1 //===-- StackFrameList.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 LLDB_TARGET_STACKFRAMELIST_H
10 #define LLDB_TARGET_STACKFRAMELIST_H
11 
12 #include <memory>
13 #include <mutex>
14 #include <vector>
15 
16 #include "lldb/Target/StackFrame.h"
17 
18 namespace lldb_private {
19 
20 class ScriptedThread;
21 
22 class StackFrameList {
23 public:
24   // Constructors and Destructors
25   StackFrameList(Thread &thread, const lldb::StackFrameListSP &prev_frames_sp,
26                  bool show_inline_frames);
27 
28   ~StackFrameList();
29 
30   /// Get the number of visible frames. Frames may be created if \p can_create
31   /// is true. Synthetic (inline) frames expanded from the concrete frame #0
32   /// (aka invisible frames) are not included in this count.
33   uint32_t GetNumFrames(bool can_create = true);
34 
35   /// Get the frame at index \p idx. Invisible frames cannot be indexed.
36   lldb::StackFrameSP GetFrameAtIndex(uint32_t idx);
37 
38   /// Get the first concrete frame with index greater than or equal to \p idx.
39   /// Unlike \ref GetFrameAtIndex, this cannot return a synthetic frame.
40   lldb::StackFrameSP GetFrameWithConcreteFrameIndex(uint32_t unwind_idx);
41 
42   /// Retrieve the stack frame with the given ID \p stack_id.
43   lldb::StackFrameSP GetFrameWithStackID(const StackID &stack_id);
44 
45   /// Mark a stack frame as the currently selected frame and return its index.
46   uint32_t SetSelectedFrame(lldb_private::StackFrame *frame);
47 
48   /// Get the currently selected frame index.
49   uint32_t GetSelectedFrameIndex() const;
50 
51   /// Mark a stack frame as the currently selected frame using the frame index
52   /// \p idx. Like \ref GetFrameAtIndex, invisible frames cannot be selected.
53   bool SetSelectedFrameByIndex(uint32_t idx);
54 
55   /// If the current inline depth (i.e the number of invisible frames) is valid,
56   /// subtract it from \p idx. Otherwise simply return \p idx.
57   uint32_t GetVisibleStackFrameIndex(uint32_t idx) {
58     if (m_current_inlined_depth < UINT32_MAX)
59       return idx - m_current_inlined_depth;
60     else
61       return idx;
62   }
63 
64   /// Calculate and set the current inline depth. This may be used to update
65   /// the StackFrameList's set of inline frames when execution stops, e.g when
66   /// a breakpoint is hit.
67   void CalculateCurrentInlinedDepth();
68 
69   /// If the currently selected frame comes from the currently selected thread,
70   /// point the default file and line of the thread's target to the location
71   /// specified by the frame.
72   void SetDefaultFileAndLineToSelectedFrame();
73 
74   /// Clear the cache of frames.
75   void Clear();
76 
77   void Dump(Stream *s);
78 
79   /// If \p stack_frame_ptr is contained in this StackFrameList, return its
80   /// wrapping shared pointer.
81   lldb::StackFrameSP
82   GetStackFrameSPForStackFramePtr(StackFrame *stack_frame_ptr);
83 
84   size_t GetStatus(Stream &strm, uint32_t first_frame, uint32_t num_frames,
85                    bool show_frame_info, uint32_t num_frames_with_source,
86                    bool show_unique = false,
87                    const char *frame_marker = nullptr);
88 
89 protected:
90   friend class Thread;
91   friend class ScriptedThread;
92 
93   bool SetFrameAtIndex(uint32_t idx, lldb::StackFrameSP &frame_sp);
94 
95   void GetFramesUpTo(uint32_t end_idx);
96 
97   void GetOnlyConcreteFramesUpTo(uint32_t end_idx, Unwind &unwinder);
98 
99   void SynthesizeTailCallFrames(StackFrame &next_frame);
100 
101   bool GetAllFramesFetched() { return m_concrete_frames_fetched == UINT32_MAX; }
102 
103   void SetAllFramesFetched() { m_concrete_frames_fetched = UINT32_MAX; }
104 
105   bool DecrementCurrentInlinedDepth();
106 
107   void ResetCurrentInlinedDepth();
108 
109   uint32_t GetCurrentInlinedDepth();
110 
111   void SetCurrentInlinedDepth(uint32_t new_depth);
112 
113   typedef std::vector<lldb::StackFrameSP> collection;
114   typedef collection::iterator iterator;
115   typedef collection::const_iterator const_iterator;
116 
117   /// The thread this frame list describes.
118   Thread &m_thread;
119 
120   /// The old stack frame list.
121   // TODO: The old stack frame list is used to fill in missing frame info
122   // heuristically when it's otherwise unavailable (say, because the unwinder
123   // fails). We should have stronger checks to make sure that this is a valid
124   // source of information.
125   lldb::StackFrameListSP m_prev_frames_sp;
126 
127   /// A mutex for this frame list.
128   // TODO: This mutex may not always be held when required. In particular, uses
129   // of the StackFrameList APIs in lldb_private::Thread look suspect. Consider
130   // passing around a lock_guard reference to enforce proper locking.
131   mutable std::recursive_mutex m_mutex;
132 
133   /// A cache of frames. This may need to be updated when the program counter
134   /// changes.
135   collection m_frames;
136 
137   /// The currently selected frame.
138   uint32_t m_selected_frame_idx;
139 
140   /// The number of concrete frames fetched while filling the frame list. This
141   /// is only used when synthetic frames are enabled.
142   uint32_t m_concrete_frames_fetched;
143 
144   /// The number of synthetic function activations (invisible frames) expanded
145   /// from the concrete frame #0 activation.
146   // TODO: Use an optional instead of UINT32_MAX to denote invalid values.
147   uint32_t m_current_inlined_depth;
148 
149   /// The program counter value at the currently selected synthetic activation.
150   /// This is only valid if m_current_inlined_depth is valid.
151   // TODO: Use an optional instead of UINT32_MAX to denote invalid values.
152   lldb::addr_t m_current_inlined_pc;
153 
154   /// Whether or not to show synthetic (inline) frames. Immutable.
155   const bool m_show_inlined_frames;
156 
157 private:
158   StackFrameList(const StackFrameList &) = delete;
159   const StackFrameList &operator=(const StackFrameList &) = delete;
160 };
161 
162 } // namespace lldb_private
163 
164 #endif // LLDB_TARGET_STACKFRAMELIST_H
165