MCContext.h revision 94c2e85bea1ab1b837a4c055ccc83d5cd32dd027
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 /// Symbols created for the start and end of this section. 112 MCSymbol *GenDwarfSectionStartSym, *GenDwarfSectionEndSym; 113 114 /// The information gathered from labels that will have dwarf subprogram 115 /// entries when generating dwarf assembly source files. 116 std::vector<const MCGenDwarfSubprogramEntry *> MCGenDwarfSubprogramEntries; 117 118 /// The string to embed in the debug information for the compile unit, if 119 /// non-empty. 120 StringRef DwarfDebugFlags; 121 122 /// Honor temporary labels, this is useful for debugging semantic 123 /// differences between temporary and non-temporary labels (primarily on 124 /// Darwin). 125 bool AllowTemporaryLabels; 126 127 /// The dwarf line information from the .loc directives for the sections 128 /// with assembled machine instructions have after seeing .loc directives. 129 DenseMap<const MCSection *, MCLineSection *> MCLineSections; 130 /// We need a deterministic iteration order, so we remember the order 131 /// the elements were added. 132 std::vector<const MCSection *> MCLineSectionOrder; 133 134 void *MachOUniquingMap, *ELFUniquingMap, *COFFUniquingMap; 135 136 MCSymbol *CreateSymbol(StringRef Name); 137 138 public: 139 explicit MCContext(const MCAsmInfo &MAI, const MCRegisterInfo &MRI, 140 const MCObjectFileInfo *MOFI); 141 ~MCContext(); 142 143 const MCAsmInfo &getAsmInfo() const { return MAI; } 144 145 const MCRegisterInfo &getRegisterInfo() const { return MRI; } 146 147 const MCObjectFileInfo *getObjectFileInfo() const { return MOFI; } 148 149 void setAllowTemporaryLabels(bool Value) { AllowTemporaryLabels = Value; } 150 151 /// @name Symbol Management 152 /// @{ 153 154 /// CreateTempSymbol - Create and return a new assembler temporary symbol 155 /// with a unique but unspecified name. 156 MCSymbol *CreateTempSymbol(); 157 158 /// CreateDirectionalLocalSymbol - Create the definition of a directional 159 /// local symbol for numbered label (used for "1:" definitions). 160 MCSymbol *CreateDirectionalLocalSymbol(int64_t LocalLabelVal); 161 162 /// GetDirectionalLocalSymbol - Create and return a directional local 163 /// symbol for numbered label (used for "1b" or 1f" references). 164 MCSymbol *GetDirectionalLocalSymbol(int64_t LocalLabelVal, int bORf); 165 166 /// GetOrCreateSymbol - Lookup the symbol inside with the specified 167 /// @p Name. If it exists, return it. If not, create a forward 168 /// reference and return it. 169 /// 170 /// @param Name - The symbol name, which must be unique across all symbols. 171 MCSymbol *GetOrCreateSymbol(StringRef Name); 172 MCSymbol *GetOrCreateSymbol(const Twine &Name); 173 174 /// LookupSymbol - Get the symbol for \p Name, or null. 175 MCSymbol *LookupSymbol(StringRef Name) const; 176 177 /// getSymbols - Get a reference for the symbol table for clients that 178 /// want to, for example, iterate over all symbols. 'const' because we 179 /// still want any modifications to the table itself to use the MCContext 180 /// APIs. 181 const SymbolTable &getSymbols() const { 182 return Symbols; 183 } 184 185 /// @} 186 187 /// @name Section Management 188 /// @{ 189 190 /// getMachOSection - Return the MCSection for the specified mach-o section. 191 /// This requires the operands to be valid. 