1 //===- MCDwarf.h - Machine Code Dwarf support -------------------*- 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 // This file contains the declaration of the MCDwarfFile to support the dwarf 11 // .file directive and the .loc directive. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_MC_MCDWARF_H 16 #define LLVM_MC_MCDWARF_H 17 18 #include "llvm/ADT/StringRef.h" 19 #include "llvm/MC/MachineLocation.h" 20 #include "llvm/Support/raw_ostream.h" 21 #include "llvm/Support/Dwarf.h" 22 #include <vector> 23 24 namespace llvm { 25 class MCContext; 26 class MCObjectWriter; 27 class MCSection; 28 class MCStreamer; 29 class MCSymbol; 30 class SourceMgr; 31 class SMLoc; 32 33 /// MCDwarfFile - Instances of this class represent the name of the dwarf 34 /// .file directive and its associated dwarf file number in the MC file, 35 /// and MCDwarfFile's are created and unique'd by the MCContext class where 36 /// the file number for each is its index into the vector of DwarfFiles (note 37 /// index 0 is not used and not a valid dwarf file number). 38 class MCDwarfFile { 39 // Name - the base name of the file without its directory path. 40 // The StringRef references memory allocated in the MCContext. 41 StringRef Name; 42 43 // DirIndex - the index into the list of directory names for this file name. 44 unsigned DirIndex; 45 46 private: // MCContext creates and uniques these. 47 friend class MCContext; 48 MCDwarfFile(StringRef name, unsigned dirIndex) 49 : Name(name), DirIndex(dirIndex) {} 50 51 MCDwarfFile(const MCDwarfFile&); // DO NOT IMPLEMENT 52 void operator=(const MCDwarfFile&); // DO NOT IMPLEMENT 53 public: 54 /// getName - Get the base name of this MCDwarfFile. 55 StringRef getName() const { return Name; } 56 57 /// getDirIndex - Get the dirIndex of this MCDwarfFile. 58 unsigned getDirIndex() const { return DirIndex; } 59 60 61 /// print - Print the value to the stream \arg OS. 62 void print(raw_ostream &OS) const; 63 64 /// dump - Print the value to stderr. 65 void dump() const; 66 }; 67 68 inline raw_ostream &operator<<(raw_ostream &OS, const MCDwarfFile &DwarfFile){ 69 DwarfFile.print(OS); 70 return OS; 71 } 72 73 /// MCDwarfLoc - Instances of this class represent the information from a 74 /// dwarf .loc directive. 75 class MCDwarfLoc { 76 // FileNum - the file number. 77 unsigned FileNum; 78 // Line - the line number. 79 unsigned Line; 80 // Column - the column position. 81 unsigned Column; 82 // Flags (see #define's below) 83 unsigned Flags; 84 // Isa 85 unsigned Isa; 86 // Discriminator 87 unsigned Discriminator; 88 89 // Flag that indicates the initial value of the is_stmt_start flag. 90 #define DWARF2_LINE_DEFAULT_IS_STMT 1 91 92 #define DWARF2_FLAG_IS_STMT (1 << 0) 93 #define DWARF2_FLAG_BASIC_BLOCK (1 << 1) 94 #define DWARF2_FLAG_PROLOGUE_END (1 << 2) 95 #define DWARF2_FLAG_EPILOGUE_BEGIN (1 << 3) 96 97 private: // MCContext manages these 98 friend class MCContext; 99 friend class MCLineEntry; 100 MCDwarfLoc(unsigned fileNum, unsigned line, unsigned column, unsigned flags, 101 unsigned isa, unsigned discriminator) 102 : FileNum(fileNum), Line(line), Column(column), Flags(flags), Isa(isa), 103 Discriminator(discriminator) {} 104 105 // Allow the default copy constructor and assignment operator to be used 106 // for an MCDwarfLoc object. 107 108 public: 109 /// getFileNum - Get the FileNum of this MCDwarfLoc. 110 unsigned getFileNum() const { return FileNum; } 111 112 /// getLine - Get the Line of this MCDwarfLoc. 113 unsigned getLine() const { return Line; } 114 115 /// getColumn - Get the Column of this MCDwarfLoc. 116 unsigned getColumn() const { return Column; } 117 118 /// getFlags - Get the Flags of this MCDwarfLoc. 119 unsigned getFlags() const { return Flags; } 120 121 /// getIsa - Get the Isa of this MCDwarfLoc. 