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
43 (
44     lldb::user_id_t frame_idx,
45     lldb::user_id_t unwind_frame_index,
46     Thread &thread,
47     lldb::addr_t cfa,
48     lldb::addr_t pc,
49     const SymbolContext *sc_ptr
50 ) :
51     m_thread (thread),
52     m_frame_index (frame_idx),
53     m_concrete_frame_index (unwind_frame_index),
54     m_reg_context_sp (),
55     m_id (pc, cfa, NULL),
56     m_frame_code_addr (NULL, pc),
57     m_sc (),
58     m_flags (),
59     m_frame_base (),
60     m_frame_base_error (),
61     m_variable_list_sp (),
62     m_variable_list_value_objects (),
63     m_disassembly ()
64 {
65     if (sc_ptr != NULL)
66     {
67         m_sc = *sc_ptr;
68         m_flags.Set(m_sc.GetResolvedMask ());
69     }
70 }
71 
72 StackFrame::StackFrame
73 (
74     lldb::user_id_t frame_idx,
75     lldb::user_id_t unwind_frame_index,
76     Thread &thread,
77     const RegisterContextSP &reg_context_sp,
78     lldb::addr_t cfa,
79     lldb::addr_t pc,
80     const SymbolContext *sc_ptr
81 ) :
82     m_thread (thread),
83     m_frame_index (frame_idx),
84     m_concrete_frame_index (unwind_frame_index),
85     m_reg_context_sp (reg_context_sp),
86     m_id (pc, cfa, NULL),
87     m_frame_code_addr (NULL, pc),
88     m_sc (),
89     m_flags (),
90     m_frame_base (),
91     m_frame_base_error (),
92     m_variable_list_sp (),
93     m_variable_list_value_objects (),
94     m_disassembly ()
95 {
96     if (sc_ptr != NULL)
97     {
98         m_sc = *sc_ptr;
99         m_flags.Set(m_sc.GetResolvedMask ());
100     }
101 
102     if (reg_context_sp && !m_sc.target_sp)
103     {
104         m_sc.target_sp = reg_context_sp->GetThread().GetProcess().GetTarget().GetSP();
105         m_flags.Set (eSymbolContextTarget);
106     }
107 }
108 
109 StackFrame::StackFrame
110 (
111     lldb::user_id_t frame_idx,
112     lldb::user_id_t unwind_frame_index,
113     Thread &thread,
114     const RegisterContextSP &reg_context_sp,
115     lldb::addr_t cfa,
116     const Address& pc_addr,
117     const SymbolContext *sc_ptr
118 ) :
119     m_thread (thread),
120     m_frame_index (frame_idx),
121     m_concrete_frame_index (unwind_frame_index),
122     m_reg_context_sp (reg_context_sp),
123     m_id (pc_addr.GetLoadAddress (&thread.GetProcess().GetTarget()), cfa, NULL),
124     m_frame_code_addr (pc_addr),
125     m_sc (),
126     m_flags (),
127     m_frame_base (),
128     m_frame_base_error (),
129     m_variable_list_sp (),
130     m_variable_list_value_objects (),
131     m_disassembly ()
132 {
133     if (sc_ptr != NULL)
134     {
135         m_sc = *sc_ptr;
136         m_flags.Set(m_sc.GetResolvedMask ());
137     }
138 
139     if (m_sc.target_sp.get() == NULL && reg_context_sp)
140     {
141         m_sc.target_sp = reg_context_sp->GetThread().GetProcess().GetTarget().GetSP();
142         m_flags.Set (eSymbolContextTarget);
143     }
144 
145     Module *pc_module = pc_addr.GetModule();
146     if (m_sc.module_sp.get() == NULL || m_sc.module_sp.get() != pc_module)
147     {
148         if (pc_module)
149         {
150             m_sc.module_sp = pc_module->GetSP();
151             m_flags.Set (eSymbolContextModule);
152         }
153         else
154         {
155             m_sc.module_sp.reset();
156         }
157 
158     }
159 }
160 
161 
162 //----------------------------------------------------------------------
163 // Destructor
164 //----------------------------------------------------------------------
165 StackFrame::~StackFrame()
166 {
167 }
168 
169 StackID&
170 StackFrame::GetStackID()
171 {
172     // Make sure we have resolved the StackID object's symbol context scope if
173     // we already haven't looked it up.
174 
175     if (m_flags.IsClear (RESOLVED_FRAME_ID_SYMBOL_SCOPE))
176     {
177         if (m_id.GetSymbolContextScope ())
178         {
179             // We already have a symbol context scope, we just don't have our
180             // flag bit set.
181             m_flags.Set (RESOLVED_FRAME_ID_SYMBOL_SCOPE);
182         }
183         else
184         {
185             // Calculate the frame block and use this for the stack ID symbol
186             // context scope if we have one.
187             SymbolContextScope *scope = GetFrameBlock ();
188             if (scope == NULL)
189             {
190                 // We don't have a block, so use the symbol
191                 if (m_flags.IsClear (eSymbolContextSymbol))
192                     GetSymbolContext (eSymbolContextSymbol);
193 
194                 // It is ok if m_sc.symbol is NULL here
195                 scope = m_sc.symbol;
196             }
197             // Set the symbol context scope (the accessor will set the
198             // RESOLVED_FRAME_ID_SYMBOL_SCOPE bit in m_flags).
