1 //===- MCContext.h - Machine Code Context -----------------------*- 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 #ifndef LLVM_MC_MCCONTEXT_H 11 #define LLVM_MC_MCCONTEXT_H 12 13 #include "llvm/ADT/DenseMap.h" 14 #include "llvm/ADT/SmallString.h" 15 #include "llvm/ADT/SmallVector.h" 16 #include "llvm/ADT/StringMap.h" 17 #include "llvm/MC/MCDwarf.h" 18 #include "llvm/MC/SectionKind.h" 19 #include "llvm/Support/Allocator.h" 20 #include "llvm/Support/Compiler.h" 21 #include "llvm/Support/raw_ostream.h" 22 #include <map> 23 #include <vector> // FIXME: Shouldn't be needed. 24 25 namespace llvm { 26 class MCAsmInfo; 27 class MCExpr; 28 class MCSection; 29 class MCSymbol; 30 class MCLabel; 31 class MCDwarfFile; 32 class MCDwarfLoc; 33 class MCObjectFileInfo; 34 class MCRegisterInfo; 35 class MCLineSection; 36 class SMLoc; 37 class StringRef; 38 class Twine; 39 class MCSectionMachO; 40 class MCSectionELF; 41 class MCSectionCOFF; 42 43 /// MCContext - Context object for machine code objects. This class owns all 44 /// of the sections that it creates. 45 /// 46 class MCContext { 47 MCContext(const MCContext&) LLVM_DELETED_FUNCTION; 48 MCContext &operator=(const MCContext&) LLVM_DELETED_FUNCTION; 49 public: 50 typedef StringMap<MCSymbol*, BumpPtrAllocator&> SymbolTable; 51 private: 52 /// The SourceMgr for this object, if any. 53 const SourceMgr *SrcMgr; 54 55 /// The MCAsmInfo for this target. 56 const MCAsmInfo *MAI; 57 58 /// The MCRegisterInfo for this target. 59 const MCRegisterInfo *MRI; 60 61 /// The MCObjectFileInfo for this target. 62 const MCObjectFileInfo *MOFI; 63 64 /// Allocator - Allocator object used for creating machine code objects. 65 /// 66 /// We use a bump pointer allocator to avoid the need to track all allocated 67 /// objects. 68 BumpPtrAllocator Allocator; 69 70 /// Symbols - Bindings of names to symbols. 71 SymbolTable Symbols; 72 73 /// UsedNames - Keeps tracks of names that were used both for used declared 74 /// and artificial symbols. 75 StringMap<bool, BumpPtrAllocator&> UsedNames; 76 77 /// NextUniqueID - The next ID to dole out to an unnamed assembler temporary 78 /// symbol. 79 unsigned NextUniqueID; 80 81 /// Instances of directional local labels. 82 DenseMap<unsigned, MCLabel *> Instances; 83 /// NextInstance() creates the next instance of the directional local label 84 /// for the LocalLabelVal and adds it to the map if needed. 85 unsigned NextInstance(int64_t LocalLabelVal); 86 /// GetInstance() gets the current instance of the directional local label 87 /// for the LocalLabelVal and adds it to the map if needed. 88 unsigned GetInstance(int64_t LocalLabelVal); 89 90 /// The file name of the log file from the environment variable 91 /// AS_SECURE_LOG_FILE. Which must be set before the .secure_log_unique 92 /// directive is used or it is an error. 93 char *SecureLogFile; 94 /// The stream that gets written to for the .secure_log_unique directive. 95 raw_ostream *SecureLog; 96 /// Boolean toggled when .secure_log_unique / .secure_log_reset is seen to 97 /// catch errors if .secure_log_unique appears twice without 98 /// .secure_log_reset appearing between them. 99 bool SecureLogUsed; 100 101 /// The compilation directory to use for DW_AT_comp_dir. 102 SmallString<128> CompilationDir; 103 104 /// The main file name if passed in explicitly. 105 std::string MainFileName; 106 107 /// The dwarf file and directory tables from the dwarf .file directive. 108 /// We now emit a line table for each compile unit. To reduce the prologue 109 /// size of each line table, the files and directories used by each compile 110 /// unit are separated. 111 typedef std::map<unsigned, SmallVector<MCDwarfFile *, 4> > MCDwarfFilesMap; 112 MCDwarfFilesMap MCDwarfFilesCUMap; 113 std::map<unsigned, SmallVector<StringRef, 4> > MCDwarfDirsCUMap; 114 115 /// The current dwarf line information from the last dwarf .loc directive. 