MCContext.h revision c35dd25ab820c3db37b7bfd506d656c14b14e331
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 MCLineSection; 30 class StringRef; 31 class Twine; 32 class TargetAsmInfo; 33 class MCSectionMachO; 34 class MCSectionELF; 35 36 /// MCContext - Context object for machine code objects. This class owns all 37 /// of the sections that it creates. 38 /// 39 class MCContext { 40 MCContext(const MCContext&); // DO NOT IMPLEMENT 41 MCContext &operator=(const MCContext&); // DO NOT IMPLEMENT 42 public: 43 typedef StringMap<MCSymbol*, BumpPtrAllocator&> SymbolTable; 44 private: 45 46 /// The MCAsmInfo for this target. 47 const MCAsmInfo &MAI; 48 49 const TargetAsmInfo *TAI; 50 51 /// Allocator - Allocator object used for creating machine code objects. 52 /// 53 /// We use a bump pointer allocator to avoid the need to track all allocated 54 /// objects. 55 BumpPtrAllocator Allocator; 56 57 /// Symbols - Bindings of names to symbols. 58 SymbolTable Symbols; 59 60 /// UsedNames - Keeps tracks of names that were used both for used declared 61 /// and artificial symbols. 62 StringMap<bool, BumpPtrAllocator&> UsedNames; 63 64 /// NextUniqueID - The next ID to dole out to an unnamed assembler temporary 65 /// symbol. 66 unsigned NextUniqueID; 67 68 /// Instances of directional local labels. 69 DenseMap<unsigned, MCLabel *> Instances; 70 /// NextInstance() creates the next instance of the directional local label 71 /// for the LocalLabelVal and adds it to the map if needed. 72 unsigned NextInstance(int64_t LocalLabelVal); 73 /// GetInstance() gets the current instance of the directional local label 74 /// for the LocalLabelVal and adds it to the map if needed. 75 unsigned GetInstance(int64_t LocalLabelVal); 76 77 /// The file name of the log file from the environment variable 78 /// AS_SECURE_LOG_FILE. Which must be set before the .secure_log_unique 79 /// directive is used or it is an error. 80 char *SecureLogFile; 81 /// The stream that gets written to for the .secure_log_unique directive. 82 raw_ostream *SecureLog; 83 /// Boolean toggled when .secure_log_unique / .secure_log_reset is seen to 84 /// catch errors if .secure_log_unique appears twice without 85 /// .secure_log_reset appearing between them. 86 bool SecureLogUsed; 87 88 /// The dwarf file and directory tables from the dwarf .file directive. 89 std::vector<MCDwarfFile *> MCDwarfFiles; 90 std::vector<StringRef> MCDwarfDirs; 91 92 /// The current dwarf line information from the last dwarf .loc directive. 93 MCDwarfLoc CurrentDwarfLoc; 94 bool DwarfLocSeen; 95 96 /// Honor temporary labels, this is useful for debugging semantic 97 /// differences between temporary and non-temporary labels (primarily on 98 /// Darwin). 99 bool AllowTemporaryLabels; 100 101 /// The dwarf line information from the .loc directives for the sections 102 /// with assembled machine instructions have after seeing .loc directives. 103 DenseMap<const MCSection *, MCLineSection *> MCLineSections; 104 /// We need a deterministic iteration order, so we remember the order 105 /// the elements were added. 106 std::vector<const MCSection *> MCLineSectionOrder; 107 108 void *MachOUniquingMap, *ELFUniquingMap, *COFFUniquingMap; 109 110 MCSymbol *CreateSymbol(StringRef Name); 111 112 public: 113 explicit MCContext(const MCAsmInfo &MAI, const TargetAsmInfo *TAI); 114 ~MCContext(); 115 116 const MCAsmInfo &getAsmInfo() const { return MAI; } 117 118 const TargetAsmInfo &getTargetAsmInfo() const { return *TAI; } 119 120 void setAllowTemporaryLabels(bool Value) { AllowTemporaryLabels = Value; } 121 122 /// @name Symbol Management 123 /// @{ 124 125 /// CreateTempSymbol - Create and return a new assembler temporary symbol 126 /// with a unique but unspecified name. 127 MCSymbol *CreateTempSymbol(); 128 129 /// CreateDirectionalLocalSymbol - Create the definition of a directional 130 /// local symbol for numbered label (used for "1:" definitions). 