summaryrefslogtreecommitdiffstats
path: root/lldb/source/Plugins/Process/Utility/UnwindLLDB.cpp
blob: 8fb7763b287162a0f47dc53f0013f27a76b096bf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
//===-- UnwindLLDB.cpp -------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "lldb/Target/Thread.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Core/Module.h"
#include "lldb/Symbol/FuncUnwinders.h"
#include "lldb/Symbol/Function.h"
#include "lldb/Utility/ArchDefaultUnwindPlan.h"
#include "UnwindLLDB.h"
#include "lldb/Symbol/UnwindPlan.h"
#include "lldb/Core/Log.h"

using namespace lldb;
using namespace lldb_private;

UnwindLLDB::UnwindLLDB (Thread &thread) :
    Unwind (thread),
    m_frames()
{
}

uint32_t
UnwindLLDB::GetFrameCount()
{
    Log *log = GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND);
    if (m_frames.empty())
    {
        // First, set up the 0th (initial) frame
        CursorSP first_cursor_sp(new Cursor ());
        RegisterContextSP no_frame; // an empty shared pointer
        RegisterContextLLDB *first_register_ctx = new RegisterContextLLDB(m_thread, no_frame, first_cursor_sp->sctx, 0);
        if (!first_register_ctx->IsValid())
        {
            delete first_register_ctx;
            return 0;
        }
        if (!first_register_ctx->GetCFA (first_cursor_sp->cfa))
        {
            delete first_register_ctx;
            return 0;
        }
        if (!first_register_ctx->GetPC (first_cursor_sp->start_pc))
        {
            delete first_register_ctx;
            return 0;
        }
        // Reuse the StackFrame provided by the processor native machine context for the first frame
        first_register_ctx->SetStackFrame (m_thread.GetStackFrameAtIndex(0).get());
        RegisterContextSP first_register_ctx_sp(first_register_ctx);
        first_cursor_sp->reg_ctx = first_register_ctx_sp;
        m_frames.push_back (first_cursor_sp);

        // Now walk up the rest of the stack
        while (1)
        {
            CursorSP cursor_sp(new Cursor ());
            RegisterContextLLDB *register_ctx;
            uint32_t cur_idx = m_frames.size ();
            register_ctx = new RegisterContextLLDB (m_thread, m_frames[cur_idx - 1]->reg_ctx, cursor_sp->sctx, cur_idx);
            if (!register_ctx->IsValid())
            {
                delete register_ctx;
                if (log)
                {
                    log->Printf("%*sFrame %d invalid RegisterContext for this frame, stopping stack walk", 
                                cur_idx < 100 ? cur_idx : 100, "", cur_idx);
                }
                break;
            }
            if (!register_ctx->GetCFA (cursor_sp->cfa))
            {
                delete register_ctx;
                if (log)
                {
                    log->Printf("%*sFrame %d did not get CFA for this frame, stopping stack walk",
                                cur_idx < 100 ? cur_idx : 100, "", cur_idx);
                }
                break;
            }
            if (cursor_sp->cfa == (addr_t) -1 || cursor_sp->cfa == 1 || cursor_sp->cfa == 0)
            {
                delete register_ctx;
                if (log)
                {
                    log->Printf("%*sFrame %d did not get a valid CFA for this frame, stopping stack walk",
                                cur_idx < 100 ? cur_idx : 100, "", cur_idx);
                }
                break;
            }
            if (!register_ctx->GetPC (cursor_sp->start_pc))
            {
                delete register_ctx;
                if (log)
                {
                    log->Printf("%*sFrame %d did not get PC for this frame, stopping stack walk",
                                cur_idx < 100 ? cur_idx : 100, "", cur_idx);
                }
                break;
            }
            RegisterContextSP register_ctx_sp(register_ctx);
            StackFrame *frame = new StackFrame(cur_idx, cur_idx, m_thread, register_ctx_sp, cursor_sp->cfa, cursor_sp->start_pc, &(cursor_sp->sctx));
            register_ctx->SetStackFrame (frame);
            cursor_sp->reg_ctx = register_ctx_sp;
            m_frames.push_back (cursor_sp);
        }
    }
    return m_frames.size ();
}

bool
UnwindLLDB::GetFrameInfoAtIndex (uint32_t idx, addr_t& cfa, addr_t& pc)
{
    // FIXME don't get the entire stack if it isn't needed.
    if (m_frames.size() == 0)
        GetFrameCount();

    if (idx < m_frames.size ())
    {
        cfa = m_frames[idx]->cfa;
        pc = m_frames[idx]->start_pc;
        return true;
    }
    return false;
}

RegisterContext *
UnwindLLDB::CreateRegisterContextForFrame (StackFrame *frame)
{
    uint32_t idx = frame->GetFrameIndex ();
    
    // FIXME don't get the entire stack if it isn't needed.
    if (m_frames.size() == 0)
        GetFrameCount();
    
    if (idx == 0)
    {
        return m_thread.GetRegisterContext();
    }
    if (idx < m_frames.size ())
        return m_frames[idx]->reg_ctx.get();
    return NULL;
}
OpenPOWER on IntegriCloud