199             SetSymbolContextScope (scope);
200         }
201     }
202     return m_id;
203 }
204 
205 void
206 StackFrame::SetSymbolContextScope (SymbolContextScope *symbol_scope)
207 {
208     m_flags.Set (RESOLVED_FRAME_ID_SYMBOL_SCOPE);
209     m_id.SetSymbolContextScope (symbol_scope);
210 }
211 
212 const Address&
213 StackFrame::GetFrameCodeAddress()
214 {
215     if (m_flags.IsClear(RESOLVED_FRAME_CODE_ADDR) && !m_frame_code_addr.IsSectionOffset())
216     {
217         m_flags.Set (RESOLVED_FRAME_CODE_ADDR);
218 
219         // Resolve the PC into a temporary address because if ResolveLoadAddress
220         // fails to resolve the address, it will clear the address object...
221 
222         if (m_frame_code_addr.SetOpcodeLoadAddress (m_frame_code_addr.GetOffset(), &m_thread.GetProcess().GetTarget()))
223         {
224             const Section *section = m_frame_code_addr.GetSection();
225             if (section)
226             {
227                 Module *module = section->GetModule();
228                 if (module)
229                 {
230                     m_sc.module_sp = module->GetSP();
231                     if (m_sc.module_sp)
232                         m_flags.Set(eSymbolContextModule);
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     m_thread.ClearStackFrames ();
248 }
249 
250 const char *
251 StackFrame::Disassemble ()
252 {
253     if (m_disassembly.GetSize() == 0)
254     {
255         ExecutionContext exe_ctx;
256         CalculateExecutionContext(exe_ctx);
257         Target &target = m_thread.GetProcess().GetTarget();
258         Disassembler::Disassemble (target.GetDebugger(),
259                                    target.GetArchitecture(),
260                                    NULL,
261                                    exe_ctx,
262                                    0,
263                                    0,
264                                    0,
265                                    m_disassembly);
266         if (m_disassembly.GetSize() == 0)
267             return NULL;
268     }
269     return m_disassembly.GetData();
270 }
271 
272 Block *
273 StackFrame::GetFrameBlock ()
274 {
275     if (m_sc.block == NULL && m_flags.IsClear (eSymbolContextBlock))
276         GetSymbolContext (eSymbolContextBlock);
277 
278     if (m_sc.block)
279     {
280         Block *inline_block = m_sc.block->GetContainingInlinedBlock();
281         if (inline_block)
282         {
283             // Use the block with the inlined function info
284             // as the frame block we want this frame to have only the variables
285             // for the inlined function and its non-inlined block child blocks.
286             return inline_block;
287         }
288         else
289         {
290             // This block is not contained withing any inlined function blocks
291             // with so we want to use the top most function block.
292             return &m_sc.function->GetBlock (false);
293         }
294     }
295     return NULL;
296 }
297 
298 //----------------------------------------------------------------------
299 // Get the symbol context if we already haven't done so by resolving the
300 // PC address as much as possible. This way when we pass around a
301 // StackFrame object, everyone will have as much information as
302 // possible and no one will ever have to look things up manually.
303 //----------------------------------------------------------------------
304 const SymbolContext&
305 StackFrame::GetSymbolContext (uint32_t resolve_scope)
306 {
307     // Copy our internal symbol context into "sc".
308     if ((m_flags.Get() & resolve_scope) != resolve_scope)
309     {
310         // Resolve our PC to section offset if we haven't alreday done so
311         // and if we don't have a module. The resolved address section will
312         // contain the module to which it belongs
313         if (!m_sc.module_sp && m_flags.IsClear(RESOLVED_FRAME_CODE_ADDR))
314             GetFrameCodeAddress();
315 
316         // If this is not frame zero, then we need to subtract 1 from the PC
317         // value when doing address lookups since the PC will be on the
318         // instruction following the function call instruction...
319 
320         Address lookup_addr(GetFrameCodeAddress());
321         if (m_frame_index > 0 && lookup_addr.IsValid())
322         {
323             addr_t offset = lookup_addr.GetOffset();
324             if (offset > 0)
325                 lookup_addr.SetOffset(offset - 1);
326         }
327 
328 
329         uint32_t resolved = 0;
330         if (m_sc.module_sp)
331         {
332             // We have something in our stack frame symbol context, lets check
333             // if we haven't already tried to lookup one of those things. If we
334             // haven't then we will do the query.