116 MCDwarfLoc CurrentDwarfLoc; 117 bool DwarfLocSeen; 118 119 /// Generate dwarf debugging info for assembly source files. 120 bool GenDwarfForAssembly; 121 122 /// The current dwarf file number when generate dwarf debugging info for 123 /// assembly source files. 124 unsigned GenDwarfFileNumber; 125 126 /// The default initial text section that we generate dwarf debugging line 127 /// info for when generating dwarf assembly source files. 128 const MCSection *GenDwarfSection; 129 /// Symbols created for the start and end of this section. 130 MCSymbol *GenDwarfSectionStartSym, *GenDwarfSectionEndSym; 131 132 /// The information gathered from labels that will have dwarf label 133 /// entries when generating dwarf assembly source files. 134 std::vector<const MCGenDwarfLabelEntry *> MCGenDwarfLabelEntries; 135 136 /// The string to embed in the debug information for the compile unit, if 137 /// non-empty. 138 StringRef DwarfDebugFlags; 139 140 /// The string to embed in as the dwarf AT_producer for the compile unit, if 141 /// non-empty. 142 StringRef DwarfDebugProducer; 143 144 /// Honor temporary labels, this is useful for debugging semantic 145 /// differences between temporary and non-temporary labels (primarily on 146 /// Darwin). 147 bool AllowTemporaryLabels; 148 149 /// The dwarf line information from the .loc directives for the sections 150 /// with assembled machine instructions have after seeing .loc directives. 151 DenseMap<const MCSection *, MCLineSection *> MCLineSections; 152 /// We need a deterministic iteration order, so we remember the order 153 /// the elements were added. 154 std::vector<const MCSection *> MCLineSectionOrder; 155 /// The Compile Unit ID that we are currently processing. 156 unsigned DwarfCompileUnitID; 157 /// The line table start symbol for each Compile Unit. 158 DenseMap<unsigned, MCSymbol *> MCLineTableSymbols; 159 160 void *MachOUniquingMap, *ELFUniquingMap, *COFFUniquingMap; 161 162 /// Do automatic reset in destructor 163 bool AutoReset; 164 165 MCSymbol *CreateSymbol(StringRef Name); 166 167 public: 168 explicit MCContext(const MCAsmInfo *MAI, const MCRegisterInfo *MRI, 169 const MCObjectFileInfo *MOFI, const SourceMgr *Mgr = 0, 170 bool DoAutoReset = true); 171 ~MCContext(); 172 173 const SourceMgr *getSourceManager() const { return SrcMgr; } 174 175 const MCAsmInfo *getAsmInfo() const { return MAI; } 176 177 const MCRegisterInfo *getRegisterInfo() const { return MRI; } 178 179 const MCObjectFileInfo *getObjectFileInfo() const { return MOFI; } 180 181 void setAllowTemporaryLabels(bool Value) { AllowTemporaryLabels = Value; } 182 183 /// @name Module Lifetime Management 184 /// @{ 185 186 /// reset - return object to right after construction state to prepare 187 /// to process a new module 188 void reset(); 189 190 /// @} 191 192 /// @name Symbol Management 193 /// @{ 194 195 /// CreateTempSymbol - Create and return a new assembler temporary symbol 196 /// with a unique but unspecified name. 197 MCSymbol *CreateTempSymbol(); 198 199 /// getUniqueSymbolID() - Return a unique identifier for use in constructing 200 /// symbol names. 201 unsigned getUniqueSymbolID() { return NextUniqueID++; } 202 203 /// CreateDirectionalLocalSymbol - Create the definition of a directional 204 /// local symbol for numbered label (used for "1:" definitions). 205 MCSymbol *CreateDirectionalLocalSymbol(int64_t LocalLabelVal); 206 207 /// GetDirectionalLocalSymbol - Create and return a directional local 208 /// symbol for numbered label (used for "1b" or 1f" references). 