MCContext.h revision 5399d2502acaf96fe8420e61913e77f0b23650ff
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/StringMap.h" 15#include "llvm/MC/MCDwarf.h" 16#include "llvm/MC/SectionKind.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 22namespace 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 /// Do automatic reset in destructor 141 bool AutoReset; 142 143 MCSymbol *CreateSymbol(StringRef Name); 144 145 public: 146 explicit MCContext(const MCAsmInfo &MAI, const MCRegisterInfo &MRI, 147 const MCObjectFileInfo *MOFI, const SourceMgr *Mgr = 0, 148 bool DoAutoReset = true); 149 ~MCContext(); 150 151 const SourceMgr *getSourceManager() const { return SrcMgr; } 152 153 const MCAsmInfo &getAsmInfo() const { return MAI; } 154 155 const MCRegisterInfo &getRegisterInfo() const { return MRI; } 156 157 const MCObjectFileInfo *getObjectFileInfo() const { return MOFI; } 158 159 void setAllowTemporaryLabels(bool Value) { AllowTemporaryLabels = Value; } 160 161 /// @name Module Lifetime Management 162 /// @{ 163 164 /// reset - return object to right after construction state to prepare 165 /// to process a new module 166 void reset(); 167 168 /// @} 169 170 /// @name Symbol Management 171 /// @{ 172 173 /// CreateTempSymbol - Create and return a new assembler temporary symbol 174 /// with a unique but unspecified name. 175 MCSymbol *CreateTempSymbol(); 176 177 /// getUniqueSymbolID() - Return a unique identifier for use in constructing 178 /// symbol names. 179 unsigned getUniqueSymbolID() { return NextUniqueID++; } 180 181 /// CreateDirectionalLocalSymbol - Create the definition of a directional 182 /// local symbol for numbered label (used for "1:" definitions). 183 MCSymbol *CreateDirectionalLocalSymbol(int64_t LocalLabelVal); 184 185 /// GetDirectionalLocalSymbol - Create and return a directional local 186 /// symbol for numbered label (used for "1b" or 1f" references). 187 MCSymbol *GetDirectionalLocalSymbol(int64_t LocalLabelVal, int bORf); 188 189 /// GetOrCreateSymbol - Lookup the symbol inside with the specified 190 /// @p Name. If it exists, return it. If not, create a forward 191 /// reference and return it. 192 /// 193 /// @param Name - The symbol name, which must be unique across all symbols. 194 MCSymbol *GetOrCreateSymbol(StringRef Name); 195 MCSymbol *GetOrCreateSymbol(const Twine &Name); 196 197 /// LookupSymbol - Get the symbol for \p Name, or null. 198 MCSymbol *LookupSymbol(StringRef Name) const; 199 MCSymbol *LookupSymbol(const Twine &Name) const; 200 201 /// getSymbols - Get a reference for the symbol table for clients that 202 /// want to, for example, iterate over all symbols. 'const' because we 203 /// still want any modifications to the table itself to use the MCContext 204 /// APIs. 205 const SymbolTable &getSymbols() const { 206 return Symbols; 207 } 208 209 /// @} 210 211 /// @name Section Management 212 /// @{ 213 214 /// getMachOSection - Return the MCSection for the specified mach-o section. 215 /// This requires the operands to be valid. 216 const MCSectionMachO *getMachOSection(StringRef Segment, 217 StringRef Section, 218 unsigned TypeAndAttributes, 219 unsigned Reserved2, 220 SectionKind K); 221 const MCSectionMachO *getMachOSection(StringRef Segment, 222 StringRef Section, 223 unsigned TypeAndAttributes, 224 SectionKind K) { 225 return getMachOSection(Segment, Section, TypeAndAttributes, 0, K); 226 } 227 228 const MCSectionELF *getELFSection(StringRef Section, unsigned Type, 229 unsigned Flags, SectionKind Kind); 230 231 const MCSectionELF *getELFSection(StringRef Section, unsigned Type, 232 unsigned Flags, SectionKind Kind, 233 unsigned EntrySize, StringRef Group); 234 235 const MCSectionELF *CreateELFGroupSection(); 236 237 const MCSection *getCOFFSection(StringRef Section, unsigned Characteristics, 238 int Selection, SectionKind Kind); 239 240 const MCSection *getCOFFSection(StringRef Section, unsigned Characteristics, 241 SectionKind Kind) { 242 return getCOFFSection (Section, Characteristics, 0, Kind); 243 } 244 245 246 /// @} 247 248 /// @name Dwarf Management 249 /// @{ 250 251 /// GetDwarfFile - creates an entry in the dwarf file and directory tables. 