335 
336             uint32_t actual_resolve_scope = 0;
337 
338             if (resolve_scope & eSymbolContextCompUnit)
339             {
340                 if (m_flags.IsClear (eSymbolContextCompUnit))
341                 {
342                     if (m_sc.comp_unit)
343                         resolved |= eSymbolContextCompUnit;
344                     else
345                         actual_resolve_scope |= eSymbolContextCompUnit;
346                 }
347             }
348 
349             if (resolve_scope & eSymbolContextFunction)
350             {
351                 if (m_flags.IsClear (eSymbolContextFunction))
352                 {
353                     if (m_sc.function)
354                         resolved |= eSymbolContextFunction;
355                     else
356                         actual_resolve_scope |= eSymbolContextFunction;
357                 }
358             }
359 
360             if (resolve_scope & eSymbolContextBlock)
361             {
362                 if (m_flags.IsClear (eSymbolContextBlock))
363                 {
364                     if (m_sc.block)
365                         resolved |= eSymbolContextBlock;
366                     else
367                         actual_resolve_scope |= eSymbolContextBlock;
368                 }
369             }
370 
371             if (resolve_scope & eSymbolContextSymbol)
372             {
373                 if (m_flags.IsClear (eSymbolContextSymbol))
374                 {
375                     if (m_sc.symbol)
376                         resolved |= eSymbolContextSymbol;
377                     else
378                         actual_resolve_scope |= eSymbolContextSymbol;
379                 }
380             }
381 
382             if (resolve_scope & eSymbolContextLineEntry)
383             {
384                 if (m_flags.IsClear (eSymbolContextLineEntry))
385                 {
386                     if (m_sc.line_entry.IsValid())
387                         resolved |= eSymbolContextLineEntry;
388                     else
389                         actual_resolve_scope |= eSymbolContextLineEntry;
390                 }
391             }
392 
393             if (actual_resolve_scope)
394             {
395                 // We might be resolving less information than what is already
396                 // in our current symbol context so resolve into a temporary
397                 // symbol context "sc" so we don't clear out data we have
398                 // already found in "m_sc"
399                 SymbolContext sc;
400                 // Set flags that indicate what we have tried to resolve
401                 resolved |= m_sc.module_sp->ResolveSymbolContextForAddress (lookup_addr, actual_resolve_scope, sc);
402                 // Only replace what we didn't already have as we may have
403                 // information for an inlined function scope that won't match
404                 // what a standard lookup by address would match
405                 if ((resolved & eSymbolContextCompUnit)  && m_sc.comp_unit == NULL)
406                     m_sc.comp_unit = sc.comp_unit;
407                 if ((resolved & eSymbolContextFunction)  && m_sc.function == NULL)
408                     m_sc.function = sc.function;
409                 if ((resolved & eSymbolContextBlock)     && m_sc.block == NULL)
410                     m_sc.block = sc.block;
411                 if ((resolved & eSymbolContextSymbol)    && m_sc.symbol == NULL)
412                     m_sc.symbol = sc.symbol;
413                 if ((resolved & eSymbolContextLineEntry) && !m_sc.line_entry.IsValid())
414                     m_sc.line_entry = sc.line_entry;
415 
416             }
417         }
418         else
419         {
420             // If we don't have a module, then we can't have the compile unit,
421             // function, block, line entry or symbol, so we can safely call
422             // ResolveSymbolContextForAddress with our symbol context member m_sc.
423             resolved |= m_thread.GetProcess().GetTarget().GetImages().ResolveSymbolContextForAddress (lookup_addr, resolve_scope, m_sc);
424         }
425 
426         // If the target was requested add that:
427         if (m_sc.target_sp.get() == NULL)
428         {
429             m_sc.target_sp = CalculateProcess()->GetTarget().GetSP();
430             if (m_sc.target_sp)
431                 resolved |= eSymbolContextTarget;
432         }
433 
434         // Update our internal flags so we remember what we have tried to locate so
435         // we don't have to keep trying when more calls to this function are made.
436         // We might have dug up more information that was requested (for example
437         // if we were asked to only get the block, we will have gotten the
438         // compile unit, and function) so set any additional bits that we resolved
439         m_flags.Set (resolve_scope | resolved);
440     }
441 
442     // Return the symbol context with everything that was possible to resolve
443     // resolved.
444     return m_sc;
445 }
446 
447 
448 VariableList *
449 StackFrame::GetVariableList (bool get_file_globals)
450 {
451     if (m_flags.IsClear(RESOLVED_VARIABLES))
452     {
453         m_flags.Set(RESOLVED_VARIABLES);
454 
455         Block *frame_block = GetFrameBlock();
456 
457         if (frame_block)
458         {
459             const bool get_child_variables = true;
460             const bool can_create = true;
461             const bool stop_if_child_block_is_inlined_function = true;
462             m_variable_list_sp.reset(new VariableList());
463             frame_block->AppendBlockVariables(can_create, get_child_variables, stop_if_child_block_is_inlined_function, m_variable_list_sp.get());
464         }
465     }
466 
467     if (m_flags.IsClear(RESOLVED_GLOBAL_VARIABLES) &&
468         get_file_globals)
469     {
470         m_flags.Set(RESOLVED_GLOBAL_VARIABLES);
471 
472         if (m_flags.IsClear (eSymbolContextCompUnit))
473             GetSymbolContext (eSymbolContextCompUnit);
474 
475         if (m_sc.comp_unit)
476         {
477             VariableListSP global_variable_list_sp (m_sc.comp_unit->GetVariableList(true));
478             if (m_variable_list_sp)
479                 m_variable_list_sp->AddVariables (global_variable_list_sp.get());
480             else
481                 m_variable_list_sp = global_variable_list_sp;
482         }
483     }
484 
485     return m_variable_list_sp.get();
486 }
487 
488 ValueObjectSP
489 StackFrame::GetValueForVariableExpressionPath (const char *var_expr_cstr,
490                                                lldb::DynamicValueType use_dynamic,
491                                                uint32_t options,
492                                                lldb::VariableSP &var_sp,
493                                                Error &error)
494 {
495 
496     if (var_expr_cstr && var_expr_cstr[0])
497     {
498         const bool check_ptr_vs_member = (options & eExpressionPathOptionCheckPtrVsMember) != 0;
499         const bool no_fragile_ivar = (options & eExpressionPathOptionsNoFragileObjcIvar) != 0;
500         error.Clear();
501         bool deref = false;
502         bool address_of = false;
503         ValueObjectSP valobj_sp;
504         const bool get_file_globals = true;
505         VariableList *variable_list = GetVariableList (get_file_globals);
506 
507         if (variable_list)
508         {
509             // If first character is a '*', then show pointer contents
510             const char *var_expr = var_expr_cstr;
511             if (var_expr[0] == '*')
512             {
513                 deref = true;
514                 var_expr++; // Skip the '*'
