1 //===-- StackFrame.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/StackFrame.h"
11 
12 // C Includes
13 // C++ Includes
14 // Other libraries and framework includes
15 // Project includes
16 #include "lldb/Core/Module.h"
17 #include "lldb/Core/Debugger.h"
18 #include "lldb/Core/Disassembler.h"
19 #include "lldb/Core/Value.h"
20 #include "lldb/Core/ValueObjectVariable.h"
21 #include "lldb/Core/ValueObjectConstResult.h"
22 #include "lldb/Symbol/Function.h"
23 #include "lldb/Symbol/VariableList.h"
24 #include "lldb/Target/ExecutionContext.h"
25 #include "lldb/Target/Process.h"
26 #include "lldb/Target/RegisterContext.h"
27 #include "lldb/Target/Target.h"
28 #include "lldb/Target/Thread.h"
29 
30 using namespace lldb;
31 using namespace lldb_private;
32 
33 // The first bits in the flags are reserved for the SymbolContext::Scope bits
34 // so we know if we have tried to look up information in our internal symbol
35 // context (m_sc) already.
36 #define RESOLVED_FRAME_CODE_ADDR        (uint32_t(eSymbolContextEverything + 1))
37 #define RESOLVED_FRAME_ID_SYMBOL_SCOPE  (RESOLVED_FRAME_CODE_ADDR << 1)
38 #define GOT_FRAME_BASE                  (RESOLVED_FRAME_ID_SYMBOL_SCOPE << 1)
39 #define RESOLVED_VARIABLES              (GOT_FRAME_BASE << 1)
40 #define RESOLVED_GLOBAL_VARIABLES       (RESOLVED_VARIABLES << 1)
41 
42 StackFrame::StackFrame (const ThreadSP &thread_sp,
43                         user_id_t frame_idx,
44                         user_id_t unwind_frame_index,
45                         addr_t cfa,
46                         addr_t pc,
47                         const SymbolContext *sc_ptr) :
48     m_thread_wp (thread_sp),
49     m_frame_index (frame_idx),
50     m_concrete_frame_index (unwind_frame_index),
51     m_reg_context_sp (),
52     m_id (pc, cfa, NULL),
53     m_frame_code_addr (NULL, pc),
54     m_sc (),
55     m_flags (),
56     m_frame_base (),
57     m_frame_base_error (),
58     m_variable_list_sp (),
59     m_variable_list_value_objects (),
60     m_disassembly ()
61 {
62     if (sc_ptr != NULL)
63     {
64         m_sc = *sc_ptr;
65         m_flags.Set(m_sc.GetResolvedMask ());
66     }
67 }
68 
69 StackFrame::StackFrame (const ThreadSP &thread_sp,
70                         user_id_t frame_idx,
71                         user_id_t unwind_frame_index,
72                         const RegisterContextSP &reg_context_sp,
73                         addr_t cfa,
74                         addr_t pc,
75                         const SymbolContext *sc_ptr) :
76     m_thread_wp (thread_sp),
77     m_frame_index (frame_idx),
78     m_concrete_frame_index (unwind_frame_index),
79     m_reg_context_sp (reg_context_sp),
80     m_id (pc, cfa, NULL),
81     m_frame_code_addr (NULL, pc),
82     m_sc (),
83     m_flags (),
84     m_frame_base (),
85     m_frame_base_error (),
86     m_variable_list_sp (),
87     m_variable_list_value_objects (),
88     m_disassembly ()
89 {
90     if (sc_ptr != NULL)
91     {
92         m_sc = *sc_ptr;
93         m_flags.Set(m_sc.GetResolvedMask ());
94     }
95 
96     if (reg_context_sp && !m_sc.target_sp)
97     {
98         m_sc.target_sp = reg_context_sp->CalculateTarget();
99         if (m_sc.target_sp)
100             m_flags.Set (eSymbolContextTarget);
101     }
102 }
103 
104 StackFrame::StackFrame (const ThreadSP &thread_sp,
105                         user_id_t frame_idx,
106                         user_id_t unwind_frame_index,
107                         const RegisterContextSP &reg_context_sp,
108                         addr_t cfa,
109                         const Address& pc_addr,
110                         const SymbolContext *sc_ptr) :
111     m_thread_wp (thread_sp),
112     m_frame_index (frame_idx),
113     m_concrete_frame_index (unwind_frame_index),
114     m_reg_context_sp (reg_context_sp),
115     m_id (pc_addr.GetLoadAddress (&thread_sp->GetProcess().GetTarget()), cfa, NULL),
116     m_frame_code_addr (pc_addr),
117     m_sc (),
118     m_flags (),
119     m_frame_base (),
120     m_frame_base_error (),
121     m_variable_list_sp (),
122     m_variable_list_value_objects (),
123     m_disassembly ()
124 {
125     if (sc_ptr != NULL)
126     {
127         m_sc = *sc_ptr;
128         m_flags.Set(m_sc.GetResolvedMask ());
129     }
130 
131     if (m_sc.target_sp.get() == NULL && reg_context_sp)
132     {
133         m_sc.target_sp = reg_context_sp->CalculateTarget();
134         if (m_sc.target_sp)
135             m_flags.Set (eSymbolContextTarget);
136     }
137 
138     Module *pc_module = pc_addr.GetModulePtr();
139     if (m_sc.module_sp.get() == NULL || m_sc.module_sp.get() != pc_module)
140     {
141         if (pc_module)
142         {
143             m_sc.module_sp = pc_module->shared_from_this();
144             m_flags.Set (eSymbolContextModule);
145         }
146         else
147         {
148             m_sc.module_sp.reset();
149         }
150 
151     }
152 }
153 
154 
155 //----------------------------------------------------------------------
156 // Destructor
157 //----------------------------------------------------------------------
158 StackFrame::~StackFrame()
159 {
160 }
161 
162 StackID&
163 StackFrame::GetStackID()
164 {
165     // Make sure we have resolved the StackID object's symbol context scope if
166     // we already haven't looked it up.
167 
168     if (m_flags.IsClear (RESOLVED_FRAME_ID_SYMBOL_SCOPE))
169     {
170         if (m_id.GetSymbolContextScope ())
171         {
172             // We already have a symbol context scope, we just don't have our
173             // flag bit set.
174             m_flags.Set (RESOLVED_FRAME_ID_SYMBOL_SCOPE);
175         }
176         else
177         {
178             // Calculate the frame block and use this for the stack ID symbol
179             // context scope if we have one.
180             SymbolContextScope *scope = GetFrameBlock ();
181             if (scope == NULL)
182             {
183                 // We don't have a block, so use the symbol
184                 if (m_flags.IsClear (eSymbolContextSymbol))
185                     GetSymbolContext (eSymbolContextSymbol);
186 
187                 // It is ok if m_sc.symbol is NULL here
188                 scope = m_sc.symbol;
189             }
190             // Set the symbol context scope (the accessor will set the
191             // RESOLVED_FRAME_ID_SYMBOL_SCOPE bit in m_flags).
