ThreadPlanStepOverRange.cpp revision 2bcbaf625afd8f521da03ddaa146e7ea7650ee38 
1//===-- ThreadPlanStepOverRange.cpp -----------------------------*- 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#include "lldb/Target/ThreadPlanStepOverRange.h"
11
12// C Includes
13// C++ Includes
14// Other libraries and framework includes
15// Project includes
16
17#include "lldb/lldb-private-log.h"
18#include "lldb/Core/Log.h"
19#include "lldb/Core/Stream.h"
20#include "lldb/Target/Process.h"
21#include "lldb/Target/RegisterContext.h"
22#include "lldb/Target/Target.h"
23#include "lldb/Target/Thread.h"
24#include "lldb/Target/ThreadPlanStepOut.h"
25#include "lldb/Target/ThreadPlanStepThrough.h"
26
27using namespace lldb_private;
28using namespace lldb;
29
30
31//----------------------------------------------------------------------
32// ThreadPlanStepOverRange: Step through a stack range, either stepping over or into
33// based on the value of \a type.
34//----------------------------------------------------------------------
35
36ThreadPlanStepOverRange::ThreadPlanStepOverRange
37(
38    Thread &thread,
39    const AddressRange &range,
40    const SymbolContext &addr_context,
41    lldb::RunMode stop_others,
42    bool okay_to_discard
43) :
44    ThreadPlanStepRange (ThreadPlan::eKindStepOverRange, "Step range stepping over", thread, range, addr_context, stop_others)
45{
46    // Step over range plans can be master plans, since you could hit a breakpoint while stepping over, step around
47    // a bit, then continue to finish up the step over.
48    SetIsMasterPlan (true);
49    SetOkayToDiscard (okay_to_discard);
50}
51
52ThreadPlanStepOverRange::~ThreadPlanStepOverRange ()
53{
54}
55
56void
57ThreadPlanStepOverRange::GetDescription (Stream *s, lldb::DescriptionLevel level)
58{
59    if (level == lldb::eDescriptionLevelBrief)
60        s->Printf("step over");
61    else
62    {
63        s->Printf ("stepping through range (stepping over functions): ");
64        DumpRanges(s);
65    }
66}
67
68bool
69ThreadPlanStepOverRange::ShouldStop (Event *event_ptr)
70{
71    LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
72
73    if (log)
74    {
75        StreamString s;
76        s.Address (m_thread.GetRegisterContext()->GetPC(),
77                   m_thread.CalculateTarget()->GetArchitecture().GetAddressByteSize());
78        log->Printf("ThreadPlanStepOverRange reached %s.", s.GetData());
79    }
80
81    // If we're out of the range but in the same frame or in our caller's frame
82    // then we should stop.
83    // When stepping out we only step if we are forcing running one thread.
84    bool stop_others;
85    if (m_stop_others == lldb::eOnlyThisThread)
86        stop_others = true;
87    else
88        stop_others = false;
89
90    ThreadPlan* new_plan = NULL;
91
92    FrameComparison frame_order = CompareCurrentFrameToStartFrame();
93
94    if (frame_order == eFrameCompareOlder)
95    {
96        // If we're in an older frame then we should stop.
97        //
98        // A caveat to this is if we think the frame is older but we're actually in a trampoline.
99        // I'm going to make the assumption that you wouldn't RETURN to a trampoline.  So if we are
100        // in a trampoline we think the frame is older because the trampoline confused the backtracer.
101        // As below, we step through first, and then try to figure out how to get back out again.
102
103        new_plan = m_thread.QueueThreadPlanForStepThrough (false, stop_others);
104
105        if (new_plan != NULL && log)
106            log->Printf("Thought I stepped out, but in fact arrived at a trampoline.");
107    }
108    else if (frame_order == eFrameCompareYounger)
109    {
110        // Make sure we really are in a new frame.  Do that by unwinding and seeing if the
111        // start function really is our start function...
112        StackFrameSP older_frame_sp = m_thread.GetStackFrameAtIndex(1);
113
114        // But if we can't even unwind one frame we should just get out of here & stop...
115        if (older_frame_sp)
116        {
117            const SymbolContext &older_context = older_frame_sp->GetSymbolContext(eSymbolContextEverything);
118            if (older_context == m_addr_context)
119            {
120                new_plan = m_thread.QueueThreadPlanForStepOut (false,
121                                                           NULL,
122                                                           true,
123                                                           stop_others,
124                                                           eVoteNo,
125                                                           eVoteNoOpinion,
126                                                           0);
127            }
128            else
129            {
130                new_plan = m_thread.QueueThreadPlanForStepThrough (false, stop_others);
131
132            }
133        }
134    }
135    else
136    {
137        // If we're still in the range, keep going.
138        if (InRange())
139        {
140            SetNextBranchBreakpoint();
141            return false;
142        }
143
144
145        if (!InSymbol())
146        {
147            // This one is a little tricky.  Sometimes we may be in a stub or something similar,
148            // in which case we need to get out of there.  But if we are in a stub then it's
149            // likely going to be hard to get out from here.  It is probably easiest to step into the
150            // stub, and then it will be straight-forward to step out.
151            new_plan = m_thread.QueueThreadPlanForStepThrough (false, stop_others);
152        }
153    }
154
155    // If we get to this point, we're not going to use a previously set "next branch" breakpoint, so delete it:
156    ClearNextBranchBreakpoint();
157
158    if (new_plan == NULL)
159        m_no_more_plans = true;
160    else
161        m_no_more_plans = false;
162
163    if (new_plan == NULL)
164    {
165        // For efficiencies sake, we know we're done here so we don't have to do this
166        // calculation again in MischiefManaged.
167        SetPlanComplete();
168        return true;
169    }
170    else
171        return false;
172}
173