192 const MCSectionMachO *getMachOSection(StringRef Segment, 193 StringRef Section, 194 unsigned TypeAndAttributes, 195 unsigned Reserved2, 196 SectionKind K); 197 const MCSectionMachO *getMachOSection(StringRef Segment, 198 StringRef Section, 199 unsigned TypeAndAttributes, 200 SectionKind K) { 201 return getMachOSection(Segment, Section, TypeAndAttributes, 0, K); 202 } 203 204 const MCSectionELF *getELFSection(StringRef Section, unsigned Type, 205 unsigned Flags, SectionKind Kind); 206 207 const MCSectionELF *getELFSection(StringRef Section, unsigned Type, 208 unsigned Flags, SectionKind Kind, 209 unsigned EntrySize, StringRef Group); 210 211 const MCSectionELF *CreateELFGroupSection(); 212 213 const MCSection *getCOFFSection(StringRef Section, unsigned Characteristics, 214 int Selection, SectionKind Kind); 215 216 const MCSection *getCOFFSection(StringRef Section, unsigned Characteristics, 217 SectionKind Kind) { 218 return getCOFFSection (Section, Characteristics, 0, Kind); 219 } 220 221 222 /// @} 223 224 /// @name Dwarf Management 225 /// @{ 226 227 /// GetDwarfFile - creates an entry in the dwarf file and directory tables. 228 unsigned GetDwarfFile(StringRef Directory, StringRef FileName, 229 unsigned FileNumber); 230 231 bool isValidDwarfFileNumber(unsigned FileNumber); 232 233 bool hasDwarfFiles() const { 234 return !MCDwarfFiles.empty(); 235 } 236 237 const std::vector<MCDwarfFile *> &getMCDwarfFiles() { 238 return MCDwarfFiles; 239 } 240 const std::vector<StringRef> &getMCDwarfDirs() { 241 return MCDwarfDirs; 242 } 243 244 const DenseMap<const MCSection *, MCLineSection *> 245 &getMCLineSections() const { 246 return MCLineSections; 247 } 248 const std::vector<const MCSection *> &getMCLineSectionOrder() const { 249 return MCLineSectionOrder; 250 } 251 void addMCLineSection(const MCSection *Sec, MCLineSection *Line) { 252 MCLineSections[Sec] = Line; 253 MCLineSectionOrder.push_back(Sec); 254 } 255 256 /// setCurrentDwarfLoc - saves the information from the currently parsed 257 /// dwarf .loc directive and sets DwarfLocSeen. When the next instruction 258 /// is assembled an entry in the line number table with this information and 259 /// the address of the instruction will be created. 260 void setCurrentDwarfLoc(unsigned FileNum, unsigned Line, unsigned Column, 261 unsigned Flags, unsigned Isa, 262 unsigned Discriminator) { 263 CurrentDwarfLoc.setFileNum(FileNum); 264 CurrentDwarfLoc.setLine(Line); 265 CurrentDwarfLoc.setColumn(Column); 266 CurrentDwarfLoc.setFlags(Flags); 267 CurrentDwarfLoc.setIsa(Isa); 268 CurrentDwarfLoc.setDiscriminator(Discriminator); 269 DwarfLocSeen = true; 270 } 271 void ClearDwarfLocSeen() { DwarfLocSeen = false; } 272 273 bool getDwarfLocSeen() { return DwarfLocSeen; } 274 const MCDwarfLoc &getCurrentDwarfLoc() { return CurrentDwarfLoc; } 275 276 bool getGenDwarfForAssembly() { return GenDwarfForAssembly; } 277 void setGenDwarfForAssembly(bool Value) { GenDwarfForAssembly = Value; } 278 unsigned getGenDwarfFileNumber() { return GenDwarfFileNumber; } 279 unsigned nextGenDwarfFileNumber() { return ++GenDwarfFileNumber; } 280 const MCSection *getGenDwarfSection() { return GenDwarfSection; } 281 void setGenDwarfSection(const MCSection *Sec) { GenDwarfSection = Sec; } 282 MCSymbol *getGenDwarfSectionStartSym() { return GenDwarfSectionStartSym; } 283 void setGenDwarfSectionStartSym(MCSymbol *Sym) { 284 GenDwarfSectionStartSym = Sym; 285 } 286 MCSymbol *getGenDwarfSectionEndSym() { return GenDwarfSectionEndSym; } 287 void setGenDwarfSectionEndSym(MCSymbol *Sym) { 288 GenDwarfSectionEndSym = Sym; 289 } 290 const std::vector<const MCGenDwarfSubprogramEntry *> 291 &getMCGenDwarfSubprogramEntries() const { 292 return MCGenDwarfSubprogramEntries; 293 } 294 void addMCGenDwarfSubprogramEntry(const MCGenDwarfSubprogramEntry *E) { 295 MCGenDwarfSubprogramEntries.push_back(E); 296 } 297 298 void setDwarfDebugFlags(StringRef S) { DwarfDebugFlags = S; } 299 StringRef getDwarfDebugFlags() { return DwarfDebugFlags; } 300 301 /// @} 302 303 char *getSecureLogFile() { return SecureLogFile; } 304 raw_ostream *getSecureLog() { return SecureLog; } 305 bool getSecureLogUsed() { return SecureLogUsed; } 306 void setSecureLog(raw_ostream *Value) { 307 SecureLog = Value; 308 } 309 void setSecureLogUsed(bool Value) { 310 SecureLogUsed = Value; 311 } 312 313 void *Allocate(unsigned Size, unsigned Align = 8) { 314 return Allocator.Allocate(Size, Align); 315 } 316 void Deallocate(void *Ptr) { 317 } 318 }; 319 320} // end namespace llvm 321 322// operator new and delete aren't allowed inside namespaces. 