122 unsigned getIsa() const { return Isa; } 123 124 /// getDiscriminator - Get the Discriminator of this MCDwarfLoc. 125 unsigned getDiscriminator() const { return Discriminator; } 126 127 /// setFileNum - Set the FileNum of this MCDwarfLoc. 128 void setFileNum(unsigned fileNum) { FileNum = fileNum; } 129 130 /// setLine - Set the Line of this MCDwarfLoc. 131 void setLine(unsigned line) { Line = line; } 132 133 /// setColumn - Set the Column of this MCDwarfLoc. 134 void setColumn(unsigned column) { Column = column; } 135 136 /// setFlags - Set the Flags of this MCDwarfLoc. 137 void setFlags(unsigned flags) { Flags = flags; } 138 139 /// setIsa - Set the Isa of this MCDwarfLoc. 140 void setIsa(unsigned isa) { Isa = isa; } 141 142 /// setDiscriminator - Set the Discriminator of this MCDwarfLoc. 143 void setDiscriminator(unsigned discriminator) { 144 Discriminator = discriminator; 145 } 146 }; 147 148 /// MCLineEntry - Instances of this class represent the line information for 149 /// the dwarf line table entries. Which is created after a machine 150 /// instruction is assembled and uses an address from a temporary label 151 /// created at the current address in the current section and the info from 152 /// the last .loc directive seen as stored in the context. 153 class MCLineEntry : public MCDwarfLoc { 154 MCSymbol *Label; 155 156 private: 157 // Allow the default copy constructor and assignment operator to be used 158 // for an MCLineEntry object. 159 160 public: 161 // Constructor to create an MCLineEntry given a symbol and the dwarf loc. 162 MCLineEntry(MCSymbol *label, const MCDwarfLoc loc) : MCDwarfLoc(loc), 163 Label(label) {} 164 165 MCSymbol *getLabel() const { return Label; } 166 167 // This is called when an instruction is assembled into the specified 168 // section and if there is information from the last .loc directive that 169 // has yet to have a line entry made for it is made. 170 static void Make(MCStreamer *MCOS, const MCSection *Section); 171 }; 172 173 /// MCLineSection - Instances of this class represent the line information 174 /// for a section where machine instructions have been assembled after seeing 175 /// .loc directives. This is the information used to build the dwarf line 176 /// table for a section. 177 class MCLineSection { 178 179 private: 180 MCLineSection(const MCLineSection&); // DO NOT IMPLEMENT 181 void operator=(const MCLineSection&); // DO NOT IMPLEMENT 182 183 public: 184 // Constructor to create an MCLineSection with an empty MCLineEntries 185 // vector. 186 MCLineSection() {} 187 188 // addLineEntry - adds an entry to this MCLineSection's line entries 189 void addLineEntry(const MCLineEntry &LineEntry) { 190 MCLineEntries.push_back(LineEntry); 191 } 192 193 typedef std::vector<MCLineEntry> MCLineEntryCollection; 194 typedef MCLineEntryCollection::iterator iterator; 195 typedef MCLineEntryCollection::const_iterator const_iterator; 196 197 private: 198 MCLineEntryCollection MCLineEntries; 199 200 public: 201 const MCLineEntryCollection *getMCLineEntries() const { 202 return &MCLineEntries; 203 } 204 }; 205 206 class MCDwarfFileTable { 207 public: 208 // 209 // This emits the Dwarf file and the line tables. 210 // 211 static const MCSymbol *Emit(MCStreamer *MCOS); 212 }; 213 214 class MCDwarfLineAddr { 215 public: 216 /// Utility function to encode a Dwarf pair of LineDelta and AddrDeltas. 217 static void Encode(int64_t LineDelta, uint64_t AddrDelta, raw_ostream &OS); 218 219 /// Utility function to emit the encoding to a streamer. 220 static void Emit(MCStreamer *MCOS, 221 int64_t LineDelta,uint64_t AddrDelta); 222 223 /// Utility function to write the encoding to an object writer. 