1 //===-- Unwind.h ------------------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #ifndef liblldb_Unwind_h_
11 #define liblldb_Unwind_h_
12 
13 #include <mutex>
14 
15 #include "lldb/lldb-private.h"
16 
17 namespace lldb_private {
18 
19 class Unwind {
20 protected:
21   //------------------------------------------------------------------
22   // Classes that inherit from Unwind can see and modify these
23   //------------------------------------------------------------------
Unwind(Thread & thread)24   Unwind(Thread &thread) : m_thread(thread), m_unwind_mutex() {}
25 
26 public:
~Unwind()27   virtual ~Unwind() {}
28 
Clear()29   void Clear() {
30     std::lock_guard<std::recursive_mutex> guard(m_unwind_mutex);
31     DoClear();
32   }
33 
GetFrameCount()34   uint32_t GetFrameCount() {
35     std::lock_guard<std::recursive_mutex> guard(m_unwind_mutex);
36     return DoGetFrameCount();
37   }
38 
GetFramesUpTo(uint32_t end_idx)39   uint32_t GetFramesUpTo(uint32_t end_idx) {
40     lldb::addr_t cfa;
41     lldb::addr_t pc;
42     uint32_t idx;
43 
44     for (idx = 0; idx < end_idx; idx++) {
45       if (!DoGetFrameInfoAtIndex(idx, cfa, pc)) {
46         break;
47       }
48     }
49     return idx;
50   }
51 
GetFrameInfoAtIndex(uint32_t frame_idx,lldb::addr_t & cfa,lldb::addr_t & pc)52   bool GetFrameInfoAtIndex(uint32_t frame_idx, lldb::addr_t &cfa,
53                            lldb::addr_t &pc) {
54     std::lock_guard<std::recursive_mutex> guard(m_unwind_mutex);
55     return DoGetFrameInfoAtIndex(frame_idx, cfa, pc);
56   }
57 
CreateRegisterContextForFrame(StackFrame * frame)58   lldb::RegisterContextSP CreateRegisterContextForFrame(StackFrame *frame) {
59     std::lock_guard<std::recursive_mutex> guard(m_unwind_mutex);
60     return DoCreateRegisterContextForFrame(frame);
61   }
62 
GetThread()63   Thread &GetThread() { return m_thread; }
64 
65 protected:
66   //------------------------------------------------------------------
67   // Classes that inherit from Unwind can see and modify these
68   //------------------------------------------------------------------
69   virtual void DoClear() = 0;
70 
71   virtual uint32_t DoGetFrameCount() = 0;
72 
73   virtual bool DoGetFrameInfoAtIndex(uint32_t frame_idx, lldb::addr_t &cfa,
74                                      lldb::addr_t &pc) = 0;
75 
76   virtual lldb::RegisterContextSP
77   DoCreateRegisterContextForFrame(StackFrame *frame) = 0;
78 
79   Thread &m_thread;
80   std::recursive_mutex m_unwind_mutex;
81 
82 private:
83   DISALLOW_COPY_AND_ASSIGN(Unwind);
84 };
85 
86 } // namespace lldb_private
87 
88 #endif // liblldb_Unwind_h_
89