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1//===-- ItaniumABILanguageRuntime.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-exception6//7//===----------------------------------------------------------------------===//8 9#include "ItaniumABILanguageRuntime.h"10 11#include "Plugins/TypeSystem/Clang/TypeSystemClang.h"12#include "lldb/Breakpoint/BreakpointLocation.h"13#include "lldb/Core/Mangled.h"14#include "lldb/Core/Module.h"15#include "lldb/Core/PluginManager.h"16#include "lldb/DataFormatters/FormattersHelpers.h"17#include "lldb/Expression/DiagnosticManager.h"18#include "lldb/Expression/FunctionCaller.h"19#include "lldb/Interpreter/CommandObject.h"20#include "lldb/Interpreter/CommandObjectMultiword.h"21#include "lldb/Interpreter/CommandReturnObject.h"22#include "lldb/Symbol/Symbol.h"23#include "lldb/Symbol/SymbolFile.h"24#include "lldb/Symbol/TypeList.h"25#include "lldb/Target/Process.h"26#include "lldb/Target/RegisterContext.h"27#include "lldb/Target/SectionLoadList.h"28#include "lldb/Target/StopInfo.h"29#include "lldb/Target/Target.h"30#include "lldb/Target/Thread.h"31#include "lldb/Utility/ConstString.h"32#include "lldb/Utility/LLDBLog.h"33#include "lldb/Utility/Log.h"34#include "lldb/Utility/Scalar.h"35#include "lldb/Utility/Status.h"36#include "lldb/ValueObject/ValueObject.h"37#include "lldb/ValueObject/ValueObjectMemory.h"38 39#include <vector>40 41using namespace lldb;42using namespace lldb_private;43 44LLDB_PLUGIN_DEFINE_ADV(ItaniumABILanguageRuntime, CXXItaniumABI)45 46static const char *vtable_demangled_prefix = "vtable for ";47 48char ItaniumABILanguageRuntime::ID = 0;49 50bool ItaniumABILanguageRuntime::CouldHaveDynamicValue(ValueObject &in_value) {51  const bool check_cxx = true;52  const bool check_objc = false;53  return in_value.GetCompilerType().IsPossibleDynamicType(nullptr, check_cxx,54                                                          check_objc);55}56 57TypeAndOrName ItaniumABILanguageRuntime::GetTypeInfo(58    ValueObject &in_value, const VTableInfo &vtable_info) {59  if (vtable_info.addr.IsSectionOffset()) {60    // See if we have cached info for this type already61    TypeAndOrName type_info = GetDynamicTypeInfo(vtable_info.addr);62    if (type_info)63      return type_info;64 65    if (vtable_info.symbol) {66      Log *log = GetLog(LLDBLog::Object);67      llvm::StringRef symbol_name =68          vtable_info.symbol->GetMangled().GetDemangledName().GetStringRef();69      LLDB_LOGF(log,70                "0x%16.16" PRIx6471                ": static-type = '%s' has vtable symbol '%s'\n",72                in_value.GetPointerValue().address,73                in_value.GetTypeName().GetCString(), symbol_name.str().c_str());74      // We are a C++ class, that's good.  Get the class name and look it75      // up:76      llvm::StringRef class_name = symbol_name;77      class_name.consume_front(vtable_demangled_prefix);78      // We know the class name is absolute, so tell FindTypes that by79      // prefixing it with the root namespace:80      std::string lookup_name("::");81      lookup_name.append(class_name.data(), class_name.size());82 83      type_info.SetName(class_name);84      ConstString const_lookup_name(lookup_name);85      TypeList class_types;86      ModuleSP module_sp = vtable_info.symbol->CalculateSymbolContextModule();87      // First look in the module that the vtable symbol came from and88      // look for a single exact match.89      TypeResults results;90      TypeQuery query(const_lookup_name.GetStringRef(),91                      TypeQueryOptions::e_exact_match |92                          TypeQueryOptions::e_strict_namespaces |93                          TypeQueryOptions::e_find_one);94      if (module_sp) {95        module_sp->FindTypes(query, results);96        TypeSP type_sp = results.GetFirstType();97        if (type_sp)98          class_types.Insert(type_sp);99      }100 101      // If we didn't find a symbol, then move on to the entire module102      // list in the target and get as many