MCContext.h revision 613b7576896fbd03fe495f4ee27b404f81386774
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 21namespace 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 /// Generate dwarf debugging info for assembly source files. 102 bool GenDwarfForAssembly; 103 104 /// The current dwarf file number when generate dwarf debugging info for 105 /// assembly source files. 106 unsigned GenDwarfFileNumber; 107 108 /// The default initial text section that we generate dwarf debugging line 109 /// info for when generating dwarf assembly source files. 110 const MCSection *GenDwarfSection; 111 112 /// Honor temporary labels, this is useful for debugging semantic 113 /// differences between temporary and non-temporary labels (primarily on 114 /// Darwin). 115 bool AllowTemporaryLabels; 116 117 /// The dwarf line information from the .loc directives for the sections 118 /// with assembled machine instructions have after seeing .loc directives. 119 DenseMap<const MCSection *, MCLineSection *> MCLineSections; 120 /// We need a deterministic iteration order, so we remember the order 121 /// the elements were added. 122 std::vector<const MCSection *> MCLineSectionOrder; 123 124 void *MachOUniquingMap, *ELFUniquingMap, *COFFUniquingMap; 125 126 MCSymbol *CreateSymbol(StringRef Name); 127 128 public: 129 explicit MCContext(const MCAsmInfo &MAI, const MCRegisterInfo &MRI, 130 const MCObjectFileInfo *MOFI); 131 ~MCContext(); 132 133 const MCAsmInfo &getAsmInfo() const { return MAI; } 134 135 const MCRegisterInfo &getRegisterInfo() const { return MRI; } 136 137 const MCObjectFileInfo *getObjectFileInfo() const { return MOFI; } 138 139 void setAllowTemporaryLabels(bool Value) { AllowTemporaryLabels = Value; } 140 141 /// @name Symbol Management 142 /// @{ 143 144 /// CreateTempSymbol - Create and return a new assembler temporary symbol 145 /// with a unique but unspecified name. 146 MCSymbol *CreateTempSymbol(); 147 148 /// CreateDirectionalLocalSymbol - Create the definition of a directional 149 /// local symbol for numbered label (used for "1:" definitions). 150 MCSymbol *CreateDirectionalLocalSymbol(int64_t LocalLabelVal); 151 152 /// GetDirectionalLocalSymbol - Create and return a directional local 153 /// symbol for numbered label (used for "1b" or 1f" references). 154 MCSymbol *GetDirectionalLocalSymbol(int64_t LocalLabelVal, int bORf); 155 156 /// GetOrCreateSymbol - Lookup the symbol inside with the specified 157 /// @p Name. If it exists, return it. If not, create a forward 158 /// reference and return it. 159 /// 160 /// @param Name - The symbol name, which must be unique across all symbols. 161 MCSymbol *GetOrCreateSymbol(StringRef Name); 162 MCSymbol *GetOrCreateSymbol(const Twine &Name); 163 164 /// LookupSymbol - Get the symbol for \p Name, or null. 165 MCSymbol *LookupSymbol(StringRef Name) const; 166 167 /// getSymbols - Get a reference for the symbol table for clients that 168 /// want to, for example, iterate over all symbols. 'const' because we 169 /// still want any modifications to the table itself to use the MCContext 170 /// APIs. 171 const SymbolTable &getSymbols() const { 172 return Symbols; 173 } 174 175 /// @} 176 177 /// @name Section Management 178 /// @{ 179 180 /// getMachOSection - Return the MCSection for the specified mach-o section. 181 /// This requires the operands to be valid. 182 const MCSectionMachO *getMachOSection(StringRef Segment, 183 StringRef Section, 184 unsigned TypeAndAttributes, 185 unsigned Reserved2, 186 SectionKind K); 187 const MCSectionMachO *getMachOSection(StringRef Segment, 188 StringRef Section, 189 unsigned TypeAndAttributes, 190 SectionKind K) { 191 return getMachOSection(Segment, Section, TypeAndAttributes, 0, K); 192 } 193 194 const MCSectionELF *getELFSection(StringRef Section, unsigned Type, 195 unsigned Flags, SectionKind Kind); 196 197 const MCSectionELF *getELFSection(StringRef Section, unsigned Type, 198 unsigned Flags, SectionKind Kind, 199 unsigned EntrySize, StringRef Group); 200 201 const MCSectionELF *CreateELFGroupSection(); 202 203 const MCSection *getCOFFSection(StringRef Section, unsigned Characteristics, 204 int Selection, SectionKind Kind); 205 206 const MCSection *getCOFFSection(StringRef Section, unsigned Characteristics, 207 SectionKind Kind) { 208 return getCOFFSection (Section, Characteristics, 0, Kind); 209 } 210 211 212 /// @} 213 214 /// @name Dwarf Management 215 /// @{ 216 217 /// GetDwarfFile - creates an entry in the dwarf file and directory tables. 218 unsigned GetDwarfFile(StringRef Directory, StringRef FileName, 219 unsigned FileNumber); 220 221 bool isValidDwarfFileNumber(unsigned FileNumber); 222 223 bool hasDwarfFiles() const { 224 return !MCDwarfFiles.empty(); 225 } 226 227 const std::vector<MCDwarfFile *> &getMCDwarfFiles() { 228 return MCDwarfFiles; 229 } 230 const std::vector<StringRef> &getMCDwarfDirs() { 231 return MCDwarfDirs; 232 } 233 234 const DenseMap<const MCSection *, MCLineSection *> 235 &getMCLineSections() const { 236 return MCLineSections; 237 } 238 const std::vector<const MCSection *> &getMCLineSectionOrder() const { 239 return MCLineSectionOrder; 240 } 241 void addMCLineSection(const MCSection *Sec, MCLineSection *Line) { 242 MCLineSections[Sec] = Line; 243 MCLineSectionOrder.push_back(Sec); 244 } 245 246 /// setCurrentDwarfLoc - saves the information from the currently parsed 247 /// dwarf .loc directive and sets DwarfLocSeen. When the next instruction 248 /// is assembled an entry in the line number table with this information and 249 /// the address of the instruction will be created. 