ThreadPlanStepOverRange.cpp revision 263363 
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/CompileUnit.h"
22#include "lldb/Symbol/Function.h"
23#include "lldb/Symbol/LineTable.h"
24#include "lldb/Target/Process.h"
25#include "lldb/Target/RegisterContext.h"
26#include "lldb/Target/Target.h"
27#include "lldb/Target/Thread.h"
28#include "lldb/Target/ThreadPlanStepOut.h"
29#include "lldb/Target/ThreadPlanStepThrough.h"
30
31using namespace lldb_private;
32using namespace lldb;
33
34
35//----------------------------------------------------------------------
36// ThreadPlanStepOverRange: Step through a stack range, either stepping over or into
37// based on the value of \a type.
38//----------------------------------------------------------------------
39
40ThreadPlanStepOverRange::ThreadPlanStepOverRange
41(
42    Thread &thread,
43    const AddressRange &range,
44    const SymbolContext &addr_context,
45    lldb::RunMode stop_others
46) :
47    ThreadPlanStepRange (ThreadPlan::eKindStepOverRange, "Step range stepping over", thread, range, addr_context, stop_others),
48    m_first_resume(true)
49{
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::IsEquivalentContext(const SymbolContext &context)
70{
71
72    // Match as much as is specified in the m_addr_context:
73    // This is a fairly loose sanity check.  Note, sometimes the target doesn't get filled
74    // in so I left out the target check.  And sometimes the module comes in as the .o file from the
75    // inlined range, so I left that out too...
76    if (m_addr_context.comp_unit)
77    {
78        if (m_addr_context.comp_unit == context.comp_unit)
79        {
80            if (m_addr_context.function && m_addr_context.function == context.function)
81            {
82                if (m_addr_context.block && m_addr_context.block == context.block)
83                    return true;
84            }
85        }
86    }
87    else if (m_addr_context.symbol && m_addr_context.symbol == context.symbol)
88    {
89        return true;
90    }
91    return false;
92}
93
94bool
95ThreadPlanStepOverRange::ShouldStop (Event *event_ptr)
96{
97    Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
98
99    if (log)
100    {
101        StreamString s;
102        s.Address (m_thread.GetRegisterContext()->GetPC(),
103                   m_thread.CalculateTarget()->GetArchitecture().GetAddressByteSize());
104        log->Printf("ThreadPlanStepOverRange reached %s.", s.GetData());
105    }
106
107    // If we're out of the range but in the same frame or in our caller's frame
108    // then we should stop.
109    // When stepping out we only stop others if we are forcing running one thread.
110    bool stop_others;
111    if (m_stop_others == lldb::eOnlyThisThread)
112        stop_others = true;
113    else
114        stop_others = false;
115
116    ThreadPlanSP new_plan_sp;
117
118    FrameComparison frame_order = CompareCurrentFrameToStartFrame();
119
120    if (frame_order == eFrameCompareOlder)
121    {
122        // If we're in an older frame then we should stop.
123        //
124        // A caveat to this is if we think the frame is older but we're actually in a trampoline.
125        // I'm going to make the assumption that you wouldn't RETURN to a trampoline.  So if we are
126        // in a trampoline we think the frame is older because the trampoline confused the backtracer.
127        // As below, we step through first, and then try to figure out how to get back out again.
128
129        new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others);
130
131        if (new_plan_sp && log)
132            log->Printf("Thought I stepped out, but in fact arrived at a trampoline.");
133    }
134    else if (frame_order == eFrameCompareYounger)
135    {
136        // Make sure we really are in a new frame.  Do that by unwinding and seeing if the
137        // start function really is our start function...
138        for(uint32_t i = 1;; ++i)
139        {
140            StackFrameSP older_frame_sp = m_thread.GetStackFrameAtIndex(i);
141            if (!older_frame_sp) {
142                // We can't unwind the next frame we should just get out of here & stop...
143                break;
144            }
145
146            const SymbolContext &older_context = older_frame_sp->GetSymbolContext(eSymbolContextEverything);
147            if (IsEquivalentContext(older_context))
148            {
149                new_plan_sp = m_thread.QueueThreadPlanForStepOut (false,
150                                                           NULL,
151                                                           true,
152                                                           stop_others,
153                                                           eVoteNo,
154                                                           eVoteNoOpinion,
155                                                           0);
156                break;
157            }
158            else
159            {
160                new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others);
161            }
162        }
163    }
164    else
165    {
166        // If we're still in the range, keep going.
