Backtrace.h revision 8fb224d32bd8526bbfd0a658c9e6cc1b28edffc3 
1/*
2 * Copyright (C) 2013 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 _BACKTRACE_BACKTRACE_H
18#define _BACKTRACE_BACKTRACE_H
19
20#include <inttypes.h>
21#include <stdint.h>
22
23#include <string>
24#include <vector>
25
26#include <backtrace/backtrace_constants.h>
27#include <backtrace/BacktraceMap.h>
28
29#if __LP64__
30#define PRIPTR "016" PRIxPTR
31typedef uint64_t word_t;
32#else
33#define PRIPTR "08" PRIxPTR
34typedef uint32_t word_t;
35#endif
36
37struct backtrace_frame_data_t {
38  size_t num;             // The current fame number.
39  uintptr_t pc;           // The absolute pc.
40  uintptr_t sp;           // The top of the stack.
41  size_t stack_size;      // The size of the stack, zero indicate an unknown stack size.
42  const backtrace_map_t* map;   // The map associated with the given pc.
43  std::string func_name;  // The function name associated with this pc, NULL if not found.
44  uintptr_t func_offset;  // pc relative to the start of the function, only valid if func_name is not NULL.
45};
46
47// Forward declarations.
48class BacktraceImpl;
49
50struct ucontext;
51typedef ucontext ucontext_t;
52
53class Backtrace {
54public:
55  // Create the correct Backtrace object based on what is to be unwound.
56  // If pid < 0 or equals the current pid, then the Backtrace object
57  // corresponds to the current process.
58  // If pid < 0 or equals the current pid and tid >= 0, then the Backtrace
59  // object corresponds to a thread in the current process.
60  // If pid >= 0 and tid < 0, then the Backtrace object corresponds to a
61  // different process.
62  // Tracing a thread in a different process is not supported.
63  // If map is NULL, then create the map and manage it internally.
64  // If map is not NULL, the map is still owned by the caller.
65  static Backtrace* Create(pid_t pid, pid_t tid, BacktraceMap* map = NULL);
66
67  virtual ~Backtrace();
68
69  // Get the current stack trace and store in the backtrace_ structure.
70  virtual bool Unwind(size_t num_ignore_frames, ucontext_t* context = NULL);
71
72  // Get the function name and offset into the function given the pc.
73  // If the string is empty, then no valid function name was found.
74  virtual std::string GetFunctionName(uintptr_t pc, uintptr_t* offset);
75
76  // Find the map associated with the given pc.
77  virtual const backtrace_map_t* FindMap(uintptr_t pc);
78
79  // Read the data at a specific address.
80  virtual bool ReadWord(uintptr_t ptr, word_t* out_value) = 0;
81
82  // Create a string representing the formatted line of backtrace information
83  // for a single frame.
84  virtual std::string FormatFrameData(size_t frame_num);
85  virtual std::string FormatFrameData(const backtrace_frame_data_t* frame);
86
87  pid_t Pid() { return pid_; }
88  pid_t Tid() { return tid_; }
89  size_t NumFrames() { return frames_.size(); }
90
91  const backtrace_frame_data_t* GetFrame(size_t frame_num) {
92    if (frame_num >= frames_.size()) {
93      return NULL;
94    }
95    return &frames_[frame_num];
96  }
97
98  typedef std::vector<backtrace_frame_data_t>::iterator iterator;
99  iterator begin() { return frames_.begin(); }
100  iterator end() { return frames_.end(); }
101
102  typedef std::vector<backtrace_frame_data_t>::const_iterator const_iterator;
103  const_iterator begin() const { return frames_.begin(); }
104  const_iterator end() const { return frames_.end(); }
105
106  BacktraceMap* GetMap() { return map_; }
107
108protected:
109  Backtrace(BacktraceImpl* impl, pid_t pid, BacktraceMap* map);
110
111  virtual bool VerifyReadWordArgs(uintptr_t ptr, word_t* out_value);
112
113  bool BuildMap();
114
115  pid_t pid_;
116  pid_t tid_;
117
118  BacktraceMap* map_;
119  bool map_shared_;
120
121  std::vector<backtrace_frame_data_t> frames_;
122
123  BacktraceImpl* impl_;
124
125  friend class BacktraceImpl;
126};
127
128#endif // _BACKTRACE_BACKTRACE_H
129