515             }
516             else if (var_expr[0] == '&')
517             {
518                 address_of = true;
519                 var_expr++; // Skip the '&'
520             }
521 
522             std::string var_path (var_expr);
523             size_t separator_idx = var_path.find_first_of(".-[=+~|&^%#@!/?,<>{}");
524             StreamString var_expr_path_strm;
525 
526             ConstString name_const_string;
527             if (separator_idx == std::string::npos)
528                 name_const_string.SetCString (var_path.c_str());
529             else
530                 name_const_string.SetCStringWithLength (var_path.c_str(), separator_idx);
531 
532             var_sp = variable_list->FindVariable(name_const_string);
533             if (var_sp)
534             {
535                 valobj_sp = GetValueObjectForFrameVariable (var_sp, use_dynamic);
536                 if (!valobj_sp)
537                     return valobj_sp;
538 
539                 var_path.erase (0, name_const_string.GetLength ());
540                 // We are dumping at least one child
541                 while (separator_idx != std::string::npos)
542                 {
543                     // Calculate the next separator index ahead of time
544                     ValueObjectSP child_valobj_sp;
545                     const char separator_type = var_path[0];
546                     switch (separator_type)
547                     {
548 
549                     case '-':
550                         if (var_path.size() >= 2 && var_path[1] != '>')
551                             return ValueObjectSP();
552 
553                         if (no_fragile_ivar)
554                         {
555                             // Make sure we aren't trying to deref an objective
556                             // C ivar if this is not allowed
557                             const uint32_t pointer_type_flags = ClangASTContext::GetTypeInfo (valobj_sp->GetClangType(), NULL, NULL);
558                             if ((pointer_type_flags & ClangASTContext::eTypeIsObjC) &&
559                                 (pointer_type_flags & ClangASTContext::eTypeIsPointer))
560                             {
561                                 // This was an objective C object pointer and
562                                 // it was requested we skip any fragile ivars
563                                 // so return nothing here
564                                 return ValueObjectSP();
565                             }
566                         }
567                         var_path.erase (0, 1); // Remove the '-'
568                         // Fall through
569                     case '.':
570                         {
571                             const bool expr_is_ptr = var_path[0] == '>';
572 
573                             var_path.erase (0, 1); // Remove the '.' or '>'
574                             separator_idx = var_path.find_first_of(".-[");
575                             ConstString child_name;
576                             if (separator_idx == std::string::npos)
577                                 child_name.SetCString (var_path.c_str());
578                             else
579                                 child_name.SetCStringWithLength(var_path.c_str(), separator_idx);
580 
581                             if (check_ptr_vs_member)
582                             {
583                                 // We either have a pointer type and need to verify
584                                 // valobj_sp is a pointer, or we have a member of a
585                                 // class/union/struct being accessed with the . syntax
586                                 // and need to verify we don't have a pointer.
587                                 const bool actual_is_ptr = valobj_sp->IsPointerType ();
588 
589                                 if (actual_is_ptr != expr_is_ptr)
590                                 {
591                                     // Incorrect use of "." with a pointer, or "->" with
592                                     // a class/union/struct instance or reference.
593                                     valobj_sp->GetExpressionPath (var_expr_path_strm, false);
594                                     if (actual_is_ptr)
595                                         error.SetErrorStringWithFormat ("\"%s\" is a pointer and . was used to attempt to access \"%s\". Did you mean \"%s->%s\"?",
596                                                                         var_expr_path_strm.GetString().c_str(),
597                                                                         child_name.GetCString(),
598                                                                         var_expr_path_strm.GetString().c_str(),
599                                                                         var_path.c_str());
600                                     else
601                                         error.SetErrorStringWithFormat ("\"%s\" is not a pointer and -> was used to attempt to access \"%s\". Did you mean \"%s.%s\"?",
602                                                                         var_expr_path_strm.GetString().c_str(),
603                                                                         child_name.GetCString(),
604                                                                         var_expr_path_strm.GetString().c_str(),
605                                                                         var_path.c_str());
606                                     return ValueObjectSP();
607                                 }
608                             }
609                             child_valobj_sp = valobj_sp->GetChildMemberWithName (child_name, true);
610                             if (!child_valobj_sp)
611                             {
612                                 // No child member with name "child_name"
613                                 valobj_sp->GetExpressionPath (var_expr_path_strm, false);
614                                 if (child_name)
615                                 {
616                                     error.SetErrorStringWithFormat ("\"%s\" is not a member of \"(%s) %s\"",
617                                                                     child_name.GetCString(),
618                                                                     valobj_sp->GetTypeName().AsCString("<invalid type>"),
619                                                                     var_expr_path_strm.GetString().c_str());
620                                 }
621                                 else
622                                 {
623                                     error.SetErrorStringWithFormat ("incomplete expression path after \"%s\" in \"%s\"",
624                                                                     var_expr_path_strm.GetString().c_str(),
625                                                                     var_expr_cstr);
626                                 }
627 
628                                 return ValueObjectSP();
629                             }
630                             // Remove the child name from the path
631                             var_path.erase(0, child_name.GetLength());
632                             if (use_dynamic != lldb::eNoDynamicValues)
633                             {
634                                 ValueObjectSP dynamic_value_sp(child_valobj_sp->GetDynamicValue(use_dynamic));
635                                 if (dynamic_value_sp)
636                                     child_valobj_sp = dynamic_value_sp;
637                             }