167        if (InRange())
168        {
169            SetNextBranchBreakpoint();
170            return false;
171        }
172
173
174        if (!InSymbol())
175        {
176            // This one is a little tricky.  Sometimes we may be in a stub or something similar,
177            // in which case we need to get out of there.  But if we are in a stub then it's
178            // likely going to be hard to get out from here.  It is probably easiest to step into the
179            // stub, and then it will be straight-forward to step out.
180            new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others);
181        }
182        else
183        {
184            // The current clang (at least through 424) doesn't always get the address range for the
185            // DW_TAG_inlined_subroutines right, so that when you leave the inlined range the line table says
186            // you are still in the source file of the inlining function.  This is bad, because now you are missing
187            // the stack frame for the function containing the inlining, and if you sensibly do "finish" to get
188            // out of this function you will instead exit the containing function.
189            // To work around this, we check whether we are still in the source file we started in, and if not assume
190            // it is an error, and push a plan to get us out of this line and back to the containing file.
191
192            if (m_addr_context.line_entry.IsValid())
193            {
194                SymbolContext sc;
195                StackFrameSP frame_sp = m_thread.GetStackFrameAtIndex(0);
196                sc = frame_sp->GetSymbolContext (eSymbolContextEverything);
197                if (sc.line_entry.IsValid())
198                {
199                    if (sc.line_entry.file != m_addr_context.line_entry.file
200                         && sc.comp_unit == m_addr_context.comp_unit
201                         && sc.function == m_addr_context.function)
202                    {
203                        // Okay, find the next occurance of this file in the line table:
204                        LineTable *line_table = m_addr_context.comp_unit->GetLineTable();
205                        if (line_table)
206                        {
207                            Address cur_address = frame_sp->GetFrameCodeAddress();
208                            uint32_t entry_idx;
209                            LineEntry line_entry;
210                            if (line_table->FindLineEntryByAddress (cur_address, line_entry, &entry_idx))
211                            {
212                                LineEntry next_line_entry;
213                                bool step_past_remaining_inline = false;
214                                if (entry_idx > 0)
215                                {
216                                    // We require the the previous line entry and the current line entry come
217                                    // from the same file.
218                                    // The other requirement is that the previous line table entry be part of an
219                                    // inlined block, we don't want to step past cases where people have inlined
220                                    // some code fragment by using #include <source-fragment.c> directly.
221                                    LineEntry prev_line_entry;
222                                    if (line_table->GetLineEntryAtIndex(entry_idx - 1, prev_line_entry)
223                                        && prev_line_entry.file == line_entry.file)
224                                    {
225                                        SymbolContext prev_sc;
226                                        Address prev_address = prev_line_entry.range.GetBaseAddress();
227                                        prev_address.CalculateSymbolContext(&prev_sc);
228                                        if (prev_sc.block)
229                                        {
230                                            Block *inlined_block = prev_sc.block->GetContainingInlinedBlock();
231                                            if (inlined_block)
232                                            {
233                                                AddressRange inline_range;
234                                                inlined_block->GetRangeContainingAddress(prev_address, inline_range);
235                                                if (!inline_range.ContainsFileAddress(cur_address))
236                                                {
237
238                                                    step_past_remaining_inline = true;
239                                                }
240
241                                            }
242                                        }
243                                    }
244                                }
245
246                                if (step_past_remaining_inline)
247                                {
248                                    uint32_t look_ahead_step = 1;
249                                    while (line_table->GetLineEntryAtIndex(entry_idx + look_ahead_step, next_line_entry))
250                                    {
251                                        // Make sure we haven't wandered out of the function we started from...
