MCContext.h revision 1c952b9cc98e84b28f68f0f6cf11197263f89863
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 43 /// The MCAsmInfo for this target. 44 const MCAsmInfo &MAI; 45 46 const TargetAsmInfo *TAI; 47 48 /// Symbols - Bindings of names to symbols. 49 StringMap<MCSymbol*> Symbols; 50 51 /// UsedNames - Keeps tracks of names that were used both for used declared 52 /// and artificial symbols. 53 StringMap<bool> UsedNames; 54 55 /// NextUniqueID - The next ID to dole out to an unnamed assembler temporary 56 /// symbol. 57 unsigned NextUniqueID; 58 59 /// Instances of directional local labels. 60 DenseMap<unsigned, MCLabel *> Instances; 61 /// NextInstance() creates the next instance of the directional local label 62 /// for the LocalLabelVal and adds it to the map if needed. 63 unsigned NextInstance(int64_t LocalLabelVal); 64 /// GetInstance() gets the current instance of the directional local label 65 /// for the LocalLabelVal and adds it to the map if needed. 66 unsigned GetInstance(int64_t LocalLabelVal); 67 68 /// The file name of the log file from the environment variable 69 /// AS_SECURE_LOG_FILE. Which must be set before the .secure_log_unique 70 /// directive is used or it is an error. 71 char *SecureLogFile; 72 /// The stream that gets written to for the .secure_log_unique directive. 73 raw_ostream *SecureLog; 74 /// Boolean toggled when .secure_log_unique / .secure_log_reset is seen to 75 /// catch errors if .secure_log_unique appears twice without 76 /// .secure_log_reset appearing between them. 77 bool SecureLogUsed; 78 79 /// The dwarf file and directory tables from the dwarf .file directive. 80 std::vector<MCDwarfFile *> MCDwarfFiles; 81 std::vector<StringRef> MCDwarfDirs; 82 83 /// The current dwarf line information from the last dwarf .loc directive. 84 MCDwarfLoc CurrentDwarfLoc; 85 bool DwarfLocSeen; 86 87 /// The dwarf line information from the .loc directives for the sections 88 /// with assembled machine instructions have after seeing .loc directives. 89 DenseMap<const MCSection *, MCLineSection *> MCLineSections; 90 /// We need a deterministic iteration order, so we remember the order 91 /// the elements were added. 92 std::vector<const MCSection *> MCLineSectionOrder; 93 94 /// Allocator - Allocator object used for creating machine code objects. 95 /// 96 /// We use a bump pointer allocator to avoid the need to track all allocated 97 /// objects. 98 BumpPtrAllocator Allocator; 99 100 void *MachOUniquingMap, *ELFUniquingMap, *COFFUniquingMap; 101 102 MCSymbol *CreateSymbol(StringRef Name); 103 104 public: 105 explicit MCContext(const MCAsmInfo &MAI, const TargetAsmInfo *TAI); 106 ~MCContext(); 107 108 const MCAsmInfo &getAsmInfo() const { return MAI; } 109 110 const TargetAsmInfo &getTargetAsmInfo() const { return *TAI; } 111 112 /// @name Symbol Management 113 /// @{ 114 115 /// CreateTempSymbol - Create and return a new assembler temporary symbol 116 /// with a unique but unspecified name. 117 MCSymbol *CreateTempSymbol(); 118 119 /// CreateDirectionalLocalSymbol - Create the definition of a directional 120 /// local symbol for numbered label (used for "1:" definitions). 121 MCSymbol *CreateDirectionalLocalSymbol(int64_t LocalLabelVal); 122 123 /// GetDirectionalLocalSymbol - Create and return a directional local 124 /// symbol for numbered label (used for "1b" or 1f" references). 125 MCSymbol *GetDirectionalLocalSymbol(int64_t LocalLabelVal, int bORf); 126 127 /// GetOrCreateSymbol - Lookup the symbol inside with the specified 128 /// @p Name. If it exists, return it. If not, create a forward 129 /// reference and return it. 130 /// 131 /// @param Name - The symbol name, which must be unique across all symbols. 