131 MCSymbol *CreateDirectionalLocalSymbol(int64_t LocalLabelVal); 132 133 /// GetDirectionalLocalSymbol - Create and return a directional local 134 /// symbol for numbered label (used for "1b" or 1f" references). 135 MCSymbol *GetDirectionalLocalSymbol(int64_t LocalLabelVal, int bORf); 136 137 /// GetOrCreateSymbol - Lookup the symbol inside with the specified 138 /// @p Name. If it exists, return it. If not, create a forward 139 /// reference and return it. 140 /// 141 /// @param Name - The symbol name, which must be unique across all symbols. 142 MCSymbol *GetOrCreateSymbol(StringRef Name); 143 MCSymbol *GetOrCreateSymbol(const Twine &Name); 144 145 /// LookupSymbol - Get the symbol for \p Name, or null. 146 MCSymbol *LookupSymbol(StringRef Name) const; 147 148 /// getSymbols - Get a reference for the symbol table for clients that 149 /// want to, for example, iterate over all symbols. 'const' because we 150 /// still want any modifications to the table itself to use the MCContext 151 /// APIs. 152 const SymbolTable &getSymbols() const { 153 return Symbols; 154 } 155 156 /// @} 157 158 /// @name Section Management 159 /// @{ 160 161 /// getMachOSection - Return the MCSection for the specified mach-o section. 162 /// This requires the operands to be valid. 163 const MCSectionMachO *getMachOSection(StringRef Segment, 164 StringRef Section, 165 unsigned TypeAndAttributes, 166 unsigned Reserved2, 167 SectionKind K); 168 const MCSectionMachO *getMachOSection(StringRef Segment, 169 StringRef Section, 170 unsigned TypeAndAttributes, 171 SectionKind K) { 172 return getMachOSection(Segment, Section, TypeAndAttributes, 0, K); 173 } 174 175 const MCSectionELF *getELFSection(StringRef Section, unsigned Type, 176 unsigned Flags, SectionKind Kind); 177 178 const MCSectionELF *getELFSection(StringRef Section, unsigned Type, 179 unsigned Flags, SectionKind Kind, 180 unsigned EntrySize, StringRef Group); 181 182 const MCSectionELF *CreateELFGroupSection(); 183 184 const MCSection *getCOFFSection(StringRef Section, unsigned Characteristics, 185 int Selection, SectionKind Kind); 186 187 const MCSection *getCOFFSection(StringRef Section, unsigned Characteristics, 188 SectionKind Kind) { 189 return getCOFFSection (Section, Characteristics, 0, Kind); 190 } 191 192 193 /// @} 194 195 /// @name Dwarf Management 196 /// @{ 197 198 /// GetDwarfFile - creates an entry in the dwarf file and directory tables. 199 unsigned GetDwarfFile(StringRef FileName, unsigned FileNumber); 200 201 bool isValidDwarfFileNumber(unsigned FileNumber); 202 203 bool hasDwarfFiles() const { 204 return !MCDwarfFiles.empty(); 205 } 206 207 const std::vector<MCDwarfFile *> &getMCDwarfFiles() { 208 return MCDwarfFiles; 209 } 210 const std::vector<StringRef> &getMCDwarfDirs() { 211 return MCDwarfDirs; 212 } 213 214 const DenseMap<const MCSection *, MCLineSection *> 215 &getMCLineSections() const { 216 return MCLineSections; 217 } 218 const std::vector<const MCSection *> &getMCLineSectionOrder() const { 219 return MCLineSectionOrder; 220 } 221 void addMCLineSection(const MCSection *Sec, MCLineSection *Line) { 222 MCLineSections[Sec] = Line; 223 MCLineSectionOrder.push_back(Sec); 224 } 225 226 /// setCurrentDwarfLoc - saves the information from the currently parsed 227 /// dwarf .loc directive and sets DwarfLocSeen. When the next instruction 228 /// is assembled an entry in the line number table with this information and 229 /// the address of the instruction will be created. 230 void setCurrentDwarfLoc(unsigned FileNum, unsigned Line, unsigned Column, 231 unsigned Flags, unsigned Isa, 232 unsigned Discriminator) { 233 CurrentDwarfLoc.setFileNum(FileNum); 234 CurrentDwarfLoc.setLine(Line); 235 CurrentDwarfLoc.setColumn(Column); 236 CurrentDwarfLoc.setFlags(Flags); 237 CurrentDwarfLoc.setIsa(Isa); 238 CurrentDwarfLoc.setDiscriminator(Discriminator); 239 DwarfLocSeen = true; 240 } 241 void ClearDwarfLocSeen() { DwarfLocSeen = false; } 242 243 bool getDwarfLocSeen() { return DwarfLocSeen; } 244 const MCDwarfLoc &getCurrentDwarfLoc() { return CurrentDwarfLoc; } 245 246 /// @} 247 248 char *getSecureLogFile() { return SecureLogFile; } 249 raw_ostream *getSecureLog() { return SecureLog; } 250 bool getSecureLogUsed() { return SecureLogUsed; } 251 void setSecureLog(raw_ostream *Value) { 252 SecureLog = Value; 253 } 254 void setSecureLogUsed(bool Value) { 255 SecureLogUsed = Value; 256 } 257 258 void *Allocate(unsigned Size, unsigned Align = 8) { 259 return Allocator.Allocate(Size, Align); 260 } 261 void Deallocate(void *Ptr) { 262 } 263 }; 264 265} // end namespace llvm 266 267// operator new and delete aren't allowed inside namespaces. 