unique matches as possible103      if (class_types.Empty()) {104        query.SetFindOne(false);105        m_process->GetTarget().GetImages().FindTypes(nullptr, query, results);106        for (const auto &type_sp : results.GetTypeMap().Types())107          class_types.Insert(type_sp);108      }109 110      lldb::TypeSP type_sp;111      if (class_types.Empty()) {112        LLDB_LOGF(log, "0x%16.16" PRIx64 ": is not dynamic\n",113                  in_value.GetPointerValue().address);114        return TypeAndOrName();115      }116      if (class_types.GetSize() == 1) {117        type_sp = class_types.GetTypeAtIndex(0);118        if (type_sp) {119          if (TypeSystemClang::IsCXXClassType(120                  type_sp->GetForwardCompilerType())) {121            LLDB_LOGF(log,122                      "0x%16.16" PRIx64123                      ": static-type = '%s' has dynamic type: uid={0x%" PRIx64124                      "}, type-name='%s'\n",125                      in_value.GetPointerValue().address,126                      in_value.GetTypeName().AsCString(), type_sp->GetID(),127                      type_sp->GetName().GetCString());128            type_info.SetTypeSP(type_sp);129          }130        }131      } else {132        size_t i;133        if (log) {134          for (i = 0; i < class_types.GetSize(); i++) {135            type_sp = class_types.GetTypeAtIndex(i);136            if (type_sp) {137              LLDB_LOGF(log,138                        "0x%16.16" PRIx64139                        ": static-type = '%s' has multiple matching dynamic "140                        "types: uid={0x%" PRIx64 "}, type-name='%s'\n",141                        in_value.GetPointerValue().address,142                        in_value.GetTypeName().AsCString(), type_sp->GetID(),143                        type_sp->GetName().GetCString());144            }145          }146        }147 148        for (i = 0; i < class_types.GetSize(); i++) {149          type_sp = class_types.GetTypeAtIndex(i);150          if (type_sp) {151            if (TypeSystemClang::IsCXXClassType(152                    type_sp->GetForwardCompilerType())) {153              LLDB_LOGF(log,154                        "0x%16.16" PRIx64 ": static-type = '%s' has multiple "155                        "matching dynamic types, picking "156                        "this one: uid={0x%" PRIx64 "}, type-name='%s'\n",157                        in_value.GetPointerValue().address,158                        in_value.GetTypeName().AsCString(), type_sp->GetID(),159                        type_sp->GetName().GetCString());160              type_info.SetTypeSP(type_sp);161            }162          }163        }164 165        if (log) {166          LLDB_LOGF(log,167                    "0x%16.16" PRIx64168                    ": static-type = '%s' has multiple matching dynamic "169                    "types, didn't find a C++ match\n",170                    in_value.GetPointerValue().address,171                    in_value.GetTypeName().AsCString());172        }173      }174      if (type_info)175        SetDynamicTypeInfo(vtable_info.addr, type_info);176      return type_info;177    }178  }179  return TypeAndOrName();180}181 182llvm::Error ItaniumABILanguageRuntime::TypeHasVTable(CompilerType type) {183  // Check to make sure the class has a vtable.184  CompilerType original_type = type;185  if (type.IsPointerOrReferenceType()) {186    CompilerType pointee_type = type.GetPointeeType();187    if (pointee_type)188      type = pointee_type;189  }190 191  // Make sure this is a class or a struct first by checking the type class192  // bitfield that gets returned.193  if ((type.GetTypeClass() & (eTypeClassStruct | eTypeClassClass)) == 0) {194    return llvm::createStringError(std::errc::invalid_argument,195        "type \"%s\" is not a class or struct or a pointer to one",196        original_type.GetTypeName().AsCString("<invalid>"));197  }198 199  // Check if the type has virtual functions by asking it if it is polymorphic.200  if (!type.IsPolymorphicClass()) {201    return llvm::createStringError(std::errc::invalid_argument,202        "type \"%s\" doesn't have a vtable",203        type.GetTypeName().AsCString("<invalid>"));204  }205  return llvm::Error::success();206}207 208// This function can accept both pointers or references to classes as well as209// instances of classes. If you are using this function during dynamic type210// detection, only valid ValueObjects that return true to211// CouldHaveDynamicValue(...) should call this function and \a check_type212// should be set to false. This function is also used by ValueObjectVTable213// and is can pass in instances of classes which is not suitable for dynamic214// type detection, these cases should pass true for \a check_type.215llvm::Expected<LanguageRuntime::VTableInfo>216 ItaniumABILanguageRuntime::GetVTableInfo(ValueObject &in_value,217                                          bool check_type) {218 219  CompilerType type = in_value.GetCompilerType();220  if (check_type) {221    if (llvm::Error err = TypeHasVTable(type))222      return std::move(err);223  }224  ExecutionContext exe_ctx(in_value.GetExecutionContextRef());225  Process *process = exe_ctx.GetProcessPtr();226  if (process == nullptr)227    return llvm::createStringError(std::errc::invalid_argument,228                                   "invalid process");229 230  auto [original_ptr, address_type] =231      type.IsPointerOrReferenceType()232          ? in_value.GetPointerValue()233          : in_value.GetAddressOf(/*scalar_is_load_address=*/true);234  if (original_ptr == LLDB_INVALID_ADDRESS || address_type != eAddressTypeLoad)235    return llvm::createStringError(std::errc::invalid_argument,236                                   "failed to get the address of the value");237 238  Status error;239  lldb::addr_t vtable_load_addr =240      process->ReadPointerFromMemory(original_ptr, error);241 242  if (!error.Success() || vtable_load_addr == LLDB_INVALID_ADDRESS)243    return llvm::createStringError(std::errc::invalid_argument,244        "failed to read vtable pointer from memory at 0x%" PRIx64,245        original_ptr);246 247  // The vtable load address can have authentication bits with248  // AArch64 targets on Darwin.249  vtable_load_addr = process->FixDataAddress(vtable_load_addr);250 251  // Find the symbol that contains the "vtable_load_addr" address252  Address vtable_addr;253  if (!process->GetTarget().ResolveLoadAddress(vtable_load_addr, vtable_addr))254    return llvm::createStringError(std::errc::invalid_argument,255                                   "failed to resolve vtable pointer 0x%"256                                   PRIx64 "to a section", vtable_load_addr);257 258  // Check our cache first to see if we already have this info259  {260    std::lock_guard<std::mutex> locker(m_mutex);261    auto pos = m_vtable_info_map.find(vtable_addr);262    if (pos != m_vtable_info_map.end())263      return pos->second;264  }265 266  Symbol *symbol = vtable_addr.CalculateSymbolContextSymbol();267  if (symbol == nullptr)268    return llvm::createStringError(std::errc::invalid_argument,269                                   "no symbol found for 0x%" PRIx64,270                                   vtable_load_addr);271  llvm::StringRef name = symbol->GetMangled().GetDemangledName().GetStringRef();272  if (name.starts_with(vtable_demangled_prefix)) {273    VTableInfo info = {vtable_addr, symbol};274    std::lock_guard<std::mutex> locker(m_mutex);275    auto pos = m_vtable_info_map[vtable_addr] = info;276    return info;277  }278  return llvm::createStringError(std::errc::invalid_argument,279      "symbol found that contains 0x%" PRIx64 " is not a vtable symbol",280      vtable_load_addr);281}282 283bool ItaniumABILanguageRuntime::GetDynamicTypeAndAddress(284    ValueObject &in_value, lldb::DynamicValueType use_dynamic,285    TypeAndOrName &class_type_or_name, Address &dynamic_address,286    Value::ValueType &value_type, llvm::ArrayRef<uint8_t> &local_buffer) {287  // For Itanium, if the type has a vtable pointer in the object, it will be at288  // offset 0 in the object.  