1 //===-- ItaniumABILanguageRuntime.cpp --------------------------------------*-
2 //C++ -*-===//
3 //
4 //                     The LLVM Compiler Infrastructure
5 //
6 // This file is distributed under the University of Illinois Open Source
7 // License. See LICENSE.TXT for details.
8 //
9 //===----------------------------------------------------------------------===//
10 
11 #include "ItaniumABILanguageRuntime.h"
12 
13 #include "lldb/Breakpoint/BreakpointLocation.h"
14 #include "lldb/Core/Mangled.h"
15 #include "lldb/Core/Module.h"
16 #include "lldb/Core/PluginManager.h"
17 #include "lldb/Core/ValueObject.h"
18 #include "lldb/Core/ValueObjectMemory.h"
19 #include "lldb/DataFormatters/FormattersHelpers.h"
20 #include "lldb/Expression/DiagnosticManager.h"
21 #include "lldb/Expression/FunctionCaller.h"
22 #include "lldb/Interpreter/CommandObject.h"
23 #include "lldb/Interpreter/CommandObjectMultiword.h"
24 #include "lldb/Interpreter/CommandReturnObject.h"
25 #include "lldb/Symbol/ClangASTContext.h"
26 #include "lldb/Symbol/Symbol.h"
27 #include "lldb/Symbol/SymbolFile.h"
28 #include "lldb/Symbol/TypeList.h"
29 #include "lldb/Target/Process.h"
30 #include "lldb/Target/RegisterContext.h"
31 #include "lldb/Target/SectionLoadList.h"
32 #include "lldb/Target/StopInfo.h"
33 #include "lldb/Target/Target.h"
34 #include "lldb/Target/Thread.h"
35 #include "lldb/Utility/ConstString.h"
36 #include "lldb/Utility/Log.h"
37 #include "lldb/Utility/Scalar.h"
38 #include "lldb/Utility/Status.h"
39 
40 #include <vector>
41 
42 using namespace lldb;
43 using namespace lldb_private;
44 
45 static const char *vtable_demangled_prefix = "vtable for ";
46 
CouldHaveDynamicValue(ValueObject & in_value)47 bool ItaniumABILanguageRuntime::CouldHaveDynamicValue(ValueObject &in_value) {
48   const bool check_cxx = true;
49   const bool check_objc = false;
50   return in_value.GetCompilerType().IsPossibleDynamicType(NULL, check_cxx,
51                                                           check_objc);
52 }
53 
GetTypeInfoFromVTableAddress(ValueObject & in_value,lldb::addr_t original_ptr,lldb::addr_t vtable_load_addr)54 TypeAndOrName ItaniumABILanguageRuntime::GetTypeInfoFromVTableAddress(
55     ValueObject &in_value, lldb::addr_t original_ptr,
56     lldb::addr_t vtable_load_addr) {
57   if (m_process && vtable_load_addr != LLDB_INVALID_ADDRESS) {
58     // Find the symbol that contains the "vtable_load_addr" address
59     Address vtable_addr;
60     Target &target = m_process->GetTarget();
61     if (!target.GetSectionLoadList().IsEmpty()) {
62       if (target.GetSectionLoadList().ResolveLoadAddress(vtable_load_addr,
63                                                          vtable_addr)) {
64         // See if we have cached info for this type already
65         TypeAndOrName type_info = GetDynamicTypeInfo(vtable_addr);
66         if (type_info)
67           return type_info;
68 
69         SymbolContext sc;
70         target.GetImages().ResolveSymbolContextForAddress(
71             vtable_addr, eSymbolContextSymbol, sc);
72         Symbol *symbol = sc.symbol;
73         if (symbol != NULL) {
74           const char *name =
75               symbol->GetMangled()
76                   .GetDemangledName(lldb::eLanguageTypeC_plus_plus)
77                   .AsCString();
78           if (name && strstr(name, vtable_demangled_prefix) == name) {
79             Log *log(
80                 lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OBJECT));
81             if (log)
82               log->Printf("0x%16.16" PRIx64
83                           ": static-type = '%s' has vtable symbol '%s'\n",
84                           original_ptr, in_value.GetTypeName().GetCString(),
85                           name);
86             // We are a C++ class, that's good.  Get the class name and look it
87             // up:
88             const char *class_name = name + strlen(vtable_demangled_prefix);
89             // We know the class name is absolute, so tell FindTypes that by
90             // prefixing it with the root namespace:
91             std::string lookup_name("::");
92             lookup_name.append(class_name);
93 
94             type_info.SetName(class_name);
95             const bool exact_match = true;
96             TypeList class_types;
97 
98             uint32_t num_matches = 0;
99             // First look in the module that the vtable symbol came from and
100             // look for a single exact match.
