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