That will point to the "address point" within the289  // vtable (not the beginning of the vtable.)  We can then look up the symbol290  // containing this "address point" and that symbol's name demangled will291  // contain the full class name. The second pointer above the "address point"292  // is the "offset_to_top".  We'll use that to get the start of the value293  // object which holds the dynamic type.294  //295 296  class_type_or_name.Clear();297  value_type = Value::ValueType::Scalar;298 299  if (!CouldHaveDynamicValue(in_value))300    return false;301 302  // Check if we have a vtable pointer in this value. If we don't it will303  // return an error, else it will return a valid resolved address. We don't304  // want GetVTableInfo to check the type since we accept void * as a possible305  // dynamic type and that won't pass the type check. We already checked the306  // type above in CouldHaveDynamicValue(...).307  llvm::Expected<VTableInfo> vtable_info_or_err =308      GetVTableInfo(in_value, /*check_type=*/false);309  if (!vtable_info_or_err) {310    llvm::consumeError(vtable_info_or_err.takeError());311    return false;312  }313 314  const VTableInfo &vtable_info = vtable_info_or_err.get();315  class_type_or_name = GetTypeInfo(in_value, vtable_info);316 317  if (!class_type_or_name)318    return false;319 320  CompilerType type = class_type_or_name.GetCompilerType();321  // There can only be one type with a given name, so we've just found322  // duplicate definitions, and this one will do as well as any other. We323  // don't consider something to have a dynamic type if it is the same as324  // the static type.  So compare against the value we were handed.325  if (!type)326    return true;327 328  if (TypeSystemClang::AreTypesSame(in_value.GetCompilerType(), type)) {329    // The dynamic type we found was the same type, so we don't have a330    // dynamic type here...331    return false;332  }333 334  // The offset_to_top is two pointers above the vtable pointer.335  Target &target = m_process->GetTarget();336  const addr_t vtable_load_addr = vtable_info.addr.GetLoadAddress(&target);337  if (vtable_load_addr == LLDB_INVALID_ADDRESS)338    return false;339  const uint32_t addr_byte_size = m_process->GetAddressByteSize();340  const lldb::addr_t offset_to_top_location =341      vtable_load_addr - 2 * addr_byte_size;342  // Watch for underflow, offset_to_top_location should be less than343  // vtable_load_addr344  if (offset_to_top_location >= vtable_load_addr)345    return false;346  Status error;347  const int64_t offset_to_top = target.ReadSignedIntegerFromMemory(348      offset_to_top_location, addr_byte_size, INT64_MIN, error);349 350  if (offset_to_top == INT64_MIN)351    return false;352  // So the dynamic type is a value that starts at offset_to_top above353  // the original address.354  lldb::addr_t dynamic_addr =355      in_value.GetPointerValue().address + offset_to_top;356  if (!m_process->GetTarget().ResolveLoadAddress(357          dynamic_addr, dynamic_address)) {358    dynamic_address.SetRawAddress(dynamic_addr);359  }360  return true;361}362 363TypeAndOrName ItaniumABILanguageRuntime::FixUpDynamicType(364    const TypeAndOrName &type_and_or_name, ValueObject &static_value) {365  CompilerType static_type(static_value.GetCompilerType());366  Flags static_type_flags(static_type.GetTypeInfo());367 368  TypeAndOrName ret(type_and_or_name);369  if (type_and_or_name.HasType()) {370    // The type will always be the type of the dynamic object.  If our parent's371    // type was a pointer, then our type should be a pointer to the type of the372    // dynamic object.  