101             llvm::DenseSet<SymbolFile *> searched_symbol_files;
102             if (sc.module_sp) {
103               num_matches = sc.module_sp->FindTypes(
104                   ConstString(lookup_name), exact_match, 1,
105                   searched_symbol_files, class_types);
106             }
107 
108             // If we didn't find a symbol, then move on to the entire module
109             // list in the target and get as many unique matches as possible
110             if (num_matches == 0) {
111               num_matches = target.GetImages().FindTypes(
112                   nullptr, ConstString(lookup_name), exact_match, UINT32_MAX,
113                   searched_symbol_files, class_types);
114             }
115 
116             lldb::TypeSP type_sp;
117             if (num_matches == 0) {
118               if (log)
119                 log->Printf("0x%16.16" PRIx64 ": is not dynamic\n",
120                             original_ptr);
121               return TypeAndOrName();
122             }
123             if (num_matches == 1) {
124               type_sp = class_types.GetTypeAtIndex(0);
125               if (type_sp) {
126                 if (ClangASTContext::IsCXXClassType(
127                         type_sp->GetForwardCompilerType())) {
128                   if (log)
129                     log->Printf(
130                         "0x%16.16" PRIx64
131                         ": static-type = '%s' has dynamic type: uid={0x%" PRIx64
132                         "}, type-name='%s'\n",
133                         original_ptr, in_value.GetTypeName().AsCString(),
134                         type_sp->GetID(), type_sp->GetName().GetCString());
135                   type_info.SetTypeSP(type_sp);
136                 }
137               }
138             } else if (num_matches > 1) {
139               size_t i;
140               if (log) {
141                 for (i = 0; i < num_matches; i++) {
142                   type_sp = class_types.GetTypeAtIndex(i);
143                   if (type_sp) {
144                     if (log)
145                       log->Printf(
146                           "0x%16.16" PRIx64
147                           ": static-type = '%s' has multiple matching dynamic "
148                           "types: uid={0x%" PRIx64 "}, type-name='%s'\n",
149                           original_ptr, in_value.GetTypeName().AsCString(),
150                           type_sp->GetID(), type_sp->GetName().GetCString());
151                   }
152                 }
153               }
154 
155               for (i = 0; i < num_matches; i++) {
156                 type_sp = class_types.GetTypeAtIndex(i);
157                 if (type_sp) {
158                   if (ClangASTContext::IsCXXClassType(
159                           type_sp->GetForwardCompilerType())) {
160                     if (log)
161                       log->Printf(
162                           "0x%16.16" PRIx64 ": static-type = '%s' has multiple "
163                                             "matching dynamic types, picking "
164                                             "this one: uid={0x%" PRIx64
165                           "}, type-name='%s'\n",
166                           original_ptr, in_value.GetTypeName().AsCString(),
167                           type_sp->GetID(), type_sp->GetName().GetCString());
168                     type_info.SetTypeSP(type_sp);
169                   }
170                 }
171               }
172 
173               if (log && i == num_matches) {
174                 log->Printf(
175                     "0x%16.16" PRIx64
176                     ": static-type = '%s' has multiple matching dynamic "
177                     "types, didn't find a C++ match\n",
178                     original_ptr, in_value.GetTypeName().AsCString());
179               }
180             }
181             if (type_info)
182               SetDynamicTypeInfo(vtable_addr, type_info);
183             return type_info;
184           }
185         }
186       }
187     }
188   }
189   return TypeAndOrName();
190 }
191 
GetDynamicTypeAndAddress(ValueObject & in_value,lldb::DynamicValueType use_dynamic,TypeAndOrName & class_type_or_name,Address & dynamic_address,Value::ValueType & value_type)192 bool ItaniumABILanguageRuntime::GetDynamicTypeAndAddress(
193     ValueObject &in_value, lldb::DynamicValueType use_dynamic,
194     TypeAndOrName &class_type_or_name, Address &dynamic_address,
195     Value::ValueType &value_type) {
196   // For Itanium, if the type has a vtable pointer in the object, it will be at
197   // offset 0 in the object.  That will point to the "address point" within the
198   // vtable (not the beginning of the vtable.)  We can then look up the symbol
199   // containing this "address point" and that symbol's name demangled will
200   // contain the full class name. The second pointer above the "address point"
201   // is the "offset_to_top".  We'll use that to get the start of the value
202   // object which holds the dynamic type.
