xref: /llvm-project/lldb/source/Target/StackFrame.cpp (revision 66a88f62cd56e55b5fa0ddb1bdffa549f7565f8f)
1 //===-- StackFrame.cpp ----------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "lldb/Target/StackFrame.h"
10 #include "lldb/Core/Debugger.h"
11 #include "lldb/Core/Disassembler.h"
12 #include "lldb/Core/FormatEntity.h"
13 #include "lldb/Core/Mangled.h"
14 #include "lldb/Core/Module.h"
15 #include "lldb/Core/Value.h"
16 #include "lldb/Symbol/CompileUnit.h"
17 #include "lldb/Symbol/Function.h"
18 #include "lldb/Symbol/Symbol.h"
19 #include "lldb/Symbol/SymbolContextScope.h"
20 #include "lldb/Symbol/SymbolFile.h"
21 #include "lldb/Symbol/Type.h"
22 #include "lldb/Symbol/VariableList.h"
23 #include "lldb/Target/ABI.h"
24 #include "lldb/Target/ExecutionContext.h"
25 #include "lldb/Target/LanguageRuntime.h"
26 #include "lldb/Target/Process.h"
27 #include "lldb/Target/RegisterContext.h"
28 #include "lldb/Target/StackFrameRecognizer.h"
29 #include "lldb/Target/Target.h"
30 #include "lldb/Target/Thread.h"
31 #include "lldb/Utility/LLDBLog.h"
32 #include "lldb/Utility/Log.h"
33 #include "lldb/Utility/RegisterValue.h"
34 #include "lldb/ValueObject/ValueObjectConstResult.h"
35 #include "lldb/ValueObject/ValueObjectMemory.h"
36 #include "lldb/ValueObject/ValueObjectVariable.h"
37 
38 #include "lldb/lldb-enumerations.h"
39 
40 #include <memory>
41 
42 using namespace lldb;
43 using namespace lldb_private;
44 
45 // The first bits in the flags are reserved for the SymbolContext::Scope bits
46 // so we know if we have tried to look up information in our internal symbol
47 // context (m_sc) already.
48 #define RESOLVED_FRAME_CODE_ADDR (uint32_t(eSymbolContextLastItem) << 1)
49 #define RESOLVED_FRAME_ID_SYMBOL_SCOPE (RESOLVED_FRAME_CODE_ADDR << 1)
50 #define GOT_FRAME_BASE (RESOLVED_FRAME_ID_SYMBOL_SCOPE << 1)
51 #define RESOLVED_VARIABLES (GOT_FRAME_BASE << 1)
52 #define RESOLVED_GLOBAL_VARIABLES (RESOLVED_VARIABLES << 1)
53 
54 StackFrame::StackFrame(const ThreadSP &thread_sp, user_id_t frame_idx,
55                        user_id_t unwind_frame_index, addr_t cfa,
56                        bool cfa_is_valid, addr_t pc, StackFrame::Kind kind,
57                        bool behaves_like_zeroth_frame,
58                        const SymbolContext *sc_ptr)
59     : m_thread_wp(thread_sp), m_frame_index(frame_idx),
60       m_concrete_frame_index(unwind_frame_index), m_reg_context_sp(),
61       m_id(pc, cfa, nullptr), m_frame_code_addr(pc), m_sc(), m_flags(),
62       m_frame_base(), m_frame_base_error(), m_cfa_is_valid(cfa_is_valid),
63       m_stack_frame_kind(kind),
64       m_behaves_like_zeroth_frame(behaves_like_zeroth_frame),
65       m_variable_list_sp(), m_variable_list_value_objects(),
66       m_recognized_frame_sp(), m_disassembly(), m_mutex() {
67   // If we don't have a CFA value, use the frame index for our StackID so that
68   // recursive functions properly aren't confused with one another on a history
69   // stack.
70   if (IsHistorical() && !m_cfa_is_valid) {
71     m_id.SetCFA(m_frame_index);
72   }
73 
74   if (sc_ptr != nullptr) {
75     m_sc = *sc_ptr;
76     m_flags.Set(m_sc.GetResolvedMask());
77   }
78 }
79 
80 StackFrame::StackFrame(const ThreadSP &thread_sp, user_id_t frame_idx,
81                        user_id_t unwind_frame_index,
82                        const RegisterContextSP &reg_context_sp, addr_t cfa,
83                        addr_t pc, bool behaves_like_zeroth_frame,
84                        const SymbolContext *sc_ptr)
85     : m_thread_wp(thread_sp), m_frame_index(frame_idx),
86       m_concrete_frame_index(unwind_frame_index),
87       m_reg_context_sp(reg_context_sp), m_id(pc, cfa, nullptr),
88       m_frame_code_addr(pc), m_sc(), m_flags(), m_frame_base(),
89       m_frame_base_error(), m_cfa_is_valid(true),
90       m_stack_frame_kind(StackFrame::Kind::Regular),
91       m_behaves_like_zeroth_frame(behaves_like_zeroth_frame),
92       m_variable_list_sp(), m_variable_list_value_objects(),
93       m_recognized_frame_sp(), m_disassembly(), m_mutex() {
94   if (sc_ptr != nullptr) {
95     m_sc = *sc_ptr;
96     m_flags.Set(m_sc.GetResolvedMask());
97   }
98 
99   if (reg_context_sp && !m_sc.target_sp) {
100     m_sc.target_sp = reg_context_sp->CalculateTarget();
101     if (m_sc.target_sp)
102       m_flags.Set(eSymbolContextTarget);
103   }
104 }
105 
106 StackFrame::StackFrame(const ThreadSP &thread_sp, user_id_t frame_idx,
107                        user_id_t unwind_frame_index,
108                        const RegisterContextSP &reg_context_sp, addr_t cfa,
109                        const Address &pc_addr, bool behaves_like_zeroth_frame,
110                        const SymbolContext *sc_ptr)
111     : m_thread_wp(thread_sp), m_frame_index(frame_idx),
112       m_concrete_frame_index(unwind_frame_index),
113       m_reg_context_sp(reg_context_sp),
114       m_id(pc_addr.GetLoadAddress(thread_sp->CalculateTarget().get()), cfa,
115            nullptr),
116       m_frame_code_addr(pc_addr), m_sc(), m_flags(), m_frame_base(),
117       m_frame_base_error(), m_cfa_is_valid(true),
118       m_stack_frame_kind(StackFrame::Kind::Regular),
119       m_behaves_like_zeroth_frame(behaves_like_zeroth_frame),
120       m_variable_list_sp(), m_variable_list_value_objects(),
121       m_recognized_frame_sp(), m_disassembly(), m_mutex() {
122   if (sc_ptr != nullptr) {
123     m_sc = *sc_ptr;
124     m_flags.Set(m_sc.GetResolvedMask());
125   }
126 
127   if (!m_sc.target_sp && reg_context_sp) {
128     m_sc.target_sp = reg_context_sp->CalculateTarget();
129     if (m_sc.target_sp)
130       m_flags.Set(eSymbolContextTarget);
131   }
132 
133   ModuleSP pc_module_sp(pc_addr.GetModule());
134   if (!m_sc.module_sp || m_sc.module_sp != pc_module_sp) {
135     if (pc_module_sp) {
136       m_sc.module_sp = pc_module_sp;
137       m_flags.Set(eSymbolContextModule);
138     } else {
139       m_sc.module_sp.reset();
140     }
141   }
142 }
143 
144 StackFrame::~StackFrame() = default;
145 
146 StackID &StackFrame::GetStackID() {
147   std::lock_guard<std::recursive_mutex> guard(m_mutex);
148   // Make sure we have resolved the StackID object's symbol context scope if we
149   // already haven't looked it up.
150 
151   if (m_flags.IsClear(RESOLVED_FRAME_ID_SYMBOL_SCOPE)) {
152     if (m_id.GetSymbolContextScope()) {
153       // We already have a symbol context scope, we just don't have our flag
154       // bit set.
155       m_flags.Set(RESOLVED_FRAME_ID_SYMBOL_SCOPE);
156     } else {
157       // Calculate the frame block and use this for the stack ID symbol context
158       // scope if we have one.
159       SymbolContextScope *scope = GetFrameBlock();
160       if (scope == nullptr) {
161         // We don't have a block, so use the symbol
162         if (m_flags.IsClear(eSymbolContextSymbol))
163           GetSymbolContext(eSymbolContextSymbol);
164 
165         // It is ok if m_sc.symbol is nullptr here
166         scope = m_sc.symbol;
167       }
168       // Set the symbol context scope (the accessor will set the
169       // RESOLVED_FRAME_ID_SYMBOL_SCOPE bit in m_flags).
170       SetSymbolContextScope(scope);
171     }
172   }
173   return m_id;
174 }
175 
176 uint32_t StackFrame::GetFrameIndex() const {
177   ThreadSP thread_sp = GetThread();
178   if (thread_sp)
179     return thread_sp->GetStackFrameList()->GetVisibleStackFrameIndex(
180         m_frame_index);
181   else
182     return m_frame_index;
183 }
184 
185 void StackFrame::SetSymbolContextScope(SymbolContextScope *symbol_scope) {
186   std::lock_guard<std::recursive_mutex> guard(m_mutex);
187   m_flags.Set(RESOLVED_FRAME_ID_SYMBOL_SCOPE);
188   m_id.SetSymbolContextScope(symbol_scope);
189 }
190 
191 const Address &StackFrame::GetFrameCodeAddress() {
192   std::lock_guard<std::recursive_mutex> guard(m_mutex);
193   if (m_flags.IsClear(RESOLVED_FRAME_CODE_ADDR) &&
194       !m_frame_code_addr.IsSectionOffset()) {
195     m_flags.Set(RESOLVED_FRAME_CODE_ADDR);
196 
197     // Resolve the PC into a temporary address because if ResolveLoadAddress
198     // fails to resolve the address, it will clear the address object...
199     ThreadSP thread_sp(GetThread());
200     if (thread_sp) {
201       TargetSP target_sp(thread_sp->CalculateTarget());
202       if (target_sp) {
203         const bool allow_section_end = true;
204         if (m_frame_code_addr.SetOpcodeLoadAddress(
205                 m_frame_code_addr.GetOffset(), target_sp.get(),
206                 AddressClass::eCode, allow_section_end)) {
207           ModuleSP module_sp(m_frame_code_addr.GetModule());
208           if (module_sp) {
209             m_sc.module_sp = module_sp;
210             m_flags.Set(eSymbolContextModule);
211           }
212         }
213       }
214     }
215   }
216   return m_frame_code_addr;
217 }
218 
219 // This can't be rewritten into a call to
220 // RegisterContext::GetPCForSymbolication because this
221 // StackFrame may have been constructed with a special pc,
222 // e.g. tail-call artificial frames.
223 Address StackFrame::GetFrameCodeAddressForSymbolication() {
224   Address lookup_addr(GetFrameCodeAddress());
225   if (!lookup_addr.IsValid())
226     return lookup_addr;
227   if (m_behaves_like_zeroth_frame)
228     return lookup_addr;
229 
230   addr_t offset = lookup_addr.GetOffset();
231   if (offset > 0) {
232     lookup_addr.SetOffset(offset - 1);
233   } else {
234     // lookup_addr is the start of a section.  We need do the math on the
235     // actual load address and re-compute the section.  We're working with
236     // a 'noreturn' function at the end of a section.
