tools/llvm-mc/Disassembler.cpp

   1 //===- Disassembler.cpp - Disassembler for hex strings --------------------===//
   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 class implements the disassembler of strings of bytes written in
  11 // hexadecimal, from standard input or from a file.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "Disassembler.h"
  16
  17 #include "llvm/ADT/OwningPtr.h"
  18 #include "llvm/ADT/Triple.h"
  19 #include "llvm/MC/MCAsmInfo.h"
  20 #include "llvm/MC/MCDisassembler.h"
  21 #include "llvm/MC/MCInst.h"
  22 #include "llvm/MC/MCInstPrinter.h"
  23 #include "llvm/Target/TargetRegistry.h"
  24 #include "llvm/Support/MemoryBuffer.h"
  25 #include "llvm/Support/MemoryObject.h"
  26 #include "llvm/Support/raw_ostream.h"
  27 #include "llvm/Support/SourceMgr.h"
  28
  29 #include "llvm-c/EnhancedDisassembly.h"
  30
  31 using namespace llvm;
  32
  33 typedef std::vector<std::pair<unsigned char, const char*> > ByteArrayTy;
  34
  35 namespace {
  36 class VectorMemoryObject : public MemoryObject {
  37 private:
  38   const ByteArrayTy &Bytes;
  39 public:
  40   VectorMemoryObject(const ByteArrayTy &bytes) : Bytes(bytes) {}
  41
  42   uint64_t getBase() const { return 0; }
  43   uint64_t getExtent() const { return Bytes.size(); }
  44
  45   int readByte(uint64_t Addr, uint8_t *Byte) const {
  46     if (Addr > getExtent())
  47       return -1;
  48     *Byte = Bytes[Addr].first;
  49     return 0;
  50   }
  51 };
  52 }
  53
  54 static bool PrintInsts(const MCDisassembler &DisAsm,
  55                        MCInstPrinter &Printer, const ByteArrayTy &Bytes,
  56                        SourceMgr &SM) {
  57   // Wrap the vector in a MemoryObject.
  58   VectorMemoryObject memoryObject(Bytes);
  59
  60   // Disassemble it to strings.
  61   uint64_t Size;
  62   uint64_t Index;
  63
  64   for (Index = 0; Index < Bytes.size(); Index += Size) {
  65     MCInst Inst;
  66
  67     if (DisAsm.getInstruction(Inst, Size, memoryObject, Index,
  68                                /*REMOVE*/ nulls())) {
  69       Printer.printInst(&Inst, outs());
  70       outs() << "\n";
  71     } else {
  72       SM.PrintMessage(SMLoc::getFromPointer(Bytes[Index].second),
  73                       "invalid instruction encoding", "warning");
  74       if (Size == 0)
  75         Size = 1; // skip illegible bytes
  76     }
  77   }
  78
  79   return false;
  80 }
  81
  82 static bool ByteArrayFromString(ByteArrayTy &ByteArray,
  83                                 StringRef &Str,
  84                                 SourceMgr &SM) {
  85   while (!Str.empty()) {
  86     // Strip horizontal whitespace.
  87     if (size_t Pos = Str.find_first_not_of(" \t\r")) {
  88       Str = Str.substr(Pos);
  89       continue;
  90     }
  91
  92     // If this is the end of a line or start of a comment, remove the rest of
  93     // the line.
  94     if (Str[0] == '\n' || Str[0] == '#') {
  95       // Strip to the end of line if we already processed any bytes on this
  96       // line.  This strips the comment and/or the \n.
  97       if (Str[0] == '\n') {
  98         Str = Str.substr(1);
  99       } else {
 100         Str = Str.substr(Str.find_first_of('\n'));
 101         if (!Str.empty())
 102           Str = Str.substr(1);
 103       }
 104       continue;
 105     }
 106
 107     // Get the current token.
 108     size_t Next = Str.find_first_of(" \t\n\r#");
 109     StringRef Value = Str.substr(0, Next);
 110
 111     // Convert to a byte and add to the byte vector.
 112     unsigned ByteVal;
 113     if (Value.getAsInteger(0, ByteVal) || ByteVal > 255) {
 114       // If we have an error, print it and skip to the end of line.