192             SetSymbolContextScope (scope);
193         }
194     }
195     return m_id;
196 }
197 
198 void
199 StackFrame::SetSymbolContextScope (SymbolContextScope *symbol_scope)
200 {
201     m_flags.Set (RESOLVED_FRAME_ID_SYMBOL_SCOPE);
202     m_id.SetSymbolContextScope (symbol_scope);
203 }
204 
205 const Address&
206 StackFrame::GetFrameCodeAddress()
207 {
208     if (m_flags.IsClear(RESOLVED_FRAME_CODE_ADDR) && !m_frame_code_addr.IsSectionOffset())
209     {
210         m_flags.Set (RESOLVED_FRAME_CODE_ADDR);
211 
212         // Resolve the PC into a temporary address because if ResolveLoadAddress
213         // fails to resolve the address, it will clear the address object...
214         ThreadSP thread_sp (GetThread());
215         if (thread_sp)
216         {
217             TargetSP target_sp (thread_sp->CalculateTarget());
218             if (target_sp)
219             {
220                 if (m_frame_code_addr.SetOpcodeLoadAddress (m_frame_code_addr.GetOffset(), target_sp.get()))
221                 {
222                     const Section *section = m_frame_code_addr.GetSection();
223                     if (section)
224                     {
225                         Module *module = section->GetModule();
226                         if (module)
227                         {
228                             m_sc.module_sp = module->shared_from_this();
229                             if (m_sc.module_sp)
230                                 m_flags.Set(eSymbolContextModule);
231                         }
232                     }
233                 }
234             }
235         }
236     }
237     return m_frame_code_addr;
238 }
239 
240 void
241 StackFrame::ChangePC (addr_t pc)
242 {
243     m_frame_code_addr.SetOffset(pc);
244     m_frame_code_addr.SetSection(NULL);
245     m_sc.Clear();
246     m_flags.Reset(0);
247     ThreadSP thread_sp (GetThread());
248     if (thread_sp)
249         thread_sp->ClearStackFrames ();
250 }
251 
252 const char *
253 StackFrame::Disassemble ()
254 {
255     if (m_disassembly.GetSize() == 0)
256     {
257         ExecutionContext exe_ctx (shared_from_this());
258         Target *target = exe_ctx.GetTargetPtr();
259         if (target)
260         {
261             Disassembler::Disassemble (target->GetDebugger(),
262                                        target->GetArchitecture(),
263                                        NULL,
264                                        exe_ctx,
265                                        0,
266                                        0,
267                                        0,
268                                        m_disassembly);
269         }
270         if (m_disassembly.GetSize() == 0)
271             return NULL;
272     }
273     return m_disassembly.GetData();
274 }
275 
276 Block *
277 StackFrame::GetFrameBlock ()
278 {
279     if (m_sc.block == NULL && m_flags.IsClear (eSymbolContextBlock))
280         GetSymbolContext (eSymbolContextBlock);
281 
282     if (m_sc.block)
283     {
284         Block *inline_block = m_sc.block->GetContainingInlinedBlock();
285         if (inline_block)
286         {
287             // Use the block with the inlined function info
288             // as the frame block we want this frame to have only the variables
289             // for the inlined function and its non-inlined block child blocks.
290             return inline_block;
291         }
292         else
293         {
294             // This block is not contained withing any inlined function blocks
295             // with so we want to use the top most function block.
296             return &m_sc.function->GetBlock (false);
297         }
298     }
299     return NULL;
300 }
301 
302 //----------------------------------------------------------------------
303 // Get the symbol context if we already haven't done so by resolving the
304 // PC address as much as possible. This way when we pass around a
305 // StackFrame object, everyone will have as much information as
306 // possible and no one will ever have to look things up manually.
307 //----------------------------------------------------------------------
308 const SymbolContext&
309 StackFrame::GetSymbolContext (uint32_t resolve_scope)
310 {
311     // Copy our internal symbol context into "sc".
312     if ((m_flags.Get() & resolve_scope) != resolve_scope)
313     {
314         // Resolve our PC to section offset if we haven't alreday done so
315         // and if we don't have a module. The resolved address section will
316         // contain the module to which it belongs
317         if (!m_sc.module_sp && m_flags.IsClear(RESOLVED_FRAME_CODE_ADDR))
318             GetFrameCodeAddress();
319 
320         // If this is not frame zero, then we need to subtract 1 from the PC
321         // value when doing address lookups since the PC will be on the
322         // instruction following the function call instruction...
323 
324         Address lookup_addr(GetFrameCodeAddress());
325         if (m_frame_index > 0 && lookup_addr.IsValid())
326         {
327             addr_t offset = lookup_addr.GetOffset();
328             if (offset > 0)
329                 lookup_addr.SetOffset(offset - 1);
330         }
331 
332 
333         uint32_t resolved = 0;
334         if (m_sc.module_sp)
335         {
336             // We have something in our stack frame symbol context, lets check
337             // if we haven't already tried to lookup one of those things. If we
338             // haven't then we will do the query.
339 
340             uint32_t actual_resolve_scope = 0;
341 
342             if (resolve_scope & eSymbolContextCompUnit)
343             {
344                 if (m_flags.IsClear (eSymbolContextCompUnit))
345                 {
346                     if (m_sc.comp_unit)
347                         resolved |= eSymbolContextCompUnit;
348                     else
349                         actual_resolve_scope |= eSymbolContextCompUnit;
350                 }
351             }
352 
353             if (resolve_scope & eSymbolContextFunction)
354             {
355                 if (m_flags.IsClear (eSymbolContextFunction))
356                 {
357                     if (m_sc.function)
358                         resolved |= eSymbolContextFunction;
359                     else
360                         actual_resolve_scope |= eSymbolContextFunction;
361                 }
362             }
363 
364             if (resolve_scope & eSymbolContextBlock)
365             {
366                 if (m_flags.IsClear (eSymbolContextBlock))
367                 {
368                     if (m_sc.block)
369                         resolved |= eSymbolContextBlock;
370                     else
371                         actual_resolve_scope |= eSymbolContextBlock;
372                 }
373             }
374 
375             if (resolve_scope & eSymbolContextSymbol)
376             {
377                 if (m_flags.IsClear (eSymbolContextSymbol))
378                 {
379                     if (m_sc.symbol)
380                         resolved |= eSymbolContextSymbol;
381                     else
382                         actual_resolve_scope |= eSymbolContextSymbol;
383                 }
384             }
385 
386             if (resolve_scope & eSymbolContextLineEntry)
387             {
388                 if (m_flags.IsClear (eSymbolContextLineEntry))
389                 {
390                     if (m_sc.line_entry.IsValid())
391                         resolved |= eSymbolContextLineEntry;
392                     else
393                         actual_resolve_scope |= eSymbolContextLineEntry;
394                 }
395             }
396 
397             if (actual_resolve_scope)
398             {
399                 // We might be resolving less information than what is already
400                 // in our current symbol context so resolve into a temporary
401                 // symbol context "sc" so we don't clear out data we have
402                 // already found in "m_sc"
403                 SymbolContext sc;
404                 // Set flags that indicate what we have tried to resolve
405                 resolved |= m_sc.module_sp->ResolveSymbolContextForAddress (lookup_addr, actual_resolve_scope, sc);
406                 // Only replace what we didn't already have as we may have
407                 // information for an inlined function scope that won't match
408                 // what a standard lookup by address would match
409                 if ((resolved & eSymbolContextCompUnit)  && m_sc.comp_unit == NULL)
410                     m_sc.comp_unit = sc.comp_unit;
411                 if ((resolved & eSymbolContextFunction)  && m_sc.function == NULL)
412                     m_sc.function = sc.function;
413                 if ((resolved & eSymbolContextBlock)     && m_sc.block == NULL)
414                     m_sc.block = sc.block;
415                 if ((resolved & eSymbolContextSymbol)    && m_sc.symbol == NULL)
416                     m_sc.symbol = sc.symbol;
417                 if ((resolved & eSymbolContextLineEntry) && !m_sc.line_entry.IsValid())
418                     m_sc.line_entry = sc.line_entry;
419 
420             }
421         }
422         else
423         {
424             // If we don't have a module, then we can't have the compile unit,
425             // function, block, line entry or symbol, so we can safely call
426             // ResolveSymbolContextForAddress with our symbol context member m_sc.