252                                        Address next_line_address = next_line_entry.range.GetBaseAddress();
253                                        Function *next_line_function = next_line_address.CalculateSymbolContextFunction();
254                                        if (next_line_function != m_addr_context.function)
255                                            break;
256
257                                        if (next_line_entry.file == m_addr_context.line_entry.file)
258                                        {
259                                            const bool abort_other_plans = false;
260                                            const bool stop_other_threads = false;
261                                            new_plan_sp = m_thread.QueueThreadPlanForRunToAddress(abort_other_plans,
262                                                                                               next_line_address,
263                                                                                               stop_other_threads);
264                                            break;
265                                        }
266                                        look_ahead_step++;
267                                    }
268                                }
269                            }
270                        }
271                    }
272                }
273            }
274        }
275    }
276
277    // If we get to this point, we're not going to use a previously set "next branch" breakpoint, so delete it:
278    ClearNextBranchBreakpoint();
279
280    if (!new_plan_sp)
281        m_no_more_plans = true;
282    else
283        m_no_more_plans = false;
284
285    if (!new_plan_sp)
286    {
287        // For efficiencies sake, we know we're done here so we don't have to do this
288        // calculation again in MischiefManaged.
289        SetPlanComplete();
290        return true;
291    }
292    else
293        return false;
294}
295
296bool
297ThreadPlanStepOverRange::DoPlanExplainsStop (Event *event_ptr)
298{
299    // For crashes, breakpoint hits, signals, etc, let the base plan (or some plan above us)
300    // handle the stop.  That way the user can see the stop, step around, and then when they
301    // are done, continue and have their step complete.  The exception is if we've hit our
302    // "run to next branch" breakpoint.
303    // Note, unlike the step in range plan, we don't mark ourselves complete if we hit an
304    // unexplained breakpoint/crash.
305
306    Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
307    StopInfoSP stop_info_sp = GetPrivateStopInfo ();
308    bool return_value;
309
310    if (stop_info_sp)
311    {
312        StopReason reason = stop_info_sp->GetStopReason();
313
314        switch (reason)
315        {
316        case eStopReasonTrace:
317            return_value = true;
318            break;
319        case eStopReasonBreakpoint:
320            if (NextRangeBreakpointExplainsStop(stop_info_sp))
321                return_value = true;
322            else
323                return_value = false;
324            break;
325        case eStopReasonWatchpoint:
326        case eStopReasonSignal:
327        case eStopReasonException:
328        case eStopReasonExec:
329        case eStopReasonThreadExiting:
330        default:
331            if (log)
332                log->PutCString ("ThreadPlanStepInRange got asked if it explains the stop for some reason other than step.");
333            return_value = false;
334            break;
335        }
336    }
337    else
338        return_value = true;
339
340    return return_value;
341}
342
343bool
344ThreadPlanStepOverRange::DoWillResume (lldb::StateType resume_state, bool current_plan)
345{
346    if (resume_state != eStateSuspended && m_first_resume)
347    {
348        m_first_resume = false;
349        if (resume_state == eStateStepping && current_plan)
350        {
351            // See if we are about to step over an inlined call in the middle of the inlined stack, if so figure
352            // out its extents and reset our range to step over that.
353            bool in_inlined_stack = m_thread.DecrementCurrentInlinedDepth();
354            if (in_inlined_stack)
355            {
356                Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
357                if (log)
358                    log->Printf ("ThreadPlanStepInRange::DoWillResume: adjusting range to the frame at inlined depth %d.",
359                                 m_thread.GetCurrentInlinedDepth());
360                StackFrameSP stack_sp = m_thread.GetStackFrameAtIndex(0);
361                if (stack_sp)
362                {
363                    Block *frame_block = stack_sp->GetFrameBlock();
364                    lldb::addr_t curr_pc = m_thread.GetRegisterContext()->GetPC();
365                    AddressRange my_range;
366                    if (frame_block->GetRangeContainingLoadAddress(curr_pc, m_thread.GetProcess()->GetTarget(), my_range))
367                    {
368                        m_address_ranges.clear();
369                        m_address_ranges.push_back(my_range);
370                        if (log)
371                        {
372                            StreamString s;
373                            const InlineFunctionInfo *inline_info = frame_block->GetInlinedFunctionInfo();
374                            const char *name;
375                            if (inline_info)
376                                name = inline_info->GetName().AsCString();
377                            else
378                                name = "<unknown-notinlined>";
379
380                            s.Printf ("Stepping over inlined function \"%s\" in inlined stack: ", name);
381                            DumpRanges(&s);
382                            log->PutCString(s.GetData());
383                        }
384                    }
385
386                }
387            }
388        }
389    }
390
391    return true;
392}
393