638                         }
639                         break;
640 
641                     case '[':
642                         // Array member access, or treating pointer as an array
643                         if (var_path.size() > 2) // Need at least two brackets and a number
644                         {
645                             char *end = NULL;
646                             long child_index = ::strtol (&var_path[1], &end, 0);
647                             if (end && *end == ']'
648                                 && *(end-1) != '[') // this code forces an error in the case of arr[]. as bitfield[] is not a good syntax we're good to go
649                             {
650                                 if (ClangASTContext::IsPointerToScalarType(valobj_sp->GetClangType()) && deref)
651                                 {
652                                     // what we have is *ptr[low]. the most similar C++ syntax is to deref ptr
653                                     // and extract bit low out of it. reading array item low
654                                     // would be done by saying ptr[low], without a deref * sign
655                                     Error error;
656                                     ValueObjectSP temp(valobj_sp->Dereference(error));
657                                     if (error.Fail())
658                                     {
659                                         valobj_sp->GetExpressionPath (var_expr_path_strm, false);
660                                         error.SetErrorStringWithFormat ("could not dereference \"(%s) %s\"",
661                                                                         valobj_sp->GetTypeName().AsCString("<invalid type>"),
662                                                                         var_expr_path_strm.GetString().c_str());
663                                         return ValueObjectSP();
664                                     }
665                                     valobj_sp = temp;
666                                     deref = false;
667                                 }
668                                 else if (ClangASTContext::IsArrayOfScalarType(valobj_sp->GetClangType()) && deref)
669                                 {
670                                     // what we have is *arr[low]. the most similar C++ syntax is to get arr[0]
671                                     // (an operation that is equivalent to deref-ing arr)
672                                     // and extract bit low out of it. reading array item low
673                                     // would be done by saying arr[low], without a deref * sign
674                                     Error error;
675                                     ValueObjectSP temp(valobj_sp->GetChildAtIndex (0, true));
676                                     if (error.Fail())
677                                     {
678                                         valobj_sp->GetExpressionPath (var_expr_path_strm, false);
679                                         error.SetErrorStringWithFormat ("could not get item 0 for \"(%s) %s\"",
680                                                                         valobj_sp->GetTypeName().AsCString("<invalid type>"),
681                                                                         var_expr_path_strm.GetString().c_str());
682                                         return ValueObjectSP();
683                                     }
684                                     valobj_sp = temp;
685                                     deref = false;
686                                 }
687 
688                                 if (valobj_sp->IsPointerType ())
689                                 {
690                                     child_valobj_sp = valobj_sp->GetSyntheticArrayMemberFromPointer (child_index, true);
691                                     if (!child_valobj_sp)
692                                     {
693                                         valobj_sp->GetExpressionPath (var_expr_path_strm, false);
694                                         error.SetErrorStringWithFormat ("failed to use pointer as array for index %i for \"(%s) %s\"",
695                                                                         child_index,
696                                                                         valobj_sp->GetTypeName().AsCString("<invalid type>"),
697                                                                         var_expr_path_strm.GetString().c_str());
698                                     }
699                                 }
700                                 else if (ClangASTContext::IsArrayType (valobj_sp->GetClangType(), NULL, NULL))
701                                 {
702                                     // Pass false to dynamic_value here so we can tell the difference between
703                                     // no dynamic value and no member of this type...
704                                     child_valobj_sp = valobj_sp->GetChildAtIndex (child_index, true);
705                                     if (!child_valobj_sp)
706                                     {
707                                         valobj_sp->GetExpressionPath (var_expr_path_strm, false);
708                                         error.SetErrorStringWithFormat ("array index %i is not valid for \"(%s) %s\"",
709                                                                         child_index,
710                                                                         valobj_sp->GetTypeName().AsCString("<invalid type>"),
711                                                                         var_expr_path_strm.GetString().c_str());
712                                     }
713                                 }
714                                 else if (ClangASTContext::IsScalarType(valobj_sp->GetClangType()))
715                                 {
716                                     // this is a bitfield asking to display just one bit
717                                     child_valobj_sp = valobj_sp->GetSyntheticBitFieldChild(child_index, child_index, true);
718                                     if (!child_valobj_sp)
719                                     {
720                                         valobj_sp->GetExpressionPath (var_expr_path_strm, false);
721                                         error.SetErrorStringWithFormat ("bitfield range %i-%i is not valid for \"(%s) %s\"",
722                                                                         child_index, child_index,
723                                                                         valobj_sp->GetTypeName().AsCString("<invalid type>"),
724                                                                         var_expr_path_strm.GetString().c_str());
725                                     }
726                                 }
727                                 else
728                                 {
729                                     valobj_sp->GetExpressionPath (var_expr_path_strm, false);
730                                     error.SetErrorStringWithFormat ("\"(%s) %s\" is not an array type",
731                                                                     valobj_sp->GetTypeName().AsCString("<invalid type>"),
732                                                                     var_expr_path_strm.GetString().c_str());
733                                 }
734 
735                                 if (!child_valobj_sp)
736                                 {
737                                     // Invalid array index...
