Unwind.h revision 360784 
1//===-- Unwind.h ------------------------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef liblldb_Unwind_h_
10#define liblldb_Unwind_h_
11
12#include <mutex>
13
14#include "lldb/lldb-private.h"
15
16namespace lldb_private {
17
18class Unwind {
19protected:
20  // Classes that inherit from Unwind can see and modify these
21  Unwind(Thread &thread) : m_thread(thread), m_unwind_mutex() {}
22
23public:
24  virtual ~Unwind() {}
25
26  void Clear() {
27    std::lock_guard<std::recursive_mutex> guard(m_unwind_mutex);
28    DoClear();
29  }
30
31  uint32_t GetFrameCount() {
32    std::lock_guard<std::recursive_mutex> guard(m_unwind_mutex);
33    return DoGetFrameCount();
34  }
35
36  uint32_t GetFramesUpTo(uint32_t end_idx) {
37    lldb::addr_t cfa;
38    lldb::addr_t pc;
39    uint32_t idx;
40    bool behaves_like_zeroth_frame = (end_idx == 0);
41
42    for (idx = 0; idx < end_idx; idx++) {
43      if (!DoGetFrameInfoAtIndex(idx, cfa, pc, behaves_like_zeroth_frame)) {
44        break;
45      }
46    }
47    return idx;
48  }
49
50  bool GetFrameInfoAtIndex(uint32_t frame_idx, lldb::addr_t &cfa,
51                           lldb::addr_t &pc, bool &behaves_like_zeroth_frame) {
52    std::lock_guard<std::recursive_mutex> guard(m_unwind_mutex);
53    return DoGetFrameInfoAtIndex(frame_idx, cfa, pc, behaves_like_zeroth_frame);
54  }
55
56  lldb::RegisterContextSP CreateRegisterContextForFrame(StackFrame *frame) {
57    std::lock_guard<std::recursive_mutex> guard(m_unwind_mutex);
58    return DoCreateRegisterContextForFrame(frame);
59  }
60
61  Thread &GetThread() { return m_thread; }
62
63protected:
64  // Classes that inherit from Unwind can see and modify these
65  virtual void DoClear() = 0;
66
67  virtual uint32_t DoGetFrameCount() = 0;
68
69  virtual bool DoGetFrameInfoAtIndex(uint32_t frame_idx, lldb::addr_t &cfa,
70                                     lldb::addr_t &pc,
71                                     bool &behaves_like_zeroth_frame) = 0;
72
73  virtual lldb::RegisterContextSP
74  DoCreateRegisterContextForFrame(StackFrame *frame) = 0;
75
76  Thread &m_thread;
77  std::recursive_mutex m_unwind_mutex;
78
79private:
80  DISALLOW_COPY_AND_ASSIGN(Unwind);
81};
82
83} // namespace lldb_private
84
85#endif // liblldb_Unwind_h_
86