132 MCSymbol *GetOrCreateSymbol(StringRef Name); 133 MCSymbol *GetOrCreateSymbol(const Twine &Name); 134 135 /// LookupSymbol - Get the symbol for \p Name, or null. 136 MCSymbol *LookupSymbol(StringRef Name) const; 137 138 /// @} 139 140 /// @name Section Management 141 /// @{ 142 143 /// getMachOSection - Return the MCSection for the specified mach-o section. 144 /// This requires the operands to be valid. 145 const MCSectionMachO *getMachOSection(StringRef Segment, 146 StringRef Section, 147 unsigned TypeAndAttributes, 148 unsigned Reserved2, 149 SectionKind K); 150 const MCSectionMachO *getMachOSection(StringRef Segment, 151 StringRef Section, 152 unsigned TypeAndAttributes, 153 SectionKind K) { 154 return getMachOSection(Segment, Section, TypeAndAttributes, 0, K); 155 } 156 157 const MCSectionELF *getELFSection(StringRef Section, unsigned Type, 158 unsigned Flags, SectionKind Kind); 159 160 const MCSectionELF *getELFSection(StringRef Section, unsigned Type, 161 unsigned Flags, SectionKind Kind, 162 unsigned EntrySize, StringRef Group); 163 164 const MCSectionELF *CreateELFGroupSection(); 165 166 const MCSection *getCOFFSection(StringRef Section, unsigned Characteristics, 167 int Selection, SectionKind Kind); 168 169 const MCSection *getCOFFSection(StringRef Section, unsigned Characteristics, 170 SectionKind Kind) { 171 return getCOFFSection (Section, Characteristics, 0, Kind); 172 } 173 174 175 /// @} 176 177 /// @name Dwarf Management 178 /// @{ 179 180 /// GetDwarfFile - creates an entry in the dwarf file and directory tables. 181 unsigned GetDwarfFile(StringRef FileName, unsigned FileNumber); 182 183 bool isValidDwarfFileNumber(unsigned FileNumber); 184 185 bool hasDwarfFiles() const { 186 return !MCDwarfFiles.empty(); 187 } 188 189 const std::vector<MCDwarfFile *> &getMCDwarfFiles() { 190 return MCDwarfFiles; 191 } 192 const std::vector<StringRef> &getMCDwarfDirs() { 193 return MCDwarfDirs; 194 } 195 196 const DenseMap<const MCSection *, MCLineSection *> 197 &getMCLineSections() const { 198 return MCLineSections; 199 } 200 const std::vector<const MCSection *> &getMCLineSectionOrder() const { 201 return MCLineSectionOrder; 202 } 203 void addMCLineSection(const MCSection *Sec, MCLineSection *Line) { 204 MCLineSections[Sec] = Line; 205 MCLineSectionOrder.push_back(Sec); 206 } 207 208 /// setCurrentDwarfLoc - saves the information from the currently parsed 209 /// dwarf .loc directive and sets DwarfLocSeen. When the next instruction 210 /// is assembled an entry in the line number table with this information and 211 /// the address of the instruction will be created. 212 void setCurrentDwarfLoc(unsigned FileNum, unsigned Line, unsigned Column, 213 unsigned Flags, unsigned Isa, 214 unsigned Discriminator) { 215 CurrentDwarfLoc.setFileNum(FileNum); 216 CurrentDwarfLoc.setLine(Line); 217 CurrentDwarfLoc.setColumn(Column); 218 CurrentDwarfLoc.setFlags(Flags); 219 CurrentDwarfLoc.setIsa(Isa); 220 CurrentDwarfLoc.setDiscriminator(Discriminator); 221 DwarfLocSeen = true; 222 } 223 void ClearDwarfLocSeen() { DwarfLocSeen = false; } 224 225 bool getDwarfLocSeen() { return DwarfLocSeen; } 226 const MCDwarfLoc &getCurrentDwarfLoc() { return CurrentDwarfLoc; } 227 228 /// @} 229 230 char *getSecureLogFile() { return SecureLogFile; } 231 raw_ostream *getSecureLog() { return SecureLog; } 232 bool getSecureLogUsed() { return SecureLogUsed; } 233 void setSecureLog(raw_ostream *Value) { 234 SecureLog = Value; 235 } 236 void setSecureLogUsed(bool Value) { 237 SecureLogUsed = Value; 238 } 239 240 void *Allocate(unsigned Size, unsigned Align = 8) { 241 return Allocator.Allocate(Size, Align); 242 } 243 void Deallocate(void *Ptr) { 244 } 245 }; 246 247} // end namespace llvm 248 249// operator new and delete aren't allowed inside namespaces. 