237     TargetSP target_sp = CalculateTarget();
238     if (target_sp) {
239       addr_t addr_minus_one = lookup_addr.GetOpcodeLoadAddress(
240                                   target_sp.get(), AddressClass::eCode) -
241                               1;
242       lookup_addr.SetOpcodeLoadAddress(addr_minus_one, target_sp.get());
243     }
244   }
245   return lookup_addr;
246 }
247 
248 bool StackFrame::ChangePC(addr_t pc) {
249   std::lock_guard<std::recursive_mutex> guard(m_mutex);
250   // We can't change the pc value of a history stack frame - it is immutable.
251   if (IsHistorical())
252     return false;
253   m_frame_code_addr.SetRawAddress(pc);
254   m_sc.Clear(false);
255   m_flags.Reset(0);
256   ThreadSP thread_sp(GetThread());
257   if (thread_sp)
258     thread_sp->ClearStackFrames();
259   return true;
260 }
261 
262 const char *StackFrame::Disassemble() {
263   std::lock_guard<std::recursive_mutex> guard(m_mutex);
264   if (!m_disassembly.Empty())
265     return m_disassembly.GetData();
266 
267   ExecutionContext exe_ctx(shared_from_this());
268   if (Target *target = exe_ctx.GetTargetPtr()) {
269     Disassembler::Disassemble(target->GetDebugger(), target->GetArchitecture(),
270                               *this, m_disassembly);
271   }
272 
273   return m_disassembly.Empty() ? nullptr : m_disassembly.GetData();
274 }
275 
276 Block *StackFrame::GetFrameBlock() {
277   if (m_sc.block == nullptr && m_flags.IsClear(eSymbolContextBlock))
278     GetSymbolContext(eSymbolContextBlock);
279 
280   if (m_sc.block) {
281     Block *inline_block = m_sc.block->GetContainingInlinedBlock();
282     if (inline_block) {
283       // Use the block with the inlined function info as the frame block we
284       // want this frame to have only the variables for the inlined function
285       // and its non-inlined block child blocks.
286       return inline_block;
287     } else {
288       // This block is not contained within any inlined function blocks with so
289       // we want to use the top most function block.
290       return &m_sc.function->GetBlock(false);
291     }
292   }
293   return nullptr;
294 }
295 
296 // Get the symbol context if we already haven't done so by resolving the
297 // PC address as much as possible. This way when we pass around a
298 // StackFrame object, everyone will have as much information as possible and no
299 // one will ever have to look things up manually.
300 const SymbolContext &
301 StackFrame::GetSymbolContext(SymbolContextItem resolve_scope) {
302   std::lock_guard<std::recursive_mutex> guard(m_mutex);
303   // Copy our internal symbol context into "sc".
304   if ((m_flags.Get() & resolve_scope) != resolve_scope) {
305     uint32_t resolved = 0;
306 
307     // If the target was requested add that:
308     if (!m_sc.target_sp) {
309       m_sc.target_sp = CalculateTarget();
310       if (m_sc.target_sp)
311         resolved |= eSymbolContextTarget;
312     }
313 
314     // Resolve our PC to section offset if we haven't already done so and if we
315     // don't have a module. The resolved address section will contain the
316     // 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 value
321     // when doing address lookups since the PC will be on the instruction
322     // following the function call instruction...
323     Address lookup_addr(GetFrameCodeAddressForSymbolication());
324 
325     if (m_sc.module_sp) {
326       // We have something in our stack frame symbol context, lets check if we
327       // haven't already tried to lookup one of those things. If we haven't
328       // then we will do the query.
329 
330       SymbolContextItem actual_resolve_scope = SymbolContextItem(0);
331 
332       if (resolve_scope & eSymbolContextCompUnit) {
333         if (m_flags.IsClear(eSymbolContextCompUnit)) {
334           if (m_sc.comp_unit)
335             resolved |= eSymbolContextCompUnit;
336           else
337             actual_resolve_scope |= eSymbolContextCompUnit;
338         }
339       }
340 
341       if (resolve_scope & eSymbolContextFunction) {
342         if (m_flags.IsClear(eSymbolContextFunction)) {
343           if (m_sc.function)
344             resolved |= eSymbolContextFunction;
345           else
346             actual_resolve_scope |= eSymbolContextFunction;
347         }
348       }
349 
350       if (resolve_scope & eSymbolContextBlock) {
351         if (m_flags.IsClear(eSymbolContextBlock)) {
352           if (m_sc.block)
353             resolved |= eSymbolContextBlock;
354           else
355             actual_resolve_scope |= eSymbolContextBlock;
356         }
357       }
358 
359       if (resolve_scope & eSymbolContextSymbol) {
360         if (m_flags.IsClear(eSymbolContextSymbol)) {
361           if (m_sc.symbol)
362             resolved |= eSymbolContextSymbol;
363           else
364             actual_resolve_scope |= eSymbolContextSymbol;
365         }
366       }
367 
368       if (resolve_scope & eSymbolContextLineEntry) {
369         if (m_flags.IsClear(eSymbolContextLineEntry)) {
370           if (m_sc.line_entry.IsValid())
371             resolved |= eSymbolContextLineEntry;
372           else
373             actual_resolve_scope |= eSymbolContextLineEntry;
374         }
375       }
376 
377       if (actual_resolve_scope) {
378         // We might be resolving less information than what is already in our
379         // current symbol context so resolve into a temporary symbol context
380         // "sc" so we don't clear out data we have already found in "m_sc"
381         SymbolContext sc;
382         // Set flags that indicate what we have tried to resolve
383         resolved |= m_sc.module_sp->ResolveSymbolContextForAddress(
384             lookup_addr, actual_resolve_scope, sc);
385         // Only replace what we didn't already have as we may have information
386         // for an inlined function scope that won't match what a standard
387         // lookup by address would match
388         if ((resolved & eSymbolContextCompUnit) && m_sc.comp_unit == nullptr)
389           m_sc.comp_unit = sc.comp_unit;
390         if ((resolved & eSymbolContextFunction) && m_sc.function == nullptr)
391           m_sc.function = sc.function;
392         if ((resolved & eSymbolContextBlock) && m_sc.block == nullptr)
393           m_sc.block = sc.block;
394         if ((resolved & eSymbolContextSymbol) && m_sc.symbol == nullptr)
395           m_sc.symbol = sc.symbol;
396         if ((resolved & eSymbolContextLineEntry) &&
397             !m_sc.line_entry.IsValid()) {
398           m_sc.line_entry = sc.line_entry;
399           m_sc.line_entry.ApplyFileMappings(m_sc.target_sp);
400         }
401       }
402     } else {
403       // If we don't have a module, then we can't have the compile unit,
404       // function, block, line entry or symbol, so we can safely call
405       // ResolveSymbolContextForAddress with our symbol context member m_sc.
406       if (m_sc.target_sp) {
407         resolved |= m_sc.target_sp->GetImages().ResolveSymbolContextForAddress(
408             lookup_addr, resolve_scope, m_sc);
409       }
410     }
411 
412     // Update our internal flags so we remember what we have tried to locate so
413     // we don't have to keep trying when more calls to this function are made.
414     // We might have dug up more information that was requested (for example if
415     // we were asked to only get the block, we will have gotten the compile
416     // unit, and function) so set any additional bits that we resolved
417     m_flags.Set(resolve_scope | resolved);
418   }
419 
420   // Return the symbol context with everything that was possible to resolve
421   // resolved.
422   return m_sc;
423 }
424 
425 VariableList *StackFrame::GetVariableList(bool get_file_globals,
426                                           Status *error_ptr) {
427   std::lock_guard<std::recursive_mutex> guard(m_mutex);
428   if (m_flags.IsClear(RESOLVED_VARIABLES)) {
429     m_flags.Set(RESOLVED_VARIABLES);
430     m_variable_list_sp = std::make_shared<VariableList>();
431 
432     Block *frame_block = GetFrameBlock();
433 
434     if (frame_block) {
435       const bool get_child_variables = true;
436       const bool can_create = true;
437       const bool stop_if_child_block_is_inlined_function = true;
438       frame_block->AppendBlockVariables(can_create, get_child_variables,
439                                         stop_if_child_block_is_inlined_function,
440                                         [](Variable *v) { return true; },
441                                         m_variable_list_sp.get());
442     }
443   }
444 
445   if (m_flags.IsClear(RESOLVED_GLOBAL_VARIABLES) && get_file_globals) {
446     m_flags.Set(RESOLVED_GLOBAL_VARIABLES);
447 
448     if (m_flags.IsClear(eSymbolContextCompUnit))
449       GetSymbolContext(eSymbolContextCompUnit);
450 
451     if (m_sc.comp_unit) {
452       VariableListSP global_variable_list_sp(
453           m_sc.comp_unit->GetVariableList(true));
454       if (m_variable_list_sp)
455         m_variable_list_sp->AddVariables(global_variable_list_sp.get());
456       else
457         m_variable_list_sp = global_variable_list_sp;
458     }
459   }
460 
461   if (error_ptr && m_variable_list_sp->GetSize() == 0) {
462     // Check with the symbol file to check if there is an error for why we
463     // don't have variables that the user might need to know about.
464     GetSymbolContext(eSymbolContextEverything);
465     if (m_sc.module_sp) {
466       SymbolFile *sym_file = m_sc.module_sp->GetSymbolFile();
467       if (sym_file)
468         *error_ptr = sym_file->GetFrameVariableError(*this);
469     }
470   }
471 
472   return m_variable_list_sp.get();
473 }
474 
475 VariableListSP
476 StackFrame::GetInScopeVariableList(bool get_file_globals,
477                                    bool must_have_valid_location) {
478   std::lock_guard<std::recursive_mutex> guard(m_mutex);
479   // We can't fetch variable information for a history stack frame.
