lldb/source/Plugins/LanguageRuntime/CPlusPlus/ItaniumABI/ItaniumABILanguageRuntime.cpp

   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-exception
   6 //
   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
  41 using namespace lldb;
  42 using namespace lldb_private;
  43
  44 LLDB_PLUGIN_DEFINE_ADV(ItaniumABILanguageRuntime, CXXItaniumABI)
  45
  46 static const char *vtable_demangled_prefix = "vtable for ";
  47
  48 char ItaniumABILanguageRuntime::ID = 0;
  49
  50 bool 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
  57 TypeAndOrName 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 already
  61     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" PRIx64
  71                 ": static-type = '%s' has vtable symbol '%s'\n",
  72                 in_value.GetPointerValue(),
  73                 in_value.GetTypeName().GetCString(),
  74                 symbol_name.str().c_str());
  75       // We are a C++ class, that's good.  Get the class name and look it
  76       // up:
  77       llvm::StringRef class_name = symbol_name;
  78       class_name.consume_front(vtable_demangled_prefix);
  79       // We know the class name is absolute, so tell FindTypes that by
  80       // prefixing it with the root namespace:
  81       std::string lookup_name("::");
  82       lookup_name.append(class_name.data(), class_name.size());
  83
  84       type_info.SetName(class_name);
  85       ConstString const_lookup_name(lookup_name);
  86       TypeList class_types;
  87       ModuleSP module_sp = vtable_info.symbol->CalculateSymbolContextModule();
  88       // First look in the module that the vtable symbol came from and
  89       // look for a single exact match.
  90       TypeResults results;
  91       TypeQuery query(const_lookup_name.GetStringRef(),
  92                       TypeQueryOptions::e_exact_match |
  93                           TypeQueryOptions::e_strict_namespaces |
  94                           TypeQueryOptions::e_find_one);
  95       if (module_sp) {
  96         module_sp->FindTypes(query, results);
  97         TypeSP type_sp = results.GetFirstType();
  98         if (type_sp)
  99           class_types.Insert(type_sp);
 100       }
 101
 102       // If we didn't find a symbol, then move on to the entire module
 103       // list in the target and get as many unique matches as possible
 104       if (class_types.Empty()) {
 105         query.SetFindOne(false);
 106         m_process->GetTarget().GetImages().FindTypes(nullptr, query, results);
 107         for (const auto &type_sp : results.GetTypeMap().Types())
 108           class_types.Insert(type_sp);
 109       }
 110
 111       lldb::TypeSP type_sp;
 112       if (class_types.Empty()) {
 113         LLDB_LOGF(log, "0x%16.16" PRIx64 ": is not dynamic\n",
 114                   in_value.GetPointerValue());
 115         return TypeAndOrName();
 116       }
 117       if (class_types.GetSize() == 1) {
 118         type_sp = class_types.GetTypeAtIndex(0);
 119         if (type_sp) {
 120           if (TypeSystemClang::IsCXXClassType(
 121                   type_sp->GetForwardCompilerType())) {
 122             LLDB_LOGF(
 123                 log,
 124                 "0x%16.16" PRIx64
 125                 ": static-type = '%s' has dynamic type: uid={0x%" PRIx64
 126                 "}, type-name='%s'\n",
 127                 in_value.GetPointerValue(), in_value.GetTypeName().AsCString(),
 128                 type_sp->GetID(), type_sp->GetName().GetCString());
 129             type_info.SetTypeSP(type_sp);
 130           }
 131         }
 132       } else {
 133         size_t i;
 134         if (log) {
 135           for (i = 0; i < class_types.GetSize(); i++) {
 136             type_sp = class_types.GetTypeAtIndex(i);
 137             if (type_sp) {
 138               LLDB_LOGF(
 139                   log,
 140                   "0x%16.16" PRIx64
 141                   ": static-type = '%s' has multiple matching dynamic "
 142                   "types: uid={0x%" PRIx64 "}, type-name='%s'\n",
 143                   in_value.GetPointerValue(),
 144                   in_value.GetTypeName().AsCString(),
 145                   type_sp->GetID(), type_sp->GetName().GetCString());
 146             }
 147           }
 148         }
 149
 150         for (i = 0; i < class_types.GetSize(); i++) {
 151           type_sp = class_types.GetTypeAtIndex(i);
 152           if (type_sp) {
 153             if (TypeSystemClang::IsCXXClassType(
 154                     type_sp->GetForwardCompilerType())) {