250// The throw specifications are mandated by the standard. 251/// @brief Placement new for using the MCContext's allocator. 252/// 253/// This placement form of operator new uses the MCContext's allocator for 254/// obtaining memory. It is a non-throwing new, which means that it returns 255/// null on error. (If that is what the allocator does. The current does, so if 256/// this ever changes, this operator will have to be changed, too.) 257/// Usage looks like this (assuming there's an MCContext 'Context' in scope): 258/// @code 259/// // Default alignment (16) 260/// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments); 261/// // Specific alignment 262/// IntegerLiteral *Ex2 = new (Context, 8) IntegerLiteral(arguments); 263/// @endcode 264/// Please note that you cannot use delete on the pointer; it must be 265/// deallocated using an explicit destructor call followed by 266/// @c Context.Deallocate(Ptr). 267/// 268/// @param Bytes The number of bytes to allocate. Calculated by the compiler. 269/// @param C The MCContext that provides the allocator. 270/// @param Alignment The alignment of the allocated memory (if the underlying 271/// allocator supports it). 272/// @return The allocated memory. Could be NULL. 273inline void *operator new(size_t Bytes, llvm::MCContext &C, 274 size_t Alignment = 16) throw () { 275 return C.Allocate(Bytes, Alignment); 276} 277/// @brief Placement delete companion to the new above. 278/// 279/// This operator is just a companion to the new above. There is no way of 280/// invoking it directly; see the new operator for more details. This operator 281/// is called implicitly by the compiler if a placement new expression using 282/// the MCContext throws in the object constructor. 283inline void operator delete(void *Ptr, llvm::MCContext &C, size_t) 284 throw () { 285 C.Deallocate(Ptr); 286} 287 288/// This placement form of operator new[] uses the MCContext's allocator for 289/// obtaining memory. It is a non-throwing new[], which means that it returns 290/// null on error. 291/// Usage looks like this (assuming there's an MCContext 'Context' in scope): 292/// @code 293/// // Default alignment (16) 294/// char *data = new (Context) char[10]; 295/// // Specific alignment 296/// char *data = new (Context, 8) char[10]; 297/// @endcode 298/// Please note that you cannot use delete on the pointer; it must be 299/// deallocated using an explicit destructor call followed by 300/// @c Context.Deallocate(Ptr). 301/// 302/// @param Bytes The number of bytes to allocate. Calculated by the compiler. 303/// @param C The MCContext that provides the allocator. 304/// @param Alignment The alignment of the allocated memory (if the underlying 305/// allocator supports it). 306/// @return The allocated memory. Could be NULL. 307inline void *operator new[](size_t Bytes, llvm::MCContext& C, 308 size_t Alignment = 16) throw () { 309 return C.Allocate(Bytes, Alignment); 310} 311 312/// @brief Placement delete[] companion to the new[] above. 313/// 314/// This operator is just a companion to the new[] above. There is no way of 315/// invoking it directly; see the new[] operator for more details. This operator 316/// is called implicitly by the compiler if a placement new[] expression using 317/// the MCContext throws in the object constructor. 318inline void operator delete[](void *Ptr, llvm::MCContext &C) throw () { 319 C.Deallocate(Ptr); 320} 321 322#endif 323