203   //
204 
205   class_type_or_name.Clear();
206   value_type = Value::ValueType::eValueTypeScalar;
207 
208   // Only a pointer or reference type can have a different dynamic and static
209   // type:
210   if (!CouldHaveDynamicValue(in_value))
211     return false;
212 
213   // First job, pull out the address at 0 offset from the object.
214   AddressType address_type;
215   lldb::addr_t original_ptr = in_value.GetPointerValue(&address_type);
216   if (original_ptr == LLDB_INVALID_ADDRESS)
217     return false;
218 
219   ExecutionContext exe_ctx(in_value.GetExecutionContextRef());
220 
221   Process *process = exe_ctx.GetProcessPtr();
222 
223   if (process == nullptr)
224     return false;
225 
226   Status error;
227   const lldb::addr_t vtable_address_point =
228       process->ReadPointerFromMemory(original_ptr, error);
229 
230   if (!error.Success() || vtable_address_point == LLDB_INVALID_ADDRESS)
231     return false;
232 
233   class_type_or_name = GetTypeInfoFromVTableAddress(in_value, original_ptr,
234                                                     vtable_address_point);
235 
236   if (!class_type_or_name)
237     return false;
238 
239   TypeSP type_sp = class_type_or_name.GetTypeSP();
240   // There can only be one type with a given name, so we've just found
241   // duplicate definitions, and this one will do as well as any other. We
242   // don't consider something to have a dynamic type if it is the same as
243   // the static type.  So compare against the value we were handed.
244   if (!type_sp)
245     return true;
246 
247   if (ClangASTContext::AreTypesSame(in_value.GetCompilerType(),
248                                     type_sp->GetForwardCompilerType())) {
249     // The dynamic type we found was the same type, so we don't have a
250     // dynamic type here...
251     return false;
252   }
253 
254   // The offset_to_top is two pointers above the vtable pointer.
255   const uint32_t addr_byte_size = process->GetAddressByteSize();
256   const lldb::addr_t offset_to_top_location =
257       vtable_address_point - 2 * addr_byte_size;
258   // Watch for underflow, offset_to_top_location should be less than
259   // vtable_address_point
260   if (offset_to_top_location >= vtable_address_point)
261     return false;
262   const int64_t offset_to_top = process->ReadSignedIntegerFromMemory(
263       offset_to_top_location, addr_byte_size, INT64_MIN, error);
264 
265   if (offset_to_top == INT64_MIN)
266     return false;
267   // So the dynamic type is a value that starts at offset_to_top above
268   // the original address.
269   lldb::addr_t dynamic_addr = original_ptr + offset_to_top;
270   if (!process->GetTarget().GetSectionLoadList().ResolveLoadAddress(
271           dynamic_addr, dynamic_address)) {
272     dynamic_address.SetRawAddress(dynamic_addr);
273   }
274   return true;
275 }
276 
FixUpDynamicType(const TypeAndOrName & type_and_or_name,ValueObject & static_value)277 TypeAndOrName ItaniumABILanguageRuntime::FixUpDynamicType(
278     const TypeAndOrName &type_and_or_name, ValueObject &static_value) {
279   CompilerType static_type(static_value.GetCompilerType());
280   Flags static_type_flags(static_type.GetTypeInfo());
281 
282   TypeAndOrName ret(type_and_or_name);
283   if (type_and_or_name.HasType()) {
284     // The type will always be the type of the dynamic object.  If our parent's
285     // type was a pointer, then our type should be a pointer to the type of the
286     // dynamic object.  If a reference, then the original type should be
287     // okay...