209 MCSymbol *GetDirectionalLocalSymbol(int64_t LocalLabelVal, int bORf); 210 211 /// GetOrCreateSymbol - Lookup the symbol inside with the specified 212 /// @p Name. If it exists, return it. If not, create a forward 213 /// reference and return it. 214 /// 215 /// @param Name - The symbol name, which must be unique across all symbols. 216 MCSymbol *GetOrCreateSymbol(StringRef Name); 217 MCSymbol *GetOrCreateSymbol(const Twine &Name); 218 219 /// LookupSymbol - Get the symbol for \p Name, or null. 220 MCSymbol *LookupSymbol(StringRef Name) const; 221 MCSymbol *LookupSymbol(const Twine &Name) const; 222 223 /// getSymbols - Get a reference for the symbol table for clients that 224 /// want to, for example, iterate over all symbols. 'const' because we 225 /// still want any modifications to the table itself to use the MCContext 226 /// APIs. 227 const SymbolTable &getSymbols() const { 228 return Symbols; 229 } 230 231 /// @} 232 233 /// @name Section Management 234 /// @{ 235 236 /// getMachOSection - Return the MCSection for the specified mach-o section. 237 /// This requires the operands to be valid. 238 const MCSectionMachO *getMachOSection(StringRef Segment, 239 StringRef Section, 240 unsigned TypeAndAttributes, 241 unsigned Reserved2, 242 SectionKind K); 243 const MCSectionMachO *getMachOSection(StringRef Segment, 244 StringRef Section, 245 unsigned TypeAndAttributes, 246 SectionKind K) { 247 return getMachOSection(Segment, Section, TypeAndAttributes, 0, K); 248 } 249 250 const MCSectionELF *getELFSection(StringRef Section, unsigned Type, 251 unsigned Flags, SectionKind Kind); 252 253 const MCSectionELF *getELFSection(StringRef Section, unsigned Type, 254 unsigned Flags, SectionKind Kind, 255 unsigned EntrySize, StringRef Group); 256 257 const MCSectionELF *CreateELFGroupSection(); 258 259 const MCSectionCOFF *getCOFFSection(StringRef Section, 260 unsigned Characteristics, 261 SectionKind Kind, int Selection = 0, 262 const MCSectionCOFF *Assoc = 0); 263 264 const MCSectionCOFF *getCOFFSection(StringRef Section); 265 266 /// @} 267 268 /// @name Dwarf Management 269 /// @{ 270 271 /// \brief Get the compilation directory for DW_AT_comp_dir 272 /// This can be overridden by clients which want to control the reported 273 /// compilation directory and have it be something other than the current 274 /// working directory. 275 StringRef getCompilationDir() const { return CompilationDir; } 276 277 /// \brief Set the compilation directory for DW_AT_comp_dir 278 /// Override the default (CWD) compilation directory. 279 void setCompilationDir(StringRef S) { CompilationDir = S.str(); } 280 281 /// \brief Get the main file name for use in error messages and debug 282 /// info. This can be set to ensure we've got the correct file name 283 /// after preprocessing or for -save-temps. 284 const std::string &getMainFileName() const { return MainFileName; } 285 286 /// \brief Set the main file name and override the default. 287 void setMainFileName(StringRef S) { MainFileName = S.str(); } 288 289 /// GetDwarfFile - creates an entry in the dwarf file and directory tables. 290 unsigned GetDwarfFile(StringRef Directory, StringRef FileName, 291 unsigned FileNumber, unsigned CUID); 292 293 bool isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID = 0); 294 295 bool hasDwarfFiles() const { 296 // Traverse MCDwarfFilesCUMap and check whether each entry is empty. 