MCContext.h revision 99cb622041a0839c7dfcf0263c5102a305a0fdb5
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 25namespace 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 42 /// MCContext - Context object for machine code objects. This class owns all 43 /// of the sections that it creates. 44 /// 45 class MCContext { 46 MCContext(const MCContext&) LLVM_DELETED_FUNCTION; 47 MCContext &operator=(const MCContext&) LLVM_DELETED_FUNCTION; 48 public: 49 typedef StringMap<MCSymbol*, BumpPtrAllocator&> SymbolTable; 50 private: 51 /// The SourceMgr for this object, if any. 52 const SourceMgr *SrcMgr; 53 54 /// The MCAsmInfo for this target. 55 const MCAsmInfo *MAI; 56 57 /// The MCRegisterInfo for this target. 58 const MCRegisterInfo *MRI; 59 60 /// The MCObjectFileInfo for this target. 61 const MCObjectFileInfo *MOFI; 62 63 /// Allocator - Allocator object used for creating machine code objects. 64 /// 65 /// We use a bump pointer allocator to avoid the need to track all allocated 66 /// objects. 67 BumpPtrAllocator Allocator; 68 69 /// Symbols - Bindings of names to symbols. 70 SymbolTable Symbols; 71 72 /// UsedNames - Keeps tracks of names that were used both for used declared 73 /// and artificial symbols. 74 StringMap<bool, BumpPtrAllocator&> UsedNames; 75 76 /// NextUniqueID - The next ID to dole out to an unnamed assembler temporary 77 /// symbol. 78 unsigned NextUniqueID; 79 80 /// Instances of directional local labels. 81 DenseMap<unsigned, MCLabel *> Instances; 82 /// NextInstance() creates the next instance of the directional local label 83 /// for the LocalLabelVal and adds it to the map if needed. 84 unsigned NextInstance(int64_t LocalLabelVal); 85 /// GetInstance() gets the current instance of the directional local label 86 /// for the LocalLabelVal and adds it to the map if needed. 87 unsigned GetInstance(int64_t LocalLabelVal); 88 89 /// The file name of the log file from the environment variable 90 /// AS_SECURE_LOG_FILE. Which must be set before the .secure_log_unique 91 /// directive is used or it is an error. 92 char *SecureLogFile; 93 /// The stream that gets written to for the .secure_log_unique directive. 94 raw_ostream *SecureLog; 95 /// Boolean toggled when .secure_log_unique / .secure_log_reset is seen to 96 /// catch errors if .secure_log_unique appears twice without 97 /// .secure_log_reset appearing between them. 98 bool SecureLogUsed; 99 100 /// The compilation directory to use for DW_AT_comp_dir. 101 SmallString<128> CompilationDir; 102 103 /// The main file name if passed in explicitly. 104 std::string MainFileName; 105 106 /// The dwarf file and directory tables from the dwarf .file directive. 107 /// We now emit a line table for each compile unit. To reduce the prologue 108 /// size of each line table, the files and directories used by each compile 109 /// unit are separated. 110 typedef std::map<unsigned, SmallVector<MCDwarfFile *, 4> > MCDwarfFilesMap; 111 MCDwarfFilesMap MCDwarfFilesCUMap; 112 std::map<unsigned, SmallVector<StringRef, 4> > MCDwarfDirsCUMap; 113 114 /// The current dwarf line information from the last dwarf .loc directive. 115 MCDwarfLoc CurrentDwarfLoc; 116 bool DwarfLocSeen; 117 118 /// Generate dwarf debugging info for assembly source files. 119 bool GenDwarfForAssembly; 120 121 /// The current dwarf file number when generate dwarf debugging info for 122 /// assembly source files. 123 unsigned GenDwarfFileNumber; 124 125 /// The default initial text section that we generate dwarf debugging line 126 /// info for when generating dwarf assembly source files. 