Disassembler.cpp revision 9cb69f6bd3b537e895f74325c931c989f3df042e 
1/*
2 * Copyright 2011-2012, The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "bcc/Support/Disassembler.h"
18
19#include <llvm/LLVMContext.h>
20
21#include <llvm/MC/MCAsmInfo.h>
22#include <llvm/MC/MCDisassembler.h>
23#include <llvm/MC/MCInst.h>
24#include <llvm/MC/MCInstPrinter.h>
25
26#include <llvm/Support/MemoryObject.h>
27#include <llvm/Support/TargetRegistry.h>
28#include <llvm/Support/TargetSelect.h>
29#include <llvm/Support/raw_ostream.h>
30
31#include <llvm/Target/TargetData.h>
32#include <llvm/Target/TargetMachine.h>
33#include <llvm/Target/TargetOptions.h>
34
35#include "bcc/Config/Config.h"
36#include "bcc/Support/Log.h"
37
38#if USE_DISASSEMBLER
39
40namespace {
41
42class BufferMemoryObject : public llvm::MemoryObject {
43private:
44  const uint8_t *mBytes;
45  uint64_t mLength;
46
47public:
48  BufferMemoryObject(const uint8_t *Bytes, uint64_t Length)
49    : mBytes(Bytes), mLength(Length) {
50  }
51
52  virtual uint64_t getBase() const { return 0; }
53  virtual uint64_t getExtent() const { return mLength; }
54
55  virtual int readByte(uint64_t Addr, uint8_t *Byte) const {
56    if (Addr > getExtent())
57      return -1;
58    *Byte = mBytes[Addr];
59    return 0;
60  }
61};
62
63} // namespace anonymous
64
65namespace bcc {
66
67void InitializeDisassembler() {
68#if defined(PROVIDE_ARM_CODEGEN)
69  LLVMInitializeARMDisassembler();
70#endif
71
72#if defined(PROVIDE_MIPS_CODEGEN)
73  LLVMInitializeMipsDisassembler();
74#endif
75
76#if defined(PROVIDE_X86_CODEGEN)
77  LLVMInitializeX86Disassembler();
78#endif
79}
80
81void Disassemble(char const *OutputFileName,
82                 llvm::Target const *Target,
83                 llvm::TargetMachine *TM,
84                 std::string const &Name,
85                 unsigned char const *Func,
86                 size_t FuncSize) {
87
88  std::string ErrorInfo;
89
90  // Open the disassembler output file
91  llvm::raw_fd_ostream OS(OutputFileName, ErrorInfo,
92                          llvm::raw_fd_ostream::F_Append);
93
94  if (!ErrorInfo.empty()) {
95    ALOGE("Unable to open disassembler output file: %s\n", OutputFileName);
96    return;
97  }
98
99  ALOGI("Writing LLVM disassembly to file: %s\n", OutputFileName);
100  // Disassemble the given function
101  OS << "Disassembled code: " << Name << "\n";
102
103  const llvm::MCAsmInfo *AsmInfo;
104  const llvm::MCSubtargetInfo *SubtargetInfo;
105  const llvm::MCDisassembler *Disassembler;
106  llvm::MCInstPrinter *IP;
107
108  const std::string& TripleName(Compiler::getTargetTriple());
109
110  AsmInfo = Target->createMCAsmInfo(Compiler::getTargetTriple());
111  SubtargetInfo = Target->createMCSubtargetInfo(TripleName, "", "");
112  Disassembler = Target->createMCDisassembler(*SubtargetInfo);
113
114  const llvm::MCInstrInfo *MII = Target->createMCInstrInfo();
115  const llvm::MCRegisterInfo *MRI = Target->createMCRegInfo(TripleName);
116
117  IP = Target->createMCInstPrinter(AsmInfo->getAssemblerDialect(),
118                                   *AsmInfo,
119                                   *MII,
120                                   *MRI,
121                                   *SubtargetInfo);
122
123  const BufferMemoryObject *BufferMObj = new BufferMemoryObject(Func, FuncSize);
124
125  uint64_t Size;
126  uint64_t Index;
127
128  for (Index = 0; Index < FuncSize; Index += Size) {
129    llvm::MCInst Inst;
130
131    if (Disassembler->getInstruction(Inst, Size, *BufferMObj, Index,
132                           /* REMOVED */ llvm::nulls(), llvm::nulls())) {
133      OS.indent(4);
134      OS.write("0x", 2);
135      OS.write_hex((uint32_t)Func + Index);
136      OS.write(": 0x", 4);
137      OS.write_hex(*(uint32_t *)(Func + Index));
138      IP->printInst(&Inst, OS, "");
139      OS << "\n";
140    } else {
141      if (Size == 0)
142        Size = 1;  // skip illegible bytes
143    }
144  }
145
146  OS << "\n";
147
148  delete BufferMObj;
149
150  delete AsmInfo;
151  delete Disassembler;
152  delete IP;
153
154  OS.close();
155}
156
157} // namespace bcc
158
159#endif // USE_DISASSEMBLER
160