250 void setCurrentDwarfLoc(unsigned FileNum, unsigned Line, unsigned Column, 251 unsigned Flags, unsigned Isa, 252 unsigned Discriminator) { 253 CurrentDwarfLoc.setFileNum(FileNum); 254 CurrentDwarfLoc.setLine(Line); 255 CurrentDwarfLoc.setColumn(Column); 256 CurrentDwarfLoc.setFlags(Flags); 257 CurrentDwarfLoc.setIsa(Isa); 258 CurrentDwarfLoc.setDiscriminator(Discriminator); 259 DwarfLocSeen = true; 260 } 261 void ClearDwarfLocSeen() { DwarfLocSeen = false; } 262 263 bool getDwarfLocSeen() { return DwarfLocSeen; } 264 const MCDwarfLoc &getCurrentDwarfLoc() { return CurrentDwarfLoc; } 265 266 bool getGenDwarfForAssembly() { return GenDwarfForAssembly; } 267 void setGenDwarfForAssembly(bool Value) { GenDwarfForAssembly = Value; } 268 unsigned getGenDwarfFileNumber() { return GenDwarfFileNumber; } 269 unsigned nextGenDwarfFileNumber() { return ++GenDwarfFileNumber; } 270 const MCSection *getGenDwarfSection() { return GenDwarfSection; } 271 void setGenDwarfSection(const MCSection *Sec) { GenDwarfSection = Sec; } 272 273 /// @} 274 275 char *getSecureLogFile() { return SecureLogFile; } 276 raw_ostream *getSecureLog() { return SecureLog; } 277 bool getSecureLogUsed() { return SecureLogUsed; } 278 void setSecureLog(raw_ostream *Value) { 279 SecureLog = Value; 280 } 281 void setSecureLogUsed(bool Value) { 282 SecureLogUsed = Value; 283 } 284 285 void *Allocate(unsigned Size, unsigned Align = 8) { 286 return Allocator.Allocate(Size, Align); 287 } 288 void Deallocate(void *Ptr) { 289 } 290 }; 291 292} // end namespace llvm 293 294// operator new and delete aren't allowed inside namespaces. 295// The throw specifications are mandated by the standard. 296/// @brief Placement new for using the MCContext's allocator. 297/// 298/// This placement form of operator new uses the MCContext's allocator for 299/// obtaining memory. It is a non-throwing new, which means that it returns 300/// null on error. (If that is what the allocator does. The current does, so if 301/// this ever changes, this operator will have to be changed, too.) 302/// Usage looks like this (assuming there's an MCContext 'Context' in scope): 303/// @code 304/// // Default alignment (16) 305/// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments); 306/// // Specific alignment 307/// IntegerLiteral *Ex2 = new (Context, 8) IntegerLiteral(arguments); 308/// @endcode 309/// Please note that you cannot use delete on the pointer; it must be 310/// deallocated using an explicit destructor call followed by 311/// @c Context.Deallocate(Ptr). 312/// 313/// @param Bytes The number of bytes to allocate. Calculated by the compiler. 314/// @param C The MCContext that provides the allocator. 315/// @param Alignment The alignment of the allocated memory (if the underlying 316/// allocator supports it). 317/// @return The allocated memory. Could be NULL. 318inline void *operator new(size_t Bytes, llvm::MCContext &C, 319 size_t Alignment = 16) throw () { 320 return C.Allocate(Bytes, Alignment); 321} 322/// @brief Placement delete companion to the new above. 323/// 324/// This operator is just a companion to the new above. There is no way of 325/// invoking it directly; see the new operator for more details. This operator 326/// is called implicitly by the compiler if a placement new expression using 327/// the MCContext throws in the object constructor. 328inline void operator delete(void *Ptr, llvm::MCContext &C, size_t) 329 throw () { 330 C.Deallocate(Ptr); 331} 332 333/// This placement form of operator new[] uses the MCContext's allocator for 334/// obtaining memory. It is a non-throwing new[], which means that it returns 335/// null on error. 336/// Usage looks like this (assuming there's an MCContext 'Context' in scope): 337/// @code 338/// // Default alignment (16) 339/// char *data = new (Context) char[10]; 340/// // Specific alignment 341/// char *data = new (Context, 8) char[10]; 342/// @endcode 343/// Please note that you cannot use delete on the pointer; it must be 344/// deallocated using an explicit destructor call followed by 345/// @c Context.Deallocate(Ptr). 346/// 347/// @param Bytes The number of bytes to allocate. Calculated by the compiler. 348/// @param C The MCContext that provides the allocator. 349/// @param Alignment The alignment of the allocated memory (if the underlying 350/// allocator supports it). 351/// @return The allocated memory. Could be NULL. 352inline void *operator new[](size_t Bytes, llvm::MCContext& C, 353 size_t Alignment = 16) throw () { 354 return C.Allocate(Bytes, Alignment); 355} 356 357/// @brief Placement delete[] companion to the new[] above. 358/// 359/// This operator is just a companion to the new[] above. There is no way of 360/// invoking it directly; see the new[] operator for more details. This operator 361/// is called implicitly by the compiler if a placement new[] expression using 362/// the MCContext throws in the object constructor. 363inline void operator delete[](void *Ptr, llvm::MCContext &C) throw () { 364 C.Deallocate(Ptr); 365} 366 367#endif 368