738                                     return ValueObjectSP();
739                                 }
740 
741                                 // Erase the array member specification '[%i]' where
742                                 // %i is the array index
743                                 var_path.erase(0, (end - var_path.c_str()) + 1);
744                                 separator_idx = var_path.find_first_of(".-[");
745                                 if (use_dynamic != lldb::eNoDynamicValues)
746                                 {
747                                     ValueObjectSP dynamic_value_sp(child_valobj_sp->GetDynamicValue(use_dynamic));
748                                     if (dynamic_value_sp)
749                                         child_valobj_sp = dynamic_value_sp;
750                                 }
751                                 // Break out early from the switch since we were
752                                 // able to find the child member
753                                 break;
754                             }
755                             else if(end && *end == '-')
756                             {
757                                 // this is most probably a BitField, let's take a look
758                                 char *real_end = NULL;
759                                 long final_index = ::strtol (end+1, &real_end, 0);
760                                 if(real_end && *real_end == ']')
761                                 {
762                                     // if the format given is [high-low], swap range
763                                     if(child_index > final_index)
764                                     {
765                                         long temp = child_index;
766                                         child_index = final_index;
767                                         final_index = temp;
768                                     }
769 
770                                     if (ClangASTContext::IsPointerToScalarType(valobj_sp->GetClangType()) && deref)
771                                     {
772                                         // what we have is *ptr[low-high]. the most similar C++ syntax is to deref ptr
773                                         // and extract bits low thru high out of it. reading array items low thru high
774                                         // would be done by saying ptr[low-high], without a deref * sign
775                                         Error error;
776                                         ValueObjectSP temp(valobj_sp->Dereference(error));
777                                         if (error.Fail())
778                                         {
779                                             valobj_sp->GetExpressionPath (var_expr_path_strm, false);
780                                             error.SetErrorStringWithFormat ("could not dereference \"(%s) %s\"",
781                                                                             valobj_sp->GetTypeName().AsCString("<invalid type>"),
782                                                                             var_expr_path_strm.GetString().c_str());
783                                             return ValueObjectSP();
784                                         }
785                                         valobj_sp = temp;
786                                         deref = false;
787                                     }
788                                     else if (ClangASTContext::IsArrayOfScalarType(valobj_sp->GetClangType()) && deref)
789                                     {
790                                         // what we have is *arr[low-high]. the most similar C++ syntax is to get arr[0]
791                                         // (an operation that is equivalent to deref-ing arr)
792                                         // and extract bits low thru high out of it. reading array items low thru high
793                                         // would be done by saying arr[low-high], without a deref * sign
794                                         Error error;
795                                         ValueObjectSP temp(valobj_sp->GetChildAtIndex (0, true));
796                                         if (error.Fail())
797                                         {
798                                             valobj_sp->GetExpressionPath (var_expr_path_strm, false);
799                                             error.SetErrorStringWithFormat ("could not get item 0 for \"(%s) %s\"",
800                                                                             valobj_sp->GetTypeName().AsCString("<invalid type>"),
801                                                                             var_expr_path_strm.GetString().c_str());
802                                             return ValueObjectSP();
803                                         }
804                                         valobj_sp = temp;
805                                         deref = false;
806                                     }
807 
808                                     child_valobj_sp = valobj_sp->GetSyntheticBitFieldChild(child_index, final_index, true);
809                                     if (!child_valobj_sp)
810                                     {
811                                         valobj_sp->GetExpressionPath (var_expr_path_strm, false);
812                                         error.SetErrorStringWithFormat ("bitfield range %i-%i is not valid for \"(%s) %s\"",
813                                                                         child_index, final_index,
814                                                                         valobj_sp->GetTypeName().AsCString("<invalid type>"),
815                                                                         var_expr_path_strm.GetString().c_str());
816                                     }
817                                 }
818 
819                                 if (!child_valobj_sp)
820                                 {
821                                     // Invalid bitfield range...
822                                     return ValueObjectSP();
823                                 }
824 
825                                 // Erase the bitfield member specification '[%i-%i]' where
826                                 // %i is the index
827                                 var_path.erase(0, (real_end - var_path.c_str()) + 1);
828                                 separator_idx = var_path.find_first_of(".-[");
829                                 if (use_dynamic != lldb::eNoDynamicValues)
830                                 {
831                                     ValueObjectSP dynamic_value_sp(child_valobj_sp->GetDynamicValue(use_dynamic));
832                                     if (dynamic_value_sp)
833                                         child_valobj_sp = dynamic_value_sp;
834                                 }
835                                 // Break out early from the switch since we were
836                                 // able to find the child member
837                                 break;
838 
839                             }
840                         }
841                         else
842                         {
843                             error.SetErrorStringWithFormat("invalid square bracket encountered after \"%s\" in \"%s\"",
844                                                            var_expr_path_strm.GetString().c_str(),
845                                                            var_path.c_str());
846                         }
847                         return ValueObjectSP();
848 
849                     default:
850                         // Failure...