480   if (IsHistorical())
481     return VariableListSP();
482 
483   VariableListSP var_list_sp(new VariableList);
484   GetSymbolContext(eSymbolContextCompUnit | eSymbolContextBlock);
485 
486   if (m_sc.block) {
487     const bool can_create = true;
488     const bool get_parent_variables = true;
489     const bool stop_if_block_is_inlined_function = true;
490     m_sc.block->AppendVariables(
491         can_create, get_parent_variables, stop_if_block_is_inlined_function,
492         [this, must_have_valid_location](Variable *v) {
493           return v->IsInScope(this) && (!must_have_valid_location ||
494                                         v->LocationIsValidForFrame(this));
495         },
496         var_list_sp.get());
497   }
498 
499   if (m_sc.comp_unit && get_file_globals) {
500     VariableListSP global_variable_list_sp(
501         m_sc.comp_unit->GetVariableList(true));
502     if (global_variable_list_sp)
503       var_list_sp->AddVariables(global_variable_list_sp.get());
504   }
505 
506   return var_list_sp;
507 }
508 
509 ValueObjectSP StackFrame::GetValueForVariableExpressionPath(
510     llvm::StringRef var_expr, DynamicValueType use_dynamic, uint32_t options,
511     VariableSP &var_sp, Status &error) {
512   ExecutionContext exe_ctx;
513   CalculateExecutionContext(exe_ctx);
514   bool use_DIL = exe_ctx.GetTargetRef().GetUseDIL(&exe_ctx);
515   if (use_DIL)
516     return DILGetValueForVariableExpressionPath(var_expr, use_dynamic, options,
517                                                 var_sp, error);
518 
519   return LegacyGetValueForVariableExpressionPath(var_expr, use_dynamic, options,
520                                                  var_sp, error);
521 }
522 
523 ValueObjectSP StackFrame::DILGetValueForVariableExpressionPath(
524     llvm::StringRef var_expr, lldb::DynamicValueType use_dynamic,
525     uint32_t options, lldb::VariableSP &var_sp, Status &error) {
526   // This is a place-holder for the calls into the DIL parser and
527   // evaluator.  For now, just call the "real" frame variable implementation.
528   return LegacyGetValueForVariableExpressionPath(var_expr, use_dynamic, options,
529                                                  var_sp, error);
530 }
531 
532 ValueObjectSP StackFrame::LegacyGetValueForVariableExpressionPath(
533     llvm::StringRef var_expr, DynamicValueType use_dynamic, uint32_t options,
534     VariableSP &var_sp, Status &error) {
535   llvm::StringRef original_var_expr = var_expr;
536   // We can't fetch variable information for a history stack frame.
537   if (IsHistorical())
538     return ValueObjectSP();
539 
540   if (var_expr.empty()) {
541     error = Status::FromErrorStringWithFormatv("invalid variable path '{0}'",
542                                                var_expr);
543     return ValueObjectSP();
544   }
545 
546   const bool check_ptr_vs_member =
547       (options & eExpressionPathOptionCheckPtrVsMember) != 0;
548   const bool no_fragile_ivar =
549       (options & eExpressionPathOptionsNoFragileObjcIvar) != 0;
550   const bool no_synth_child =
551       (options & eExpressionPathOptionsNoSyntheticChildren) != 0;
552   // const bool no_synth_array = (options &
553   // eExpressionPathOptionsNoSyntheticArrayRange) != 0;
554   error.Clear();
555   bool deref = false;
556   bool address_of = false;
557   ValueObjectSP valobj_sp;
558   const bool get_file_globals = true;
559   // When looking up a variable for an expression, we need only consider the
560   // variables that are in scope.
561   VariableListSP var_list_sp(GetInScopeVariableList(get_file_globals));
562   VariableList *variable_list = var_list_sp.get();
563 
564   if (!variable_list)
565     return ValueObjectSP();
566 
567   // If first character is a '*', then show pointer contents
568   std::string var_expr_storage;
569   if (var_expr[0] == '*') {
570     deref = true;
571     var_expr = var_expr.drop_front(); // Skip the '*'
572   } else if (var_expr[0] == '&') {
573     address_of = true;
574     var_expr = var_expr.drop_front(); // Skip the '&'
575   }
576 
577   size_t separator_idx = var_expr.find_first_of(".-[=+~|&^%#@!/?,<>{}");
578   StreamString var_expr_path_strm;
579 
580   ConstString name_const_string(var_expr.substr(0, separator_idx));
581 
582   var_sp = variable_list->FindVariable(name_const_string, false);
583 
584   bool synthetically_added_instance_object = false;
585 
586   if (var_sp) {
587     var_expr = var_expr.drop_front(name_const_string.GetLength());
588   }
589 
590   if (!var_sp && (options & eExpressionPathOptionsAllowDirectIVarAccess)) {
591     // Check for direct ivars access which helps us with implicit access to
592     // ivars using "this" or "self".
593     GetSymbolContext(eSymbolContextFunction | eSymbolContextBlock);
594     llvm::StringRef instance_var_name = m_sc.GetInstanceVariableName();
595     if (!instance_var_name.empty()) {
596       var_sp = variable_list->FindVariable(ConstString(instance_var_name));
597       if (var_sp) {
598         separator_idx = 0;
599         if (Type *var_type = var_sp->GetType())
600           if (auto compiler_type = var_type->GetForwardCompilerType())
601             if (!compiler_type.IsPointerType())
602               var_expr_storage = ".";
603 
604         if (var_expr_storage.empty())
605           var_expr_storage = "->";
606         var_expr_storage += var_expr;
607         var_expr = var_expr_storage;
608         synthetically_added_instance_object = true;
609       }
610     }
611   }
612 
613   if (!var_sp && (options & eExpressionPathOptionsInspectAnonymousUnions)) {
614     // Check if any anonymous unions are there which contain a variable with
615     // the name we need
616     for (const VariableSP &variable_sp : *variable_list) {
617       if (!variable_sp)
618         continue;
619       if (!variable_sp->GetName().IsEmpty())
620         continue;
621 
622       Type *var_type = variable_sp->GetType();
623       if (!var_type)
624         continue;
625 
626       if (!var_type->GetForwardCompilerType().IsAnonymousType())
627         continue;
628       valobj_sp = GetValueObjectForFrameVariable(variable_sp, use_dynamic);
629       if (!valobj_sp)
630         return valobj_sp;
631       valobj_sp = valobj_sp->GetChildMemberWithName(name_const_string);
632       if (valobj_sp)
633         break;
634     }
635   }
636 
637   if (var_sp && !valobj_sp) {
638     valobj_sp = GetValueObjectForFrameVariable(var_sp, use_dynamic);
639     if (!valobj_sp)
640       return valobj_sp;
641   }
642   if (!valobj_sp) {
643     error = Status::FromErrorStringWithFormatv(
644         "no variable named '{0}' found in this frame", name_const_string);
645     return ValueObjectSP();
646   }
647 
648   // We are dumping at least one child
649   while (!var_expr.empty()) {
650     // Calculate the next separator index ahead of time
651     ValueObjectSP child_valobj_sp;
652     const char separator_type = var_expr[0];
653     bool expr_is_ptr = false;
654     switch (separator_type) {
655     case '-':
656       expr_is_ptr = true;
657       if (var_expr.size() >= 2 && var_expr[1] != '>')
658         return ValueObjectSP();
659 
660       if (no_fragile_ivar) {
661         // Make sure we aren't trying to deref an objective
662         // C ivar if this is not allowed
663         const uint32_t pointer_type_flags =
664             valobj_sp->GetCompilerType().GetTypeInfo(nullptr);
665         if ((pointer_type_flags & eTypeIsObjC) &&
666             (pointer_type_flags & eTypeIsPointer)) {
667           // This was an objective C object pointer and it was requested we
668           // skip any fragile ivars so return nothing here
669           return ValueObjectSP();
670         }
671       }
672 
673       // If we have a non-pointer type with a synthetic value then lets check if
674       // we have a synthetic dereference specified.
675       if (!valobj_sp->IsPointerType() && valobj_sp->HasSyntheticValue()) {
676         Status deref_error;
677         if (valobj_sp->GetCompilerType().IsReferenceType()) {
678           valobj_sp = valobj_sp->GetSyntheticValue()->Dereference(deref_error);
679           if (!valobj_sp || deref_error.Fail()) {
680             error = Status::FromErrorStringWithFormatv(
681                 "Failed to dereference reference type: {0}", deref_error);
682             return ValueObjectSP();
683           }
684         }
685 
686         valobj_sp = valobj_sp->Dereference(deref_error);
687         if (!valobj_sp || deref_error.Fail()) {
688           error = Status::FromErrorStringWithFormatv(
689               "Failed to dereference synthetic value: {0}", deref_error);
690           return ValueObjectSP();
691         }
692         // Some synthetic plug-ins fail to set the error in Dereference
693         if (!valobj_sp) {
694           error =
695               Status::FromErrorString("Failed to dereference synthetic value");
696           return ValueObjectSP();
697         }
698         expr_is_ptr = false;
699       }
700 
701       var_expr = var_expr.drop_front(); // Remove the '-'
702       [[fallthrough]];
703     case '.': {
704       var_expr = var_expr.drop_front(); // Remove the '.' or '>'
705       separator_idx = var_expr.find_first_of(".-[");
706       ConstString child_name(var_expr.substr(0, var_expr.find_first_of(".-[")));
707 
708       if (check_ptr_vs_member) {
709         // We either have a pointer type and need to verify valobj_sp is a
710         // pointer, or we have a member of a class/union/struct being accessed
711         // with the . syntax and need to verify we don't have a pointer.
712         const bool actual_is_ptr = valobj_sp->IsPointerType();
713 
714         if (actual_is_ptr != expr_is_ptr) {
715           // Incorrect use of "." with a pointer, or "->" with a
716           // class/union/struct instance or reference.
717           valobj_sp->GetExpressionPath(var_expr_path_strm);
718           if (actual_is_ptr)
719             error = Status::FromErrorStringWithFormat(
720                 "\"%s\" is a pointer and . was used to attempt to access "
721                 "\"%s\". Did you mean \"%s->%s\"?",
722                 var_expr_path_strm.GetData(), child_name.GetCString(),
723                 var_expr_path_strm.GetData(), var_expr.str().c_str());
724           else
725             error = Status::FromErrorStringWithFormat(
726                 "\"%s\" is not a pointer and -> was used to attempt to "
727                 "access \"%s\". Did you mean \"%s.%s\"?",
728                 var_expr_path_strm.GetData(), child_name.GetCString(),
729                 var_expr_path_strm.GetData(), var_expr.str().c_str());
730           return ValueObjectSP();
731         }
732       }
733       child_valobj_sp = valobj_sp->GetChildMemberWithName(child_name);
734       if (!child_valobj_sp) {
735         if (!no_synth_child) {
736           child_valobj_sp = valobj_sp->GetSyntheticValue();
737           if (child_valobj_sp)
738             child_valobj_sp =
739                 child_valobj_sp->GetChildMemberWithName(child_name);
740         }
741 
742         if (no_synth_child || !child_valobj_sp) {
743           // No child member with name "child_name"
744           if (synthetically_added_instance_object) {
745             // We added a "this->" or "self->" to the beginning of the
746             // expression and this is the first pointer ivar access, so just
747             // return the normal error
748             error = Status::FromErrorStringWithFormat(
749                 "no variable or instance variable named '%s' found in "
750                 "this frame",
751                 name_const_string.GetCString());
752           } else {
753             valobj_sp->GetExpressionPath(var_expr_path_strm);
754             if (child_name) {
755               error = Status::FromErrorStringWithFormat(
756                   "\"%s\" is not a member of \"(%s) %s\"",
757                   child_name.GetCString(),
758                   valobj_sp->GetTypeName().AsCString("<invalid type>"),
759                   var_expr_path_strm.GetData());
760             } else {
761               error = Status::FromErrorStringWithFormat(
762                   "incomplete expression path after \"%s\" in \"%s\"",
763                   var_expr_path_strm.GetData(),
764                   original_var_expr.str().c_str());
765             }
766           }
767           return ValueObjectSP();
768         }
769       }
770       synthetically_added_instance_object = false;
771       // Remove the child name from the path
772       var_expr = var_expr.drop_front(child_name.GetLength());
773       if (use_dynamic != eNoDynamicValues) {
774         ValueObjectSP dynamic_value_sp(
775             child_valobj_sp->GetDynamicValue(use_dynamic));
776         if (dynamic_value_sp)
777           child_valobj_sp = dynamic_value_sp;
778       }
779     } break;
780 
781     case '[': {
782       // Array member access, or treating pointer as an array Need at least two
783       // brackets and a number
784       if (var_expr.size() <= 2) {
785         error = Status::FromErrorStringWithFormat(
786             "invalid square bracket encountered after \"%s\" in \"%s\"",
787             var_expr_path_strm.GetData(), var_expr.str().c_str());
788         return ValueObjectSP();
789       }
790 
791       // Drop the open brace.