If a reference, then the original type should be373    // okay...374    CompilerType orig_type = type_and_or_name.GetCompilerType();375    CompilerType corrected_type = orig_type;376    if (static_type_flags.AllSet(eTypeIsPointer))377      corrected_type = orig_type.GetPointerType();378    else if (static_type_flags.AllSet(eTypeIsReference))379      corrected_type = orig_type.GetLValueReferenceType();380    ret.SetCompilerType(corrected_type);381  } else {382    // If we are here we need to adjust our dynamic type name to include the383    // correct & or * symbol384    std::string corrected_name(type_and_or_name.GetName().GetCString());385    if (static_type_flags.AllSet(eTypeIsPointer))386      corrected_name.append(" *");387    else if (static_type_flags.AllSet(eTypeIsReference))388      corrected_name.append(" &");389    // the parent type should be a correctly pointer'ed or referenc'ed type390    ret.SetCompilerType(static_type);391    ret.SetName(corrected_name.c_str());392  }393  return ret;394}395 396// Static Functions397LanguageRuntime *398ItaniumABILanguageRuntime::CreateInstance(Process *process,399                                          lldb::LanguageType language) {400  // FIXME: We have to check the process and make sure we actually know that401  // this process supports402  // the Itanium ABI.403  if (language == eLanguageTypeC_plus_plus ||404      language == eLanguageTypeC_plus_plus_03 ||405      language == eLanguageTypeC_plus_plus_11 ||406      language == eLanguageTypeC_plus_plus_14)407    return new ItaniumABILanguageRuntime(process);408  else409    return nullptr;410}411 412class CommandObjectMultiwordItaniumABI_Demangle : public CommandObjectParsed {413public:414  CommandObjectMultiwordItaniumABI_Demangle(CommandInterpreter &interpreter)415      : CommandObjectParsed(416            interpreter, "demangle", "Demangle a C++ mangled name.",417            "language cplusplus demangle [<mangled-name> ...]") {418    AddSimpleArgumentList(eArgTypeSymbol, eArgRepeatPlus);419  }420 421  ~CommandObjectMultiwordItaniumABI_Demangle() override = default;422 423protected:424  void DoExecute(Args &command, CommandReturnObject &result) override {425    bool demangled_any = false;426    bool error_any = false;427    for (auto &entry : command.entries()) {428      if (entry.ref().empty())429        continue;430 431      // the actual Mangled class should be strict about this, but on the432      // command line if you're copying mangled names out of 'nm' on Darwin,433      // they will come out with an extra underscore - be willing to strip this434      // on behalf of the user.   This is the moral equivalent of the -_/-n435      // options to c++filt436      auto name = entry.ref();437      if (name.starts_with("__Z"))438        name = name.drop_front();439 440      Mangled mangled(name);441      if (mangled.GuessLanguage() == lldb::eLanguageTypeC_plus_plus) {442        ConstString demangled(mangled.GetDisplayDemangledName());443        demangled_any = true;444        result.AppendMessageWithFormat("%s ---> %s\n", entry.c_str(),445                                       demangled.GetCString());446      } else {447        error_any = true;448        result.AppendErrorWithFormat("%s is not a valid C++ mangled name\n",449                                     entry.ref().str().c_str());450      }451    }452 453    result.SetStatus(454        error_any ? lldb::eReturnStatusFailed455                  : (demangled_any ? lldb::eReturnStatusSuccessFinishResult456                                   : lldb::eReturnStatusSuccessFinishNoResult));457  }458};459 460class CommandObjectMultiwordItaniumABI : public CommandObjectMultiword {461public:462  CommandObjectMultiwordItaniumABI(CommandInterpreter &interpreter)463      : CommandObjectMultiword(464            interpreter, "cplusplus",465            "Commands for operating on the C++ language runtime.",466            "cplusplus <subcommand> [<subcommand-options>]") {467    LoadSubCommand(468        "demangle",469        CommandObjectSP(470            new CommandObjectMultiwordItaniumABI_Demangle(interpreter)));471  }472 473  ~CommandObjectMultiwordItaniumABI() override = default;474};475 476void ItaniumABILanguageRuntime::Initialize() {477  PluginManager::RegisterPlugin(478      GetPluginNameStatic(), "Itanium