Disassembler.cpp revision 98c5ddabca1debf935a07d14d0cbc9732374bdb8 
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#include "../../lib/MC/MCDisassembler/EDDisassembler.h"
17#include "../../lib/MC/MCDisassembler/EDInst.h"
18#include "../../lib/MC/MCDisassembler/EDOperand.h"
19#include "../../lib/MC/MCDisassembler/EDToken.h"
20#include "llvm/MC/MCAsmInfo.h"
21#include "llvm/MC/MCDisassembler.h"
22#include "llvm/MC/MCInst.h"
23#include "llvm/MC/MCInstPrinter.h"
24#include "llvm/MC/MCSubtargetInfo.h"
25#include "llvm/ADT/OwningPtr.h"
26#include "llvm/ADT/Triple.h"
27#include "llvm/ADT/Twine.h"
28#include "llvm/Support/MemoryBuffer.h"
29#include "llvm/Support/MemoryObject.h"
30#include "llvm/Support/SourceMgr.h"
31#include "llvm/Support/TargetRegistry.h"
32#include "llvm/Support/raw_ostream.h"
33using namespace llvm;
34
35typedef std::vector<std::pair<unsigned char, const char*> > ByteArrayTy;
36
37namespace {
38class VectorMemoryObject : public MemoryObject {
39private:
40  const ByteArrayTy &Bytes;
41public:
42  VectorMemoryObject(const ByteArrayTy &bytes) : Bytes(bytes) {}
43
44  uint64_t getBase() const { return 0; }
45  uint64_t getExtent() const { return Bytes.size(); }
46
47  int readByte(uint64_t Addr, uint8_t *Byte) const {
48    if (Addr >= getExtent())
49      return -1;
50    *Byte = Bytes[Addr].first;
51    return 0;
52  }
53};
54}
55
56static bool PrintInsts(const MCDisassembler &DisAsm,
57                       MCInstPrinter &Printer, const ByteArrayTy &Bytes,
58                       SourceMgr &SM, raw_ostream &Out) {
59  // Wrap the vector in a MemoryObject.
60  VectorMemoryObject memoryObject(Bytes);
61
62  // Disassemble it to strings.
63  uint64_t Size;
64  uint64_t Index;
65
66  for (Index = 0; Index < Bytes.size(); Index += Size) {
67    MCInst Inst;
68
69    MCDisassembler::DecodeStatus S;
70    S = DisAsm.getInstruction(Inst, Size, memoryObject, Index,
71                              /*REMOVE*/ nulls(), nulls());
72    switch (S) {
73    case MCDisassembler::Fail:
74      SM.PrintMessage(SMLoc::getFromPointer(Bytes[Index].second),
75                      "invalid instruction encoding", "warning");
76      if (Size == 0)
77        Size = 1; // skip illegible bytes
78      break;
79
80    case MCDisassembler::SoftFail:
81      SM.PrintMessage(SMLoc::getFromPointer(Bytes[Index].second),
82                      "potentially undefined instruction encoding", "warning");
83      // Fall through
84
85    case MCDisassembler::Success:
86      Printer.printInst(&Inst, Out, "");
87      Out << "\n";
88      break;
89    }
90  }
91
92  return false;
93}
94
95static bool ByteArrayFromString(ByteArrayTy &ByteArray,
96                                StringRef &Str,
97                                SourceMgr &SM) {
98  while (!Str.empty()) {
99    // Strip horizontal whitespace.
100    if (size_t Pos = Str.find_first_not_of(" \t\r")) {
101      Str = Str.substr(Pos);
102      continue;
103    }
104
105    // If this is the end of a line or start of a comment, remove the rest of
106    // the line.
107    if (Str[0] == '\n' || Str[0] == '#') {
108      // Strip to the end of line if we already processed any bytes on this
109      // line.  This strips the comment and/or the \n.
110      if (Str[0] == '\n') {
111        Str = Str.substr(1);
112      } else {
113        Str = Str.substr(Str.find_first_of('\n'));
114        if (!Str.empty())
115          Str = Str.substr(1);
116      }
117      continue;
118    }
119
120    // Get the current token.