792       var_expr = var_expr.drop_front();
793       long child_index = 0;
794 
795       // If there's no closing brace, this is an invalid expression.
796       size_t end_pos = var_expr.find_first_of(']');
797       if (end_pos == llvm::StringRef::npos) {
798         error = Status::FromErrorStringWithFormat(
799             "missing closing square bracket in expression \"%s\"",
800             var_expr_path_strm.GetData());
801         return ValueObjectSP();
802       }
803       llvm::StringRef index_expr = var_expr.take_front(end_pos);
804       llvm::StringRef original_index_expr = index_expr;
805       // Drop all of "[index_expr]"
806       var_expr = var_expr.drop_front(end_pos + 1);
807 
808       if (index_expr.consumeInteger(0, child_index)) {
809         // If there was no integer anywhere in the index expression, this is
810         // erroneous expression.
811         error = Status::FromErrorStringWithFormat(
812             "invalid index expression \"%s\"", index_expr.str().c_str());
813         return ValueObjectSP();
814       }
815 
816       if (index_expr.empty()) {
817         // The entire index expression was a single integer.
818 
819         if (valobj_sp->GetCompilerType().IsPointerToScalarType() && deref) {
820           // what we have is *ptr[low]. the most similar C++ syntax is to deref
821           // ptr and extract bit low out of it. reading array item low would be
822           // done by saying ptr[low], without a deref * sign
823           Status deref_error;
824           ValueObjectSP temp(valobj_sp->Dereference(deref_error));
825           if (!temp || deref_error.Fail()) {
826             valobj_sp->GetExpressionPath(var_expr_path_strm);
827             error = Status::FromErrorStringWithFormat(
828                 "could not dereference \"(%s) %s\"",
829                 valobj_sp->GetTypeName().AsCString("<invalid type>"),
830                 var_expr_path_strm.GetData());
831             return ValueObjectSP();
832           }
833           valobj_sp = temp;
834           deref = false;
835         } else if (valobj_sp->GetCompilerType().IsArrayOfScalarType() &&
836                    deref) {
837           // what we have is *arr[low]. the most similar C++ syntax is to get
838           // arr[0] (an operation that is equivalent to deref-ing arr) and
839           // extract bit low out of it. reading array item low would be done by
840           // saying arr[low], without a deref * sign
841           ValueObjectSP temp(valobj_sp->GetChildAtIndex(0));
842           if (!temp) {
843             valobj_sp->GetExpressionPath(var_expr_path_strm);
844             error = Status::FromErrorStringWithFormat(
845                 "could not get item 0 for \"(%s) %s\"",
846                 valobj_sp->GetTypeName().AsCString("<invalid type>"),
847                 var_expr_path_strm.GetData());
848             return ValueObjectSP();
849           }
850           valobj_sp = temp;
851           deref = false;
852         }
853 
854         bool is_incomplete_array = false;
855         if (valobj_sp->IsPointerType()) {
856           bool is_objc_pointer = true;
857 
858           if (valobj_sp->GetCompilerType().GetMinimumLanguage() !=
859               eLanguageTypeObjC)
860             is_objc_pointer = false;
861           else if (!valobj_sp->GetCompilerType().IsPointerType())
862             is_objc_pointer = false;
863 
864           if (no_synth_child && is_objc_pointer) {
865             error = Status::FromErrorStringWithFormat(
866                 "\"(%s) %s\" is an Objective-C pointer, and cannot be "
867                 "subscripted",
868                 valobj_sp->GetTypeName().AsCString("<invalid type>"),
869                 var_expr_path_strm.GetData());
870 
871             return ValueObjectSP();
872           } else if (is_objc_pointer) {
873             // dereferencing ObjC variables is not valid.. so let's try and
874             // recur to synthetic children
875             ValueObjectSP synthetic = valobj_sp->GetSyntheticValue();
876             if (!synthetic                 /* no synthetic */
877                 || synthetic == valobj_sp) /* synthetic is the same as
878                                               the original object */
879             {
880               valobj_sp->GetExpressionPath(var_expr_path_strm);
881               error = Status::FromErrorStringWithFormat(
882                   "\"(%s) %s\" is not an array type",
883                   valobj_sp->GetTypeName().AsCString("<invalid type>"),
884                   var_expr_path_strm.GetData());
885             } else if (static_cast<uint32_t>(child_index) >=
886                        synthetic
887                            ->GetNumChildrenIgnoringErrors() /* synthetic does
888                                                                 not have that
889                                                                 many values */) {
890               valobj_sp->GetExpressionPath(var_expr_path_strm);
891               error = Status::FromErrorStringWithFormat(
892                   "array index %ld is not valid for \"(%s) %s\"", child_index,
893                   valobj_sp->GetTypeName().AsCString("<invalid type>"),
894                   var_expr_path_strm.GetData());
895             } else {
896               child_valobj_sp = synthetic->GetChildAtIndex(child_index);
897               if (!child_valobj_sp) {
898                 valobj_sp->GetExpressionPath(var_expr_path_strm);
899                 error = Status::FromErrorStringWithFormat(
900                     "array index %ld is not valid for \"(%s) %s\"", child_index,
901                     valobj_sp->GetTypeName().AsCString("<invalid type>"),
902                     var_expr_path_strm.GetData());
903               }
904             }
905           } else {
906             child_valobj_sp =
907                 valobj_sp->GetSyntheticArrayMember(child_index, true);
908             if (!child_valobj_sp) {
909               valobj_sp->GetExpressionPath(var_expr_path_strm);
910               error = Status::FromErrorStringWithFormat(
911                   "failed to use pointer as array for index %ld for "
912                   "\"(%s) %s\"",
913                   child_index,
914                   valobj_sp->GetTypeName().AsCString("<invalid type>"),
915                   var_expr_path_strm.GetData());
916             }
917           }
918         } else if (valobj_sp->GetCompilerType().IsArrayType(
919                        nullptr, nullptr, &is_incomplete_array)) {
920           // Pass false to dynamic_value here so we can tell the difference
921           // between no dynamic value and no member of this type...
922           child_valobj_sp = valobj_sp->GetChildAtIndex(child_index);
923           if (!child_valobj_sp && (is_incomplete_array || !no_synth_child))
924             child_valobj_sp =
925                 valobj_sp->GetSyntheticArrayMember(child_index, true);
926 
927           if (!child_valobj_sp) {
928             valobj_sp->GetExpressionPath(var_expr_path_strm);
929             error = Status::FromErrorStringWithFormat(
930                 "array index %ld is not valid for \"(%s) %s\"", child_index,
931                 valobj_sp->GetTypeName().AsCString("<invalid type>"),
932                 var_expr_path_strm.GetData());
933           }
934         } else if (valobj_sp->GetCompilerType().IsScalarType()) {
935           // this is a bitfield asking to display just one bit
936           child_valobj_sp = valobj_sp->GetSyntheticBitFieldChild(
937               child_index, child_index, true);
938           if (!child_valobj_sp) {
939             valobj_sp->GetExpressionPath(var_expr_path_strm);
940             error = Status::FromErrorStringWithFormat(
941                 "bitfield range %ld-%ld is not valid for \"(%s) %s\"",
942                 child_index, child_index,
943                 valobj_sp->GetTypeName().AsCString("<invalid type>"),
944                 var_expr_path_strm.GetData());
945           }
946         } else {
947           ValueObjectSP synthetic = valobj_sp->GetSyntheticValue();
948           if (no_synth_child /* synthetic is forbidden */ ||
949               !synthetic                 /* no synthetic */
950               || synthetic == valobj_sp) /* synthetic is the same as the
951                                             original object */
952           {
953             valobj_sp->GetExpressionPath(var_expr_path_strm);
954             error = Status::FromErrorStringWithFormat(
955                 "\"(%s) %s\" is not an array type",
956                 valobj_sp->GetTypeName().AsCString("<invalid type>"),
957                 var_expr_path_strm.GetData());
958           } else if (static_cast<uint32_t>(child_index) >=
959                      synthetic->GetNumChildrenIgnoringErrors() /* synthetic
960                                      does not have that many values */) {
961             valobj_sp->GetExpressionPath(var_expr_path_strm);
962             error = Status::FromErrorStringWithFormat(
963                 "array index %ld is not valid for \"(%s) %s\"", child_index,
964                 valobj_sp->GetTypeName().AsCString("<invalid type>"),
965                 var_expr_path_strm.GetData());
966           } else {
967             child_valobj_sp = synthetic->GetChildAtIndex(child_index);
968             if (!child_valobj_sp) {
969               valobj_sp->GetExpressionPath(var_expr_path_strm);
970               error = Status::FromErrorStringWithFormat(
971                   "array index %ld is not valid for \"(%s) %s\"", child_index,
972                   valobj_sp->GetTypeName().AsCString("<invalid type>"),
973                   var_expr_path_strm.GetData());
974             }
975           }
976         }
977 
978         if (!child_valobj_sp) {
979           // Invalid array index...
