - Emit NumBytes worth of zeros. This is a convenience 315 /// function that just wraps EmitFill. 316 void EmitZeros(uint64_t NumBytes, unsigned AddrSpace) { 317 EmitFill(NumBytes, 0, AddrSpace); 318 } 319 320 321 /// EmitValueToAlignment - Emit some number of copies of @p Value until 322 /// the byte alignment @p ByteAlignment is reached. 323 /// 324 /// If the number of bytes need to emit for the alignment is not a multiple 325 /// of @p ValueSize, then the contents of the emitted fill bytes is 326 /// undefined. 327 /// 328 /// This used to implement the .align assembler directive. 329 /// 330 /// @param ByteAlignment - The alignment to reach. This must be a power of 331 /// two on some targets. 332 /// @param Value - The value to use when filling bytes. 333 /// @param ValueSize - The size of the integer (in bytes) to emit for 334 /// @p Value. This must match a native machine width. 335 /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If 336 /// the alignment cannot be reached in this many bytes, no bytes are 337 /// emitted. 338 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0, 339 unsigned ValueSize = 1, 340 unsigned MaxBytesToEmit = 0) = 0; 341 342 /// EmitCodeAlignment - Emit nops until the byte alignment @p ByteAlignment 343 /// is reached. 344 /// 345 /// This used to align code where the alignment bytes may be executed. This 346 /// can emit different bytes for different sizes to optimize execution. 347 /// 348 /// @param ByteAlignment - The alignment to reach. This must be a power of 349 /// two on some targets. 350 /// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If 351 /// the alignment cannot be reached in this many bytes, no bytes are 352 /// emitted. 353 virtual void EmitCodeAlignment(unsigned ByteAlignment, 354 unsigned MaxBytesToEmit = 0) = 0; 355 356 /// EmitValueToOffset - Emit some number of copies of @p Value until the 357 /// byte offset @p Offset is reached. 358 /// 359 /// This is used to implement assembler directives such as .org. 360 /// 361 /// @param Offset - The offset to reach. This may be an expression, but the 362 /// expression must be associated with the current section. 363 /// @param Value - The value to use when filling bytes. 364 virtual void EmitValueToOffset(const MCExpr *Offset, 365 unsigned char Value = 0) = 0; 366 367 /// @} 368 369 /// EmitFileDirective - Switch to a new logical file. This is used to 370 /// implement the '.file "foo.c"' assembler directive. 371 virtual void EmitFileDirective(StringRef Filename) = 0; 372 373 /// EmitDwarfFileDirective - Associate a filename with a specified logical 374 /// file number. This implements the DWARF2 '.file 4 "foo.c"' assembler 375 /// directive. 376 virtual bool EmitDwarfFileDirective(unsigned FileNo,StringRef Filename); 377 378 /// EmitDwarfLocDirective - This implements the DWARF2 379 // '.loc fileno lineno ...' assembler directive. 380 virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line, 381 unsigned Column, unsigned Flags, 382 unsigned Isa, 383 unsigned Discriminator); 384 385 virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta, 386 const MCSymbol *LastLabel, 387 const MCSymbol *Label) = 0; 388 389 void EmitDwarfSetLineAddr(int64_t LineDelta, const MCSymbol *Label, 390 int PointerSize); 391 392 virtual bool EmitCFIStartProc(); 393 virtual bool EmitCFIEndProc(); 394 virtual bool EmitCFIDefCfaOffset(int64_t Offset); 395 virtual bool EmitCFIDefCfaRegister(int64_t Register); 396 virtual bool EmitCFIOffset(int64_t Register, int64_t Offset); 397 virtual bool EmitCFIPersonality(const MCSymbol *Sym); 398 virtual bool EmitCFILsda(const MCSymbol *Sym); 399 400 /// EmitInstruction - Emit the given @p Instruction into the current 401 /// section. 402 virtual void EmitInstruction(const MCInst &Inst) = 0; 403 404 /// EmitRawText - If this file is backed by a assembly streamer, this dumps 405 /// the specified string in the output .s file. This capability is 406 /// indicated by the hasRawTextSupport() predicate. By default this aborts. 407 virtual void EmitRawText(StringRef String); 408 void EmitRawText(const Twine &String); 409 410 /// Finish - Finish emission of machine code. 411 virtual void Finish() = 0; 412 }; 413 414 /// createNullStreamer - Create a dummy machine code streamer, which does 415 /// nothing. This is useful for timing the assembler front end. 416 MCStreamer *createNullStreamer(MCContext &Ctx); 417 418 /// createAsmStreamer - Create a machine code streamer which will print out 419 /// assembly for the native target, suitable for compiling with a native 420 /// assembler. 421 /// 422 /// \param InstPrint - If given, the instruction printer to use. If not given 423 /// the MCInst representation will be printed. This method takes ownership of 424 /// InstPrint. 425 /// 426 /// \param CE - If given, a code emitter to use to show the instruction 427 /// encoding inline with the assembly. This method takes ownership of \arg CE. 428 /// 429 /// \param TAB - If given, a target asm backend to use to show the fixup 430 /// information in conjunction with encoding information. This method takes 431 /// ownership of \arg TAB. 432 /// 433 /// \param ShowInst - Whether to show the MCInst representation inline with 434 /// the assembly. 435 MCStreamer *createAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS, 436 bool isVerboseAsm, 437 bool useLoc, 438 MCInstPrinter *InstPrint = 0, 439 MCCodeEmitter *CE = 0, 440 TargetAsmBackend *TAB = 0, 441 bool ShowInst = false); 442 443 /// createMachOStreamer - Create a machine code streamer which will generate 444 /// Mach-O format object files. 445 /// 446 /// Takes ownership of \arg TAB and \arg CE. 447 MCStreamer *createMachOStreamer(MCContext &Ctx, TargetAsmBackend &TAB, 448 raw_ostream &OS, MCCodeEmitter *CE, 449 bool RelaxAll = false); 450 451 /// createWinCOFFStreamer - Create a machine code streamer which will 452 /// generate Microsoft COFF format object files. 453 /// 454 /// Takes ownership of \arg TAB and \arg CE. 455 MCStreamer *createWinCOFFStreamer(MCContext &Ctx, 456 TargetAsmBackend &TAB, 457 MCCodeEmitter &CE, raw_ostream &OS, 458 bool RelaxAll = false); 459 460 /// createELFStreamer - Create a machine code streamer which will generate 461 /// ELF format object files. 462 MCStreamer *createELFStreamer(MCContext &Ctx, TargetAsmBackend &TAB, 463 raw_ostream &OS, MCCodeEmitter *CE, 464 bool RelaxAll = false); 465 466 /// createLoggingStreamer - Create a machine code streamer which just logs the 467 /// API calls and then dispatches to another streamer. 468 /// 469 /// The new streamer takes ownership of the \arg Child. 470 MCStreamer *createLoggingStreamer(MCStreamer *Child, raw_ostream &OS); 471 472 /// createPureStreamer - Create a machine code streamer which will generate 473 /// "pure" MC object files, for use with MC-JIT and testing tools. 474 /// 475 /// Takes ownership of \arg TAB and \arg CE. 476 MCStreamer *createPureStreamer(MCContext &Ctx, TargetAsmBackend &TAB, 477 raw_ostream &OS, MCCodeEmitter *CE); 478 479} // end namespace llvm 480 481#endif 482