297 MCDwarfFilesMap::const_iterator MapB, MapE; 298 for (MapB = MCDwarfFilesCUMap.begin(), MapE = MCDwarfFilesCUMap.end(); 299 MapB != MapE; MapB++) 300 if (!MapB->second.empty()) 301 return true; 302 return false; 303 } 304 305 const SmallVectorImpl<MCDwarfFile *> &getMCDwarfFiles(unsigned CUID = 0) { 306 return MCDwarfFilesCUMap[CUID]; 307 } 308 const SmallVectorImpl<StringRef> &getMCDwarfDirs(unsigned CUID = 0) { 309 return MCDwarfDirsCUMap[CUID]; 310 } 311 312 const DenseMap<const MCSection *, MCLineSection *> 313 &getMCLineSections() const { 314 return MCLineSections; 315 } 316 const std::vector<const MCSection *> &getMCLineSectionOrder() const { 317 return MCLineSectionOrder; 318 } 319 void addMCLineSection(const MCSection *Sec, MCLineSection *Line) { 320 MCLineSections[Sec] = Line; 321 MCLineSectionOrder.push_back(Sec); 322 } 323 unsigned getDwarfCompileUnitID() { 324 return DwarfCompileUnitID; 325 } 326 void setDwarfCompileUnitID(unsigned CUIndex) { 327 DwarfCompileUnitID = CUIndex; 328 } 329 const DenseMap<unsigned, MCSymbol *> &getMCLineTableSymbols() const { 330 return MCLineTableSymbols; 331 } 332 MCSymbol *getMCLineTableSymbol(unsigned ID) const { 333 DenseMap<unsigned, MCSymbol *>::const_iterator CIter = 334 MCLineTableSymbols.find(ID); 335 if (CIter == MCLineTableSymbols.end()) 336 return NULL; 337 return CIter->second; 338 } 339 void setMCLineTableSymbol(MCSymbol *Sym, unsigned ID) { 340 MCLineTableSymbols[ID] = Sym; 341 } 342 343 /// setCurrentDwarfLoc - saves the information from the currently parsed 344 /// dwarf .loc directive and sets DwarfLocSeen. When the next instruction 345 /// is assembled an entry in the line number table with this information and 346 /// the address of the instruction will be created. 347 void setCurrentDwarfLoc(unsigned FileNum, unsigned Line, unsigned Column, 348 unsigned Flags, unsigned Isa, 349 unsigned Discriminator) { 350 CurrentDwarfLoc.setFileNum(FileNum); 351 CurrentDwarfLoc.setLine(Line); 352 CurrentDwarfLoc.setColumn(Column); 353 CurrentDwarfLoc.setFlags(Flags); 354 CurrentDwarfLoc.setIsa(Isa); 355 CurrentDwarfLoc.setDiscriminator(Discriminator); 356 DwarfLocSeen = true; 357 } 358 void ClearDwarfLocSeen() { DwarfLocSeen = false; } 359 360 bool getDwarfLocSeen() { return DwarfLocSeen; } 361 const MCDwarfLoc &getCurrentDwarfLoc() { return CurrentDwarfLoc; } 362 363 bool getGenDwarfForAssembly() { return GenDwarfForAssembly; } 364 void setGenDwarfForAssembly(bool Value) { GenDwarfForAssembly = Value; } 365 unsigned getGenDwarfFileNumber() { return GenDwarfFileNumber; } 366 unsigned nextGenDwarfFileNumber() { return ++GenDwarfFileNumber; } 367 const MCSection *getGenDwarfSection() { return GenDwarfSection; } 368 void setGenDwarfSection(const MCSection *Sec) { GenDwarfSection = Sec; } 369 MCSymbol *getGenDwarfSectionStartSym() { return GenDwarfSectionStartSym; } 370 void setGenDwarfSectionStartSym(MCSymbol *Sym) { 371 GenDwarfSectionStartSym = Sym; 372 } 373 MCSymbol *getGenDwarfSectionEndSym() { return GenDwarfSectionEndSym; } 374 void setGenDwarfSectionEndSym(MCSymbol *Sym) { 375 GenDwarfSectionEndSym = Sym; 376 } 377 const std::vector<const MCGenDwarfLabelEntry *> 378 &getMCGenDwarfLabelEntries() const { 379 return MCGenDwarfLabelEntries; 380 } 381 void addMCGenDwarfLabelEntry(const MCGenDwarfLabelEntry *E) { 382 MCGenDwarfLabelEntries.push_back(E); 383 } 384 385 void setDwarfDebugFlags(StringRef S) { DwarfDebugFlags = S; } 386 StringRef getDwarfDebugFlags() { return DwarfDebugFlags; } 387 388 void setDwarfDebugProducer(StringRef S) { DwarfDebugProducer = S; } 389 StringRef getDwarfDebugProducer() { return DwarfDebugProducer; } 390 391 /// @} 392 393 char *getSecureLogFile() { return SecureLogFile; } 394 raw_ostream *getSecureLog() { return SecureLog; } 395 bool getSecureLogUsed() { return SecureLogUsed; } 396 void setSecureLog(raw_ostream *Value) { 397 SecureLog = Value; 398 } 399 void setSecureLogUsed(bool Value) { 400 SecureLogUsed = Value; 401 } 402 403 void *Allocate(unsigned Size, unsigned Align = 8) { 404 return Allocator.Allocate(Size, Align); 405 } 406 void Deallocate(void *Ptr) { 407 } 408 409 // Unrecoverable error has occured. Display the best diagnostic we can 410 // and bail via exit(1). For now, most MC backend errors are unrecoverable. 