121    size_t Next = Str.find_first_of(" \t\n\r#");
122    StringRef Value = Str.substr(0, Next);
123
124    // Convert to a byte and add to the byte vector.
125    unsigned ByteVal;
126    if (Value.getAsInteger(0, ByteVal) || ByteVal > 255) {
127      // If we have an error, print it and skip to the end of line.
128      SM.PrintMessage(SMLoc::getFromPointer(Value.data()),
129                      "invalid input token", "error");
130      Str = Str.substr(Str.find('\n'));
131      ByteArray.clear();
132      continue;
133    }
134
135    ByteArray.push_back(std::make_pair((unsigned char)ByteVal, Value.data()));
136    Str = Str.substr(Next);
137  }
138
139  return false;
140}
141
142int Disassembler::disassemble(const Target &T,
143                              const std::string &Triple,
144                              const std::string &Cpu,
145                              const std::string &FeaturesStr,
146                              MemoryBuffer &Buffer,
147                              raw_ostream &Out) {
148  // Set up disassembler.
149  OwningPtr<const MCAsmInfo> AsmInfo(T.createMCAsmInfo(Triple));
150
151  if (!AsmInfo) {
152    errs() << "error: no assembly info for target " << Triple << "\n";
153    return -1;
154  }
155
156  OwningPtr<const MCSubtargetInfo> STI(T.createMCSubtargetInfo(Triple, Cpu, FeaturesStr));
157  if (!STI) {
158    errs() << "error: no subtarget info for target " << Triple << "\n";
159    return -1;
160  }
161
162  OwningPtr<const MCDisassembler> DisAsm(T.createMCDisassembler(*STI));
163  if (!DisAsm) {
164    errs() << "error: no disassembler for target " << Triple << "\n";
165    return -1;
166  }
167
168  int AsmPrinterVariant = AsmInfo->getAssemblerDialect();
169  OwningPtr<MCInstPrinter> IP(T.createMCInstPrinter(AsmPrinterVariant,
170                                                    *AsmInfo, *STI));
171  if (!IP) {
172    errs() << "error: no instruction printer for target " << Triple << '\n';
173    return -1;
174  }
175
176  bool ErrorOccurred = false;
177
178  SourceMgr SM;
179  SM.AddNewSourceBuffer(&Buffer, SMLoc());
180
181  // Convert the input to a vector for disassembly.
182  ByteArrayTy ByteArray;
183  StringRef Str = Buffer.getBuffer();
184
185  ErrorOccurred |= ByteArrayFromString(ByteArray, Str, SM);
186
187  if (!ByteArray.empty())
188    ErrorOccurred |= PrintInsts(*DisAsm, *IP, ByteArray, SM, Out);
189
190  return ErrorOccurred;
191}
192
193static int byteArrayReader(uint8_t *B, uint64_t A, void *Arg) {
194  ByteArrayTy &ByteArray = *((ByteArrayTy*)Arg);
195
196  if (A >= ByteArray.size())
197    return -1;
198
199  *B = ByteArray[A].first;
200
201  return 0;
202}
203
204static int verboseEvaluator(uint64_t *V, unsigned R, void *Arg) {
205  EDDisassembler &disassembler = *(EDDisassembler *)((void **)Arg)[0];
206  raw_ostream &Out = *(raw_ostream *)((void **)Arg)[1];
207
208  if (const char *regName = disassembler.nameWithRegisterID(R))
209    Out << "[" << regName << "/" << R << "]";
210
211  if (disassembler.registerIsStackPointer(R))
212    Out << "(sp)";
213  if (disassembler.registerIsProgramCounter(R))
214    Out << "(pc)";
215
216  *V = 0;
217  return 0;
218}
219
220int Disassembler::disassembleEnhanced(const std::string &TS,
221                                      MemoryBuffer &Buffer,
222                                      raw_ostream &Out) {
223  ByteArrayTy ByteArray;
224  StringRef Str = Buffer.getBuffer();
225  SourceMgr SM;
226
227  SM.AddNewSourceBuffer(&Buffer, SMLoc());
228
229  if (ByteArrayFromString(ByteArray, Str, SM)) {
230    return -1;
231  }
232
233  Triple T(TS);
234  EDDisassembler::AssemblySyntax AS;
235
236  switch (T.getArch()) {
237  default:
238    errs() << "error: no default assembly syntax for " << TS.c_str() << "\n";