288     CompilerType orig_type = type_and_or_name.GetCompilerType();
289     CompilerType corrected_type = orig_type;
290     if (static_type_flags.AllSet(eTypeIsPointer))
291       corrected_type = orig_type.GetPointerType();
292     else if (static_type_flags.AllSet(eTypeIsReference))
293       corrected_type = orig_type.GetLValueReferenceType();
294     ret.SetCompilerType(corrected_type);
295   } else {
296     // If we are here we need to adjust our dynamic type name to include the
297     // correct & or * symbol
298     std::string corrected_name(type_and_or_name.GetName().GetCString());
299     if (static_type_flags.AllSet(eTypeIsPointer))
300       corrected_name.append(" *");
301     else if (static_type_flags.AllSet(eTypeIsReference))
302       corrected_name.append(" &");
303     // the parent type should be a correctly pointer'ed or referenc'ed type
304     ret.SetCompilerType(static_type);
305     ret.SetName(corrected_name.c_str());
306   }
307   return ret;
308 }
309 
IsVTableName(const char * name)310 bool ItaniumABILanguageRuntime::IsVTableName(const char *name) {
311   if (name == NULL)
312     return false;
313 
314   // Can we maybe ask Clang about this?
315   return strstr(name, "_vptr$") == name;
316 }
317 
318 //------------------------------------------------------------------
319 // Static Functions
320 //------------------------------------------------------------------
321 LanguageRuntime *
CreateInstance(Process * process,lldb::LanguageType language)322 ItaniumABILanguageRuntime::CreateInstance(Process *process,
323                                           lldb::LanguageType language) {
324   // FIXME: We have to check the process and make sure we actually know that
325   // this process supports
326   // the Itanium ABI.
327   if (language == eLanguageTypeC_plus_plus ||
328       language == eLanguageTypeC_plus_plus_03 ||
329       language == eLanguageTypeC_plus_plus_11 ||
330       language == eLanguageTypeC_plus_plus_14)
331     return new ItaniumABILanguageRuntime(process);
332   else
333     return NULL;
334 }
335 
336 class CommandObjectMultiwordItaniumABI_Demangle : public CommandObjectParsed {
337 public:
CommandObjectMultiwordItaniumABI_Demangle(CommandInterpreter & interpreter)338   CommandObjectMultiwordItaniumABI_Demangle(CommandInterpreter &interpreter)
339       : CommandObjectParsed(interpreter, "demangle",
340                             "Demangle a C++ mangled name.",
341                             "language cplusplus demangle") {
342     CommandArgumentEntry arg;
343     CommandArgumentData index_arg;
344 
345     // Define the first (and only) variant of this arg.
346     index_arg.arg_type = eArgTypeSymbol;
347     index_arg.arg_repetition = eArgRepeatPlus;
348 
349     // There is only one variant this argument could be; put it into the
350     // argument entry.
351     arg.push_back(index_arg);
352 
353     // Push the data for the first argument into the m_arguments vector.
