1//===-- UnwindLLDB.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 lldb_UnwindLLDB_h_
11#define lldb_UnwindLLDB_h_
12
13#include <vector>
14
15#include "lldb/lldb-public.h"
16#include "lldb/Symbol/FuncUnwinders.h"
17#include "lldb/Symbol/UnwindPlan.h"
18#include "lldb/Target/RegisterContext.h"
19#include "lldb/Target/Unwind.h"
20
21namespace lldb_private {
22
23class RegisterContextLLDB;
24
25class UnwindLLDB : public lldb_private::Unwind
26{
27public:
28    UnwindLLDB (lldb_private::Thread &thread);
29
30    virtual
31    ~UnwindLLDB() { }
32
33    enum RegisterSearchResult
34    {
35        eRegisterFound = 0,
36        eRegisterNotFound,
37        eRegisterIsVolatile
38    };
39
40protected:
41    friend class lldb_private::RegisterContextLLDB;
42
43    struct RegisterLocation {
44        enum RegisterLocationTypes
45        {
46            eRegisterNotSaved = 0,              // register was not preserved by callee.  If volatile reg, is unavailable
47            eRegisterSavedAtMemoryLocation,     // register is saved at a specific word of target mem (target_memory_location)
48            eRegisterInRegister,                // register is available in a (possible other) register (register_number)
49            eRegisterSavedAtHostMemoryLocation, // register is saved at a word in lldb's address space
50            eRegisterValueInferred              // register val was computed (and is in inferred_value)
51        };
52        int type;
53        union
54        {
55            lldb::addr_t target_memory_location;
56            uint32_t     register_number;       // in eRegisterKindLLDB register numbering system
57            void*        host_memory_location;
58            uint64_t     inferred_value;        // eRegisterValueInferred - e.g. stack pointer == cfa + offset
59        } location;
60    };
61
62    void
63    DoClear()
64    {
65        m_frames.clear();
66        m_unwind_complete = false;
67    }
68
69    virtual uint32_t
70    DoGetFrameCount();
71
72    bool
73    DoGetFrameInfoAtIndex (uint32_t frame_idx,
74                         lldb::addr_t& cfa,
75                         lldb::addr_t& start_pc);
76
77    lldb::RegisterContextSP
78    DoCreateRegisterContextForFrame (lldb_private::StackFrame *frame);
79
80    typedef std::shared_ptr<RegisterContextLLDB> RegisterContextLLDBSP;
81
82    // Needed to retrieve the "next" frame (e.g. frame 2 needs to retrieve frame 1's RegisterContextLLDB)
83    // The RegisterContext for frame_num must already exist or this returns an empty shared pointer.
84    RegisterContextLLDBSP
85    GetRegisterContextForFrameNum (uint32_t frame_num);
86
87    // Iterate over the RegisterContextLLDB's in our m_frames vector, look for the first one that
88    // has a saved location for this reg.
89    bool
90    SearchForSavedLocationForRegister (uint32_t lldb_regnum, lldb_private::UnwindLLDB::RegisterLocation &regloc, uint32_t starting_frame_num, bool pc_register);
91
92
93private:
94
95    struct Cursor
96    {
97        lldb::addr_t start_pc;  // The start address of the function/symbol for this frame - current pc if unknown
98        lldb::addr_t cfa;       // The canonical frame address for this stack frame
99        lldb_private::SymbolContext sctx;  // A symbol context we'll contribute to & provide to the StackFrame creation
100        RegisterContextLLDBSP reg_ctx_lldb_sp; // These are all RegisterContextLLDB's
101
102        Cursor () : start_pc (LLDB_INVALID_ADDRESS), cfa (LLDB_INVALID_ADDRESS), sctx(), reg_ctx_lldb_sp() { }
103    private:
104        DISALLOW_COPY_AND_ASSIGN (Cursor);
105    };
106
107    typedef std::shared_ptr<Cursor> CursorSP;
108    std::vector<CursorSP> m_frames;
109    bool m_unwind_complete; // If this is true, we've enumerated all the frames in the stack, and m_frames.size() is the
110                            // number of frames, etc.  Otherwise we've only gone as far as directly asked, and m_frames.size()
111                            // is how far we've currently gone.
112
113
114    bool AddOneMoreFrame (ABI *abi);
115    bool AddFirstFrame ();
116
117    //------------------------------------------------------------------
118    // For UnwindLLDB only
119    //------------------------------------------------------------------
120    DISALLOW_COPY_AND_ASSIGN (UnwindLLDB);
121};
122
123}   // namespace lldb_private
124
125#endif  // lldb_UnwindLLDB_h_
126