980           return ValueObjectSP();
981         }
982 
983         if (use_dynamic != eNoDynamicValues) {
984           ValueObjectSP dynamic_value_sp(
985               child_valobj_sp->GetDynamicValue(use_dynamic));
986           if (dynamic_value_sp)
987             child_valobj_sp = dynamic_value_sp;
988         }
989         // Break out early from the switch since we were able to find the child
990         // member
991         break;
992       }
993 
994       // this is most probably a BitField, let's take a look
995       if (index_expr.front() != '-') {
996         error = Status::FromErrorStringWithFormat(
997             "invalid range expression \"'%s'\"",
998             original_index_expr.str().c_str());
999         return ValueObjectSP();
1000       }
1001 
1002       index_expr = index_expr.drop_front();
1003       long final_index = 0;
1004       if (index_expr.getAsInteger(0, final_index)) {
1005         error = Status::FromErrorStringWithFormat(
1006             "invalid range expression \"'%s'\"",
1007             original_index_expr.str().c_str());
1008         return ValueObjectSP();
1009       }
1010 
1011       // if the format given is [high-low], swap range
1012       if (child_index > final_index) {
1013         long temp = child_index;
1014         child_index = final_index;
1015         final_index = temp;
1016       }
1017 
1018       if (valobj_sp->GetCompilerType().IsPointerToScalarType() && deref) {
1019         // what we have is *ptr[low-high]. the most similar C++ syntax is to
1020         // deref ptr and extract bits low thru high out of it. reading array
1021         // items low thru high would be done by saying ptr[low-high], without a
1022         // deref * sign
1023         Status deref_error;
1024         ValueObjectSP temp(valobj_sp->Dereference(deref_error));
1025         if (!temp || deref_error.Fail()) {
1026           valobj_sp->GetExpressionPath(var_expr_path_strm);
1027           error = Status::FromErrorStringWithFormat(
1028               "could not dereference \"(%s) %s\"",
1029               valobj_sp->GetTypeName().AsCString("<invalid type>"),
1030               var_expr_path_strm.GetData());
1031           return ValueObjectSP();
1032         }
1033         valobj_sp = temp;
1034         deref = false;
1035       } else if (valobj_sp->GetCompilerType().IsArrayOfScalarType() && deref) {
1036         // what we have is *arr[low-high]. the most similar C++ syntax is to
1037         // get arr[0] (an operation that is equivalent to deref-ing arr) and
1038         // extract bits low thru high out of it. reading array items low thru
1039         // high would be done by saying arr[low-high], without a deref * sign
1040         ValueObjectSP temp(valobj_sp->GetChildAtIndex(0));
1041         if (!temp) {
1042           valobj_sp->GetExpressionPath(var_expr_path_strm);
1043           error = Status::FromErrorStringWithFormat(
1044               "could not get item 0 for \"(%s) %s\"",
1045               valobj_sp->GetTypeName().AsCString("<invalid type>"),
1046               var_expr_path_strm.GetData());
1047           return ValueObjectSP();
1048         }
1049         valobj_sp = temp;
1050         deref = false;
1051       }
1052 
1053       child_valobj_sp =
1054           valobj_sp->GetSyntheticBitFieldChild(child_index, final_index, true);
1055       if (!child_valobj_sp) {
1056         valobj_sp->GetExpressionPath(var_expr_path_strm);
1057         error = Status::FromErrorStringWithFormat(
1058             "bitfield range %ld-%ld is not valid for \"(%s) %s\"", child_index,
1059             final_index, valobj_sp->GetTypeName().AsCString("<invalid type>"),
1060             var_expr_path_strm.GetData());
1061       }
1062 
1063       if (!child_valobj_sp) {
1064         // Invalid bitfield range...
1065         return ValueObjectSP();
1066       }
1067 
1068       if (use_dynamic != eNoDynamicValues) {
1069         ValueObjectSP dynamic_value_sp(
1070             child_valobj_sp->GetDynamicValue(use_dynamic));
1071         if (dynamic_value_sp)
1072           child_valobj_sp = dynamic_value_sp;
1073       }
1074       // Break out early from the switch since we were able to find the child
1075       // member
1076       break;
1077     }
1078     default:
1079       // Failure...
1080       {
1081         valobj_sp->GetExpressionPath(var_expr_path_strm);
1082         error = Status::FromErrorStringWithFormat(
1083             "unexpected char '%c' encountered after \"%s\" in \"%s\"",
1084             separator_type, var_expr_path_strm.GetData(),
1085             var_expr.str().c_str());
1086 
1087         return ValueObjectSP();
1088       }
1089     }
1090 
1091     if (child_valobj_sp)
1092       valobj_sp = child_valobj_sp;
1093   }
1094   if (valobj_sp) {
1095     if (deref) {
1096       ValueObjectSP deref_valobj_sp(valobj_sp->Dereference(error));
1097       valobj_sp = deref_valobj_sp;
1098     } else if (address_of) {
1099       ValueObjectSP address_of_valobj_sp(valobj_sp->AddressOf(error));
1100       valobj_sp = address_of_valobj_sp;
1101     }
1102   }
1103   return valobj_sp;
1104 }
1105 
1106 llvm::Error StackFrame::GetFrameBaseValue(Scalar &frame_base) {
1107   std::lock_guard<std::recursive_mutex> guard(m_mutex);
1108   if (!m_cfa_is_valid) {
1109     m_frame_base_error = Status::FromErrorString(
1110         "No frame base available for this historical stack frame.");
1111     return m_frame_base_error.ToError();
1112   }
1113 
1114   if (m_flags.IsClear(GOT_FRAME_BASE)) {
1115     if (m_sc.function) {
1116       m_frame_base.Clear();
1117       m_frame_base_error.Clear();
1118 
1119       m_flags.Set(GOT_FRAME_BASE);
1120       ExecutionContext exe_ctx(shared_from_this());
1121       addr_t loclist_base_addr = LLDB_INVALID_ADDRESS;
1122       if (!m_sc.function->GetFrameBaseExpression().IsAlwaysValidSingleExpr())
1123         loclist_base_addr =
1124             m_sc.function->GetAddress().GetLoadAddress(exe_ctx.GetTargetPtr());
1125 
1126       llvm::Expected<Value> expr_value =
1127           m_sc.function->GetFrameBaseExpression().Evaluate(
1128               &exe_ctx, nullptr, loclist_base_addr, nullptr, nullptr);
1129       if (!expr_value)
1130         m_frame_base_error = Status::FromError(expr_value.takeError());
1131       else
1132         m_frame_base = expr_value->ResolveValue(&exe_ctx);
1133     } else {
1134       m_frame_base_error =
1135           Status::FromErrorString("No function in symbol context.");
1136     }
1137   }
1138 
1139   if (m_frame_base_error.Fail())
1140     return m_frame_base_error.ToError();
1141 
1142   frame_base = m_frame_base;
1143   return llvm::Error::success();
1144 }
1145 
1146 DWARFExpressionList *StackFrame::GetFrameBaseExpression(Status *error_ptr) {
1147   if (!m_sc.function) {
1148     if (error_ptr) {
1149       *error_ptr = Status::FromErrorString("No function in symbol context.");
1150     }
1151     return nullptr;
1152   }
1153 
1154   return &m_sc.function->GetFrameBaseExpression();
1155 }
1156 
1157 RegisterContextSP StackFrame::GetRegisterContext() {
1158   std::lock_guard<std::recursive_mutex> guard(m_mutex);
1159   if (!m_reg_context_sp) {
1160     ThreadSP thread_sp(GetThread());
1161     if (thread_sp)
1162       m_reg_context_sp = thread_sp->CreateRegisterContextForFrame(this);
1163   }
1164   return m_reg_context_sp;
1165 }
1166 
1167 bool StackFrame::HasDebugInformation() {
1168   GetSymbolContext(eSymbolContextLineEntry);
1169   return m_sc.line_entry.IsValid();
1170 }
1171 
1172 ValueObjectSP
1173 StackFrame::GetValueObjectForFrameVariable(const VariableSP &variable_sp,
1174                                            DynamicValueType use_dynamic) {
1175   ValueObjectSP valobj_sp;
1176   { // Scope for stack frame mutex.  We need to drop this mutex before we figure
1177     // out the dynamic value.  That will require converting the StackID in the
1178     // VO back to a StackFrame, which will in turn require locking the
1179     // StackFrameList.  If we still hold the StackFrame mutex, we could suffer
1180     // lock inversion against the pattern of getting the StackFrameList and
1181     // then the stack frame, which is fairly common.
1182     std::lock_guard<std::recursive_mutex> guard(m_mutex);
1183     if (IsHistorical()) {
1184       return valobj_sp;
1185     }
1186     VariableList *var_list = GetVariableList(true, nullptr);
1187     if (var_list) {
1188       // Make sure the variable is a frame variable
1189       const uint32_t var_idx = var_list->FindIndexForVariable(variable_sp.get());
1190       const uint32_t num_variables = var_list->GetSize();
1191       if (var_idx < num_variables) {
1192         valobj_sp = m_variable_list_value_objects.GetValueObjectAtIndex(var_idx);
1193         if (!valobj_sp) {
1194           if (m_variable_list_value_objects.GetSize() < num_variables)
1195             m_variable_list_value_objects.Resize(num_variables);
1196           valobj_sp = ValueObjectVariable::Create(this, variable_sp);
1197           m_variable_list_value_objects.SetValueObjectAtIndex(var_idx,
1198                                                               valobj_sp);
1199         }
1200       }
1201     }
1202   } // End of StackFrame mutex scope.