427             TargetSP target_sp (CalculateTarget());
428             if (target_sp)
429                 resolved |= target_sp->GetImages().ResolveSymbolContextForAddress (lookup_addr, resolve_scope, m_sc);
430         }
431 
432         // If the target was requested add that:
433         if (!m_sc.target_sp)
434         {
435             m_sc.target_sp = CalculateTarget();
436             if (m_sc.target_sp)
437                 resolved |= eSymbolContextTarget;
438         }
439 
440         // Update our internal flags so we remember what we have tried to locate so
441         // we don't have to keep trying when more calls to this function are made.
442         // We might have dug up more information that was requested (for example
443         // if we were asked to only get the block, we will have gotten the
444         // compile unit, and function) so set any additional bits that we resolved
445         m_flags.Set (resolve_scope | resolved);
446     }
447 
448     // Return the symbol context with everything that was possible to resolve
449     // resolved.
450     return m_sc;
451 }
452 
453 
454 VariableList *
455 StackFrame::GetVariableList (bool get_file_globals)
456 {
457     if (m_flags.IsClear(RESOLVED_VARIABLES))
458     {
459         m_flags.Set(RESOLVED_VARIABLES);
460 
461         Block *frame_block = GetFrameBlock();
462 
463         if (frame_block)
464         {
465             const bool get_child_variables = true;
466             const bool can_create = true;
467             const bool stop_if_child_block_is_inlined_function = true;
468             m_variable_list_sp.reset(new VariableList());
469             frame_block->AppendBlockVariables(can_create, get_child_variables, stop_if_child_block_is_inlined_function, m_variable_list_sp.get());
470         }
471     }
472 
473     if (m_flags.IsClear(RESOLVED_GLOBAL_VARIABLES) &&
474         get_file_globals)
475     {
476         m_flags.Set(RESOLVED_GLOBAL_VARIABLES);
477 
478         if (m_flags.IsClear (eSymbolContextCompUnit))
479             GetSymbolContext (eSymbolContextCompUnit);
480 
481         if (m_sc.comp_unit)
482         {
483             VariableListSP global_variable_list_sp (m_sc.comp_unit->GetVariableList(true));
484             if (m_variable_list_sp)
485                 m_variable_list_sp->AddVariables (global_variable_list_sp.get());
486             else
487                 m_variable_list_sp = global_variable_list_sp;
488         }
489     }
490 
491     return m_variable_list_sp.get();
492 }
493 
494 VariableListSP
495 StackFrame::GetInScopeVariableList (bool get_file_globals)
496 {
497     VariableListSP var_list_sp(new VariableList);
498     GetSymbolContext (eSymbolContextCompUnit | eSymbolContextBlock);
499 
500     if (m_sc.block)
501     {
502         const bool can_create = true;
503         const bool get_parent_variables = true;
504         const bool stop_if_block_is_inlined_function = true;
505         m_sc.block->AppendVariables (can_create,
506                                      get_parent_variables,
507                                      stop_if_block_is_inlined_function,
508                                      var_list_sp.get());
509     }
510 
511     if (m_sc.comp_unit)
512     {
513         VariableListSP global_variable_list_sp (m_sc.comp_unit->GetVariableList(true));
514         if (global_variable_list_sp)
515             var_list_sp->AddVariables (global_variable_list_sp.get());
516     }
517 
518     return var_list_sp;
519 }
520 
521 
522 ValueObjectSP
523 StackFrame::GetValueForVariableExpressionPath (const char *var_expr_cstr,
524                                                DynamicValueType use_dynamic,
525                                                uint32_t options,
526                                                VariableSP &var_sp,
527                                                Error &error)
528 {
529 
530     if (var_expr_cstr && var_expr_cstr[0])
531     {
532         const bool check_ptr_vs_member = (options & eExpressionPathOptionCheckPtrVsMember) != 0;
533         const bool no_fragile_ivar = (options & eExpressionPathOptionsNoFragileObjcIvar) != 0;
534         const bool no_synth_child = (options & eExpressionPathOptionsNoSyntheticChildren) != 0;
535         //const bool no_synth_array = (options & eExpressionPathOptionsNoSyntheticArrayRange) != 0;
536         error.Clear();
537         bool deref = false;
538         bool address_of = false;
539         ValueObjectSP valobj_sp;
540         const bool get_file_globals = true;
541         // When looking up a variable for an expression, we need only consider the
542         // variables that are in scope.