268// The throw specifications are mandated by the standard. 269/// @brief Placement new for using the MCContext's allocator. 270/// 271/// This placement form of operator new uses the MCContext's allocator for 272/// obtaining memory. It is a non-throwing new, which means that it returns 273/// null on error. (If that is what the allocator does. The current does, so if 274/// this ever changes, this operator will have to be changed, too.) 275/// Usage looks like this (assuming there's an MCContext 'Context' in scope): 276/// @code 277/// // Default alignment (16) 278/// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments); 279/// // Specific alignment 280/// IntegerLiteral *Ex2 = new (Context, 8) IntegerLiteral(arguments); 281/// @endcode 282/// Please note that you cannot use delete on the pointer; it must be 283/// deallocated using an explicit destructor call followed by 284/// @c Context.Deallocate(Ptr). 285/// 286/// @param Bytes The number of bytes to allocate. Calculated by the compiler. 287/// @param C The MCContext that provides the allocator. 288/// @param Alignment The alignment of the allocated memory (if the underlying 289/// allocator supports it). 290/// @return The allocated memory. Could be NULL. 291inline void *operator new(size_t Bytes, llvm::MCContext &C, 292 size_t Alignment = 16) throw () { 293 return C.Allocate(Bytes, Alignment); 294} 295/// @brief Placement delete companion to the new above. 296/// 297/// This operator is just a companion to the new above. There is no way of 298/// invoking it directly; see the new operator for more details. This operator 299/// is called implicitly by the compiler if a placement new expression using 300/// the MCContext throws in the object constructor. 301inline void operator delete(void *Ptr, llvm::MCContext &C, size_t) 302 throw () { 303 C.Deallocate(Ptr); 304} 305 306/// This placement form of operator new[] uses the MCContext's allocator for 307/// obtaining memory. It is a non-throwing new[], which means that it returns 308/// null on error. 309/// Usage looks like this (assuming there's an MCContext 'Context' in scope): 310/// @code 311/// // Default alignment (16) 312/// char *data = new (Context) char[10]; 313/// // Specific alignment 314/// char *data = new (Context, 8) char[10]; 315/// @endcode 316/// Please note that you cannot use delete on the pointer; it must be 317/// deallocated using an explicit destructor call followed by 318/// @c Context.Deallocate(Ptr). 319/// 320/// @param Bytes The number of bytes to allocate. Calculated by the compiler. 321/// @param C The MCContext that provides the allocator. 322/// @param Alignment The alignment of the allocated memory (if the underlying 323/// allocator supports it). 324/// @return The allocated memory. Could be NULL. 325inline void *operator new[](size_t Bytes, llvm::MCContext& C, 326 size_t Alignment = 16) throw () { 327 return C.Allocate(Bytes, Alignment); 328} 329 330/// @brief Placement delete[] companion to the new[] above. 331/// 332/// This operator is just a companion to the new[] above. There is no way of 333/// invoking it directly; see the new[] operator for more details. This operator 334/// is called implicitly by the compiler if a placement new[] expression using 335/// the MCContext throws in the object constructor. 336inline void operator delete[](void *Ptr, llvm::MCContext &C) throw () { 337 C.Deallocate(Ptr); 338} 339 340#endif 341