127 const MCSection *GenDwarfSection; 128 /// Symbols created for the start and end of this section. 129 MCSymbol *GenDwarfSectionStartSym, *GenDwarfSectionEndSym; 130 131 /// The information gathered from labels that will have dwarf label 132 /// entries when generating dwarf assembly source files. 133 std::vector<const MCGenDwarfLabelEntry *> MCGenDwarfLabelEntries; 134 135 /// The string to embed in the debug information for the compile unit, if 136 /// non-empty. 137 StringRef DwarfDebugFlags; 138 139 /// The string to embed in as the dwarf AT_producer for the compile unit, if 140 /// non-empty. 141 StringRef DwarfDebugProducer; 142 143 /// Honor temporary labels, this is useful for debugging semantic 144 /// differences between temporary and non-temporary labels (primarily on 145 /// Darwin). 146 bool AllowTemporaryLabels; 147 148 /// The dwarf line information from the .loc directives for the sections 149 /// with assembled machine instructions have after seeing .loc directives. 150 DenseMap<const MCSection *, MCLineSection *> MCLineSections; 151 /// We need a deterministic iteration order, so we remember the order 152 /// the elements were added. 153 std::vector<const MCSection *> MCLineSectionOrder; 154 /// The Compile Unit ID that we are currently processing. 155 unsigned DwarfCompileUnitID; 156 /// The line table start symbol for each Compile Unit. 157 DenseMap<unsigned, MCSymbol *> MCLineTableSymbols; 158 159 void *MachOUniquingMap, *ELFUniquingMap, *COFFUniquingMap; 160 161 /// Do automatic reset in destructor 162 bool AutoReset; 163 164 MCSymbol *CreateSymbol(StringRef Name); 165 166 public: 167 explicit MCContext(const MCAsmInfo *MAI, const MCRegisterInfo *MRI, 168 const MCObjectFileInfo *MOFI, const SourceMgr *Mgr = 0, 169 bool DoAutoReset = true); 170 ~MCContext(); 171 172 const SourceMgr *getSourceManager() const { return SrcMgr; } 173 174 const MCAsmInfo *getAsmInfo() const { return MAI; } 175 176 const MCRegisterInfo *getRegisterInfo() const { return MRI; } 177 178 const MCObjectFileInfo *getObjectFileInfo() const { return MOFI; } 179 180 void setAllowTemporaryLabels(bool Value) { AllowTemporaryLabels = Value; } 181 182 /// @name Module Lifetime Management 183 /// @{ 184 185 /// reset - return object to right after construction state to prepare 186 /// to process a new module 187 void reset(); 188 189 /// @} 190 191 /// @name Symbol Management 192 /// @{ 193 194 /// CreateTempSymbol - Create and return a new assembler temporary symbol 195 /// with a unique but unspecified name. 196 MCSymbol *CreateTempSymbol(); 197 198 /// getUniqueSymbolID() - Return a unique identifier for use in constructing 199 /// symbol names. 200 unsigned getUniqueSymbolID() { return NextUniqueID++; } 201 202 /// CreateDirectionalLocalSymbol - Create the definition of a directional 203 /// local symbol for numbered label (used for "1:" definitions). 204 MCSymbol *CreateDirectionalLocalSymbol(int64_t LocalLabelVal); 205 206 /// GetDirectionalLocalSymbol - Create and return a directional local 207 /// symbol for numbered label (used for "1b" or 1f" references). 208 MCSymbol *GetDirectionalLocalSymbol(int64_t LocalLabelVal, int bORf); 209 210 /// GetOrCreateSymbol - Lookup the symbol inside with the specified 211 /// @p Name. If it exists, return it. If not, create a forward 212 /// reference and return it. 213 /// 214 /// @param Name - The symbol name, which must be unique across all symbols. 215 MCSymbol *GetOrCreateSymbol(StringRef Name); 216 MCSymbol *GetOrCreateSymbol(const Twine &Name); 217 218 /// LookupSymbol - Get the symbol for \p Name, or null. 219 MCSymbol *LookupSymbol(StringRef Name) const; 220 MCSymbol *LookupSymbol(const Twine &Name) const; 221 222 /// getSymbols - Get a reference for the symbol table for clients that 223 /// want to, for example, iterate over all symbols. 