543         VariableListSP var_list_sp (GetInScopeVariableList (get_file_globals));
544         VariableList *variable_list = var_list_sp.get();
545 
546         if (variable_list)
547         {
548             // If first character is a '*', then show pointer contents
549             const char *var_expr = var_expr_cstr;
550             if (var_expr[0] == '*')
551             {
552                 deref = true;
553                 var_expr++; // Skip the '*'
554             }
555             else if (var_expr[0] == '&')
556             {
557                 address_of = true;
558                 var_expr++; // Skip the '&'
559             }
560 
561             std::string var_path (var_expr);
562             size_t separator_idx = var_path.find_first_of(".-[=+~|&^%#@!/?,<>{}");
563             StreamString var_expr_path_strm;
564 
565             ConstString name_const_string;
566             if (separator_idx == std::string::npos)
567                 name_const_string.SetCString (var_path.c_str());
568             else
569                 name_const_string.SetCStringWithLength (var_path.c_str(), separator_idx);
570 
571             var_sp = variable_list->FindVariable(name_const_string);
572             if (var_sp)
573             {
574                 valobj_sp = GetValueObjectForFrameVariable (var_sp, use_dynamic);
575                 if (!valobj_sp)
576                     return valobj_sp;
577 
578                 var_path.erase (0, name_const_string.GetLength ());
579                 // We are dumping at least one child
580                 while (separator_idx != std::string::npos)
581                 {
582                     // Calculate the next separator index ahead of time
583                     ValueObjectSP child_valobj_sp;
584                     const char separator_type = var_path[0];
585                     switch (separator_type)
586                     {
587 
588                     case '-':
589                         if (var_path.size() >= 2 && var_path[1] != '>')
590                             return ValueObjectSP();
591 
592                         if (no_fragile_ivar)
593                         {
594                             // Make sure we aren't trying to deref an objective
595                             // C ivar if this is not allowed
596                             const uint32_t pointer_type_flags = ClangASTContext::GetTypeInfo (valobj_sp->GetClangType(), NULL, NULL);
597                             if ((pointer_type_flags & ClangASTContext::eTypeIsObjC) &&
598                                 (pointer_type_flags & ClangASTContext::eTypeIsPointer))
599                             {
600                                 // This was an objective C object pointer and
601                                 // it was requested we skip any fragile ivars
602                                 // so return nothing here
603                                 return ValueObjectSP();
604                             }
605                         }
606                         var_path.erase (0, 1); // Remove the '-'
607                         // Fall through
608                     case '.':
609                         {
610                             const bool expr_is_ptr = var_path[0] == '>';
611 
612                             var_path.erase (0, 1); // Remove the '.' or '>'
613                             separator_idx = var_path.find_first_of(".-[");
614                             ConstString child_name;
615                             if (separator_idx == std::string::npos)
616                                 child_name.SetCString (var_path.c_str());
617                             else
618                                 child_name.SetCStringWithLength(var_path.c_str(), separator_idx);
619 
620                             if (check_ptr_vs_member)
621                             {
622                                 // We either have a pointer type and need to verify
623                                 // valobj_sp is a pointer, or we have a member of a
624                                 // class/union/struct being accessed with the . syntax
625                                 // and need to verify we don't have a pointer.
626                                 const bool actual_is_ptr = valobj_sp->IsPointerType ();
627 
628                                 if (actual_is_ptr != expr_is_ptr)
629                                 {
630                                     // Incorrect use of "." with a pointer, or "->" with
631                                     // a class/union/struct instance or reference.
632                                     valobj_sp->GetExpressionPath (var_expr_path_strm, false);
633                                     if (actual_is_ptr)
634                                         error.SetErrorStringWithFormat ("\"%s\" is a pointer and . was used to attempt to access \"%s\". Did you mean \"%s->%s\"?",
635                                                                         var_expr_path_strm.GetString().c_str(),
636                                                                         child_name.GetCString(),
637                                                                         var_expr_path_strm.GetString().c_str(),
638                                                                         var_path.c_str());
639                                     else
640                                         error.SetErrorStringWithFormat ("\"%s\" is not a pointer and -> was used to attempt to access \"%s\". Did you mean \"%s.%s\"?",
641                                                                         var_expr_path_strm.GetString().c_str(),
642                                                                         child_name.GetCString(),
643                                                                         var_expr_path_strm.GetString().c_str(),
644                                                                         var_path.c_str());
645                                     return ValueObjectSP();
646                                 }
647                             }
648                             child_valobj_sp = valobj_sp->GetChildMemberWithName (child_name, true);
649                             if (!child_valobj_sp)
650                             {
651                                 if (no_synth_child == false)
652                                     child_valobj_sp = valobj_sp->GetSyntheticValue(eUseSyntheticFilter)->GetChildMemberWithName (child_name, true);
653 
654                                 if (no_synth_child || !child_valobj_sp)
655                                 {
656                                     // No child member with name "child_name"
657                                     valobj_sp->GetExpressionPath (var_expr_path_strm, false);
658                                     if (child_name)
659                                     {
660                                         error.SetErrorStringWithFormat ("\"%s\" is not a member of \"(%s) %s\"",
661                                                                         child_name.GetCString(),
662                                                                         valobj_sp->GetTypeName().AsCString("<invalid type>"),
663                                                                         var_expr_path_strm.GetString().c_str());
664                                     }
665                                     else
666                                     {
667                                         error.SetErrorStringWithFormat ("incomplete expression path after \"%s\" in \"%s\"",
668                                                                         var_expr_path_strm.GetString().c_str(),
669                                                                         var_expr_cstr);
670                                     }
671                                     return ValueObjectSP();
672                                 }
673                             }
674                             // Remove the child name from the path
675                             var_path.erase(0, child_name.GetLength());
676                             if (use_dynamic != eNoDynamicValues)
677                             {
678                                 ValueObjectSP dynamic_value_sp(child_valobj_sp->GetDynamicValue(use_dynamic));
679                                 if (dynamic_value_sp)
680                                     child_valobj_sp = dynamic_value_sp;
681                             }
682                         }
683                         break;
684 
685                     case '[':
686                         // Array member access, or treating pointer as an array
687                         if (var_path.size() > 2) // Need at least two brackets and a number
688                         {
689                             char *end = NULL;
690                             long child_index = ::strtol (&var_path[1], &end, 0);
691                             if (end && *end == ']'
692                                 && *(end-1) != '[') // this code forces an error in the case of arr[]. as bitfield[] is not a good syntax we're good to go
693                             {
694                                 if (ClangASTContext::IsPointerToScalarType(valobj_sp->GetClangType()) && deref)
695                                 {
696                                     // what we have is *ptr[low]. the most similar C++ syntax is to deref ptr
697                                     // and extract bit low out of it. reading array item low
698                                     // would be done by saying ptr[low], without a deref * sign
699                                     Error error;
700                                     ValueObjectSP temp(valobj_sp->Dereference(error));
701                                     if (error.Fail())
702                                     {
703                                         valobj_sp->GetExpressionPath (var_expr_path_strm, false);
704                                         error.SetErrorStringWithFormat ("could not dereference \"(%s) %s\"",
705                                                                         valobj_sp->GetTypeName().AsCString("<invalid type>"),
706                                                                         var_expr_path_strm.GetString().c_str());
707                                         return ValueObjectSP();
708                                     }
709                                     valobj_sp = temp;
710                                     deref = false;
711                                 }
712                                 else if (ClangASTContext::IsArrayOfScalarType(valobj_sp->GetClangType()) && deref)
713                                 {
714                                     // what we have is *arr[low]. the most similar C++ syntax is to get arr[0]
715                                     // (an operation that is equivalent to deref-ing arr)
716                                     // and extract bit low out of it. reading array item low