851                         {
852                             valobj_sp->GetExpressionPath (var_expr_path_strm, false);
853                             error.SetErrorStringWithFormat ("unexpected char '%c' encountered after \"%s\" in \"%s\"",
854                                                             separator_type,
855                                                             var_expr_path_strm.GetString().c_str(),
856                                                             var_path.c_str());
857 
858                             return ValueObjectSP();
859                         }
860                     }
861 
862                     if (child_valobj_sp)
863                         valobj_sp = child_valobj_sp;
864 
865                     if (var_path.empty())
866                         break;
867 
868                 }
869                 if (valobj_sp)
870                 {
871                     if (deref)
872                     {
873                         ValueObjectSP deref_valobj_sp (valobj_sp->Dereference(error));
874                         valobj_sp = deref_valobj_sp;
875                     }
876                     else if (address_of)
877                     {
878                         ValueObjectSP address_of_valobj_sp (valobj_sp->AddressOf(error));
879                         valobj_sp = address_of_valobj_sp;
880                     }
881                 }
882                 return valobj_sp;
883             }
884             else
885             {
886                 error.SetErrorStringWithFormat("no variable named '%s' found in this frame",
887                                                name_const_string.GetCString());
888             }
889         }
890     }
891     else
892     {
893         error.SetErrorStringWithFormat("invalid variable path '%s'", var_expr_cstr);
894     }
895     return ValueObjectSP();
896 }
897 
898 bool
899 StackFrame::GetFrameBaseValue (Scalar &frame_base, Error *error_ptr)
900 {
901     if (m_flags.IsClear(GOT_FRAME_BASE))
902     {
903         if (m_sc.function)
904         {
905             m_frame_base.Clear();
906             m_frame_base_error.Clear();
907 
908             m_flags.Set(GOT_FRAME_BASE);
909             ExecutionContext exe_ctx (&m_thread.GetProcess(), &m_thread, this);
910             Value expr_value;
911             addr_t loclist_base_addr = LLDB_INVALID_ADDRESS;
912             if (m_sc.function->GetFrameBaseExpression().IsLocationList())
913                 loclist_base_addr = m_sc.function->GetAddressRange().GetBaseAddress().GetLoadAddress (&m_thread.GetProcess().GetTarget());
914 
915             if (m_sc.function->GetFrameBaseExpression().Evaluate(&exe_ctx, NULL, NULL, NULL, NULL, loclist_base_addr, NULL, expr_value, &m_frame_base_error) == false)
916             {
917                 // We should really have an error if evaluate returns, but in case
918                 // we don't, lets set the error to something at least.
919                 if (m_frame_base_error.Success())
920                     m_frame_base_error.SetErrorString("Evaluation of the frame base expression failed.");
921             }
922             else
923             {
924                 m_frame_base = expr_value.ResolveValue(&exe_ctx, NULL);
925             }
926         }
927         else
928         {
929             m_frame_base_error.SetErrorString ("No function in symbol context.");
930         }
931     }
932 
933     if (m_frame_base_error.Success())
934         frame_base = m_frame_base;
935 
936     if (error_ptr)
937         *error_ptr = m_frame_base_error;
938     return m_frame_base_error.Success();
939 }
940 
941 RegisterContextSP
942 StackFrame::GetRegisterContext ()
943 {
944     if (!m_reg_context_sp)
945         m_reg_context_sp = m_thread.CreateRegisterContextForFrame (this);
946     return m_reg_context_sp;
947 }
948 
949 bool
950 StackFrame::HasDebugInformation ()
951 {
952     GetSymbolContext (eSymbolContextLineEntry);
953     return m_sc.line_entry.IsValid();
954 }
955 
956 
957 ValueObjectSP
958 StackFrame::GetValueObjectForFrameVariable (const VariableSP &variable_sp, lldb::DynamicValueType use_dynamic)
959 {
960     ValueObjectSP valobj_sp;
961     VariableList *var_list = GetVariableList (true);
962     if (var_list)
963     {
964         // Make sure the variable is a frame variable
965         const uint32_t var_idx = var_list->FindIndexForVariable (variable_sp.get());
966         const uint32_t num_variables = var_list->GetSize();
967         if (var_idx < num_variables)
968         {
969             valobj_sp = m_variable_list_value_objects.GetValueObjectAtIndex (var_idx);
970             if (valobj_sp.get() == NULL)
971             {
972                 if (m_variable_list_value_objects.GetSize() < num_variables)
973                     m_variable_list_value_objects.Resize(num_variables);
974                 valobj_sp = ValueObjectVariable::Create (this, variable_sp);
975                 m_variable_list_value_objects.SetValueObjectAtIndex (var_idx, valobj_sp);
976             }
977         }
978     }
979     if (use_dynamic != lldb::eNoDynamicValues && valobj_sp)
980     {
981         ValueObjectSP dynamic_sp = valobj_sp->GetDynamicValue (use_dynamic);
982         if (dynamic_sp)
983             return dynamic_sp;
984     }
985     return valobj_sp;
986 }
987 
988 ValueObjectSP
989 StackFrame::TrackGlobalVariable (const VariableSP &variable_sp, lldb::DynamicValueType use_dynamic)
990 {
991     // Check to make sure we aren't already tracking this variable?
