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/Symbol/Block.h"
21 #include "lldb/Symbol/Function.h"
22 #include "lldb/Target/Process.h"
23 #include "lldb/Target/RegisterContext.h"
24 #include "lldb/Target/Target.h"
25 #include "lldb/Target/Thread.h"
26 #include "lldb/Target/ThreadPlanStepOut.h"
27 #include "lldb/Target/ThreadPlanStepThrough.h"
28 
29 using namespace lldb_private;
30 using namespace lldb;
31 
32 
33 //----------------------------------------------------------------------
34 // ThreadPlanStepOverRange: Step through a stack range, either stepping over or into
35 // based on the value of \a type.
36 //----------------------------------------------------------------------
37 
38 ThreadPlanStepOverRange::ThreadPlanStepOverRange
39 (
40     Thread &thread,
41     const AddressRange &range,
42     const SymbolContext &addr_context,
43     lldb::RunMode stop_others
44 ) :
45     ThreadPlanStepRange (ThreadPlan::eKindStepOverRange, "Step range stepping over", thread, range, addr_context, stop_others),
46     m_first_resume(true)
47 {
48 }
49 
50 ThreadPlanStepOverRange::~ThreadPlanStepOverRange ()
51 {
52 }
53 
54 void
55 ThreadPlanStepOverRange::GetDescription (Stream *s, lldb::DescriptionLevel level)
56 {
57     if (level == lldb::eDescriptionLevelBrief)
58         s->Printf("step over");
59     else
60     {
61         s->Printf ("stepping through range (stepping over functions): ");
62         DumpRanges(s);
63     }
64 }
65 
66 bool
67 ThreadPlanStepOverRange::ShouldStop (Event *event_ptr)
68 {
69     LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
70 
71     if (log)
72     {
73         StreamString s;
74         s.Address (m_thread.GetRegisterContext()->GetPC(),
75                    m_thread.CalculateTarget()->GetArchitecture().GetAddressByteSize());
76         log->Printf("ThreadPlanStepOverRange reached %s.", s.GetData());
77     }
78 
79     // If we're out of the range but in the same frame or in our caller's frame
80     // then we should stop.
81     // When stepping out we only step if we are forcing running one thread.
82     bool stop_others;
83     if (m_stop_others == lldb::eOnlyThisThread)
84         stop_others = true;
85     else
86         stop_others = false;
87 
88     ThreadPlan* new_plan = NULL;
89 
90     FrameComparison frame_order = CompareCurrentFrameToStartFrame();
91 
92     if (frame_order == eFrameCompareOlder)
93     {
94         // If we're in an older frame then we should stop.
95         //
96         // A caveat to this is if we think the frame is older but we're actually in a trampoline.
97         // I'm going to make the assumption that you wouldn't RETURN to a trampoline.  So if we are
98         // in a trampoline we think the frame is older because the trampoline confused the backtracer.
99         // As below, we step through first, and then try to figure out how to get back out again.
100 
101         new_plan = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others);
102 
103         if (new_plan != NULL && log)
104             log->Printf("Thought I stepped out, but in fact arrived at a trampoline.");
105     }
106     else if (frame_order == eFrameCompareYounger)
107     {
108         // Make sure we really are in a new frame.  Do that by unwinding and seeing if the
109         // start function really is our start function...
110         StackFrameSP older_frame_sp = m_thread.GetStackFrameAtIndex(1);
111 
112         // But if we can't even unwind one frame we should just get out of here & stop...
113         if (older_frame_sp)
114         {
115             const SymbolContext &older_context = older_frame_sp->GetSymbolContext(eSymbolContextEverything);
116 
117             // Match as much as is specified in the m_addr_context:
118             // This is a fairly loose sanity check.  Note, sometimes the target doesn't get filled
119             // in so I left out the target check.  And sometimes the module comes in as the .o file from the
120             // inlined range, so I left that out too...
121 
122             bool older_ctx_is_equivalent = true;
123             if (m_addr_context.comp_unit)
124             {
125                 if (m_addr_context.comp_unit == older_context.comp_unit)
126                 {
127                     if (m_addr_context.function && m_addr_context.function == older_context.function)
128                     {
129                         if (m_addr_context.block && m_addr_context.block == older_context.block)
130                         {
131                             older_ctx_is_equivalent = true;
132                         }
133                     }
134                 }
135             }
136             else if (m_addr_context.symbol && m_addr_context.symbol == older_context.symbol)
137             {
138                 older_ctx_is_equivalent = true;
139             }
140 
141             if (older_ctx_is_equivalent)
142             {
143                 new_plan = m_thread.QueueThreadPlanForStepOut (false,
144                                                            NULL,
145                                                            true,
146                                                            stop_others,
147                                                            eVoteNo,
148                                                            eVoteNoOpinion,
149                                                            0);
150             }
151             else
152             {
153                 new_plan = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others);
154 
155             }
156         }
157     }
158     else
159     {
160         // If we're still in the range, keep going.