1203   if (use_dynamic != eNoDynamicValues && valobj_sp) {
1204     ValueObjectSP dynamic_sp = valobj_sp->GetDynamicValue(use_dynamic);
1205     if (dynamic_sp)
1206       return dynamic_sp;
1207   }
1208   return valobj_sp;
1209 }
1210 
1211 bool StackFrame::IsInlined() {
1212   if (m_sc.block == nullptr)
1213     GetSymbolContext(eSymbolContextBlock);
1214   if (m_sc.block)
1215     return m_sc.block->GetContainingInlinedBlock() != nullptr;
1216   return false;
1217 }
1218 
1219 bool StackFrame::IsHistorical() const {
1220   return m_stack_frame_kind == StackFrame::Kind::History;
1221 }
1222 
1223 bool StackFrame::IsArtificial() const {
1224   return m_stack_frame_kind == StackFrame::Kind::Artificial;
1225 }
1226 
1227 bool StackFrame::IsHidden() {
1228   if (auto recognized_frame_sp = GetRecognizedFrame())
1229     return recognized_frame_sp->ShouldHide();
1230   return false;
1231 }
1232 
1233 StructuredData::ObjectSP StackFrame::GetLanguageSpecificData() {
1234   auto process_sp = CalculateProcess();
1235   SourceLanguage language = GetLanguage();
1236   if (!language)
1237     return {};
1238   if (auto runtime_sp =
1239           process_sp->GetLanguageRuntime(language.AsLanguageType()))
1240     return runtime_sp->GetLanguageSpecificData(
1241         GetSymbolContext(eSymbolContextFunction));
1242   return {};
1243 }
1244 
1245 const char *StackFrame::GetFunctionName() {
1246   const char *name = nullptr;
1247   SymbolContext sc = GetSymbolContext(
1248       eSymbolContextFunction | eSymbolContextBlock | eSymbolContextSymbol);
1249   if (sc.block) {
1250     Block *inlined_block = sc.block->GetContainingInlinedBlock();
1251     if (inlined_block) {
1252       const InlineFunctionInfo *inlined_info =
1253           inlined_block->GetInlinedFunctionInfo();
1254       if (inlined_info)
1255         name = inlined_info->GetName().AsCString();
1256     }
1257   }
1258 
1259   if (name == nullptr) {
1260     if (sc.function)
1261       name = sc.function->GetName().GetCString();
1262   }
1263 
1264   if (name == nullptr) {
1265     if (sc.symbol)
1266       name = sc.symbol->GetName().GetCString();
1267   }
1268 
1269   return name;
1270 }
1271 
1272 const char *StackFrame::GetDisplayFunctionName() {
1273   const char *name = nullptr;
1274   SymbolContext sc = GetSymbolContext(
1275       eSymbolContextFunction | eSymbolContextBlock | eSymbolContextSymbol);
1276   if (sc.block) {
1277     Block *inlined_block = sc.block->GetContainingInlinedBlock();
1278     if (inlined_block) {
1279       const InlineFunctionInfo *inlined_info =
1280           inlined_block->GetInlinedFunctionInfo();
1281       if (inlined_info)
1282         name = inlined_info->GetDisplayName().AsCString();
1283     }
1284   }
1285 
1286   if (name == nullptr) {
1287     if (sc.function)
1288       name = sc.function->GetDisplayName().GetCString();
1289   }
1290 
1291   if (name == nullptr) {
1292     if (sc.symbol)
1293       name = sc.symbol->GetDisplayName().GetCString();
1294   }
1295   return name;
1296 }
1297 
1298 SourceLanguage StackFrame::GetLanguage() {
1299   CompileUnit *cu = GetSymbolContext(eSymbolContextCompUnit).comp_unit;
1300   if (cu)
1301     return cu->GetLanguage();
1302   return {};
1303 }
1304 
1305 SourceLanguage StackFrame::GuessLanguage() {
1306   SourceLanguage lang_type = GetLanguage();
1307 
1308   if (lang_type == eLanguageTypeUnknown) {
1309     SymbolContext sc =
1310         GetSymbolContext(eSymbolContextFunction | eSymbolContextSymbol);
1311     if (sc.function)
1312       lang_type = LanguageType(sc.function->GetMangled().GuessLanguage());
1313     else if (sc.symbol)
1314       lang_type = SourceLanguage(sc.symbol->GetMangled().GuessLanguage());
1315   }
1316 
1317   return lang_type;
1318 }
1319 
1320 namespace {
1321 std::pair<const Instruction::Operand *, int64_t>
1322 GetBaseExplainingValue(const Instruction::Operand &operand,
1323                        RegisterContext &register_context, lldb::addr_t value) {
1324   switch (operand.m_type) {
1325   case Instruction::Operand::Type::Dereference:
1326   case Instruction::Operand::Type::Immediate:
1327   case Instruction::Operand::Type::Invalid:
1328   case Instruction::Operand::Type::Product:
1329     // These are not currently interesting
1330     return std::make_pair(nullptr, 0);
1331   case Instruction::Operand::Type::Sum: {
1332     const Instruction::Operand *immediate_child = nullptr;
1333     const Instruction::Operand *variable_child = nullptr;
1334     if (operand.m_children[0].m_type == Instruction::Operand::Type::Immediate) {
1335       immediate_child = &operand.m_children[0];
1336       variable_child = &operand.m_children[1];
1337     } else if (operand.m_children[1].m_type ==
1338                Instruction::Operand::Type::Immediate) {
1339       immediate_child = &operand.m_children[1];
1340       variable_child = &operand.m_children[0];
1341     }
1342     if (!immediate_child) {
1343       return std::make_pair(nullptr, 0);
1344     }
1345     lldb::addr_t adjusted_value = value;
1346     if (immediate_child->m_negative) {
1347       adjusted_value += immediate_child->m_immediate;
1348     } else {
1349       adjusted_value -= immediate_child->m_immediate;
1350     }
1351     std::pair<const Instruction::Operand *, int64_t> base_and_offset =
1352         GetBaseExplainingValue(*variable_child, register_context,
1353                                adjusted_value);
1354     if (!base_and_offset.first) {
1355       return std::make_pair(nullptr, 0);
1356     }
1357     if (immediate_child->m_negative) {
1358       base_and_offset.second -= immediate_child->m_immediate;
1359     } else {
1360       base_and_offset.second += immediate_child->m_immediate;
1361     }
1362     return base_and_offset;
1363   }
1364   case Instruction::Operand::Type::Register: {
1365     const RegisterInfo *info =
1366         register_context.GetRegisterInfoByName(operand.m_register.AsCString());
1367     if (!info) {
1368       return std::make_pair(nullptr, 0);
1369     }
1370     RegisterValue reg_value;
1371     if (!register_context.ReadRegister(info, reg_value)) {
1372       return std::make_pair(nullptr, 0);
1373     }
1374     if (reg_value.GetAsUInt64() == value) {
1375       return std::make_pair(&operand, 0);
1376     } else {
1377       return std::make_pair(nullptr, 0);
1378     }
1379   }
1380   }
1381   return std::make_pair(nullptr, 0);
1382 }
1383 
1384 std::pair<const Instruction::Operand *, int64_t>
1385 GetBaseExplainingDereference(const Instruction::Operand &operand,
1386                              RegisterContext &register_context,
1387                              lldb::addr_t addr) {
1388   if (operand.m_type == Instruction::Operand::Type::Dereference) {
1389     return GetBaseExplainingValue(operand.m_children[0], register_context,
1390                                   addr);
1391   }
1392   return std::make_pair(nullptr, 0);
1393 }
1394 } // namespace
1395 
1396 lldb::ValueObjectSP StackFrame::GuessValueForAddress(lldb::addr_t addr) {
1397   TargetSP target_sp = CalculateTarget();
1398 
1399   const ArchSpec &target_arch = target_sp->GetArchitecture();
1400 
1401   AddressRange pc_range;
1402   pc_range.GetBaseAddress() = GetFrameCodeAddress();
1403   pc_range.SetByteSize(target_arch.GetMaximumOpcodeByteSize());
1404 
1405   const char *plugin_name = nullptr;
1406   const char *flavor = nullptr;
1407   const char *cpu = nullptr;
1408   const char *features = nullptr;
1409   const bool force_live_memory = true;
1410 
1411   DisassemblerSP disassembler_sp = Disassembler::DisassembleRange(
1412       target_arch, plugin_name, flavor, cpu, features, *target_sp, pc_range,
1413       force_live_memory);
1414 
1415   if (!disassembler_sp || !disassembler_sp->GetInstructionList().GetSize()) {
1416     return ValueObjectSP();
1417   }
1418 
1419   InstructionSP instruction_sp =
1420       disassembler_sp->GetInstructionList().GetInstructionAtIndex(0);
1421 
1422   llvm::SmallVector<Instruction::Operand, 3> operands;
1423 
1424   if (!instruction_sp->ParseOperands(operands)) {
1425     return ValueObjectSP();
1426   }
1427 
1428   RegisterContextSP register_context_sp = GetRegisterContext();
1429 
1430   if (!register_context_sp) {
1431     return ValueObjectSP();
1432   }
1433 
1434   for (const Instruction::Operand &operand : operands) {
1435     std::pair<const Instruction::Operand *, int64_t> base_and_offset =
1436         GetBaseExplainingDereference(operand, *register_context_sp, addr);
1437 
1438     if (!base_and_offset.first) {
1439       continue;
1440     }
1441 
1442     switch (base_and_offset.first->m_type) {
1443     case Instruction::Operand::Type::Immediate: {
1444       lldb_private::Address addr;
1445       if (target_sp->ResolveLoadAddress(base_and_offset.first->m_immediate +
1446                                             base_and_offset.second,
1447                                         addr)) {
1448         auto c_type_system_or_err =
1449             target_sp->GetScratchTypeSystemForLanguage(eLanguageTypeC);
1450         if (auto err = c_type_system_or_err.takeError()) {
1451           LLDB_LOG_ERROR(GetLog(LLDBLog::Thread), std::move(err),
1452                          "Unable to guess value for given address: {0}");
1453           return ValueObjectSP();
1454         } else {
1455           auto ts = *c_type_system_or_err;
1456           if (!ts)
1457             return {};
1458           CompilerType void_ptr_type =
1459               ts->GetBasicTypeFromAST(lldb::BasicType::eBasicTypeChar)
1460                   .GetPointerType();
1461           return ValueObjectMemory::Create(this, "", addr, void_ptr_type);
1462         }
1463       } else {
1464         return ValueObjectSP();
1465       }
1466       break;
1467     }
1468     case Instruction::Operand::Type::Register: {
1469       return GuessValueForRegisterAndOffset(base_and_offset.first->m_register,
1470                                             base_and_offset.second);
1471     }
1472     default:
1473       return ValueObjectSP();
1474     }
1475   }
1476 
1477   return ValueObjectSP();
1478 }
1479 
1480 namespace {
1481 ValueObjectSP GetValueForOffset(StackFrame &frame, ValueObjectSP &parent,
1482                                 int64_t offset) {
1483   if (offset < 0 || uint64_t(offset) >= parent->GetByteSize()) {
1484     return ValueObjectSP();
1485   }
1486 
1487   if (parent->IsPointerOrReferenceType()) {
1488     return parent;
1489   }
1490 
1491   for (int ci = 0, ce = parent->GetNumChildrenIgnoringErrors(); ci != ce;
1492        ++ci) {
1493     ValueObjectSP child_sp = parent->GetChildAtIndex(ci);
1494 
1495     if (!child_sp) {
1496       return ValueObjectSP();
1497     }
1498 
1499     int64_t child_offset = child_sp->GetByteOffset();
1500     int64_t child_size = child_sp->GetByteSize().value_or(0);
1501 
1502     if (offset >= child_offset && offset < (child_offset + child_size)) {
1503       return GetValueForOffset(frame, child_sp, offset - child_offset);
1504     }
1505   }
1506 
1507   if (offset == 0) {
1508     return parent;
1509   } else {
1510     return ValueObjectSP();
1511   }
1512 }
1513 
1514 ValueObjectSP GetValueForDereferincingOffset(StackFrame &frame,
1515                                              ValueObjectSP &base,
1516                                              int64_t offset) {
1517   // base is a pointer to something
1518   // offset is the thing to add to the pointer We return the most sensible
1519   // ValueObject for the result of *(base+offset)
1520 
1521   if (!base->IsPointerOrReferenceType()) {
1522     return ValueObjectSP();
1523   }
1524 
1525   Status error;
1526   ValueObjectSP pointee = base->Dereference(error);
1527 
1528   if (!pointee) {
1529     return ValueObjectSP();
1530   }
1531 
1532   if (offset >= 0 && uint64_t(offset) >= pointee->GetByteSize()) {
1533     int64_t index = offset / pointee->GetByteSize().value_or(1);
1534     offset = offset % pointee->GetByteSize().value_or(1);
1535     const bool can_create = true;
1536     pointee = base->GetSyntheticArrayMember(index, can_create);
1537   }
1538 
1539   if (!pointee || error.Fail()) {
1540     return ValueObjectSP();
1541   }
1542 
1543   return GetValueForOffset(frame, pointee, offset);
1544 }
1545 
1546 /// Attempt to reconstruct the ValueObject for the address contained in a
1547 /// given register plus an offset.
1548 ///
1549 /// \param [in] frame
1550 ///   The current stack frame.
1551 ///
1552 /// \param [in] reg
1553 ///   The register.
1554 ///
1555 /// \param [in] offset
1556 ///   The offset from the register.
1557 ///
1558 /// \param [in] disassembler
1559 ///   A disassembler containing instructions valid up to the current PC.
