1/*
2 * Copyright (C) 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#ifndef ART_RUNTIME_ELF_FILE_H_
18#define ART_RUNTIME_ELF_FILE_H_
19
20#include <memory>
21#include <string>
22
23#include "base/macros.h"
24#include "base/os.h"
25// Explicitly include our own elf.h to avoid Linux and other dependencies.
26#include "./elf.h"
27
28namespace art {
29template <typename ElfTypes>
30class ElfFileImpl;
31
32// Explicitly instantiated in elf_file.cc
33typedef ElfFileImpl<ElfTypes32> ElfFileImpl32;
34typedef ElfFileImpl<ElfTypes64> ElfFileImpl64;
35
36// Used for compile time and runtime for ElfFile access. Because of
37// the need for use at runtime, cannot directly use LLVM classes such as
38// ELFObjectFile.
39class ElfFile {
40 public:
41  static ElfFile* Open(File* file,
42                       bool writable,
43                       bool program_header_only,
44                       bool low_4gb,
45                       std::string* error_msg,
46                       uint8_t* requested_base = nullptr);  // TODO: move arg to before error_msg.
47  // Open with specific mmap flags, Always maps in the whole file, not just the
48  // program header sections.
49  static ElfFile* Open(File* file,
50                       int mmap_prot,
51                       int mmap_flags,
52                       std::string* error_msg);
53  ~ElfFile();
54
55  // Load segments into memory based on PT_LOAD program headers
56  bool Load(File* file, bool executable, bool low_4gb, std::string* error_msg);
57
58  const uint8_t* FindDynamicSymbolAddress(const std::string& symbol_name) const;
59
60  size_t Size() const;
61
62  // The start of the memory map address range for this ELF file.
63  uint8_t* Begin() const;
64
65  // The end of the memory map address range for this ELF file.
66  uint8_t* End() const;
67
68  const std::string& GetFilePath() const;
69
70  bool GetSectionOffsetAndSize(const char* section_name, uint64_t* offset, uint64_t* size) const;
71
72  bool HasSection(const std::string& name) const;
73
74  uint64_t FindSymbolAddress(unsigned section_type,
75                             const std::string& symbol_name,
76                             bool build_map);
77
78  bool GetLoadedSize(size_t* size, std::string* error_msg) const;
79
80  // Strip an ELF file of unneeded debugging information.
81  // Returns true on success, false on failure.
82  static bool Strip(File* file, std::string* error_msg);
83
84  // Fixup an ELF file so that that oat header will be loaded at oat_begin.
85  // Returns true on success, false on failure.
86  static bool Fixup(File* file, uint64_t oat_data_begin);
87
88  bool Fixup(uint64_t base_address);
89
90  bool Is64Bit() const {
91    return elf64_.get() != nullptr;
92  }
93
94  ElfFileImpl32* GetImpl32() const {
95    return elf32_.get();
96  }
97
98  ElfFileImpl64* GetImpl64() const {
99    return elf64_.get();
100  }
101
102 private:
103  explicit ElfFile(ElfFileImpl32* elf32);
104  explicit ElfFile(ElfFileImpl64* elf64);
105
106  const std::unique_ptr<ElfFileImpl32> elf32_;
107  const std::unique_ptr<ElfFileImpl64> elf64_;
108
109  DISALLOW_COPY_AND_ASSIGN(ElfFile);
110};
111
112}  // namespace art
113
114#endif  // ART_RUNTIME_ELF_FILE_H_
115