161         if (InRange())
162         {
163             SetNextBranchBreakpoint();
164             return false;
165         }
166 
167 
168         if (!InSymbol())
169         {
170             // This one is a little tricky.  Sometimes we may be in a stub or something similar,
171             // in which case we need to get out of there.  But if we are in a stub then it's
172             // likely going to be hard to get out from here.  It is probably easiest to step into the
173             // stub, and then it will be straight-forward to step out.
174             new_plan = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others);
175         }
176     }
177 
178     // If we get to this point, we're not going to use a previously set "next branch" breakpoint, so delete it:
179     ClearNextBranchBreakpoint();
180 
181     if (new_plan == NULL)
182         m_no_more_plans = true;
183     else
184         m_no_more_plans = false;
185 
186     if (new_plan == NULL)
187     {
188         // For efficiencies sake, we know we're done here so we don't have to do this
189         // calculation again in MischiefManaged.
190         SetPlanComplete();
191         return true;
192     }
193     else
194         return false;
195 }
196 
197 bool
198 ThreadPlanStepOverRange::PlanExplainsStop ()
199 {
200     // For crashes, breakpoint hits, signals, etc, let the base plan (or some plan above us)
201     // handle the stop.  That way the user can see the stop, step around, and then when they
202     // are done, continue and have their step complete.  The exception is if we've hit our
203     // "run to next branch" breakpoint.
204     // Note, unlike the step in range plan, we don't mark ourselves complete if we hit an
205     // unexplained breakpoint/crash.
206 
207     LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
208     StopInfoSP stop_info_sp = GetPrivateStopReason();
209     if (stop_info_sp)
210     {
211         StopReason reason = stop_info_sp->GetStopReason();
212 
213         switch (reason)
214         {
215         case eStopReasonTrace:
216             return true;
217             break;
218         case eStopReasonBreakpoint:
219             if (NextRangeBreakpointExplainsStop(stop_info_sp))
220                 return true;
221             else
222                 return false;
223             break;
224         case eStopReasonWatchpoint:
225         case eStopReasonSignal:
226         case eStopReasonException:
227         default:
228             if (log)
229                 log->PutCString ("ThreadPlanStepInRange got asked if it explains the stop for some reason other than step.");
230             return false;
231             break;
232         }
233     }
234     return true;
235 }
236 
237 bool
238 ThreadPlanStepOverRange::WillResume (lldb::StateType resume_state, bool current_plan)
239 {
240     if (resume_state != eStateSuspended && m_first_resume)
241     {
242         m_first_resume = false;
243         if (resume_state == eStateStepping && current_plan)
244         {
245             // See if we are about to step over an inlined call in the middle of the inlined stack, if so figure
246             // out its extents and reset our range to step over that.
247             bool in_inlined_stack = m_thread.DecrementCurrentInlinedDepth();
248             if (in_inlined_stack)
249             {
250                 LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
251                 if (log)
252                     log->Printf ("ThreadPlanStepInRange::WillResume: adjusting range to the frame at inlined depth %d.",
253                                  m_thread.GetCurrentInlinedDepth());
254                 StackFrameSP stack_sp = m_thread.GetStackFrameAtIndex(0);
255                 if (stack_sp)
256                 {
257                     Block *frame_block = stack_sp->GetFrameBlock();
258                     lldb::addr_t curr_pc = m_thread.GetRegisterContext()->GetPC();
259                     AddressRange my_range;
260                     if (frame_block->GetRangeContainingLoadAddress(curr_pc, m_thread.GetProcess()->GetTarget(), my_range))
261                     {
262                         m_address_ranges.clear();
263                         m_address_ranges.push_back(my_range);
264                         if (log)
265                         {
266                             StreamString s;
267                             const InlineFunctionInfo *inline_info = frame_block->GetInlinedFunctionInfo();
268                             const char *name;
269                             if (inline_info)
270                                 name = inline_info->GetName().AsCString();
271                             else
272                                 name = "<unknown-notinlined>";
273 
274                             s.Printf ("Stepping over inlined function \"%s\" in inlined stack: ", name);
275                             DumpRanges(&s);
276                             log->PutCString(s.GetData());
277                         }
278                     }
279 
280                 }
281             }
282         }
283     }
284 
285     return ThreadPlan::WillResume(resume_state, current_plan);
286 }
287