'const' because we 224 /// still want any modifications to the table itself to use the MCContext 225 /// APIs. 226 const SymbolTable &getSymbols() const { 227 return Symbols; 228 } 229 230 /// @} 231 232 /// @name Section Management 233 /// @{ 234 235 /// getMachOSection - Return the MCSection for the specified mach-o section. 236 /// This requires the operands to be valid. 237 const MCSectionMachO *getMachOSection(StringRef Segment, 238 StringRef Section, 239 unsigned TypeAndAttributes, 240 unsigned Reserved2, 241 SectionKind K); 242 const MCSectionMachO *getMachOSection(StringRef Segment, 243 StringRef Section, 244 unsigned TypeAndAttributes, 245 SectionKind K) { 246 return getMachOSection(Segment, Section, TypeAndAttributes, 0, K); 247 } 248 249 const MCSectionELF *getELFSection(StringRef Section, unsigned Type, 250 unsigned Flags, SectionKind Kind); 251 252 const MCSectionELF *getELFSection(StringRef Section, unsigned Type, 253 unsigned Flags, SectionKind Kind, 254 unsigned EntrySize, StringRef Group); 255 256 const MCSectionELF *CreateELFGroupSection(); 257 258 const MCSection *getCOFFSection(StringRef Section, unsigned Characteristics, 259 int Selection, SectionKind Kind); 260 261 const MCSection *getCOFFSection(StringRef Section, unsigned Characteristics, 262 SectionKind Kind) { 263 return getCOFFSection (Section, Characteristics, 0, Kind); 264 } 265 266 267 /// @} 268 269 /// @name Dwarf Management 270 /// @{ 271 272 /// \brief Get the compilation directory for DW_AT_comp_dir 273 /// This can be overridden by clients which want to control the reported 274 /// compilation directory and have it be something other than the current 275 /// working directory. 276 StringRef getCompilationDir() const { return CompilationDir; } 277 278 /// \brief Set the compilation directory for DW_AT_comp_dir 279 /// Override the default (CWD) compilation directory. 280 void setCompilationDir(StringRef S) { CompilationDir = S.str(); } 281 282 /// \brief Get the main file name for use in error messages and debug 283 /// info. This can be set to ensure we've got the correct file name 284 /// after preprocessing or for -save-temps. 285 const std::string &getMainFileName() const { return MainFileName; } 286 287 /// \brief Set the main file name and override the default. 288 void setMainFileName(StringRef S) { MainFileName = S.str(); } 289 290 /// GetDwarfFile - creates an entry in the dwarf file and directory tables. 291 unsigned GetDwarfFile(StringRef Directory, StringRef FileName, 292 unsigned FileNumber, unsigned CUID); 293 294 bool isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID = 0); 295 296 bool hasDwarfFiles() const { 297 // Traverse MCDwarfFilesCUMap and check whether each entry is empty. 298 MCDwarfFilesMap::const_iterator MapB, MapE; 299 for (MapB = MCDwarfFilesCUMap.begin(), MapE = MCDwarfFilesCUMap.end(); 300 MapB != MapE; MapB++) 301 if (!MapB->second.empty()) 302 return true; 303 return false; 304 } 305 306 const SmallVectorImpl<MCDwarfFile *> &getMCDwarfFiles(unsigned CUID = 0) { 307 return MCDwarfFilesCUMap[CUID]; 308 } 309 const SmallVectorImpl<StringRef> &getMCDwarfDirs(unsigned CUID = 0) { 310 return MCDwarfDirsCUMap[CUID]; 311 } 312 313 const DenseMap<const MCSection *, MCLineSection *> 314 &getMCLineSections() const { 315 return MCLineSections; 316 } 317 const std::vector<const MCSection *> &getMCLineSectionOrder() const { 318 return MCLineSectionOrder; 319 } 320 void