354     m_arguments.push_back(arg);
355   }
356 
357   ~CommandObjectMultiwordItaniumABI_Demangle() override = default;
358 
359 protected:
DoExecute(Args & command,CommandReturnObject & result)360   bool DoExecute(Args &command, CommandReturnObject &result) override {
361     bool demangled_any = false;
362     bool error_any = false;
363     for (auto &entry : command.entries()) {
364       if (entry.ref.empty())
365         continue;
366 
367       // the actual Mangled class should be strict about this, but on the
368       // command line if you're copying mangled names out of 'nm' on Darwin,
369       // they will come out with an extra underscore - be willing to strip this
370       // on behalf of the user.   This is the moral equivalent of the -_/-n
371       // options to c++filt
372       auto name = entry.ref;
373       if (name.startswith("__Z"))
374         name = name.drop_front();
375 
376       Mangled mangled(name, true);
377       if (mangled.GuessLanguage() == lldb::eLanguageTypeC_plus_plus) {
378         ConstString demangled(
379             mangled.GetDisplayDemangledName(lldb::eLanguageTypeC_plus_plus));
380         demangled_any = true;
381         result.AppendMessageWithFormat("%s ---> %s\n", entry.ref.str().c_str(),
382                                        demangled.GetCString());
383       } else {
384         error_any = true;
385         result.AppendErrorWithFormat("%s is not a valid C++ mangled name\n",
386                                      entry.ref.str().c_str());
387       }
388     }
389 
390     result.SetStatus(
391         error_any ? lldb::eReturnStatusFailed
392                   : (demangled_any ? lldb::eReturnStatusSuccessFinishResult
393                                    : lldb::eReturnStatusSuccessFinishNoResult));
394     return result.Succeeded();
395   }
396 };
397 
398 class CommandObjectMultiwordItaniumABI : public CommandObjectMultiword {
399 public:
CommandObjectMultiwordItaniumABI(CommandInterpreter & interpreter)400   CommandObjectMultiwordItaniumABI(CommandInterpreter &interpreter)
401       : CommandObjectMultiword(
402             interpreter, "cplusplus",
403             "Commands for operating on the C++ language runtime.",
404             "cplusplus <subcommand> [<subcommand-options>]") {
405     LoadSubCommand(
406         "demangle",
407         CommandObjectSP(
408             new CommandObjectMultiwordItaniumABI_Demangle(interpreter)));
409   }
410 
411   ~CommandObjectMultiwordItaniumABI() override = default;
412 };
413 
Initialize()414 void ItaniumABILanguageRuntime::Initialize() {
415   PluginManager::RegisterPlugin(
416       GetPluginNameStatic(), "Itanium ABI for the C++ language", CreateInstance,
417       [](CommandInterpreter &interpreter) -> lldb::CommandObjectSP {
418         return CommandObjectSP(
419             new CommandObjectMultiwordItaniumABI(interpreter));
420       });
421 }
422 
Terminate()423 void ItaniumABILanguageRuntime::Terminate() {
424   PluginManager::UnregisterPlugin(CreateInstance);
425 }
426 
GetPluginNameStatic()427 lldb_private::ConstString ItaniumABILanguageRuntime::GetPluginNameStatic() {
428   static ConstString g_name("itanium");
429   return g_name;
430 }
431 
432 //------------------------------------------------------------------
433 // PluginInterface protocol
434 //------------------------------------------------------------------
GetPluginName()435 lldb_private::ConstString ItaniumABILanguageRuntime::GetPluginName() {
436   return GetPluginNameStatic();
437 }
438 
GetPluginVersion()439 uint32_t ItaniumABILanguageRuntime::GetPluginVersion() { return 1; }
440 
CreateExceptionResolver(Breakpoint * bkpt,bool catch_bp,bool throw_bp)441 BreakpointResolverSP ItaniumABILanguageRuntime::CreateExceptionResolver(
442     Breakpoint *bkpt, bool catch_bp, bool throw_bp) {
443   return CreateExceptionResolver(bkpt, catch_bp, throw_bp, false);
444 }
445 
CreateExceptionResolver(Breakpoint * bkpt,bool catch_bp,bool throw_bp,bool for_expressions)446 BreakpointResolverSP ItaniumABILanguageRuntime::CreateExceptionResolver(
447     Breakpoint *bkpt, bool catch_bp, bool throw_bp, bool for_expressions) {
448   // One complication here is that most users DON'T want to stop at
449   // __cxa_allocate_expression, but until we can do anything better with
450   // predicting unwinding the expression parser does.  So we have two forms of
451   // the exception breakpoints, one for expressions that leaves out
452   // __cxa_allocate_exception, and one that includes it. The
453   // SetExceptionBreakpoints does the latter, the CreateExceptionBreakpoint in
454   // the runtime the former.