323// The throw specifications are mandated by the standard. 324/// @brief Placement new for using the MCContext's allocator. 325/// 326/// This placement form of operator new uses the MCContext's allocator for 327/// obtaining memory. It is a non-throwing new, which means that it returns 328/// null on error. (If that is what the allocator does. The current does, so if 329/// this ever changes, this operator will have to be changed, too.) 330/// Usage looks like this (assuming there's an MCContext 'Context' in scope): 331/// @code 332/// // Default alignment (16) 333/// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments); 334/// // Specific alignment 335/// IntegerLiteral *Ex2 = new (Context, 8) IntegerLiteral(arguments); 336/// @endcode 337/// Please note that you cannot use delete on the pointer; it must be 338/// deallocated using an explicit destructor call followed by 339/// @c Context.Deallocate(Ptr). 340/// 341/// @param Bytes The number of bytes to allocate. Calculated by the compiler. 342/// @param C The MCContext that provides the allocator. 343/// @param Alignment The alignment of the allocated memory (if the underlying 344/// allocator supports it). 345/// @return The allocated memory. Could be NULL. 346inline void *operator new(size_t Bytes, llvm::MCContext &C, 347 size_t Alignment = 16) throw () { 348 return C.Allocate(Bytes, Alignment); 349} 350/// @brief Placement delete companion to the new above. 351/// 352/// This operator is just a companion to the new above. There is no way of 353/// invoking it directly; see the new operator for more details. This operator 354/// is called implicitly by the compiler if a placement new expression using 355/// the MCContext throws in the object constructor. 356inline void operator delete(void *Ptr, llvm::MCContext &C, size_t) 357 throw () { 358 C.Deallocate(Ptr); 359} 360 361/// This placement form of operator new[] uses the MCContext's allocator for 362/// obtaining memory. It is a non-throwing new[], which means that it returns 363/// null on error. 364/// Usage looks like this (assuming there's an MCContext 'Context' in scope): 365/// @code 366/// // Default alignment (16) 367/// char *data = new (Context) char[10]; 368/// // Specific alignment 369/// char *data = new (Context, 8) char[10]; 370/// @endcode 371/// Please note that you cannot use delete on the pointer; it must be 372/// deallocated using an explicit destructor call followed by 373/// @c Context.Deallocate(Ptr). 374/// 375/// @param Bytes The number of bytes to allocate. Calculated by the compiler. 376/// @param C The MCContext that provides the allocator. 377/// @param Alignment The alignment of the allocated memory (if the underlying 378/// allocator supports it). 379/// @return The allocated memory. Could be NULL. 380inline void *operator new[](size_t Bytes, llvm::MCContext& C, 381 size_t Alignment = 16) throw () { 382 return C.Allocate(Bytes, Alignment); 383} 384 385/// @brief Placement delete[] companion to the new[] above. 386/// 387/// This operator is just a companion to the new[] above. There is no way of 388/// invoking it directly; see the new[] operator for more details. This operator 389/// is called implicitly by the compiler if a placement new[] expression using 390/// the MCContext throws in the object constructor. 391inline void operator delete[](void *Ptr, llvm::MCContext &C) throw () { 392 C.Deallocate(Ptr); 393} 394 395#endif 396