addMCLineSection(const MCSection *Sec, MCLineSection *Line) { 321 MCLineSections[Sec] = Line; 322 MCLineSectionOrder.push_back(Sec); 323 } 324 unsigned getDwarfCompileUnitID() { 325 return DwarfCompileUnitID; 326 } 327 void setDwarfCompileUnitID(unsigned CUIndex) { 328 DwarfCompileUnitID = CUIndex; 329 } 330 const DenseMap<unsigned, MCSymbol *> &getMCLineTableSymbols() const { 331 return MCLineTableSymbols; 332 } 333 MCSymbol *getMCLineTableSymbol(unsigned ID) const { 334 DenseMap<unsigned, MCSymbol *>::const_iterator CIter = 335 MCLineTableSymbols.find(ID); 336 if (CIter == MCLineTableSymbols.end()) 337 return NULL; 338 return CIter->second; 339 } 340 void setMCLineTableSymbol(MCSymbol *Sym, unsigned ID) { 341 MCLineTableSymbols[ID] = Sym; 342 } 343 344 /// setCurrentDwarfLoc - saves the information from the currently parsed 345 /// dwarf .loc directive and sets DwarfLocSeen. When the next instruction 346 /// is assembled an entry in the line number table with this information and 347 /// the address of the instruction will be created. 348 void setCurrentDwarfLoc(unsigned FileNum, unsigned Line, unsigned Column, 349 unsigned Flags, unsigned Isa, 350 unsigned Discriminator) { 351 CurrentDwarfLoc.setFileNum(FileNum); 352 CurrentDwarfLoc.setLine(Line); 353 CurrentDwarfLoc.setColumn(Column); 354 CurrentDwarfLoc.setFlags(Flags); 355 CurrentDwarfLoc.setIsa(Isa); 356 CurrentDwarfLoc.setDiscriminator(Discriminator); 357 DwarfLocSeen = true; 358 } 359 void ClearDwarfLocSeen() { DwarfLocSeen = false; } 360 361 bool getDwarfLocSeen() { return DwarfLocSeen; } 362 const MCDwarfLoc &getCurrentDwarfLoc() { return CurrentDwarfLoc; } 363 364 bool getGenDwarfForAssembly() { return GenDwarfForAssembly; } 365 void setGenDwarfForAssembly(bool Value) { GenDwarfForAssembly = Value; } 366 unsigned getGenDwarfFileNumber() { return GenDwarfFileNumber; } 367 unsigned nextGenDwarfFileNumber() { return ++GenDwarfFileNumber; } 368 const MCSection *getGenDwarfSection() { return GenDwarfSection; } 369 void setGenDwarfSection(const MCSection *Sec) { GenDwarfSection = Sec; } 370 MCSymbol *getGenDwarfSectionStartSym() { return GenDwarfSectionStartSym; } 371 void setGenDwarfSectionStartSym(MCSymbol *Sym) { 372 GenDwarfSectionStartSym = Sym; 373 } 374 MCSymbol *getGenDwarfSectionEndSym() { return GenDwarfSectionEndSym; } 375 void setGenDwarfSectionEndSym(MCSymbol *Sym) { 376 GenDwarfSectionEndSym = Sym; 377 } 378 const std::vector<const MCGenDwarfLabelEntry *> 379 &getMCGenDwarfLabelEntries() const { 380 return MCGenDwarfLabelEntries; 381 } 382 void addMCGenDwarfLabelEntry(const MCGenDwarfLabelEntry *E) { 383 MCGenDwarfLabelEntries.push_back(E); 384 } 385 386 void setDwarfDebugFlags(StringRef S) { DwarfDebugFlags = S; } 387 StringRef getDwarfDebugFlags() { return DwarfDebugFlags; } 388 389 void setDwarfDebugProducer(StringRef S) { DwarfDebugProducer = S; } 390 StringRef getDwarfDebugProducer() { return DwarfDebugProducer; } 391 392 /// @} 393 394 char *getSecureLogFile() { return SecureLogFile; } 395 raw_ostream *getSecureLog() { return SecureLog; } 396 bool getSecureLogUsed() { return SecureLogUsed; } 397 void setSecureLog(raw_ostream *Value) { 398 SecureLog = Value; 399 } 400 void setSecureLogUsed(bool Value) { 401 SecureLogUsed = Value; 402 } 403 404 void *Allocate(unsigned Size, unsigned Align = 8) { 405 return Allocator.Allocate(Size, Align); 406 } 407 void Deallocate(void *Ptr) { 408 } 409 410 // Unrecoverable error has occured. Display the best diagnostic we can 411 // and bail via exit(1). For now, most MC backend errors are unrecoverable. 