455   static const char *g_catch_name = "__cxa_begin_catch";
456   static const char *g_throw_name1 = "__cxa_throw";
457   static const char *g_throw_name2 = "__cxa_rethrow";
458   static const char *g_exception_throw_name = "__cxa_allocate_exception";
459   std::vector<const char *> exception_names;
460   exception_names.reserve(4);
461   if (catch_bp)
462     exception_names.push_back(g_catch_name);
463 
464   if (throw_bp) {
465     exception_names.push_back(g_throw_name1);
466     exception_names.push_back(g_throw_name2);
467   }
468 
469   if (for_expressions)
470     exception_names.push_back(g_exception_throw_name);
471 
472   BreakpointResolverSP resolver_sp(new BreakpointResolverName(
473       bkpt, exception_names.data(), exception_names.size(),
474       eFunctionNameTypeBase, eLanguageTypeUnknown, 0, eLazyBoolNo));
475 
476   return resolver_sp;
477 }
478 
CreateExceptionSearchFilter()479 lldb::SearchFilterSP ItaniumABILanguageRuntime::CreateExceptionSearchFilter() {
480   Target &target = m_process->GetTarget();
481 
482   if (target.GetArchitecture().GetTriple().getVendor() == llvm::Triple::Apple) {
483     // Limit the number of modules that are searched for these breakpoints for
484     // Apple binaries.
485     FileSpecList filter_modules;
486     filter_modules.Append(FileSpec("libc++abi.dylib"));
487     filter_modules.Append(FileSpec("libSystem.B.dylib"));
488     return target.GetSearchFilterForModuleList(&filter_modules);
489   } else {
490     return LanguageRuntime::CreateExceptionSearchFilter();
491   }
492 }
493 
CreateExceptionBreakpoint(bool catch_bp,bool throw_bp,bool for_expressions,bool is_internal)494 lldb::BreakpointSP ItaniumABILanguageRuntime::CreateExceptionBreakpoint(
495     bool catch_bp, bool throw_bp, bool for_expressions, bool is_internal) {
496   Target &target = m_process->GetTarget();
497   FileSpecList filter_modules;
498   BreakpointResolverSP exception_resolver_sp =
499       CreateExceptionResolver(NULL, catch_bp, throw_bp, for_expressions);
500   SearchFilterSP filter_sp(CreateExceptionSearchFilter());
501   const bool hardware = false;
502   const bool resolve_indirect_functions = false;
503   return target.CreateBreakpoint(filter_sp, exception_resolver_sp, is_internal,
504                                  hardware, resolve_indirect_functions);
505 }
506 
SetExceptionBreakpoints()507 void ItaniumABILanguageRuntime::SetExceptionBreakpoints() {
508   if (!m_process)
509     return;
510 
511   const bool catch_bp = false;
512   const bool throw_bp = true;
513   const bool is_internal = true;
514   const bool for_expressions = true;
515 
516   // For the exception breakpoints set by the Expression parser, we'll be a
517   // little more aggressive and stop at exception allocation as well.