992     ValueObjectSP valobj_sp (GetValueObjectForFrameVariable (variable_sp, use_dynamic));
993     if (!valobj_sp)
994     {
995         // We aren't already tracking this global
996         VariableList *var_list = GetVariableList (true);
997         // If this frame has no variables, create a new list
998         if (var_list == NULL)
999             m_variable_list_sp.reset (new VariableList());
1000 
1001         // Add the global/static variable to this frame
1002         m_variable_list_sp->AddVariable (variable_sp);
1003 
1004         // Now make a value object for it so we can track its changes
1005         valobj_sp = GetValueObjectForFrameVariable (variable_sp, use_dynamic);
1006     }
1007     return valobj_sp;
1008 }
1009 
1010 bool
1011 StackFrame::IsInlined ()
1012 {
1013     if (m_sc.block == NULL)
1014         GetSymbolContext (eSymbolContextBlock);
1015     if (m_sc.block)
1016         return m_sc.block->GetContainingInlinedBlock() != NULL;
1017     return false;
1018 }
1019 
1020 Target *
1021 StackFrame::CalculateTarget ()
1022 {
1023     return m_thread.CalculateTarget();
1024 }
1025 
1026 Process *
1027 StackFrame::CalculateProcess ()
1028 {
1029     return m_thread.CalculateProcess();
1030 }
1031 
1032 Thread *
1033 StackFrame::CalculateThread ()
1034 {
1035     return &m_thread;
1036 }
1037 
1038 StackFrame *
1039 StackFrame::CalculateStackFrame ()
1040 {
1041     return this;
1042 }
1043 
1044 
1045 void
1046 StackFrame::CalculateExecutionContext (ExecutionContext &exe_ctx)
1047 {
1048     m_thread.CalculateExecutionContext (exe_ctx);
1049     exe_ctx.frame = this;
1050 }
1051 
1052 void
1053 StackFrame::DumpUsingSettingsFormat (Stream *strm)
1054 {
1055     if (strm == NULL)
1056         return;
1057 
1058     GetSymbolContext(eSymbolContextEverything);
1059     ExecutionContext exe_ctx;
1060     CalculateExecutionContext(exe_ctx);
1061     const char *end = NULL;
1062     StreamString s;
1063     const char *frame_format = m_thread.GetProcess().GetTarget().GetDebugger().GetFrameFormat();
1064     if (frame_format && Debugger::FormatPrompt (frame_format, &m_sc, &exe_ctx, NULL, s, &end))
1065     {
1066         strm->Write(s.GetData(), s.GetSize());
1067     }
1068     else
1069     {
1070         Dump (strm, true, false);
1071         strm->EOL();
1072     }
1073 }
1074 
1075 void
1076 StackFrame::Dump (Stream *strm, bool show_frame_index, bool show_fullpaths)
1077 {
1078     if (strm == NULL)
1079         return;
1080 
1081     if (show_frame_index)
1082         strm->Printf("frame #%u: ", m_frame_index);
1083     strm->Printf("0x%0*llx ", m_thread.GetProcess().GetTarget().GetArchitecture().GetAddressByteSize() * 2, GetFrameCodeAddress().GetLoadAddress(&m_thread.GetProcess().GetTarget()));
1084     GetSymbolContext(eSymbolContextEverything);
1085     const bool show_module = true;
1086     const bool show_inline = true;
1087     m_sc.DumpStopContext(strm, &m_thread.GetProcess(), GetFrameCodeAddress(), show_fullpaths, show_module, show_inline);
1088 }
1089 
1090 void
1091 StackFrame::UpdateCurrentFrameFromPreviousFrame (StackFrame &prev_frame)
1092 {
1093     assert (GetStackID() == prev_frame.GetStackID());    // TODO: remove this after some testing
1094     m_variable_list_sp = prev_frame.m_variable_list_sp;
1095     m_variable_list_value_objects.Swap (prev_frame.m_variable_list_value_objects);
1096     if (!m_disassembly.GetString().empty())
1097         m_disassembly.GetString().swap (m_disassembly.GetString());
1098 }
1099 
1100 
1101 void
1102 StackFrame::UpdatePreviousFrameFromCurrentFrame (StackFrame &curr_frame)
1103 {
1104     assert (GetStackID() == curr_frame.GetStackID());        // TODO: remove this after some testing
1105     m_id.SetPC (curr_frame.m_id.GetPC());       // Update the Stack ID PC value
1106     assert (&m_thread == &curr_frame.m_thread);
1107     m_frame_index = curr_frame.m_frame_index;
1108     m_concrete_frame_index = curr_frame.m_concrete_frame_index;
1109     m_reg_context_sp = curr_frame.m_reg_context_sp;
1110     m_frame_code_addr = curr_frame.m_frame_code_addr;
1111     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());
1112     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());
1113     assert (m_sc.comp_unit == NULL || curr_frame.m_sc.comp_unit == NULL || m_sc.comp_unit == curr_frame.m_sc.comp_unit);
1114     assert (m_sc.function == NULL || curr_frame.m_sc.function == NULL || m_sc.function == curr_frame.m_sc.function);
1115     m_sc = curr_frame.m_sc;
1116     m_flags.Clear(GOT_FRAME_BASE | eSymbolContextEverything);
1117     m_flags.Set (m_sc.GetResolvedMask());
1118     m_frame_base.Clear();
1119     m_frame_base_error.Clear();
1120 }
1121 
1122 
1123 bool
1124 StackFrame::HasCachedData () const
1125 {
1126     if (m_variable_list_sp.get())
1127         return true;
1128     if (m_variable_list_value_objects.GetSize() > 0)
1129         return true;
1130     if (!m_disassembly.GetString().empty())
1131         return true;
1132     return false;
1133 }
1134 
1135 lldb::StackFrameSP
1136 StackFrame::GetSP ()
1137 {
1138     return m_thread.GetStackFrameSPForStackFramePtr (this);
1139 }
1140 
1141 
1142 
1143 bool
1144 StackFrame::GetStatus (Stream& strm,
1145                        bool show_frame_info,
1146                        bool show_source,
1147                        uint32_t source_lines_before,
1148                        uint32_t source_lines_after)
1149 {
1150     if (show_frame_info)
1151     {
1152         strm.Indent();
1153         DumpUsingSettingsFormat (&strm);
1154     }
1155 
1156     if (show_source)
1157     {
1158         GetSymbolContext(eSymbolContextCompUnit | eSymbolContextLineEntry);
1159 
1160         if (m_sc.comp_unit && m_sc.line_entry.IsValid())
1161         {
1162             Target &target = GetThread().GetProcess().GetTarget();
1163             target.GetDebugger().GetSourceManager().DisplaySourceLinesWithLineNumbers (
1164                 &target,
1165                 m_sc.line_entry.file,
1166                 m_sc.line_entry.line,
1167                 3,
1168                 3,
1169                 "->",
1170                 &strm);
1171 
1172         }
1173     }
1174     return true;
1175 }
1176 
1177