717                                     // would be done by saying arr[low], without a deref * sign
718                                     Error error;
719                                     ValueObjectSP temp(valobj_sp->GetChildAtIndex (0, true));
720                                     if (error.Fail())
721                                     {
722                                         valobj_sp->GetExpressionPath (var_expr_path_strm, false);
723                                         error.SetErrorStringWithFormat ("could not get item 0 for \"(%s) %s\"",
724                                                                         valobj_sp->GetTypeName().AsCString("<invalid type>"),
725                                                                         var_expr_path_strm.GetString().c_str());
726                                         return ValueObjectSP();
727                                     }
728                                     valobj_sp = temp;
729                                     deref = false;
730                                 }
731 
732                                 if (valobj_sp->IsPointerType ())
733                                 {
734                                     if (no_synth_child == false
735                                         &&
736                                         ClangASTType::GetMinimumLanguage(valobj_sp->GetClangAST(),
737                                                                          valobj_sp->GetClangType()) == eLanguageTypeObjC /* is ObjC pointer */
738                                         &&
739                                         ClangASTContext::IsPointerType(ClangASTType::GetPointeeType(valobj_sp->GetClangType())) == false /* is not double-ptr */)
740                                     {
741                                         // dereferencing ObjC variables is not valid.. so let's try and recur to synthetic children
742                                         ValueObjectSP synthetic = valobj_sp->GetSyntheticValue(eUseSyntheticFilter);
743                                         if (synthetic.get() == NULL /* no synthetic */
744                                             || synthetic == valobj_sp) /* synthetic is the same as the original object */
745                                         {
746                                             valobj_sp->GetExpressionPath (var_expr_path_strm, false);
747                                             error.SetErrorStringWithFormat ("\"(%s) %s\" is not an array type",
748                                                                             valobj_sp->GetTypeName().AsCString("<invalid type>"),
749                                                                             var_expr_path_strm.GetString().c_str());
750                                         }
751                                         else if (child_index >= synthetic->GetNumChildren() /* synthetic does not have that many values */)
752                                         {
753                                             valobj_sp->GetExpressionPath (var_expr_path_strm, false);
754                                             error.SetErrorStringWithFormat ("array index %ld is not valid for \"(%s) %s\"",
755                                                                             child_index,
756                                                                             valobj_sp->GetTypeName().AsCString("<invalid type>"),
757                                                                             var_expr_path_strm.GetString().c_str());
758                                         }
759                                         else
760                                         {
761                                             child_valobj_sp = synthetic->GetChildAtIndex(child_index, true);
762                                             if (!child_valobj_sp)
763                                             {
764                                                 valobj_sp->GetExpressionPath (var_expr_path_strm, false);
765                                                 error.SetErrorStringWithFormat ("array index %ld is not valid for \"(%s) %s\"",
766                                                                                 child_index,
767                                                                                 valobj_sp->GetTypeName().AsCString("<invalid type>"),
768                                                                                 var_expr_path_strm.GetString().c_str());
769                                             }
770                                         }
771                                     }
772                                     else
773                                     {
774                                         child_valobj_sp = valobj_sp->GetSyntheticArrayMemberFromPointer (child_index, true);
775                                         if (!child_valobj_sp)
776                                         {
777                                             valobj_sp->GetExpressionPath (var_expr_path_strm, false);
778                                             error.SetErrorStringWithFormat ("failed to use pointer as array for index %ld for \"(%s) %s\"",
779                                                                             child_index,
780                                                                             valobj_sp->GetTypeName().AsCString("<invalid type>"),
781                                                                             var_expr_path_strm.GetString().c_str());
782                                         }
783                                     }
784                                 }
785                                 else if (ClangASTContext::IsArrayType (valobj_sp->GetClangType(), NULL, NULL))
786                                 {
787                                     // Pass false to dynamic_value here so we can tell the difference between
788                                     // no dynamic value and no member of this type...
789                                     child_valobj_sp = valobj_sp->GetChildAtIndex (child_index, true);
790                                     if (!child_valobj_sp)
791                                     {
792                                         valobj_sp->GetExpressionPath (var_expr_path_strm, false);
793                                         error.SetErrorStringWithFormat ("array index %ld is not valid for \"(%s) %s\"",
794                                                                         child_index,
795                                                                         valobj_sp->GetTypeName().AsCString("<invalid type>"),
796                                                                         var_expr_path_strm.GetString().c_str());
797                                     }
798                                 }
799                                 else if (ClangASTContext::IsScalarType(valobj_sp->GetClangType()))
800                                 {
801                                     // this is a bitfield asking to display just one bit
802                                     child_valobj_sp = valobj_sp->GetSyntheticBitFieldChild(child_index, child_index, true);
803                                     if (!child_valobj_sp)
804                                     {
805                                         valobj_sp->GetExpressionPath (var_expr_path_strm, false);
806                                         error.SetErrorStringWithFormat ("bitfield range %ld-%ld is not valid for \"(%s) %s\"",
807                                                                         child_index, child_index,
808                                                                         valobj_sp->GetTypeName().AsCString("<invalid type>"),
809                                                                         var_expr_path_strm.GetString().c_str());
810                                     }
811                                 }
812                                 else
813                                 {
814                                     ValueObjectSP synthetic = valobj_sp->GetSyntheticValue(eUseSyntheticFilter);
815                                     if (no_synth_child /* synthetic is forbidden */ ||
816                                         synthetic.get() == NULL /* no synthetic */
817                                         || synthetic == valobj_sp) /* synthetic is the same as the original object */
818                                     {
819                                         valobj_sp->GetExpressionPath (var_expr_path_strm, false);
820                                         error.SetErrorStringWithFormat ("\"(%s) %s\" is not an array type",
821                                                                         valobj_sp->GetTypeName().AsCString("<invalid type>"),
822                                                                         var_expr_path_strm.GetString().c_str());
823                                     }
824                                     else if (child_index >= synthetic->GetNumChildren() /* synthetic does not have that many values */)
825                                     {
826                                         valobj_sp->GetExpressionPath (var_expr_path_strm, false);
827                                         error.SetErrorStringWithFormat ("array index %ld is not valid for \"(%s) %s\"",
828                                                                         child_index,
829                                                                         valobj_sp->GetTypeName().AsCString("<invalid type>"),
830                                                                         var_expr_path_strm.GetString().c_str());
831                                     }
832                                     else
833                                     {
834                                         child_valobj_sp = synthetic->GetChildAtIndex(child_index, true);
835                                         if (!child_valobj_sp)
836                                         {
837                                             valobj_sp->GetExpressionPath (var_expr_path_strm, false);
838                                             error.SetErrorStringWithFormat ("array index %ld is not valid for \"(%s) %s\"",
839                                                                             child_index,
840                                                                             valobj_sp->GetTypeName().AsCString("<invalid type>"),
841                                                                             var_expr_path_strm.GetString().c_str());
842                                         }
843                                     }
844                                 }
845 
846                                 if (!child_valobj_sp)
847                                 {
848                                     // Invalid array index...