239    return -1;
240  case Triple::arm:
241  case Triple::thumb:
242    AS = EDDisassembler::kEDAssemblySyntaxARMUAL;
243    break;
244  case Triple::x86:
245  case Triple::x86_64:
246    AS = EDDisassembler::kEDAssemblySyntaxX86ATT;
247    break;
248  }
249
250  EDDisassembler::initialize();
251  OwningPtr<EDDisassembler>
252    disassembler(EDDisassembler::getDisassembler(TS.c_str(), AS));
253
254  if (disassembler == 0) {
255    errs() << "error: couldn't get disassembler for " << TS << '\n';
256    return -1;
257  }
258
259  while (ByteArray.size()) {
260    OwningPtr<EDInst>
261      inst(disassembler->createInst(byteArrayReader, 0, &ByteArray));
262
263    if (inst == 0) {
264      errs() << "error: Didn't get an instruction\n";
265      return -1;
266    }
267
268    ByteArray.erase (ByteArray.begin(), ByteArray.begin() + inst->byteSize());
269
270    unsigned numTokens = inst->numTokens();
271    if ((int)numTokens < 0) {
272      errs() << "error: couldn't count the instruction's tokens\n";
273      return -1;
274    }
275
276    for (unsigned tokenIndex = 0; tokenIndex != numTokens; ++tokenIndex) {
277      EDToken *token;
278
279      if (inst->getToken(token, tokenIndex)) {
280        errs() << "error: Couldn't get token\n";
281        return -1;
282      }
283
284      const char *buf;
285      if (token->getString(buf)) {
286        errs() << "error: Couldn't get string for token\n";
287        return -1;
288      }
289
290      Out << '[';
291      int operandIndex = token->operandID();
292
293      if (operandIndex >= 0)
294        Out << operandIndex << "-";
295
296      switch (token->type()) {
297      default: Out << "?"; break;
298      case EDToken::kTokenWhitespace: Out << "w"; break;
299      case EDToken::kTokenPunctuation: Out << "p"; break;
300      case EDToken::kTokenOpcode: Out << "o"; break;
301      case EDToken::kTokenLiteral: Out << "l"; break;
302      case EDToken::kTokenRegister: Out << "r"; break;
303      }
304
305      Out << ":" << buf;
306
307      if (token->type() == EDToken::kTokenLiteral) {
308        Out << "=";
309        if (token->literalSign())
310          Out << "-";
311        uint64_t absoluteValue;
312        if (token->literalAbsoluteValue(absoluteValue)) {
313          errs() << "error: Couldn't get the value of a literal token\n";
314          return -1;
315        }
316        Out << absoluteValue;
317      } else if (token->type() == EDToken::kTokenRegister) {
318        Out << "=";
319        unsigned regID;
320        if (token->registerID(regID)) {
321          errs() << "error: Couldn't get the ID of a register token\n";
322          return -1;
323        }
324        Out << "r" << regID;
325      }
326
327      Out << "]";
328    }
329
330    Out << " ";
331
332    if (inst->isBranch())
333      Out << "<br> ";
334    if (inst->isMove())
335      Out << "<mov> ";
336
337    unsigned numOperands = inst->numOperands();
338
339    if ((int)numOperands < 0) {
340      errs() << "error: Couldn't count operands\n";
341      return -1;
342    }
343
344    for (unsigned operandIndex = 0; operandIndex != numOperands;
345         ++operandIndex) {
346      Out << operandIndex << ":";
347
348      EDOperand *operand;
349      if (inst->getOperand(operand, operandIndex)) {
350        errs() << "error: couldn't get operand\n";
351        return -1;
352      }
353
354      uint64_t evaluatedResult;
355      void *Arg[] = { disassembler.get(), &Out };
356      if (operand->evaluate(evaluatedResult, verboseEvaluator, Arg)) {
357        errs() << "error: Couldn't evaluate an operand\n";
358        return -1;
359      }
360      Out << "=" << evaluatedResult << " ";
361    }
362
363    Out << '\n';
364  }
365
366  return 0;
367}
368
369