ABI for the C++ language", CreateInstance,479      [](CommandInterpreter &interpreter) -> lldb::CommandObjectSP {480        return CommandObjectSP(481            new CommandObjectMultiwordItaniumABI(interpreter));482      });483}484 485void ItaniumABILanguageRuntime::Terminate() {486  PluginManager::UnregisterPlugin(CreateInstance);487}488 489BreakpointResolverSP ItaniumABILanguageRuntime::CreateExceptionResolver(490    const BreakpointSP &bkpt, bool catch_bp, bool throw_bp) {491  return CreateExceptionResolver(bkpt, catch_bp, throw_bp, false);492}493 494BreakpointResolverSP ItaniumABILanguageRuntime::CreateExceptionResolver(495    const BreakpointSP &bkpt, bool catch_bp, bool throw_bp,496    bool for_expressions) {497  // One complication here is that most users DON'T want to stop at498  // __cxa_allocate_expression, but until we can do anything better with499  // predicting unwinding the expression parser does.  So we have two forms of500  // the exception breakpoints, one for expressions that leaves out501  // __cxa_allocate_exception, and one that includes it. The502  // SetExceptionBreakpoints does the latter, the CreateExceptionBreakpoint in503  // the runtime the former.504  static const char *g_catch_name = "__cxa_begin_catch";505  static const char *g_throw_name1 = "__cxa_throw";506  static const char *g_throw_name2 = "__cxa_rethrow";507  static const char *g_exception_throw_name = "__cxa_allocate_exception";508  std::vector<const char *> exception_names;509  exception_names.reserve(4);510  if (catch_bp)511    exception_names.push_back(g_catch_name);512 513  if (throw_bp) {514    exception_names.push_back(g_throw_name1);515    exception_names.push_back(g_throw_name2);516  }517 518  if (for_expressions)519    exception_names.push_back(g_exception_throw_name);520 521  BreakpointResolverSP resolver_sp(new BreakpointResolverName(522      bkpt, exception_names.data(), exception_names.size(),523      eFunctionNameTypeBase, eLanguageTypeUnknown, 0, eLazyBoolNo));524 525  return resolver_sp;526}527 528lldb::SearchFilterSP ItaniumABILanguageRuntime::CreateExceptionSearchFilter() {529  Target &target = m_process->GetTarget();530 531  FileSpecList filter_modules;532  if (target.GetArchitecture().GetTriple().getVendor() == llvm::Triple::Apple) {533    // Limit the number of modules that are searched for these breakpoints for534    // Apple binaries.535    filter_modules.EmplaceBack("libc++abi.dylib");536    filter_modules.EmplaceBack("libSystem.B.dylib");537    filter_modules.EmplaceBack("libc++abi.1.0.dylib");538    filter_modules.EmplaceBack("libc++abi.1.dylib");539  }540  return target.GetSearchFilterForModuleList(&filter_modules);541}542 543lldb::BreakpointSP ItaniumABILanguageRuntime::CreateExceptionBreakpoint(544    bool catch_bp, bool throw_bp, bool for_expressions, bool is_internal) {545  Target &target = m_process->GetTarget();546  FileSpecList filter_modules;547  BreakpointResolverSP exception_resolver_sp =548      CreateExceptionResolver(nullptr, catch_bp, throw_bp, for_expressions);549  SearchFilterSP filter_sp(CreateExceptionSearchFilter());550  const bool hardware = false;551  const bool resolve_indirect_functions = false;552  return target.CreateBreakpoint(filter_sp, exception_resolver_sp, is_internal,553                                 hardware, resolve_indirect_functions);554}555 556void ItaniumABILanguageRuntime::SetExceptionBreakpoints() {557  if (!m_process)558    return;559 560  const bool catch_bp = false;561  const bool throw_bp = true;562  const bool is_internal = true;563  const bool for_expressions = true;564 565  // For the exception breakpoints set by the Expression parser, we'll be a566  // little more aggressive and stop at exception allocation as well.567 568  if (m_cxx_exception_bp_sp) {569    m_cxx_exception_bp_sp->SetEnabled(true);570  } else {571    m_cxx_exception_bp_sp = CreateExceptionBreakpoint(572        catch_bp, throw_bp, for_expressions, is_internal);573    if (m_cxx_exception_bp_sp)574      