 155               LLDB_LOGF(
 156                   log,
 157                   "0x%16.16" PRIx64 ": static-type = '%s' has multiple "
 158                   "matching dynamic types, picking "
 159                   "this one: uid={0x%" PRIx64 "}, type-name='%s'\n",
 160                   in_value.GetPointerValue(),
 161                   in_value.GetTypeName().AsCString(),
 162                   type_sp->GetID(), type_sp->GetName().GetCString());
 163               type_info.SetTypeSP(type_sp);
 164             }
 165           }
 166         }
 167
 168         if (log) {
 169           LLDB_LOGF(log,
 170                     "0x%16.16" PRIx64
 171                     ": static-type = '%s' has multiple matching dynamic "
 172                     "types, didn't find a C++ match\n",
 173                     in_value.GetPointerValue(),
 174                     in_value.GetTypeName().AsCString());
 175         }
 176       }
 177       if (type_info)
 178         SetDynamicTypeInfo(vtable_info.addr, type_info);
 179       return type_info;
 180     }
 181   }
 182   return TypeAndOrName();
 183 }
 184
 185 llvm::Error ItaniumABILanguageRuntime::TypeHasVTable(CompilerType type) {
 186   // Check to make sure the class has a vtable.
 187   CompilerType original_type = type;
 188   if (type.IsPointerOrReferenceType()) {
 189     CompilerType pointee_type = type.GetPointeeType();
 190     if (pointee_type)
 191       type = pointee_type;
 192   }
 193
 194   // Make sure this is a class or a struct first by checking the type class
 195   // bitfield that gets returned.
 196   if ((type.GetTypeClass() & (eTypeClassStruct | eTypeClassClass)) == 0) {
 197     return llvm::createStringError(std::errc::invalid_argument,
 198         "type \"%s\" is not a class or struct or a pointer to one",
 199         original_type.GetTypeName().AsCString("<invalid>"));
 200   }
 201
 202   // Check if the type has virtual functions by asking it if it is polymorphic.
 203   if (!type.IsPolymorphicClass()) {
 204     return llvm::createStringError(std::errc::invalid_argument,
 205         "type \"%s\" doesn't have a vtable",
 206         type.GetTypeName().AsCString("<invalid>"));
 207   }
 208   return llvm::Error::success();
 209 }
 210
 211 // This function can accept both pointers or references to classes as well as
 212 // instances of classes. If you are using this function during dynamic type
 213 // detection, only valid ValueObjects that return true to
 214 // CouldHaveDynamicValue(...) should call this function and \a check_type
 215 // should be set to false. This function is also used by ValueObjectVTable
 216 // and is can pass in instances of classes which is not suitable for dynamic
 217 // type detection, these cases should pass true for \a check_type.
 218 llvm::Expected<LanguageRuntime::VTableInfo>
 219  ItaniumABILanguageRuntime::GetVTableInfo(ValueObject &in_value,
 220                                           bool check_type) {
 221
 222   CompilerType type = in_value.GetCompilerType();
 223   if (check_type) {
 224     if (llvm::Error err = TypeHasVTable(type))
 225       return std::move(err);
 226   }
 227   ExecutionContext exe_ctx(in_value.GetExecutionContextRef());
 228   Process *process = exe_ctx.GetProcessPtr();
 229   if (process == nullptr)
 230     return llvm::createStringError(std::errc::invalid_argument,
 231                                    "invalid process");
 232
 233   AddressType address_type;
 234   lldb::addr_t original_ptr = LLDB_INVALID_ADDRESS;
 235   if (type.IsPointerOrReferenceType())
 236     original_ptr = in_value.GetPointerValue(&address_type);
 237   else
 238     original_ptr = in_value.GetAddressOf(/*scalar_is_load_address=*/true,
 239                                          &address_type);
 240   if (original_ptr == LLDB_INVALID_ADDRESS || address_type != eAddressTypeLoad)
 241     return llvm::createStringError(std::errc::invalid_argument,
 242                                    "failed to get the address of the value");
 243
 244   Status error;
 245   lldb::addr_t vtable_load_addr =
 246       process->ReadPointerFromMemory(original_ptr, error);
 247
 248   if (!error.Success() || vtable_load_addr == LLDB_INVALID_ADDRESS)
 249     return llvm::createStringError(std::errc::invalid_argument,
 250         "failed to read vtable pointer from memory at 0x%" PRIx64,
 251         original_ptr);
 252
 253   // The vtable load address can have authentication bits with
 254   // AArch64 targets on Darwin.
