Backtrace.h revision 94ece83270deca76c69f5755f8c0ff5c859341fd 
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  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#if defined(__APPLE__)
48struct __darwin_ucontext;
49typedef __darwin_ucontext ucontext_t;
50#else
51struct ucontext;
52typedef ucontext ucontext_t;
53#endif
54
55class Backtrace {
56public:
57  // Create the correct Backtrace object based on what is to be unwound.
58  // If pid < 0 or equals the current pid, then the Backtrace object
59  // corresponds to the current process.
60  // If pid < 0 or equals the current pid and tid >= 0, then the Backtrace
61  // object corresponds to a thread in the current process.
62  // If pid >= 0 and tid < 0, then the Backtrace object corresponds to a
63  // different process.
64  // Tracing a thread in a different process is not supported.
65  // If map is NULL, then create the map and manage it internally.
66  // If map is not NULL, the map is still owned by the caller.
67  static Backtrace* Create(pid_t pid, pid_t tid, BacktraceMap* map = NULL);
68
69  virtual ~Backtrace();
70
71  // Get the current stack trace and store in the backtrace_ structure.
72  virtual bool Unwind(size_t num_ignore_frames, ucontext_t* context = NULL) = 0;
73
74  // Get the function name and offset into the function given the pc.
75  // If the string is empty, then no valid function name was found.
76  virtual std::string GetFunctionName(uintptr_t pc, uintptr_t* offset);
77
78  // Fill in the map data associated with the given pc.
79  virtual void FillInMap(uintptr_t pc, backtrace_map_t* map);
80
81  // Read the data at a specific address.
82  virtual bool ReadWord(uintptr_t ptr, word_t* out_value) = 0;
83
84  // Read arbitrary data from a specific address. If a read request would
85  // span from one map to another, this call only reads up until the end
86  // of the current map.
87  // Returns the total number of bytes actually read.
88  virtual size_t Read(uintptr_t addr, uint8_t* buffer, size_t bytes) = 0;
89
90  // Create a string representing the formatted line of backtrace information
91  // for a single frame.
92  virtual std::string FormatFrameData(size_t frame_num);
93  virtual std::string FormatFrameData(const backtrace_frame_data_t* frame);
94
95  pid_t Pid() const { return pid_; }
96  pid_t Tid() const { return tid_; }
97  size_t NumFrames() const { return frames_.size(); }
98
99  const backtrace_frame_data_t* GetFrame(size_t frame_num) {
100    if (frame_num >= frames_.size()) {
101      return NULL;
102    }
103    return &frames_[frame_num];
104  }
105
106  typedef std::vector<backtrace_frame_data_t>::iterator iterator;
107  iterator begin() { return frames_.begin(); }
108  iterator end() { return frames_.end(); }
109
110  typedef std::vector<backtrace_frame_data_t>::const_iterator const_iterator;
111  const_iterator begin() const { return frames_.begin(); }
112  const_iterator end() const { return frames_.end(); }
113
114  BacktraceMap* GetMap() { return map_; }
115
116protected:
117  Backtrace(pid_t pid, pid_t tid, BacktraceMap* map);
118
119  // The name returned is not demangled, GetFunctionName() takes care of
120  // demangling the name.
121  virtual std::string GetFunctionNameRaw(uintptr_t pc, uintptr_t* offset) = 0;
122
123  virtual bool VerifyReadWordArgs(uintptr_t ptr, word_t* out_value);
124
125  bool BuildMap();
126
127  pid_t pid_;
128  pid_t tid_;
129
130  BacktraceMap* map_;
131  bool map_shared_;
132
133  std::vector<backtrace_frame_data_t> frames_;
134};
135
136#endif // _BACKTRACE_BACKTRACE_H
137