849                                     return ValueObjectSP();
850                                 }
851 
852                                 // Erase the array member specification '[%i]' where
853                                 // %i is the array index
854                                 var_path.erase(0, (end - var_path.c_str()) + 1);
855                                 separator_idx = var_path.find_first_of(".-[");
856                                 if (use_dynamic != eNoDynamicValues)
857                                 {
858                                     ValueObjectSP dynamic_value_sp(child_valobj_sp->GetDynamicValue(use_dynamic));
859                                     if (dynamic_value_sp)
860                                         child_valobj_sp = dynamic_value_sp;
861                                 }
862                                 // Break out early from the switch since we were
863                                 // able to find the child member
864                                 break;
865                             }
866                             else if (end && *end == '-')
867                             {
868                                 // this is most probably a BitField, let's take a look
869                                 char *real_end = NULL;
870                                 long final_index = ::strtol (end+1, &real_end, 0);
871                                 bool expand_bitfield = true;
872                                 if (real_end && *real_end == ']')
873                                 {
874                                     // if the format given is [high-low], swap range
875                                     if (child_index > final_index)
876                                     {
877                                         long temp = child_index;
878                                         child_index = final_index;
879                                         final_index = temp;
880                                     }
881 
882                                     if (ClangASTContext::IsPointerToScalarType(valobj_sp->GetClangType()) && deref)
883                                     {
884                                         // what we have is *ptr[low-high]. the most similar C++ syntax is to deref ptr
885                                         // and extract bits low thru high out of it. reading array items low thru high
886                                         // would be done by saying ptr[low-high], without a deref * sign
887                                         Error error;
888                                         ValueObjectSP temp(valobj_sp->Dereference(error));
889                                         if (error.Fail())
890                                         {
891                                             valobj_sp->GetExpressionPath (var_expr_path_strm, false);
892                                             error.SetErrorStringWithFormat ("could not dereference \"(%s) %s\"",
893                                                                             valobj_sp->GetTypeName().AsCString("<invalid type>"),
894                                                                             var_expr_path_strm.GetString().c_str());
895                                             return ValueObjectSP();
896                                         }
897                                         valobj_sp = temp;
898                                         deref = false;
899                                     }
900                                     else if (ClangASTContext::IsArrayOfScalarType(valobj_sp->GetClangType()) && deref)
901                                     {
902                                         // what we have is *arr[low-high]. the most similar C++ syntax is to get arr[0]
903                                         // (an operation that is equivalent to deref-ing arr)
904                                         // and extract bits low thru high out of it. reading array items low thru high
905                                         // would be done by saying arr[low-high], without a deref * sign
906                                         Error error;
907                                         ValueObjectSP temp(valobj_sp->GetChildAtIndex (0, true));
908                                         if (error.Fail())
909                                         {
910                                             valobj_sp->GetExpressionPath (var_expr_path_strm, false);
911                                             error.SetErrorStringWithFormat ("could not get item 0 for \"(%s) %s\"",
912                                                                             valobj_sp->GetTypeName().AsCString("<invalid type>"),
913                                                                             var_expr_path_strm.GetString().c_str());
914                                             return ValueObjectSP();
915                                         }
916                                         valobj_sp = temp;
917                                         deref = false;
918                                     }
919                                     /*else if (valobj_sp->IsArrayType() || valobj_sp->IsPointerType())
920                                     {
921                                         child_valobj_sp = valobj_sp->GetSyntheticArrayRangeChild(child_index, final_index, true);
922                                         expand_bitfield = false;
923                                         if (!child_valobj_sp)
924                                         {
925                                             valobj_sp->GetExpressionPath (var_expr_path_strm, false);
926                                             error.SetErrorStringWithFormat ("array range %i-%i is not valid for \"(%s) %s\"",
927                                                                             child_index, final_index,
928                                                                             valobj_sp->GetTypeName().AsCString("<invalid type>"),
929                                                                             var_expr_path_strm.GetString().c_str());
930                                         }
931                                     }*/
932 
933                                     if (expand_bitfield)
934                                     {
935                                         child_valobj_sp = valobj_sp->GetSyntheticBitFieldChild(child_index, final_index, true);
936                                         if (!child_valobj_sp)
937                                         {
938                                             valobj_sp->GetExpressionPath (var_expr_path_strm, false);
939                                             error.SetErrorStringWithFormat ("bitfield range %ld-%ld is not valid for \"(%s) %s\"",
940                                                                             child_index, final_index,
941                                                                             valobj_sp->GetTypeName().AsCString("<invalid type>"),
942                                                                             var_expr_path_strm.GetString().c_str());
943                                         }
944                                     }
945                                 }
946 
947                                 if (!child_valobj_sp)
948                                 {
949                                     // Invalid bitfield range...
950                                     return ValueObjectSP();
951                                 }
952 
953                                 // Erase the bitfield member specification '[%i-%i]' where
954                                 // %i is the index
955                                 var_path.erase(0, (real_end - var_path.c_str()) + 1);
956                                 separator_idx = var_path.find_first_of(".-[");
957                                 if (use_dynamic != eNoDynamicValues)
958                                 {
959                                     ValueObjectSP dynamic_value_sp(child_valobj_sp->GetDynamicValue(use_dynamic));
960                                     if (dynamic_value_sp)
961                                         child_valobj_sp = dynamic_value_sp;
962                                 }
963                                 // Break out early from the switch since we were
964                                 // able to find the child member
965                                 break;
966 
967                             }
968                         }
969                         else
970                         {
971                             error.SetErrorStringWithFormat("invalid square bracket encountered after \"%s\" in \"%s\"",
972                                                            var_expr_path_strm.GetString().c_str(),
973                                                            var_path.c_str());
974                         }
975                         return ValueObjectSP();
976 
977                     default:
978                         // Failure...