1560 ///
1561 /// \param [in] variables
1562 ///   The variable list from the current frame,
1563 ///
1564 /// \param [in] pc
1565 ///   The program counter for the instruction considered the 'user'.
1566 ///
1567 /// \return
1568 ///   A string describing the base for the ExpressionPath.  This could be a
1569 ///     variable, a register value, an argument, or a function return value.
1570 ///   The ValueObject if found.  If valid, it has a valid ExpressionPath.
1571 lldb::ValueObjectSP DoGuessValueAt(StackFrame &frame, ConstString reg,
1572                                    int64_t offset, Disassembler &disassembler,
1573                                    VariableList &variables, const Address &pc) {
1574   // Example of operation for Intel:
1575   //
1576   // +14: movq   -0x8(%rbp), %rdi
1577   // +18: movq   0x8(%rdi), %rdi
1578   // +22: addl   0x4(%rdi), %eax
1579   //
1580   // f, a pointer to a struct, is known to be at -0x8(%rbp).
1581   //
1582   // DoGuessValueAt(frame, rdi, 4, dis, vars, 0x22) finds the instruction at
1583   // +18 that assigns to rdi, and calls itself recursively for that dereference
1584   //   DoGuessValueAt(frame, rdi, 8, dis, vars, 0x18) finds the instruction at
1585   //   +14 that assigns to rdi, and calls itself recursively for that
1586   //   dereference
1587   //     DoGuessValueAt(frame, rbp, -8, dis, vars, 0x14) finds "f" in the
1588   //     variable list.
1589   //     Returns a ValueObject for f.  (That's what was stored at rbp-8 at +14)
1590   //   Returns a ValueObject for *(f+8) or f->b (That's what was stored at rdi+8
1591   //   at +18)
1592   // Returns a ValueObject for *(f->b+4) or f->b->a (That's what was stored at
1593   // rdi+4 at +22)
1594 
1595   // First, check the variable list to see if anything is at the specified
1596   // location.
1597 
1598   using namespace OperandMatchers;
1599 
1600   const RegisterInfo *reg_info =
1601       frame.GetRegisterContext()->GetRegisterInfoByName(reg.AsCString());
1602   if (!reg_info) {
1603     return ValueObjectSP();
1604   }
1605 
1606   Instruction::Operand op =
1607       offset ? Instruction::Operand::BuildDereference(
1608                    Instruction::Operand::BuildSum(
1609                        Instruction::Operand::BuildRegister(reg),
1610                        Instruction::Operand::BuildImmediate(offset)))
1611              : Instruction::Operand::BuildDereference(
1612                    Instruction::Operand::BuildRegister(reg));
1613 
1614   for (VariableSP var_sp : variables) {
1615     if (var_sp->LocationExpressionList().MatchesOperand(frame, op))
1616       return frame.GetValueObjectForFrameVariable(var_sp, eNoDynamicValues);
1617   }
1618 
1619   const uint32_t current_inst =
1620       disassembler.GetInstructionList().GetIndexOfInstructionAtAddress(pc);
1621   if (current_inst == UINT32_MAX) {
1622     return ValueObjectSP();
1623   }
1624 
1625   for (uint32_t ii = current_inst - 1; ii != (uint32_t)-1; --ii) {
1626     // This is not an exact algorithm, and it sacrifices accuracy for
1627     // generality.  Recognizing "mov" and "ld" instructions –– and which
1628     // are their source and destination operands -- is something the
1629     // disassembler should do for us.
1630     InstructionSP instruction_sp =
1631         disassembler.GetInstructionList().GetInstructionAtIndex(ii);
1632 
1633     if (instruction_sp->IsCall()) {
1634       ABISP abi_sp = frame.CalculateProcess()->GetABI();
1635       if (!abi_sp) {
1636         continue;
1637       }
1638 
1639       const char *return_register_name;
1640       if (!abi_sp->GetPointerReturnRegister(return_register_name)) {
1641         continue;
1642       }
1643 
1644       const RegisterInfo *return_register_info =
1645           frame.GetRegisterContext()->GetRegisterInfoByName(
1646               return_register_name);
1647       if (!return_register_info) {
1648         continue;
1649       }
1650 
1651       int64_t offset = 0;
1652 
1653       if (!MatchUnaryOp(MatchOpType(Instruction::Operand::Type::Dereference),
1654                         MatchRegOp(*return_register_info))(op) &&
1655           !MatchUnaryOp(
1656               MatchOpType(Instruction::Operand::Type::Dereference),
1657               MatchBinaryOp(MatchOpType(Instruction::Operand::Type::Sum),
1658                             MatchRegOp(*return_register_info),
1659                             FetchImmOp(offset)))(op)) {
1660         continue;
1661       }
1662 
1663       llvm::SmallVector<Instruction::Operand, 1> operands;
1664       if (!instruction_sp->ParseOperands(operands) || operands.size() != 1) {
1665         continue;
1666       }
1667 
1668       switch (operands[0].m_type) {
1669       default:
1670         break;
1671       case Instruction::Operand::Type::Immediate: {
1672         SymbolContext sc;
1673         Address load_address;
1674         if (!frame.CalculateTarget()->ResolveLoadAddress(
1675                 operands[0].m_immediate, load_address)) {
1676           break;
1677         }
1678         frame.CalculateTarget()->GetImages().ResolveSymbolContextForAddress(
1679             load_address, eSymbolContextFunction, sc);
1680         if (!sc.function) {
1681           break;
1682         }
1683         CompilerType function_type = sc.function->GetCompilerType();
1684         if (!function_type.IsFunctionType()) {
1685           break;
1686         }
1687         CompilerType return_type = function_type.GetFunctionReturnType();
1688         RegisterValue return_value;
1689         if (!frame.GetRegisterContext()->ReadRegister(return_register_info,
1690                                                       return_value)) {
1691           break;
1692         }
1693         std::string name_str(
1694             sc.function->GetName().AsCString("<unknown function>"));
1695         name_str.append("()");
1696         Address return_value_address(return_value.GetAsUInt64());
1697         ValueObjectSP return_value_sp = ValueObjectMemory::Create(
1698             &frame, name_str, return_value_address, return_type);
1699         return GetValueForDereferincingOffset(frame, return_value_sp, offset);
1700       }
1701       }
1702 
1703       continue;
1704     }
1705 
1706     llvm::SmallVector<Instruction::Operand, 2> operands;
1707     if (!instruction_sp->ParseOperands(operands) || operands.size() != 2) {
1708       continue;
1709     }
1710 
1711     Instruction::Operand *origin_operand = nullptr;
1712     auto clobbered_reg_matcher = [reg_info](const Instruction::Operand &op) {
1713       return MatchRegOp(*reg_info)(op) && op.m_clobbered;
1714     };
1715 
1716     if (clobbered_reg_matcher(operands[0])) {
1717       origin_operand = &operands[1];
1718     }
1719     else if (clobbered_reg_matcher(operands[1])) {
1720       origin_operand = &operands[0];
1721     }
1722     else {
1723       continue;
1724     }
1725 
1726     // We have an origin operand.  Can we track its value down?
1727     ValueObjectSP source_path;
1728     ConstString origin_register;
1729     int64_t origin_offset = 0;
1730 
1731     if (FetchRegOp(origin_register)(*origin_operand)) {
1732       source_path = DoGuessValueAt(frame, origin_register, 0, disassembler,
1733                                    variables, instruction_sp->GetAddress());
1734     } else if (MatchUnaryOp(
1735                    MatchOpType(Instruction::Operand::Type::Dereference),
1736                    FetchRegOp(origin_register))(*origin_operand) ||
1737                MatchUnaryOp(
1738                    MatchOpType(Instruction::Operand::Type::Dereference),
1739                    MatchBinaryOp(MatchOpType(Instruction::Operand::Type::Sum),
1740                                  FetchRegOp(origin_register),
1741                                  FetchImmOp(origin_offset)))(*origin_operand)) {
1742       source_path =
1743           DoGuessValueAt(frame, origin_register, origin_offset, disassembler,
1744                          variables, instruction_sp->GetAddress());
1745       if (!source_path) {
1746         continue;
1747       }
1748       source_path =
1749           GetValueForDereferincingOffset(frame, source_path, offset);
1750     }
1751 
1752     if (source_path) {
1753       return source_path;
1754     }
1755   }
1756 
1757   return ValueObjectSP();
1758 }
1759 }
1760 
1761 lldb::ValueObjectSP StackFrame::GuessValueForRegisterAndOffset(ConstString reg,
1762                                                                int64_t offset) {
1763   TargetSP target_sp = CalculateTarget();
1764 
1765   const ArchSpec &target_arch = target_sp->GetArchitecture();
1766 
1767   Block *frame_block = GetFrameBlock();
1768 
1769   if (!frame_block) {
1770     return ValueObjectSP();
1771   }
1772 
1773   Function *function = frame_block->CalculateSymbolContextFunction();
1774   if (!function) {
1775     return ValueObjectSP();
1776   }
1777 
1778   AddressRange pc_range = function->GetAddressRange();
1779 
1780   if (GetFrameCodeAddress().GetFileAddress() <
1781           pc_range.GetBaseAddress().GetFileAddress() ||
1782       GetFrameCodeAddress().GetFileAddress() -
1783               pc_range.GetBaseAddress().GetFileAddress() >=
1784           pc_range.GetByteSize()) {
1785     return ValueObjectSP();
1786   }
1787 
1788   const char *plugin_name = nullptr;
1789   const char *flavor = nullptr;
1790   const char *cpu = nullptr;
1791   const char *features = nullptr;
1792   const bool force_live_memory = true;
1793   DisassemblerSP disassembler_sp = Disassembler::DisassembleRange(
1794       target_arch, plugin_name, flavor, cpu, features, *target_sp, pc_range,
1795       force_live_memory);
1796 
1797   if (!disassembler_sp || !disassembler_sp->GetInstructionList().GetSize()) {
1798     return ValueObjectSP();
1799   }
1800 
1801   const bool get_file_globals = false;
1802   VariableList *variables = GetVariableList(get_file_globals, nullptr);
1803 
1804   if (!variables) {
1805     return ValueObjectSP();
1806   }
1807 
1808   return DoGuessValueAt(*this, reg, offset, *disassembler_sp, *variables,
1809                         GetFrameCodeAddress());
1810 }
1811 
1812 lldb::ValueObjectSP StackFrame::FindVariable(ConstString name) {
1813   ValueObjectSP value_sp;
1814 
1815   if (!name)
1816     return value_sp;
1817 
1818   TargetSP target_sp = CalculateTarget();
1819   ProcessSP process_sp = CalculateProcess();
1820 
1821   if (!target_sp && !process_sp)
1822     return value_sp;
1823 
1824   VariableList variable_list;
