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     // 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 
52 ThreadPlanStepOverRange::~ThreadPlanStepOverRange ()
53 {
54 }
55 
56 void
57 ThreadPlanStepOverRange::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 
68 bool
69 ThreadPlanStepOverRange::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