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