 115       SM.PrintMessage(SMLoc::getFromPointer(Value.data()),
 116                       "invalid input token", "error");
 117       Str = Str.substr(Str.find('\n'));
 118       ByteArray.clear();
 119       continue;
 120     }
 121
 122     ByteArray.push_back(std::make_pair((unsigned char)ByteVal, Value.data()));
 123     Str = Str.substr(Next);
 124   }
 125
 126   return false;
 127 }
 128
 129 int Disassembler::disassemble(const Target &T, const std::string &Triple,
 130                               MemoryBuffer &Buffer) {
 131   // Set up disassembler.
 132   OwningPtr<const MCAsmInfo> AsmInfo(T.createAsmInfo(Triple));
 133
 134   if (!AsmInfo) {
 135     errs() << "error: no assembly info for target " << Triple << "\n";
 136     return -1;
 137   }
 138
 139   OwningPtr<const MCDisassembler> DisAsm(T.createMCDisassembler());
 140   if (!DisAsm) {
 141     errs() << "error: no disassembler for target " << Triple << "\n";
 142     return -1;
 143   }
 144
 145   int AsmPrinterVariant = AsmInfo->getAssemblerDialect();
 146   OwningPtr<MCInstPrinter> IP(T.createMCInstPrinter(AsmPrinterVariant,
 147                                                     *AsmInfo));
 148   if (!IP) {
 149     errs() << "error: no instruction printer for target " << Triple << '\n';
 150     return -1;
 151   }
 152
 153   bool ErrorOccurred = false;
 154
 155   SourceMgr SM;
 156   SM.AddNewSourceBuffer(&Buffer, SMLoc());
 157
 158   // Convert the input to a vector for disassembly.
 159   ByteArrayTy ByteArray;
 160   StringRef Str = Buffer.getBuffer();
 161
 162   ErrorOccurred |= ByteArrayFromString(ByteArray, Str, SM);
 163
 164   if (!ByteArray.empty())
 165     ErrorOccurred |= PrintInsts(*DisAsm, *IP, ByteArray, SM);
 166
 167   return ErrorOccurred;
 168 }
 169
 170 static int byteArrayReader(uint8_t *B, uint64_t A, void *Arg) {
 171   ByteArrayTy &ByteArray = *((ByteArrayTy*)Arg);
 172
 173   if (A >= ByteArray.size())
 174     return -1;
 175
 176   *B = ByteArray[A].first;
 177
 178   return 0;
 179 }
 180
 181 static int verboseEvaluator(uint64_t *V, unsigned R, void *Arg) {
 182   EDDisassemblerRef &disassembler = *((EDDisassemblerRef*)Arg);
 183
 184   const char *regName;
 185
 186   if (!EDGetRegisterName(&regName,
 187                         disassembler,
 188                         R))
 189     outs() << "[" << regName << "/" << R << "]";
 190   if (EDRegisterIsStackPointer(disassembler, R))
 191     outs() << "(sp)";
 192   if (EDRegisterIsProgramCounter(disassembler, R))
 193     outs() << "(pc)";
 194
 195   *V = 0;
 196
 197   return 0;
 198 }
 199
 200 int Disassembler::disassembleEnhanced(const std::string &TS,
 201                                       MemoryBuffer &Buffer) {
 202   ByteArrayTy ByteArray;
 203   StringRef Str = Buffer.getBuffer();
 204   SourceMgr SM;
 205
 206   SM.AddNewSourceBuffer(&Buffer, SMLoc());
 207
 208   if (ByteArrayFromString(ByteArray, Str, SM)) {
 209     return -1;
 210   }
 211
 212   EDDisassemblerRef disassembler;
 213
 214   Triple T(TS);
 215   EDAssemblySyntax_t AS;
 216
 217   switch (T.getArch()) {
 218   default:
 219     errs() << "error: no default assembly syntax for " << TS.c_str() << "\n";
 220     return -1;
 221   case Triple::arm:
 222   case Triple::thumb:
 223     AS = kEDAssemblySyntaxARMUAL;
 224     break;
 225   case Triple::x86:
 226   case Triple::x86_64:
 227     AS = kEDAssemblySyntaxX86ATT;
 228     break;
 229   }
 230
 231   if (EDGetDisassembler(&disassembler,