 255   vtable_load_addr = process->FixDataAddress(vtable_load_addr);
 256
 257   // Find the symbol that contains the "vtable_load_addr" address
 258   Address vtable_addr;
 259   if (!process->GetTarget().ResolveLoadAddress(vtable_load_addr, vtable_addr))
 260     return llvm::createStringError(std::errc::invalid_argument,
 261                                    "failed to resolve vtable pointer 0x%"
 262                                    PRIx64 "to a section", vtable_load_addr);
 263
 264   // Check our cache first to see if we already have this info
 265   {
 266     std::lock_guard<std::mutex> locker(m_mutex);
 267     auto pos = m_vtable_info_map.find(vtable_addr);
 268     if (pos != m_vtable_info_map.end())
 269       return pos->second;
 270   }
 271
 272   Symbol *symbol = vtable_addr.CalculateSymbolContextSymbol();
 273   if (symbol == nullptr)
 274     return llvm::createStringError(std::errc::invalid_argument,
 275                                    "no symbol found for 0x%" PRIx64,
 276                                    vtable_load_addr);
 277   llvm::StringRef name = symbol->GetMangled().GetDemangledName().GetStringRef();
 278   if (name.starts_with(vtable_demangled_prefix)) {
 279     VTableInfo info = {vtable_addr, symbol};
 280     std::lock_guard<std::mutex> locker(m_mutex);
 281     auto pos = m_vtable_info_map[vtable_addr] = info;
 282     return info;
 283   }
 284   return llvm::createStringError(std::errc::invalid_argument,
 285       "symbol found that contains 0x%" PRIx64 " is not a vtable symbol",
 286       vtable_load_addr);
 287 }
 288
 289 bool ItaniumABILanguageRuntime::GetDynamicTypeAndAddress(
 290     ValueObject &in_value, lldb::DynamicValueType use_dynamic,
 291     TypeAndOrName &class_type_or_name, Address &dynamic_address,
 292     Value::ValueType &value_type) {
 293   // For Itanium, if the type has a vtable pointer in the object, it will be at
 294   // offset 0 in the object.  That will point to the "address point" within the
 295   // vtable (not the beginning of the vtable.)  We can then look up the symbol
 296   // containing this "address point" and that symbol's name demangled will
 297   // contain the full class name. The second pointer above the "address point"
 298   // is the "offset_to_top".  We'll use that to get the start of the value
 299   // object which holds the dynamic type.
 300   //
 301
 302   class_type_or_name.Clear();
 303   value_type = Value::ValueType::Scalar;
 304
 305   if (!CouldHaveDynamicValue(in_value))
 306     return false;
 307
 308   // Check if we have a vtable pointer in this value. If we don't it will
 309   // return an error, else it will return a valid resolved address. We don't
 310   // want GetVTableInfo to check the type since we accept void * as a possible
 311   // dynamic type and that won't pass the type check. We already checked the
 312   // type above in CouldHaveDynamicValue(...).
 313   llvm::Expected<VTableInfo> vtable_info_or_err =
 314       GetVTableInfo(in_value, /*check_type=*/false);
 315   if (!vtable_info_or_err) {
 316     llvm::consumeError(vtable_info_or_err.takeError());
 317     return false;
 318   }
 319
 320   const VTableInfo &vtable_info = vtable_info_or_err.get();
 321   class_type_or_name = GetTypeInfo(in_value, vtable_info);
 322
 323   if (!class_type_or_name)
 324     return false;
 325
 326   CompilerType type = class_type_or_name.GetCompilerType();
 327   // There can only be one type with a given name, so we've just found
 328   // duplicate definitions, and this one will do as well as any other. We
 329   // don't consider something to have a dynamic type if it is the same as
 330   // the static type.  So compare against the value we were handed.