1825   VariableSP var_sp;
1826   SymbolContext sc(GetSymbolContext(eSymbolContextBlock));
1827 
1828   if (sc.block) {
1829     const bool can_create = true;
1830     const bool get_parent_variables = true;
1831     const bool stop_if_block_is_inlined_function = true;
1832 
1833     if (sc.block->AppendVariables(
1834             can_create, get_parent_variables, stop_if_block_is_inlined_function,
1835             [this](Variable *v) { return v->IsInScope(this); },
1836             &variable_list)) {
1837       var_sp = variable_list.FindVariable(name);
1838     }
1839 
1840     if (var_sp)
1841       value_sp = GetValueObjectForFrameVariable(var_sp, eNoDynamicValues);
1842   }
1843 
1844   return value_sp;
1845 }
1846 
1847 TargetSP StackFrame::CalculateTarget() {
1848   TargetSP target_sp;
1849   ThreadSP thread_sp(GetThread());
1850   if (thread_sp) {
1851     ProcessSP process_sp(thread_sp->CalculateProcess());
1852     if (process_sp)
1853       target_sp = process_sp->CalculateTarget();
1854   }
1855   return target_sp;
1856 }
1857 
1858 ProcessSP StackFrame::CalculateProcess() {
1859   ProcessSP process_sp;
1860   ThreadSP thread_sp(GetThread());
1861   if (thread_sp)
1862     process_sp = thread_sp->CalculateProcess();
1863   return process_sp;
1864 }
1865 
1866 ThreadSP StackFrame::CalculateThread() { return GetThread(); }
1867 
1868 StackFrameSP StackFrame::CalculateStackFrame() { return shared_from_this(); }
1869 
1870 void StackFrame::CalculateExecutionContext(ExecutionContext &exe_ctx) {
1871   exe_ctx.SetContext(shared_from_this());
1872 }
1873 
1874 bool StackFrame::DumpUsingFormat(Stream &strm,
1875                                  const FormatEntity::Entry *format,
1876                                  llvm::StringRef frame_marker) {
1877   GetSymbolContext(eSymbolContextEverything);
1878   ExecutionContext exe_ctx(shared_from_this());
1879   StreamString s;
1880   s.PutCString(frame_marker);
1881 
1882   if (format && FormatEntity::Format(*format, s, &m_sc, &exe_ctx, nullptr,
1883                                      nullptr, false, false)) {
1884     strm.PutCString(s.GetString());
1885     return true;
1886   }
1887   return false;
1888 }
1889 
1890 void StackFrame::DumpUsingSettingsFormat(Stream *strm, bool show_unique,
1891                                          const char *frame_marker) {
1892   if (strm == nullptr)
1893     return;
1894 
1895   ExecutionContext exe_ctx(shared_from_this());
1896 
1897   const FormatEntity::Entry *frame_format = nullptr;
1898   Target *target = exe_ctx.GetTargetPtr();
1899   if (target) {
1900     if (show_unique) {
1901       frame_format = target->GetDebugger().GetFrameFormatUnique();
1902     } else {
1903       frame_format = target->GetDebugger().GetFrameFormat();
1904     }
1905   }
1906   if (!DumpUsingFormat(*strm, frame_format, frame_marker)) {
1907     Dump(strm, true, false);
1908     strm->EOL();
1909   }
1910 }
1911 
1912 void StackFrame::Dump(Stream *strm, bool show_frame_index,
1913                       bool show_fullpaths) {
1914   if (strm == nullptr)
1915     return;
1916 
1917   if (show_frame_index)
1918     strm->Printf("frame #%u: ", m_frame_index);
1919   ExecutionContext exe_ctx(shared_from_this());
1920   Target *target = exe_ctx.GetTargetPtr();
1921   strm->Printf("0x%0*" PRIx64 " ",
1922                target ? (target->GetArchitecture().GetAddressByteSize() * 2)
1923                       : 16,
1924                GetFrameCodeAddress().GetLoadAddress(target));
1925   GetSymbolContext(eSymbolContextEverything);
1926   const bool show_module = true;
1927   const bool show_inline = true;
1928   const bool show_function_arguments = true;
1929   const bool show_function_name = true;
1930   m_sc.DumpStopContext(strm, exe_ctx.GetBestExecutionContextScope(),
1931                        GetFrameCodeAddress(), show_fullpaths, show_module,
1932                        show_inline, show_function_arguments,
1933                        show_function_name);
1934 }
1935 
1936 void StackFrame::UpdateCurrentFrameFromPreviousFrame(StackFrame &prev_frame) {
1937   std::lock_guard<std::recursive_mutex> guard(m_mutex);
1938   assert(GetStackID() ==
1939          prev_frame.GetStackID()); // TODO: remove this after some testing
1940   m_variable_list_sp = prev_frame.m_variable_list_sp;
1941   m_variable_list_value_objects.Swap(prev_frame.m_variable_list_value_objects);
1942   if (!m_disassembly.GetString().empty()) {
1943     m_disassembly.Clear();
1944     m_disassembly.PutCString(prev_frame.m_disassembly.GetString());
1945   }
1946 }
1947 
1948 void StackFrame::UpdatePreviousFrameFromCurrentFrame(StackFrame &curr_frame) {
1949   std::lock_guard<std::recursive_mutex> guard(m_mutex);
1950   assert(GetStackID() ==
1951          curr_frame.GetStackID());     // TODO: remove this after some testing
1952   m_id.SetPC(curr_frame.m_id.GetPC()); // Update the Stack ID PC value
1953   assert(GetThread() == curr_frame.GetThread());
1954   m_frame_index = curr_frame.m_frame_index;
1955   m_concrete_frame_index = curr_frame.m_concrete_frame_index;
1956   m_reg_context_sp = curr_frame.m_reg_context_sp;
1957   m_frame_code_addr = curr_frame.m_frame_code_addr;
1958   m_behaves_like_zeroth_frame = curr_frame.m_behaves_like_zeroth_frame;
1959   assert(!m_sc.target_sp || !curr_frame.m_sc.target_sp ||
1960          m_sc.target_sp.get() == curr_frame.m_sc.target_sp.get());
1961   assert(!m_sc.module_sp || !curr_frame.m_sc.module_sp ||
1962          m_sc.module_sp.get() == curr_frame.m_sc.module_sp.get());
1963   assert(m_sc.comp_unit == nullptr || curr_frame.m_sc.comp_unit == nullptr ||
1964          m_sc.comp_unit == curr_frame.m_sc.comp_unit);
1965   assert(m_sc.function == nullptr || curr_frame.m_sc.function == nullptr ||
1966          m_sc.function == curr_frame.m_sc.function);
1967   m_sc = curr_frame.m_sc;
1968   m_flags.Clear(GOT_FRAME_BASE | eSymbolContextEverything);
1969   m_flags.Set(m_sc.GetResolvedMask());
1970   m_frame_base.Clear();
1971   m_frame_base_error.Clear();
1972 }
1973 
1974 bool StackFrame::HasCachedData() const {
1975   if (m_variable_list_sp)
1976     return true;
1977   if (m_variable_list_value_objects.GetSize() > 0)
1978     return true;
1979   if (!m_disassembly.GetString().empty())
1980     return true;
1981   return false;
1982 }
1983 
1984 bool StackFrame::GetStatus(Stream &strm, bool show_frame_info, bool show_source,
1985                            bool show_unique, const char *frame_marker) {
1986   if (show_frame_info) {
1987     strm.Indent();
1988     DumpUsingSettingsFormat(&strm, show_unique, frame_marker);
1989   }
1990 
1991   if (show_source) {
1992     ExecutionContext exe_ctx(shared_from_this());
1993     bool have_source = false, have_debuginfo = false;
1994     Debugger::StopDisassemblyType disasm_display =
1995         Debugger::eStopDisassemblyTypeNever;
1996     Target *target = exe_ctx.GetTargetPtr();
1997     if (target) {
1998       Debugger &debugger = target->GetDebugger();
1999       const uint32_t source_lines_before =
2000           debugger.GetStopSourceLineCount(true);
2001       const uint32_t source_lines_after =
2002           debugger.GetStopSourceLineCount(false);
2003       disasm_display = debugger.GetStopDisassemblyDisplay();
2004 
2005       GetSymbolContext(eSymbolContextCompUnit | eSymbolContextLineEntry);
2006       if (m_sc.comp_unit && m_sc.line_entry.IsValid()) {
2007         have_debuginfo = true;
2008         if (source_lines_before > 0 || source_lines_after > 0) {
2009           SupportFileSP source_file_sp = m_sc.line_entry.file_sp;
2010           uint32_t start_line = m_sc.line_entry.line;
2011           if (!start_line && m_sc.function) {
2012             m_sc.function->GetStartLineSourceInfo(source_file_sp, start_line);
2013           }
2014 
2015           size_t num_lines =
2016               target->GetSourceManager().DisplaySourceLinesWithLineNumbers(
2017                   source_file_sp, start_line, m_sc.line_entry.column,
2018                   source_lines_before, source_lines_after, "->", &strm);
2019           if (num_lines != 0)
2020             have_source = true;
2021           // TODO: Give here a one time warning if source file is missing.
2022           if (!m_sc.line_entry.line)
2023             strm << "note: This address is not associated with a specific line "
2024                     "of code. This may be due to compiler optimizations.\n";
2025         }
2026       }
2027       switch (disasm_display) {
2028       case Debugger::eStopDisassemblyTypeNever:
2029         break;
2030 
2031       case Debugger::eStopDisassemblyTypeNoDebugInfo:
2032         if (have_debuginfo)
2033           break;
2034         [[fallthrough]];
2035 
2036       case Debugger::eStopDisassemblyTypeNoSource:
2037         if (have_source)
2038           break;
2039         [[fallthrough]];
2040 
2041       case Debugger::eStopDisassemblyTypeAlways:
2042         if (target) {
2043           const uint32_t disasm_lines = debugger.GetDisassemblyLineCount();
2044           if (disasm_lines > 0) {
2045             const ArchSpec &target_arch = target->GetArchitecture();
2046             const char *plugin_name = nullptr;
2047             const char *flavor = nullptr;
2048             const bool mixed_source_and_assembly = false;
2049             Disassembler::Disassemble(
2050                 target->GetDebugger(), target_arch, plugin_name, flavor,
2051                 target->GetDisassemblyCPU(), target->GetDisassemblyFeatures(),
2052                 exe_ctx, GetFrameCodeAddress(),
2053                 {Disassembler::Limit::Instructions, disasm_lines},
2054                 mixed_source_and_assembly, 0,
2055                 Disassembler::eOptionMarkPCAddress, strm);
2056           }
2057         }
2058         break;
2059       }
2060     }
2061   }
2062   return true;
2063 }
2064 
2065 RecognizedStackFrameSP StackFrame::GetRecognizedFrame() {
2066   auto process = GetThread()->GetProcess();
2067   if (!process)
2068     return {};
2069   // If recognizer list has been modified, discard cache.
2070   auto &manager = process->GetTarget().GetFrameRecognizerManager();
2071   auto new_generation = manager.GetGeneration();
2072   if (m_frame_recognizer_generation != new_generation)
2073     m_recognized_frame_sp.reset();
2074   m_frame_recognizer_generation = new_generation;
2075   if (!m_recognized_frame_sp.has_value())
2076     m_recognized_frame_sp = manager.RecognizeFrame(CalculateStackFrame());
2077   return m_recognized_frame_sp.value();
2078 }
2079