224 static void Write(MCObjectWriter *OW, 225 int64_t LineDelta, uint64_t AddrDelta); 226 }; 227 228 class MCGenDwarfInfo { 229 public: 230 // 231 // When generating dwarf for assembly source files this emits the Dwarf 232 // sections. 233 // 234 static void Emit(MCStreamer *MCOS, const MCSymbol *LineSectionSymbol); 235 }; 236 237 // When generating dwarf for assembly source files this is the info that is 238 // needed to be gathered for each symbol that will have a dwarf label. 239 class MCGenDwarfLabelEntry { 240 private: 241 // Name of the symbol without a leading underbar, if any. 242 StringRef Name; 243 // The dwarf file number this symbol is in. 244 unsigned FileNumber; 245 // The line number this symbol is at. 246 unsigned LineNumber; 247 // The low_pc for the dwarf label is taken from this symbol. 248 MCSymbol *Label; 249 250 public: 251 MCGenDwarfLabelEntry(StringRef name, unsigned fileNumber, 252 unsigned lineNumber, MCSymbol *label) : 253 Name(name), FileNumber(fileNumber), LineNumber(lineNumber), Label(label){} 254 255 StringRef getName() const { return Name; } 256 unsigned getFileNumber() const { return FileNumber; } 257 unsigned getLineNumber() const { return LineNumber; } 258 MCSymbol *getLabel() const { return Label; } 259 260 // This is called when label is created when we are generating dwarf for 261 // assembly source files. 262 static void Make(MCSymbol *Symbol, MCStreamer *MCOS, SourceMgr &SrcMgr, 263 SMLoc &Loc); 264 }; 265 266 class MCCFIInstruction { 267 public: 268 enum OpType { SameValue, RememberState, RestoreState, Move, RelMove, Escape, 269 Restore}; 270 private: 271 OpType Operation; 272 MCSymbol *Label; 273 // Move to & from location. 274 MachineLocation Destination; 275 MachineLocation Source; 276 std::vector<char> Values; 277 public: 278 MCCFIInstruction(OpType Op, MCSymbol *L) 279 : Operation(Op), Label(L) { 280 assert(Op == RememberState || Op == RestoreState); 281 } 282 MCCFIInstruction(OpType Op, MCSymbol *L, unsigned Register) 283 : Operation(Op), Label(L), Destination(Register) { 284 assert(Op == SameValue || Op == Restore); 285 } 286 MCCFIInstruction(MCSymbol *L, const MachineLocation &D, 287 const MachineLocation &S) 288 : Operation(Move), Label(L), Destination(D), Source(S) { 289 } 290 MCCFIInstruction(OpType Op, MCSymbol *L, const MachineLocation &D, 291 const MachineLocation &S) 292 : Operation(Op), Label(L), Destination(D), Source(S) { 293 assert(Op == RelMove); 294 } 295 MCCFIInstruction(OpType Op, MCSymbol *L, StringRef Vals) 296 : Operation(Op), Label(L), Values(Vals.begin(), Vals.end()) { 297 assert(Op == Escape); 298 } 299 OpType getOperation() const { return Operation; } 300 MCSymbol *getLabel() const { return Label; } 301 const MachineLocation &getDestination() const { return Destination; } 302 const MachineLocation &getSource() const { return Source; } 303 const StringRef getValues() const { 304 return StringRef(&Values[0], Values.size()); 305 } 306 }; 307 308 struct MCDwarfFrameInfo { 309 MCDwarfFrameInfo() : Begin(0), End(0), Personality(0), Lsda(0), 310 Function(0), Instructions(), PersonalityEncoding(), 311 LsdaEncoding(0), CompactUnwindEncoding(0), 312 IsSignalFrame(false) {} 313 MCSymbol *Begin; 314 MCSymbol *End; 315 const MCSymbol *Personality; 316 const MCSymbol *Lsda; 317 const MCSymbol *Function; 318 std::vector<MCCFIInstruction> Instructions; 319 unsigned PersonalityEncoding; 320 unsigned LsdaEncoding; 321 uint32_t CompactUnwindEncoding; 322 bool IsSignalFrame; 323 }; 324 325 class MCDwarfFrameEmitter { 326 public: 327 // 328 // This emits the frame info section. 329 // 330 static void Emit(MCStreamer &streamer, bool usingCFI, 331 bool isEH); 332 static void EmitAdvanceLoc(MCStreamer &Streamer, uint64_t AddrDelta); 333 static void EncodeAdvanceLoc(uint64_t AddrDelta, raw_ostream &OS); 334 }; 335 } // end namespace llvm 336 337 #endif 338