 331   if (!type)
 332     return true;
 333
 334   if (TypeSystemClang::AreTypesSame(in_value.GetCompilerType(), type)) {
 335     // The dynamic type we found was the same type, so we don't have a
 336     // dynamic type here...
 337     return false;
 338   }
 339
 340   // The offset_to_top is two pointers above the vtable pointer.
 341   Target &target = m_process->GetTarget();
 342   const addr_t vtable_load_addr = vtable_info.addr.GetLoadAddress(&target);
 343   if (vtable_load_addr == LLDB_INVALID_ADDRESS)
 344     return false;
 345   const uint32_t addr_byte_size = m_process->GetAddressByteSize();
 346   const lldb::addr_t offset_to_top_location =
 347       vtable_load_addr - 2 * addr_byte_size;
 348   // Watch for underflow, offset_to_top_location should be less than
 349   // vtable_load_addr
 350   if (offset_to_top_location >= vtable_load_addr)
 351     return false;
 352   Status error;
 353   const int64_t offset_to_top = m_process->ReadSignedIntegerFromMemory(
 354       offset_to_top_location, addr_byte_size, INT64_MIN, error);
 355
 356   if (offset_to_top == INT64_MIN)
 357     return false;
 358   // So the dynamic type is a value that starts at offset_to_top above
 359   // the original address.
 360   lldb::addr_t dynamic_addr = in_value.GetPointerValue() + offset_to_top;
 361   if (!m_process->GetTarget().ResolveLoadAddress(
 362           dynamic_addr, dynamic_address)) {
 363     dynamic_address.SetRawAddress(dynamic_addr);
 364   }
 365   return true;
 366 }
 367
 368 TypeAndOrName ItaniumABILanguageRuntime::FixUpDynamicType(
 369     const TypeAndOrName &type_and_or_name, ValueObject &static_value) {
 370   CompilerType static_type(static_value.GetCompilerType());
 371   Flags static_type_flags(static_type.GetTypeInfo());
 372
 373   TypeAndOrName ret(type_and_or_name);
 374   if (type_and_or_name.HasType()) {
 375     // The type will always be the type of the dynamic object.  If our parent's
 376     // type was a pointer, then our type should be a pointer to the type of the
 377     // dynamic object.  If a reference, then the original type should be
 378     // okay...
 379     CompilerType orig_type = type_and_or_name.GetCompilerType();
 380     CompilerType corrected_type = orig_type;
 381     if (static_type_flags.AllSet(eTypeIsPointer))
 382       corrected_type = orig_type.GetPointerType();
 383     else if (static_type_flags.AllSet(eTypeIsReference))
 384       corrected_type = orig_type.GetLValueReferenceType();
 385     ret.SetCompilerType(corrected_type);
 386   } else {
 387     // If we are here we need to adjust our dynamic type name to include the
 388     // correct & or * symbol
 389     std::string corrected_name(type_and_or_name.GetName().GetCString());
 390     if (static_type_flags.AllSet(eTypeIsPointer))
 391       corrected_name.append(" *");
 392     else if (static_type_flags.AllSet(eTypeIsReference))
 393       corrected_name.append(" &");
 394     // the parent type should be a correctly pointer'ed or referenc'ed type
 395     ret.SetCompilerType(static_type);
 396     ret.SetName(corrected_name.c_str());
 397   }
 398   return ret;
 399 }
 400
 401 // Static Functions
 402 LanguageRuntime *
 403 ItaniumABILanguageRuntime::CreateInstance(Process *process,
 404                                           lldb::LanguageType language) {
 405   // FIXME: We have to check the process and make sure we actually know that
 406   // this process supports
 407   // the Itanium ABI.