412 // FIXME: We should really do something about that. 413 LLVM_ATTRIBUTE_NORETURN void FatalError(SMLoc L, const Twine &Msg); 414 }; 415 416} // end namespace llvm 417 418// operator new and delete aren't allowed inside namespaces. 419// The throw specifications are mandated by the standard. 420/// @brief Placement new for using the MCContext's allocator. 421/// 422/// This placement form of operator new uses the MCContext's allocator for 423/// obtaining memory. It is a non-throwing new, which means that it returns 424/// null on error. (If that is what the allocator does. The current does, so if 425/// this ever changes, this operator will have to be changed, too.) 426/// Usage looks like this (assuming there's an MCContext 'Context' in scope): 427/// @code 428/// // Default alignment (16) 429/// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments); 430/// // Specific alignment 431/// IntegerLiteral *Ex2 = new (Context, 8) IntegerLiteral(arguments); 432/// @endcode 433/// Please note that you cannot use delete on the pointer; it must be 434/// deallocated using an explicit destructor call followed by 435/// @c Context.Deallocate(Ptr). 436/// 437/// @param Bytes The number of bytes to allocate. Calculated by the compiler. 438/// @param C The MCContext that provides the allocator. 439/// @param Alignment The alignment of the allocated memory (if the underlying 440/// allocator supports it). 441/// @return The allocated memory. Could be NULL. 442inline void *operator new(size_t Bytes, llvm::MCContext &C, 443 size_t Alignment = 16) throw () { 444 return C.Allocate(Bytes, Alignment); 445} 446/// @brief Placement delete companion to the new above. 447/// 448/// This operator is just a companion to the new above. There is no way of 449/// invoking it directly; see the new operator for more details. This operator 450/// is called implicitly by the compiler if a placement new expression using 451/// the MCContext throws in the object constructor. 452inline void operator delete(void *Ptr, llvm::MCContext &C, size_t) 453 throw () { 454 C.Deallocate(Ptr); 455} 456 457/// This placement form of operator new[] uses the MCContext's allocator for 458/// obtaining memory. It is a non-throwing new[], which means that it returns 459/// null on error. 460/// Usage looks like this (assuming there's an MCContext 'Context' in scope): 461/// @code 462/// // Default alignment (16) 463/// char *data = new (Context) char[10]; 464/// // Specific alignment 465/// char *data = new (Context, 8) char[10]; 466/// @endcode 467/// Please note that you cannot use delete on the pointer; it must be 468/// deallocated using an explicit destructor call followed by 469/// @c Context.Deallocate(Ptr). 470/// 471/// @param Bytes The number of bytes to allocate. Calculated by the compiler. 472/// @param C The MCContext that provides the allocator. 473/// @param Alignment The alignment of the allocated memory (if the underlying 474/// allocator supports it). 475/// @return The allocated memory. Could be NULL. 476inline void *operator new[](size_t Bytes, llvm::MCContext& C, 477 size_t Alignment = 16) throw () { 478 return C.Allocate(Bytes, Alignment); 479} 480 481/// @brief Placement delete[] companion to the new[] above. 482/// 483/// This operator is just a companion to the new[] above. There is no way of 484/// invoking it directly; see the new[] operator for more details. This operator 485/// is called implicitly by the compiler if a placement new[] expression using 486/// the MCContext throws in the object constructor. 487inline void operator delete[](void *Ptr, llvm::MCContext &C) throw () { 488 C.Deallocate(Ptr); 489} 490 491#endif 492