Disassembler.cpp revision 5b948190e3b311d06526addbb8f0e77a76da2467 
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/DebugHelper.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_X86_CODEGEN)
73  LLVMInitializeX86Disassembler();
74#endif
75}
76
77void Disassemble(char const *OutputFileName,
78                 llvm::Target const *Target,
79                 llvm::TargetMachine *TM,
80                 std::string const &Name,
81                 unsigned char const *Func,
82                 size_t FuncSize) {
83
84  std::string ErrorInfo;
85
86  // Open the disassembler output file
87  llvm::raw_fd_ostream OS(OutputFileName, ErrorInfo,
88                          llvm::raw_fd_ostream::F_Append);
89
90  if (!ErrorInfo.empty()) {
91    ALOGE("Unable to open disassembler output file: %s\n", OutputFileName);
92    return;
93  }
94
95  // Disassemble the given function
96  OS << "Disassembled code: " << Name << "\n";
97
98  const llvm::MCAsmInfo *AsmInfo;
99  const llvm::MCSubtargetInfo *SubtargetInfo;
100  const llvm::MCDisassembler *Disassmbler;
101  llvm::MCInstPrinter *IP;
102
103  AsmInfo = Target->createMCAsmInfo(TM->getTargetTriple());
104  SubtargetInfo = Target->createMCSubtargetInfo(TM->getTargetTriple(),
105                                                TM->getTargetCPU(),
106                                                TM->getTargetFeatureString());
107  Disassmbler = Target->createMCDisassembler(*SubtargetInfo);
108  IP = Target->createMCInstPrinter(AsmInfo->getAssemblerDialect(),
109                                   *AsmInfo, *SubtargetInfo);
110
111  const BufferMemoryObject *BufferMObj = new BufferMemoryObject(Func, FuncSize);
112
113  uint64_t Size;
114  uint64_t Index;
115
116  for (Index = 0; Index < FuncSize; Index += Size) {
117    llvm::MCInst Inst;
118
119    if (Disassmbler->getInstruction(Inst, Size, *BufferMObj, Index,
120                           /* REMOVED */ llvm::nulls(), llvm::nulls())) {
121      OS.indent(4);
122      OS.write("0x", 2);
123      OS.write_hex((uint32_t)Func + Index);
124      OS.write(": 0x", 4);
125      OS.write_hex(*(uint32_t *)(Func + Index));
126      IP->printInst(&Inst, OS, "");
127      OS << "\n";
128    } else {
129      if (Size == 0)
130        Size = 1;  // skip illegible bytes
131    }
132  }
133
134  OS << "\n";
135
136  delete BufferMObj;
137
138  delete AsmInfo;
139  delete Disassmbler;
140  delete IP;
141
142  OS.close();
143}
144
145} // namespace bcc
146
147#endif // USE_DISASSEMBLER
148