518 
519   if (m_cxx_exception_bp_sp) {
520     m_cxx_exception_bp_sp->SetEnabled(true);
521   } else {
522     m_cxx_exception_bp_sp = CreateExceptionBreakpoint(
523         catch_bp, throw_bp, for_expressions, is_internal);
524     if (m_cxx_exception_bp_sp)
525       m_cxx_exception_bp_sp->SetBreakpointKind("c++ exception");
526   }
527 }
528 
ClearExceptionBreakpoints()529 void ItaniumABILanguageRuntime::ClearExceptionBreakpoints() {
530   if (!m_process)
531     return;
532 
533   if (m_cxx_exception_bp_sp) {
534     m_cxx_exception_bp_sp->SetEnabled(false);
535   }
536 }
537 
ExceptionBreakpointsAreSet()538 bool ItaniumABILanguageRuntime::ExceptionBreakpointsAreSet() {
539   return m_cxx_exception_bp_sp && m_cxx_exception_bp_sp->IsEnabled();
540 }
541 
ExceptionBreakpointsExplainStop(lldb::StopInfoSP stop_reason)542 bool ItaniumABILanguageRuntime::ExceptionBreakpointsExplainStop(
543     lldb::StopInfoSP stop_reason) {
544   if (!m_process)
545     return false;
546 
547   if (!stop_reason || stop_reason->GetStopReason() != eStopReasonBreakpoint)
548     return false;
549 
550   uint64_t break_site_id = stop_reason->GetValue();
551   return m_process->GetBreakpointSiteList().BreakpointSiteContainsBreakpoint(
552       break_site_id, m_cxx_exception_bp_sp->GetID());
553 }
554 
GetExceptionObjectForThread(ThreadSP thread_sp)555 ValueObjectSP ItaniumABILanguageRuntime::GetExceptionObjectForThread(
556     ThreadSP thread_sp) {
557   if (!thread_sp->SafeToCallFunctions())
558     return {};
559 
560   ClangASTContext *clang_ast_context =
561       m_process->GetTarget().GetScratchClangASTContext();
562   CompilerType voidstar =
563       clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType();
564 
565   DiagnosticManager diagnostics;
566   ExecutionContext exe_ctx;
567   EvaluateExpressionOptions options;
568 
569   options.SetUnwindOnError(true);
570   options.SetIgnoreBreakpoints(true);
571   options.SetStopOthers(true);
572   options.SetTimeout(std::chrono::milliseconds(500));
573   options.SetTryAllThreads(false);
574   thread_sp->CalculateExecutionContext(exe_ctx);
575 
576   const ModuleList &modules = m_process->GetTarget().GetImages();
577   SymbolContextList contexts;
578   SymbolContext context;
579 
580   modules.FindSymbolsWithNameAndType(
581       ConstString("__cxa_current_exception_type"), eSymbolTypeCode, contexts);
582   contexts.GetContextAtIndex(0, context);
583   Address addr = context.symbol->GetAddress();
584 
585   Status error;
586   FunctionCaller *function_caller =
587       m_process->GetTarget().GetFunctionCallerForLanguage(
588           eLanguageTypeC, voidstar, addr, ValueList(), "caller", error);
589 
590   ExpressionResults func_call_ret;
591   Value results;
592   func_call_ret = function_caller->ExecuteFunction(exe_ctx, nullptr, options,
593                                                    diagnostics, results);
594   if (func_call_ret != eExpressionCompleted || !error.Success()) {
595     return ValueObjectSP();
596   }
597 
598   size_t ptr_size = m_process->GetAddressByteSize();
599   addr_t result_ptr = results.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
600   addr_t exception_addr =
601       m_process->ReadPointerFromMemory(result_ptr - ptr_size, error);
602 
603   lldb_private::formatters::InferiorSizedWord exception_isw(exception_addr,
604                                                             *m_process);
605   ValueObjectSP exception = ValueObject::CreateValueObjectFromData(
606       "exception", exception_isw.GetAsData(m_process->GetByteOrder()), exe_ctx,
607       voidstar);
608   exception = exception->GetDynamicValue(eDynamicDontRunTarget);
609 
610   return exception;
611 }
612 
GetDynamicTypeInfo(const lldb_private::Address & vtable_addr)613 TypeAndOrName ItaniumABILanguageRuntime::GetDynamicTypeInfo(
614     const lldb_private::Address &vtable_addr) {
615   std::lock_guard<std::mutex> locker(m_dynamic_type_map_mutex);
616   DynamicTypeCache::const_iterator pos = m_dynamic_type_map.find(vtable_addr);
617   if (pos == m_dynamic_type_map.end())
618     return TypeAndOrName();
619   else
620     return pos->second;
621 }
622 
SetDynamicTypeInfo(const lldb_private::Address & vtable_addr,const TypeAndOrName & type_info)623 void ItaniumABILanguageRuntime::SetDynamicTypeInfo(
624     const lldb_private::Address &vtable_addr, const TypeAndOrName &type_info) {
625   std::lock_guard<std::mutex> locker(m_dynamic_type_map_mutex);
626   m_dynamic_type_map[vtable_addr] = type_info;
627 }
628