 232                         TS.c_str(),
 233                         AS)) {
 234     errs() << "error: couldn't get disassembler for " << TS.c_str() << "\n";
 235     return -1;
 236   }
 237
 238   EDInstRef inst;
 239
 240   if (EDCreateInsts(&inst, 1, disassembler, byteArrayReader, 0,&ByteArray)
 241       != 1) {
 242     errs() << "error: Didn't get an instruction\n";
 243     return -1;
 244   }
 245
 246   int numTokens = EDNumTokens(inst);
 247
 248   if (numTokens < 0) {
 249     errs() << "error: Couldn't count the instruction's tokens\n";
 250     return -1;
 251   }
 252
 253   int tokenIndex;
 254
 255   for (tokenIndex = 0; tokenIndex < numTokens; ++tokenIndex) {
 256     EDTokenRef token;
 257
 258     if (EDGetToken(&token, inst, tokenIndex)) {
 259       errs() << "error: Couldn't get token\n";
 260       return -1;
 261     }
 262
 263     const char *buf;
 264
 265     if (EDGetTokenString(&buf, token)) {
 266       errs() << "error: Couldn't get string for token\n";
 267       return -1;
 268     }
 269
 270     outs() << "[";
 271
 272     int operandIndex = EDOperandIndexForToken(token);
 273
 274     if (operandIndex >= 0)
 275       outs() << operandIndex << "-";
 276
 277     if (EDTokenIsWhitespace(token)) {
 278       outs() << "w";
 279     } else if (EDTokenIsPunctuation(token)) {
 280       outs() << "p";
 281     } else if (EDTokenIsOpcode(token)) {
 282       outs() << "o";
 283     } else if (EDTokenIsLiteral(token)) {
 284       outs() << "l";
 285     } else if (EDTokenIsRegister(token)) {
 286       outs() << "r";
 287     } else {
 288       outs() << "?";
 289     }
 290
 291     outs() << ":" << buf;
 292
 293     if (EDTokenIsLiteral(token)) {
 294       outs() << "=";
 295       if (EDTokenIsNegativeLiteral(token))
 296         outs() << "-";
 297       uint64_t absoluteValue;
 298       if (EDLiteralTokenAbsoluteValue(&absoluteValue, token)) {
 299         errs() << "error: Couldn't get the value of a literal token\n";
 300         return -1;
 301       }
 302       outs() << absoluteValue;
 303     } else if (EDTokenIsRegister(token)) {
 304       outs() << "=";
 305       unsigned regID;
 306       if (EDRegisterTokenValue(&regID, token)) {
 307         errs() << "error: Couldn't get the ID of a register token\n";
 308         return -1;
 309       }
 310       outs() << "r" << regID;
 311     }
 312
 313     outs() << "]";
 314   }
 315
 316   outs() << " ";
 317
 318   if (EDInstIsBranch(inst))
 319     outs() << "<br> ";
 320   if (EDInstIsMove(inst))
 321     outs() << "<mov> ";
 322
 323   int numOperands = EDNumOperands(inst);
 324
 325   if (numOperands < 0) {
 326     errs() << "error: Couldn't count operands\n";
 327     return -1;
 328   }
 329
 330   int operandIndex;
 331
 332   for (operandIndex = 0; operandIndex < numOperands; ++operandIndex) {
 333     outs() << operandIndex << ":";
 334
 335     EDOperandRef operand;
 336
 337     if (EDGetOperand(&operand,
 338                      inst,
 339                      operandIndex)) {
 340       errs() << "error: Couldn't get operand\n";
 341       return -1;
 342     }
 343
 344     uint64_t evaluatedResult;
 345
 346     EDEvaluateOperand(&evaluatedResult,
 347                       operand,
 348                       verboseEvaluator,
 349                       &disassembler);
 350
 351     outs() << "=" << evaluatedResult;
 352
 353     outs() << " ";
 354   }
 355
 356   outs() << "\n";
 357
 358   return 0;
 359 }
 360