252 unsigned GetDwarfFile(StringRef Directory, StringRef FileName, 253 unsigned FileNumber); 254 255 bool isValidDwarfFileNumber(unsigned FileNumber); 256 257 bool hasDwarfFiles() const { 258 return !MCDwarfFiles.empty(); 259 } 260 261 const std::vector<MCDwarfFile *> &getMCDwarfFiles() { 262 return MCDwarfFiles; 263 } 264 const std::vector<StringRef> &getMCDwarfDirs() { 265 return MCDwarfDirs; 266 } 267 268 const DenseMap<const MCSection *, MCLineSection *> 269 &getMCLineSections() const { 270 return MCLineSections; 271 } 272 const std::vector<const MCSection *> &getMCLineSectionOrder() const { 273 return MCLineSectionOrder; 274 } 275 void addMCLineSection(const MCSection *Sec, MCLineSection *Line) { 276 MCLineSections[Sec] = Line; 277 MCLineSectionOrder.push_back(Sec); 278 } 279 280 /// setCurrentDwarfLoc - saves the information from the currently parsed 281 /// dwarf .loc directive and sets DwarfLocSeen. When the next instruction 282 /// is assembled an entry in the line number table with this information and 283 /// the address of the instruction will be created. 284 void setCurrentDwarfLoc(unsigned FileNum, unsigned Line, unsigned Column, 285 unsigned Flags, unsigned Isa, 286 unsigned Discriminator) { 287 CurrentDwarfLoc.setFileNum(FileNum); 288 CurrentDwarfLoc.setLine(Line); 289 CurrentDwarfLoc.setColumn(Column); 290 CurrentDwarfLoc.setFlags(Flags); 291 CurrentDwarfLoc.setIsa(Isa); 292 CurrentDwarfLoc.setDiscriminator(Discriminator); 293 DwarfLocSeen = true; 294 } 295 void ClearDwarfLocSeen() { DwarfLocSeen = false; } 296 297 bool getDwarfLocSeen() { return DwarfLocSeen; } 298 const MCDwarfLoc &getCurrentDwarfLoc() { return CurrentDwarfLoc; } 299 300 bool getGenDwarfForAssembly() { return GenDwarfForAssembly; } 301 void setGenDwarfForAssembly(bool Value) { GenDwarfForAssembly = Value; } 302 unsigned getGenDwarfFileNumber() { return GenDwarfFileNumber; } 303 unsigned nextGenDwarfFileNumber() { return ++GenDwarfFileNumber; } 304 const MCSection *getGenDwarfSection() { return GenDwarfSection; } 305 void setGenDwarfSection(const MCSection *Sec) { GenDwarfSection = Sec; } 306 MCSymbol *getGenDwarfSectionStartSym() { return GenDwarfSectionStartSym; } 307 void setGenDwarfSectionStartSym(MCSymbol *Sym) { 308 GenDwarfSectionStartSym = Sym; 309 } 310 MCSymbol *getGenDwarfSectionEndSym() { return GenDwarfSectionEndSym; } 311 void setGenDwarfSectionEndSym(MCSymbol *Sym) { 312 GenDwarfSectionEndSym = Sym; 313 } 314 const std::vector<const MCGenDwarfLabelEntry *> 315 &getMCGenDwarfLabelEntries() const { 316 return MCGenDwarfLabelEntries; 317 } 318 void addMCGenDwarfLabelEntry(const MCGenDwarfLabelEntry *E) { 319 MCGenDwarfLabelEntries.push_back(E); 320 } 321 322 void setDwarfDebugFlags(StringRef S) { DwarfDebugFlags = S; } 323 StringRef getDwarfDebugFlags() { return DwarfDebugFlags; } 324 325 /// @} 326 327 char *getSecureLogFile() { return SecureLogFile; } 328 raw_ostream *getSecureLog() { return SecureLog; } 329 bool getSecureLogUsed() { return SecureLogUsed; } 330 void setSecureLog(raw_ostream *Value) { 331 SecureLog = Value; 332 } 333 void setSecureLogUsed(bool Value) { 334 SecureLogUsed = Value; 335 } 336 337 void *Allocate(unsigned Size, unsigned Align = 8) { 338 return Allocator.Allocate(Size, Align); 339 } 340 void Deallocate(void *Ptr) { 341 } 342 343 // Unrecoverable error has occured. Display the best diagnostic we can 344 // and bail via exit(1). For now, most MC backend errors are unrecoverable. 