 408   if (language == eLanguageTypeC_plus_plus ||
 409       language == eLanguageTypeC_plus_plus_03 ||
 410       language == eLanguageTypeC_plus_plus_11 ||
 411       language == eLanguageTypeC_plus_plus_14)
 412     return new ItaniumABILanguageRuntime(process);
 413   else
 414     return nullptr;
 415 }
 416
 417 class CommandObjectMultiwordItaniumABI_Demangle : public CommandObjectParsed {
 418 public:
 419   CommandObjectMultiwordItaniumABI_Demangle(CommandInterpreter &interpreter)
 420       : CommandObjectParsed(
 421             interpreter, "demangle", "Demangle a C++ mangled name.",
 422             "language cplusplus demangle [<mangled-name> ...]") {
 423     AddSimpleArgumentList(eArgTypeSymbol, eArgRepeatPlus);
 424   }
 425
 426   ~CommandObjectMultiwordItaniumABI_Demangle() override = default;
 427
 428 protected:
 429   void DoExecute(Args &command, CommandReturnObject &result) override {
 430     bool demangled_any = false;
 431     bool error_any = false;
 432     for (auto &entry : command.entries()) {
 433       if (entry.ref().empty())
 434         continue;
 435
 436       // the actual Mangled class should be strict about this, but on the
 437       // command line if you're copying mangled names out of 'nm' on Darwin,
 438       // they will come out with an extra underscore - be willing to strip this
 439       // on behalf of the user.   This is the moral equivalent of the -_/-n
 440       // options to c++filt
 441       auto name = entry.ref();
 442       if (name.starts_with("__Z"))
 443         name = name.drop_front();
 444
 445       Mangled mangled(name);
 446       if (mangled.GuessLanguage() == lldb::eLanguageTypeC_plus_plus) {
 447         ConstString demangled(mangled.GetDisplayDemangledName());
 448         demangled_any = true;
 449         result.AppendMessageWithFormat("%s ---> %s\n", entry.c_str(),
 450                                        demangled.GetCString());
 451       } else {
 452         error_any = true;
 453         result.AppendErrorWithFormat("%s is not a valid C++ mangled name\n",
 454                                      entry.ref().str().c_str());
 455       }
 456     }
 457
 458     result.SetStatus(
 459         error_any ? lldb::eReturnStatusFailed
 460                   : (demangled_any ? lldb::eReturnStatusSuccessFinishResult
 461                                    : lldb::eReturnStatusSuccessFinishNoResult));
 462   }
 463 };
 464
 465 class CommandObjectMultiwordItaniumABI : public CommandObjectMultiword {
 466 public:
 467   CommandObjectMultiwordItaniumABI(CommandInterpreter &interpreter)
 468       : CommandObjectMultiword(
 469             interpreter, "cplusplus",
 470             "Commands for operating on the C++ language runtime.",
 471             "cplusplus <subcommand> [<subcommand-options>]") {
 472     LoadSubCommand(
 473         "demangle",
 474         CommandObjectSP(
 475             new CommandObjectMultiwordItaniumABI_Demangle(interpreter)));
 476   }
 477
 478   ~CommandObjectMultiwordItaniumABI() override = default;
 479 };
 480
 481 void ItaniumABILanguageRuntime::Initialize() {
 482   PluginManager::RegisterPlugin(
 483       GetPluginNameStatic(), "Itanium ABI for the C++ language", CreateInstance,
 484       [](CommandInterpreter &interpreter) -> lldb::CommandObjectSP {
 485         return CommandObjectSP(
 486             new CommandObjectMultiwordItaniumABI(interpreter));
 487       });
 488 }
 489
 490 void ItaniumABILanguageRuntime::Terminate() {
 491   PluginManager::UnregisterPlugin(CreateInstance);
 492 }
 493
 494 BreakpointResolverSP ItaniumABILanguageRuntime::CreateExceptionResolver(
 495     const BreakpointSP &bkpt, bool catch_bp, bool throw_bp) {
 496   return CreateExceptionResolver(bkpt, catch_bp, throw_bp, false);
 497 }
 498
 499 BreakpointResolverSP ItaniumABILanguageRuntime::CreateExceptionResolver(
 500     const BreakpointSP &bkpt, bool catch_bp, bool throw_bp,
 501     bool for_expressions) {
 502   // One complication here is that most users DON'T want to stop at
 503   // __cxa_allocate_expression, but until we can do anything better with
 504   // predicting unwinding the expression parser does.  So we have two forms of
 505   // the exception breakpoints, one for expressions that leaves out
 506   // __cxa_allocate_exception, and one that includes it. The
 507   // SetExceptionBreakpoints does the latter, the CreateExceptionBreakpoint in
 508   // the runtime the former.