979                         {
980                             valobj_sp->GetExpressionPath (var_expr_path_strm, false);
981                             error.SetErrorStringWithFormat ("unexpected char '%c' encountered after \"%s\" in \"%s\"",
982                                                             separator_type,
983                                                             var_expr_path_strm.GetString().c_str(),
984                                                             var_path.c_str());
985 
986                             return ValueObjectSP();
987                         }
988                     }
989 
990                     if (child_valobj_sp)
991                         valobj_sp = child_valobj_sp;
992 
993                     if (var_path.empty())
994                         break;
995 
996                 }
997                 if (valobj_sp)
998                 {
999                     if (deref)
1000                     {
1001                         ValueObjectSP deref_valobj_sp (valobj_sp->Dereference(error));
1002                         valobj_sp = deref_valobj_sp;
1003                     }
1004                     else if (address_of)
1005                     {
1006                         ValueObjectSP address_of_valobj_sp (valobj_sp->AddressOf(error));
1007                         valobj_sp = address_of_valobj_sp;
1008                     }
1009                 }
1010                 return valobj_sp;
1011             }
1012             else
1013             {
1014                 error.SetErrorStringWithFormat("no variable named '%s' found in this frame",
1015                                                name_const_string.GetCString());
1016             }
1017         }
1018     }
1019     else
1020     {
1021         error.SetErrorStringWithFormat("invalid variable path '%s'", var_expr_cstr);
1022     }
1023     return ValueObjectSP();
1024 }
1025 
1026 bool
1027 StackFrame::GetFrameBaseValue (Scalar &frame_base, Error *error_ptr)
1028 {
1029     if (m_flags.IsClear(GOT_FRAME_BASE))
1030     {
1031         if (m_sc.function)
1032         {
1033             m_frame_base.Clear();
1034             m_frame_base_error.Clear();
1035 
1036             m_flags.Set(GOT_FRAME_BASE);
1037             ExecutionContext exe_ctx (shared_from_this());
1038             Value expr_value;
1039             addr_t loclist_base_addr = LLDB_INVALID_ADDRESS;
1040             if (m_sc.function->GetFrameBaseExpression().IsLocationList())
1041                 loclist_base_addr = m_sc.function->GetAddressRange().GetBaseAddress().GetLoadAddress (exe_ctx.GetTargetPtr());
1042 
1043             if (m_sc.function->GetFrameBaseExpression().Evaluate(&exe_ctx, NULL, NULL, NULL, NULL, loclist_base_addr, NULL, expr_value, &m_frame_base_error) == false)
1044             {
1045                 // We should really have an error if evaluate returns, but in case
1046                 // we don't, lets set the error to something at least.
1047                 if (m_frame_base_error.Success())
1048                     m_frame_base_error.SetErrorString("Evaluation of the frame base expression failed.");
1049             }
1050             else
1051             {
1052                 m_frame_base = expr_value.ResolveValue(&exe_ctx, NULL);
1053             }
1054         }
1055         else
1056         {
1057             m_frame_base_error.SetErrorString ("No function in symbol context.");
1058         }
1059     }
1060 
1061     if (m_frame_base_error.Success())
1062         frame_base = m_frame_base;
1063 
1064     if (error_ptr)
1065         *error_ptr = m_frame_base_error;
1066     return m_frame_base_error.Success();
1067 }
1068 
1069 RegisterContextSP
1070 StackFrame::GetRegisterContext ()
1071 {
1072     if (!m_reg_context_sp)
1073     {
1074         ThreadSP thread_sp (GetThread());
1075         if (thread_sp)
1076             m_reg_context_sp = thread_sp->CreateRegisterContextForFrame (this);
1077     }
1078     return m_reg_context_sp;
1079 }
1080 
1081 bool
1082 StackFrame::HasDebugInformation ()
1083 {
1084     GetSymbolContext (eSymbolContextLineEntry);
1085     return m_sc.line_entry.IsValid();
1086 }
1087 
1088 
1089 ValueObjectSP
1090 StackFrame::GetValueObjectForFrameVariable (const VariableSP &variable_sp, DynamicValueType use_dynamic)
1091 {
1092     ValueObjectSP valobj_sp;
1093     VariableList *var_list = GetVariableList (true);
1094     if (var_list)
1095     {
1096         // Make sure the variable is a frame variable
1097         const uint32_t var_idx = var_list->FindIndexForVariable (variable_sp.get());
1098         const uint32_t num_variables = var_list->GetSize();
1099         if (var_idx < num_variables)
1100         {
1101             valobj_sp = m_variable_list_value_objects.GetValueObjectAtIndex (var_idx);
1102             if (valobj_sp.get() == NULL)
1103             {
1104                 if (m_variable_list_value_objects.GetSize() < num_variables)
1105                     m_variable_list_value_objects.Resize(num_variables);
1106                 valobj_sp = ValueObjectVariable::Create (this, variable_sp);
1107                 m_variable_list_value_objects.SetValueObjectAtIndex (var_idx, valobj_sp);
1108             }
1109         }
1110     }
1111     if (use_dynamic != eNoDynamicValues && valobj_sp)
1112     {
1113         ValueObjectSP dynamic_sp = valobj_sp->GetDynamicValue (use_dynamic);
1114         if (dynamic_sp)
1115             return dynamic_sp;
1116     }
1117     return valobj_sp;
1118 }
1119 
1120 ValueObjectSP
1121 StackFrame::TrackGlobalVariable (const VariableSP &variable_sp, DynamicValueType use_dynamic)
1122 {
1123     // Check to make sure we aren't already tracking this variable?
1124     ValueObjectSP valobj_sp (GetValueObjectForFrameVariable (variable_sp, use_dynamic));
1125     if (!valobj_sp)
1126     {
1127         // We aren't already tracking this global
1128         VariableList *var_list = GetVariableList (true);
1129         // If this frame has no variables, create a new list
1130         if (var_list == NULL)
1131             m_variable_list_sp.reset (new VariableList());
1132 
1133         // Add the global/static variable to this frame
1134         m_variable_list_sp->AddVariable (variable_sp);
1135 
1136         // Now make a value object for it so we can track its changes
1137         valobj_sp = GetValueObjectForFrameVariable (variable_sp, use_dynamic);
1138     }
1139     return valobj_sp;
1140 }
1141 
1142 bool
1143 StackFrame::IsInlined ()
1144 {
1145     if (m_sc.block == NULL)
1146         GetSymbolContext (eSymbolContextBlock);
1147     if (m_sc.block)
1148         return m_sc.block->GetContainingInlinedBlock() != NULL;
1149     return false;
1150 }
1151 
1152 TargetSP
1153 StackFrame::CalculateTarget ()
1154 {
1155     TargetSP target_sp;
1156     ThreadSP thread_sp(GetThread());
1157     if (thread_sp)
1158     {
1159         ProcessSP process_sp (thread_sp->CalculateProcess());
1160         if (process_sp)
1161             target_sp = process_sp->CalculateTarget();
1162     }
1163     return target_sp;
1164 }
1165 
1166 ProcessSP
1167 StackFrame::CalculateProcess ()
1168 {
1169     ProcessSP process_sp;
1170     ThreadSP thread_sp(GetThread());
1171     if (thread_sp)
1172         process_sp = thread_sp->CalculateProcess();
1173     return process_sp;
1174 }
1175 
1176 ThreadSP
1177 StackFrame::CalculateThread ()
1178 {
1179     return GetThread();
1180 }
1181 
1182 StackFrameSP
1183 StackFrame::CalculateStackFrame ()
1184 {
1185     return shared_from_this();