m_cxx_exception_bp_sp->SetBreakpointKind("c++ exception");575  }576}577 578void ItaniumABILanguageRuntime::ClearExceptionBreakpoints() {579  if (!m_process)580    return;581 582  if (m_cxx_exception_bp_sp) {583    m_cxx_exception_bp_sp->SetEnabled(false);584  }585}586 587bool ItaniumABILanguageRuntime::ExceptionBreakpointsAreSet() {588  return m_cxx_exception_bp_sp && m_cxx_exception_bp_sp->IsEnabled();589}590 591bool ItaniumABILanguageRuntime::ExceptionBreakpointsExplainStop(592    lldb::StopInfoSP stop_reason) {593  if (!m_process)594    return false;595 596  if (!stop_reason || stop_reason->GetStopReason() != eStopReasonBreakpoint)597    return false;598 599  uint64_t break_site_id = stop_reason->GetValue();600  return m_process->GetBreakpointSiteList().StopPointSiteContainsBreakpoint(601      break_site_id, m_cxx_exception_bp_sp->GetID());602}603 604ValueObjectSP ItaniumABILanguageRuntime::GetExceptionObjectForThread(605    ThreadSP thread_sp) {606  if (!thread_sp->SafeToCallFunctions())607    return {};608 609  TypeSystemClangSP scratch_ts_sp =610      ScratchTypeSystemClang::GetForTarget(m_process->GetTarget());611  if (!scratch_ts_sp)612    return {};613 614  CompilerType voidstar =615      scratch_ts_sp->GetBasicType(eBasicTypeVoid).GetPointerType();616 617  DiagnosticManager diagnostics;618  ExecutionContext exe_ctx;619  EvaluateExpressionOptions options;620 621  options.SetUnwindOnError(true);622  options.SetIgnoreBreakpoints(true);623  options.SetStopOthers(true);624  options.SetTimeout(m_process->GetUtilityExpressionTimeout());625  options.SetTryAllThreads(false);626  thread_sp->CalculateExecutionContext(exe_ctx);627 628  const ModuleList &modules = m_process->GetTarget().GetImages();629  SymbolContextList contexts;630  SymbolContext context;631 632  modules.FindSymbolsWithNameAndType(633      ConstString("__cxa_current_exception_type"), eSymbolTypeCode, contexts);634  contexts.GetContextAtIndex(0, context);635  if (!context.symbol) {636    return {};637  }638  Address addr = context.symbol->GetAddress();639 640  Status error;641  FunctionCaller *function_caller =642      m_process->GetTarget().GetFunctionCallerForLanguage(643          eLanguageTypeC, voidstar, addr, ValueList(), "caller", error);644 645  ExpressionResults func_call_ret;646  Value results;647  func_call_ret = function_caller->ExecuteFunction(exe_ctx, nullptr, options,648                                                   diagnostics, results);649  if (func_call_ret != eExpressionCompleted || !error.Success()) {650    return ValueObjectSP();651  }652 653  size_t ptr_size = m_process->GetAddressByteSize();654  addr_t result_ptr = results.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);655  addr_t exception_addr =656      m_process->ReadPointerFromMemory(result_ptr - ptr_size, error);657 658  if (!error.Success()) {659    return ValueObjectSP();660  }661 662  lldb_private::formatters::InferiorSizedWord exception_isw(exception_addr,663                                                            *m_process);664  ValueObjectSP exception = ValueObject::CreateValueObjectFromData(665      "exception", exception_isw.GetAsData(m_process->GetByteOrder()), exe_ctx,666      voidstar);667  ValueObjectSP dyn_exception668      = exception->GetDynamicValue(eDynamicDontRunTarget);669  // If we succeed in making a dynamic value, return that:670  if (dyn_exception)671     return dyn_exception;672 673  return exception;674}675 676TypeAndOrName ItaniumABILanguageRuntime::GetDynamicTypeInfo(677    const lldb_private::Address &vtable_addr) {678  std::lock_guard<std::mutex> locker(m_mutex);679  DynamicTypeCache::const_iterator pos = m_dynamic_type_map.find(vtable_addr);680  if (pos == m_dynamic_type_map.end())681    return TypeAndOrName();682  else683    return pos->second;684}685 686void ItaniumABILanguageRuntime::SetDynamicTypeInfo(687    const lldb_private::Address &vtable_addr, const TypeAndOrName &type_info) {688  std::lock_guard<std::mutex> locker(m_mutex);689  m_dynamic_type_map[vtable_addr] = type_info;690}691