 509   static const char *g_catch_name = "__cxa_begin_catch";
 510   static const char *g_throw_name1 = "__cxa_throw";
 511   static const char *g_throw_name2 = "__cxa_rethrow";
 512   static const char *g_exception_throw_name = "__cxa_allocate_exception";
 513   std::vector<const char *> exception_names;
 514   exception_names.reserve(4);
 515   if (catch_bp)
 516     exception_names.push_back(g_catch_name);
 517
 518   if (throw_bp) {
 519     exception_names.push_back(g_throw_name1);
 520     exception_names.push_back(g_throw_name2);
 521   }
 522
 523   if (for_expressions)
 524     exception_names.push_back(g_exception_throw_name);
 525
 526   BreakpointResolverSP resolver_sp(new BreakpointResolverName(
 527       bkpt, exception_names.data(), exception_names.size(),
 528       eFunctionNameTypeBase, eLanguageTypeUnknown, 0, eLazyBoolNo));
 529
 530   return resolver_sp;
 531 }
 532
 533 lldb::SearchFilterSP ItaniumABILanguageRuntime::CreateExceptionSearchFilter() {
 534   Target &target = m_process->GetTarget();
 535
 536   FileSpecList filter_modules;
 537   if (target.GetArchitecture().GetTriple().getVendor() == llvm::Triple::Apple) {
 538     // Limit the number of modules that are searched for these breakpoints for
 539     // Apple binaries.
 540     filter_modules.EmplaceBack("libc++abi.dylib");
 541     filter_modules.EmplaceBack("libSystem.B.dylib");
 542     filter_modules.EmplaceBack("libc++abi.1.0.dylib");
 543     filter_modules.EmplaceBack("libc++abi.1.dylib");
 544   }
 545   return target.GetSearchFilterForModuleList(&filter_modules);
 546 }
 547
 548 lldb::BreakpointSP ItaniumABILanguageRuntime::CreateExceptionBreakpoint(
 549     bool catch_bp, bool throw_bp, bool for_expressions, bool is_internal) {
 550   Target &target = m_process->GetTarget();
 551   FileSpecList filter_modules;
 552   BreakpointResolverSP exception_resolver_sp =
 553       CreateExceptionResolver(nullptr, catch_bp, throw_bp, for_expressions);
 554   SearchFilterSP filter_sp(CreateExceptionSearchFilter());
 555   const bool hardware = false;
 556   const bool resolve_indirect_functions = false;
 557   return target.CreateBreakpoint(filter_sp, exception_resolver_sp, is_internal,
 558                                  hardware, resolve_indirect_functions);
 559 }
 560
 561 void ItaniumABILanguageRuntime::SetExceptionBreakpoints() {
 562   if (!m_process)
 563     return;
 564
 565   const bool catch_bp = false;
 566   const bool throw_bp = true;
 567   const bool is_internal = true;
 568   const bool for_expressions = true;
 569
 570   // For the exception breakpoints set by the Expression parser, we'll be a
 571   // little more aggressive and stop at exception allocation as well.