411 // FIXME: We should really do something about that. 412 LLVM_ATTRIBUTE_NORETURN void FatalError(SMLoc L, const Twine &Msg); 413 }; 414 415 } // end namespace llvm 416 417 // operator new and delete aren't allowed inside namespaces. 418 // The throw specifications are mandated by the standard. 419 /// @brief Placement new for using the MCContext's allocator. 420 /// 421 /// This placement form of operator new uses the MCContext's allocator for 422 /// obtaining memory. It is a non-throwing new, which means that it returns 423 /// null on error. (If that is what the allocator does. The current does, so if 424 /// this ever changes, this operator will have to be changed, too.) 425 /// Usage looks like this (assuming there's an MCContext 'Context' in scope): 426 /// @code 427 /// // Default alignment (16) 428 /// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments); 429 /// // Specific alignment 430 /// IntegerLiteral *Ex2 = new (Context, 8) IntegerLiteral(arguments); 431 /// @endcode 432 /// Please note that you cannot use delete on the pointer; it must be 433 /// deallocated using an explicit destructor call followed by 434 /// @c Context.Deallocate(Ptr). 435 /// 436 /// @param Bytes The number of bytes to allocate. Calculated by the compiler. 437 /// @param C The MCContext that provides the allocator. 438 /// @param Alignment The alignment of the allocated memory (if the underlying 439 /// allocator supports it). 440 /// @return The allocated memory. Could be NULL. 441 inline void *operator new(size_t Bytes, llvm::MCContext &C, 442 size_t Alignment = 16) throw () { 443 return C.Allocate(Bytes, Alignment); 444 } 445 /// @brief Placement delete companion to the new above. 446 /// 447 /// This operator is just a companion to the new above. There is no way of 448 /// invoking it directly; see the new operator for more details. This operator 449 /// is called implicitly by the compiler if a placement new expression using 450 /// the MCContext throws in the object constructor. 451 inline void operator delete(void *Ptr, llvm::MCContext &C, size_t) 452 throw () { 453 C.Deallocate(Ptr); 454 } 455 456 /// This placement form of operator new[] uses the MCContext's allocator for 457 /// obtaining memory. It is a non-throwing new[], which means that it returns 458 /// null on error. 459 /// Usage looks like this (assuming there's an MCContext 'Context' in scope): 460 /// @code 461 /// // Default alignment (16) 462 /// char *data = new (Context) char[10]; 463 /// // Specific alignment 464 /// char *data = new (Context, 8) char[10]; 465 /// @endcode 466 /// Please note that you cannot use delete on the pointer; it must be 467 /// deallocated using an explicit destructor call followed by 468 /// @c Context.Deallocate(Ptr). 469 /// 470 /// @param Bytes The number of bytes to allocate. Calculated by the compiler. 471 /// @param C The MCContext that provides the allocator. 472 /// @param Alignment The alignment of the allocated memory (if the underlying 473 /// allocator supports it). 474 /// @return The allocated memory. Could be NULL. 475 inline void *operator new[](size_t Bytes, llvm::MCContext& C, 476 size_t Alignment = 16) throw () { 477 return C.Allocate(Bytes, Alignment); 478 } 479 480 /// @brief Placement delete[] companion to the new[] above. 481 /// 482 /// This operator is just a companion to the new[] above. There is no way of 483 /// invoking it directly; see the new[] operator for more details. This operator 484 /// is called implicitly by the compiler if a placement new[] expression using 485 /// the MCContext throws in the object constructor. 486 inline void operator delete[](void *Ptr, llvm::MCContext &C) throw () { 487 C.Deallocate(Ptr); 488 } 489 490 #endif 491
