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