 572
 573   if (m_cxx_exception_bp_sp) {
 574     m_cxx_exception_bp_sp->SetEnabled(true);
 575   } else {
 576     m_cxx_exception_bp_sp = CreateExceptionBreakpoint(
 577         catch_bp, throw_bp, for_expressions, is_internal);
 578     if (m_cxx_exception_bp_sp)
 579       m_cxx_exception_bp_sp->SetBreakpointKind("c++ exception");
 580   }
 581 }
 582
 583 void ItaniumABILanguageRuntime::ClearExceptionBreakpoints() {
 584   if (!m_process)
 585     return;
 586
 587   if (m_cxx_exception_bp_sp) {
 588     m_cxx_exception_bp_sp->SetEnabled(false);
 589   }
 590 }
 591
 592 bool ItaniumABILanguageRuntime::ExceptionBreakpointsAreSet() {
 593   return m_cxx_exception_bp_sp && m_cxx_exception_bp_sp->IsEnabled();
 594 }
 595
 596 bool ItaniumABILanguageRuntime::ExceptionBreakpointsExplainStop(
 597     lldb::StopInfoSP stop_reason) {
 598   if (!m_process)
 599     return false;
 600
 601   if (!stop_reason || stop_reason->GetStopReason() != eStopReasonBreakpoint)
 602     return false;
 603
 604   uint64_t break_site_id = stop_reason->GetValue();
 605   return m_process->GetBreakpointSiteList().StopPointSiteContainsBreakpoint(
 606       break_site_id, m_cxx_exception_bp_sp->GetID());
 607 }
 608
 609 ValueObjectSP ItaniumABILanguageRuntime::GetExceptionObjectForThread(
 610     ThreadSP thread_sp) {
 611   if (!thread_sp->SafeToCallFunctions())
 612     return {};
 613
 614   TypeSystemClangSP scratch_ts_sp =
 615       ScratchTypeSystemClang::GetForTarget(m_process->GetTarget());
 616   if (!scratch_ts_sp)
 617     return {};
 618
 619   CompilerType voidstar =
 620       scratch_ts_sp->GetBasicType(eBasicTypeVoid).GetPointerType();
 621
 622   DiagnosticManager diagnostics;
 623   ExecutionContext exe_ctx;
 624   EvaluateExpressionOptions options;
 625
 626   options.SetUnwindOnError(true);
 627   options.SetIgnoreBreakpoints(true);
 628   options.SetStopOthers(true);
 629   options.SetTimeout(m_process->GetUtilityExpressionTimeout());
 630   options.SetTryAllThreads(false);
 631   thread_sp->CalculateExecutionContext(exe_ctx);
 632
 633   const ModuleList &modules = m_process->GetTarget().GetImages();
 634   SymbolContextList contexts;
 635   SymbolContext context;
 636
 637   modules.FindSymbolsWithNameAndType(
 638       ConstString("__cxa_current_exception_type"), eSymbolTypeCode, contexts);
 639   contexts.GetContextAtIndex(0, context);
 640   if (!context.symbol) {
 641     return {};
 642   }
 643   Address addr = context.symbol->GetAddress();
 644
 645   Status error;
 646   FunctionCaller *function_caller =
 647       m_process->GetTarget().GetFunctionCallerForLanguage(
 648           eLanguageTypeC, voidstar, addr, ValueList(), "caller", error);
 649
 650   ExpressionResults func_call_ret;
 651   Value results;
 652   func_call_ret = function_caller->ExecuteFunction(exe_ctx, nullptr, options,
 653                                                    diagnostics, results);
 654   if (func_call_ret != eExpressionCompleted || !error.Success()) {
 655     return ValueObjectSP();
 656   }
 657
 658   size_t ptr_size = m_process->GetAddressByteSize();
 659   addr_t result_ptr = results.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
 660   addr_t exception_addr =
 661       m_process->ReadPointerFromMemory(result_ptr - ptr_size, error);
 662
 663   if (!error.Success()) {
 664     return ValueObjectSP();
 665   }
 666
 667   lldb_private::formatters::InferiorSizedWord exception_isw(exception_addr,
 668                                                             *m_process);
 669   ValueObjectSP exception = ValueObject::CreateValueObjectFromData(
 670       "exception", exception_isw.GetAsData(m_process->GetByteOrder()), exe_ctx,
 671       voidstar);
 672   ValueObjectSP dyn_exception
 673       = exception->GetDynamicValue(eDynamicDontRunTarget);
 674   // If we succeed in making a dynamic value, return that:
 675   if (dyn_exception)
 676      return dyn_exception;
 677
 678   return exception;
 679 }
 680
 681 TypeAndOrName ItaniumABILanguageRuntime::GetDynamicTypeInfo(
 682     const lldb_private::Address &vtable_addr) {
 683   std::lock_guard<std::mutex> locker(m_mutex);
 684   DynamicTypeCache::const_iterator pos = m_dynamic_type_map.find(vtable_addr);
 685   if (pos == m_dynamic_type_map.end())
 686     return TypeAndOrName();
 687   else
 688     return pos->second;
 689 }
 690
 691 void ItaniumABILanguageRuntime::SetDynamicTypeInfo(
 692     const lldb_private::Address &vtable_addr, const TypeAndOrName &type_info) {
 693   std::lock_guard<std::mutex> locker(m_mutex);
 694   m_dynamic_type_map[vtable_addr] = type_info;
 695 }