345 // FIXME: We should really do something about that. 346 LLVM_ATTRIBUTE_NORETURN void FatalError(SMLoc L, const Twine &Msg); 347 }; 348 349} // end namespace llvm 350 351// operator new and delete aren't allowed inside namespaces. 352// The throw specifications are mandated by the standard. 353/// @brief Placement new for using the MCContext's allocator. 354/// 355/// This placement form of operator new uses the MCContext's allocator for 356/// obtaining memory. It is a non-throwing new, which means that it returns 357/// null on error. (If that is what the allocator does. The current does, so if 358/// this ever changes, this operator will have to be changed, too.) 359/// Usage looks like this (assuming there's an MCContext 'Context' in scope): 360/// @code 361/// // Default alignment (16) 362/// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments); 363/// // Specific alignment 364/// IntegerLiteral *Ex2 = new (Context, 8) IntegerLiteral(arguments); 365/// @endcode 366/// Please note that you cannot use delete on the pointer; it must be 367/// deallocated using an explicit destructor call followed by 368/// @c Context.Deallocate(Ptr). 369/// 370/// @param Bytes The number of bytes to allocate. Calculated by the compiler. 371/// @param C The MCContext that provides the allocator. 372/// @param Alignment The alignment of the allocated memory (if the underlying 373/// allocator supports it). 374/// @return The allocated memory. Could be NULL. 375inline void *operator new(size_t Bytes, llvm::MCContext &C, 376 size_t Alignment = 16) throw () { 377 return C.Allocate(Bytes, Alignment); 378} 379/// @brief Placement delete companion to the new above. 380/// 381/// This operator is just a companion to the new above. There is no way of 382/// invoking it directly; see the new operator for more details. This operator 383/// is called implicitly by the compiler if a placement new expression using 384/// the MCContext throws in the object constructor. 385inline void operator delete(void *Ptr, llvm::MCContext &C, size_t) 386 throw () { 387 C.Deallocate(Ptr); 388} 389 390/// This placement form of operator new[] uses the MCContext's allocator for 391/// obtaining memory. It is a non-throwing new[], which means that it returns 392/// null on error. 393/// Usage looks like this (assuming there's an MCContext 'Context' in scope): 394/// @code 395/// // Default alignment (16) 396/// char *data = new (Context) char[10]; 397/// // Specific alignment 398/// char *data = new (Context, 8) char[10]; 399/// @endcode 400/// Please note that you cannot use delete on the pointer; it must be 401/// deallocated using an explicit destructor call followed by 402/// @c Context.Deallocate(Ptr). 403/// 404/// @param Bytes The number of bytes to allocate. Calculated by the compiler. 405/// @param C The MCContext that provides the allocator. 406/// @param Alignment The alignment of the allocated memory (if the underlying 407/// allocator supports it). 408/// @return The allocated memory. Could be NULL. 409inline void *operator new[](size_t Bytes, llvm::MCContext& C, 410 size_t Alignment = 16) throw () { 411 return C.Allocate(Bytes, Alignment); 412} 413 414/// @brief Placement delete[] companion to the new[] above. 415/// 416/// This operator is just a companion to the new[] above. There is no way of 417/// invoking it directly; see the new[] operator for more details. This operator 418/// is called implicitly by the compiler if a placement new[] expression using 419/// the MCContext throws in the object constructor. 420inline void operator delete[](void *Ptr, llvm::MCContext &C) throw () { 421 C.Deallocate(Ptr); 422} 423 424#endif 425