1186 }
1187 
1188 
1189 void
1190 StackFrame::CalculateExecutionContext (ExecutionContext &exe_ctx)
1191 {
1192     exe_ctx.SetContext (shared_from_this());
1193 }
1194 
1195 void
1196 StackFrame::DumpUsingSettingsFormat (Stream *strm)
1197 {
1198     if (strm == NULL)
1199         return;
1200 
1201     GetSymbolContext(eSymbolContextEverything);
1202     ExecutionContext exe_ctx (shared_from_this());
1203     const char *end = NULL;
1204     StreamString s;
1205     const char *frame_format = NULL;
1206     Target *target = exe_ctx.GetTargetPtr();
1207     if (target)
1208         frame_format = target->GetDebugger().GetFrameFormat();
1209     if (frame_format && Debugger::FormatPrompt (frame_format, &m_sc, &exe_ctx, NULL, s, &end))
1210     {
1211         strm->Write(s.GetData(), s.GetSize());
1212     }
1213     else
1214     {
1215         Dump (strm, true, false);
1216         strm->EOL();
1217     }
1218 }
1219 
1220 void
1221 StackFrame::Dump (Stream *strm, bool show_frame_index, bool show_fullpaths)
1222 {
1223     if (strm == NULL)
1224         return;
1225 
1226     if (show_frame_index)
1227         strm->Printf("frame #%u: ", m_frame_index);
1228     ExecutionContext exe_ctx (shared_from_this());
1229     Target *target = exe_ctx.GetTargetPtr();
1230     strm->Printf("0x%0*llx ",
1231                  target ? (target->GetArchitecture().GetAddressByteSize() * 2) : 16,
1232                  GetFrameCodeAddress().GetLoadAddress(target));
1233     GetSymbolContext(eSymbolContextEverything);
1234     const bool show_module = true;
1235     const bool show_inline = true;
1236     m_sc.DumpStopContext (strm,
1237                           exe_ctx.GetBestExecutionContextScope(),
1238                           GetFrameCodeAddress(),
1239                           show_fullpaths,
1240                           show_module,
1241                           show_inline);
1242 }
1243 
1244 void
1245 StackFrame::UpdateCurrentFrameFromPreviousFrame (StackFrame &prev_frame)
1246 {
1247     assert (GetStackID() == prev_frame.GetStackID());    // TODO: remove this after some testing
1248     m_variable_list_sp = prev_frame.m_variable_list_sp;
1249     m_variable_list_value_objects.Swap (prev_frame.m_variable_list_value_objects);
1250     if (!m_disassembly.GetString().empty())
1251         m_disassembly.GetString().swap (m_disassembly.GetString());
1252 }
1253 
1254 
1255 void
1256 StackFrame::UpdatePreviousFrameFromCurrentFrame (StackFrame &curr_frame)
1257 {
1258     assert (GetStackID() == curr_frame.GetStackID());        // TODO: remove this after some testing
1259     m_id.SetPC (curr_frame.m_id.GetPC());       // Update the Stack ID PC value
1260     assert (GetThread() == curr_frame.GetThread());
1261     m_frame_index = curr_frame.m_frame_index;
1262     m_concrete_frame_index = curr_frame.m_concrete_frame_index;
1263     m_reg_context_sp = curr_frame.m_reg_context_sp;
1264     m_frame_code_addr = curr_frame.m_frame_code_addr;
1265     assert (m_sc.target_sp.get() == NULL || curr_frame.m_sc.target_sp.get() == NULL || m_sc.target_sp.get() == curr_frame.m_sc.target_sp.get());
1266     assert (m_sc.module_sp.get() == NULL || curr_frame.m_sc.module_sp.get() == NULL || m_sc.module_sp.get() == curr_frame.m_sc.module_sp.get());
1267     assert (m_sc.comp_unit == NULL || curr_frame.m_sc.comp_unit == NULL || m_sc.comp_unit == curr_frame.m_sc.comp_unit);
1268     assert (m_sc.function == NULL || curr_frame.m_sc.function == NULL || m_sc.function == curr_frame.m_sc.function);
1269     m_sc = curr_frame.m_sc;
1270     m_flags.Clear(GOT_FRAME_BASE | eSymbolContextEverything);
1271     m_flags.Set (m_sc.GetResolvedMask());
1272     m_frame_base.Clear();
1273     m_frame_base_error.Clear();
1274 }
1275 
1276 
1277 bool
1278 StackFrame::HasCachedData () const
1279 {
1280     if (m_variable_list_sp.get())
1281         return true;
1282     if (m_variable_list_value_objects.GetSize() > 0)
1283         return true;
1284     if (!m_disassembly.GetString().empty())
1285         return true;
1286     return false;
1287 }
1288 
1289 bool
1290 StackFrame::GetStatus (Stream& strm,
1291                        bool show_frame_info,
1292                        bool show_source,
1293                        uint32_t source_lines_before,
1294                        uint32_t source_lines_after)
1295 {
1296     if (show_frame_info)
1297     {
1298         strm.Indent();
1299         DumpUsingSettingsFormat (&strm);
1300     }
1301 
1302     if (show_source)
1303     {
1304         ExecutionContext exe_ctx (shared_from_this());
1305         bool have_source = false;
1306         DebuggerInstanceSettings::StopDisassemblyType disasm_display = DebuggerInstanceSettings::eStopDisassemblyTypeNever;
1307         Target *target = exe_ctx.GetTargetPtr();
1308         if (target && (source_lines_before || source_lines_after))
1309         {
1310             GetSymbolContext(eSymbolContextCompUnit | eSymbolContextLineEntry);
1311 
1312             if (m_sc.comp_unit && m_sc.line_entry.IsValid())
1313             {
1314                 if (target->GetSourceManager().DisplaySourceLinesWithLineNumbers (m_sc.line_entry.file,
1315                                                                                   m_sc.line_entry.line,
1316                                                                                   source_lines_before,
1317                                                                                   source_lines_after,
1318                                                                                   "->",
1319                                                                                   &strm))
1320                 {
1321                     have_source = true;
1322                 }
1323             }
1324             disasm_display = target->GetDebugger().GetStopDisassemblyDisplay ();
1325         }
1326 
1327         switch (disasm_display)
1328         {
1329         case DebuggerInstanceSettings::eStopDisassemblyTypeNever:
1330             break;
1331 
1332         case DebuggerInstanceSettings::eStopDisassemblyTypeNoSource:
1333             if (have_source)
1334                 break;
1335             // Fall through to next case
1336         case DebuggerInstanceSettings::eStopDisassemblyTypeAlways:
1337             if (target)
1338             {
1339                 const uint32_t disasm_lines = target->GetDebugger().GetDisassemblyLineCount();
1340                 if (disasm_lines > 0)
1341                 {
1342                     const ArchSpec &target_arch = target->GetArchitecture();
1343                     AddressRange pc_range;
1344                     pc_range.GetBaseAddress() = GetFrameCodeAddress();
1345                     pc_range.SetByteSize(disasm_lines * target_arch.GetMaximumOpcodeByteSize());
1346                     Disassembler::Disassemble (target->GetDebugger(),
1347                                                target_arch,
1348                                                NULL,
1349                                                exe_ctx,
1350                                                pc_range,
1351                                                disasm_lines,
1352                                                0,
1353                                                Disassembler::eOptionMarkPCAddress,
1354                                                strm);
1355                 }
1356             }
1357             break;
1358         }
1359     }
1360     return true;
1361 }
1362 
1363