| //===----------------------------------------------------------------------===// | |
| // | |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | |
| // See https://llvm.org/LICENSE.txt for license information. | |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | |
| // | |
| //===----------------------------------------------------------------------===// | |
| #include "ItaniumABIRuntime.h" | |
| #include "Plugins/TypeSystem/Clang/TypeSystemClang.h" | |
| #include "lldb/DataFormatters/FormattersHelpers.h" | |
| #include "lldb/Expression/DiagnosticManager.h" | |
| #include "lldb/Expression/FunctionCaller.h" | |
| #include "lldb/Utility/LLDBLog.h" | |
| using namespace lldb; | |
| using namespace lldb_private; | |
| static const char *vtable_demangled_prefix = "vtable for "; | |
| ItaniumABIRuntime::ItaniumABIRuntime(Process *process) : m_process(process) {} | |
| TypeAndOrName | |
| ItaniumABIRuntime::GetTypeInfo(ValueObject &in_value, | |
| const LanguageRuntime::VTableInfo &vtable_info) { | |
| if (vtable_info.addr.IsSectionOffset()) { | |
| // See if we have cached info for this type already | |
| TypeAndOrName type_info = GetDynamicTypeInfo(vtable_info.addr); | |
| if (type_info) | |
| return type_info; | |
| if (vtable_info.symbol) { | |
| Log *log = GetLog(LLDBLog::Object); | |
| llvm::StringRef symbol_name = | |
| vtable_info.symbol->GetMangled().GetDemangledName().GetStringRef(); | |
| LLDB_LOGF(log, | |
| "0x%16.16" PRIx64 | |
| ": static-type = '%s' has vtable symbol '%s'\n", | |
| in_value.GetPointerValue().address, | |
| in_value.GetTypeName().GetCString(), symbol_name.str().c_str()); | |
| // We are a C++ class, that's good. Get the class name and look it | |
| // up: | |
| llvm::StringRef class_name = symbol_name; | |
| class_name.consume_front(vtable_demangled_prefix); | |
| // We know the class name is absolute, so tell FindTypes that by | |
| // prefixing it with the root namespace: | |
| std::string lookup_name("::"); | |
| lookup_name.append(class_name.data(), class_name.size()); | |
| type_info.SetName(class_name); | |
| ConstString const_lookup_name(lookup_name); | |
| TypeList class_types; | |
| ModuleSP module_sp = vtable_info.symbol->CalculateSymbolContextModule(); | |
| // First look in the module that the vtable symbol came from and | |
| // look for a single exact match. | |
| TypeResults results; | |
| TypeQuery query(const_lookup_name.GetStringRef(), | |
| TypeQueryOptions::e_exact_match | | |
| TypeQueryOptions::e_strict_namespaces | | |
| TypeQueryOptions::e_find_one); | |
| if (module_sp) { | |
| module_sp->FindTypes(query, results); | |
| TypeSP type_sp = results.GetFirstType(); | |
| if (type_sp) | |
| class_types.Insert(type_sp); | |
| } | |
| // If we didn't find a symbol, then move on to the entire module | |
| // list in the target and get as many unique matches as possible | |
| if (class_types.Empty()) { | |
| query.SetFindOne(false); | |
| m_process->GetTarget().GetImages().FindTypes(nullptr, query, results); | |
| for (const auto &type_sp : results.GetTypeMap().Types()) | |
| class_types.Insert(type_sp); | |
| } | |
| lldb::TypeSP type_sp; | |
| if (class_types.Empty()) { | |
| LLDB_LOGF(log, "0x%16.16" PRIx64 ": is not dynamic\n", | |
| in_value.GetPointerValue().address); | |
| return TypeAndOrName(); | |
| } | |
| if (class_types.GetSize() == 1) { | |
| type_sp = class_types.GetTypeAtIndex(0); | |
| if (type_sp) { | |
| if (TypeSystemClang::IsCXXClassType( | |
| type_sp->GetForwardCompilerType())) { | |
| LLDB_LOGF(log, | |
| "0x%16.16" PRIx64 | |
| ": static-type = '%s' has dynamic type: uid={0x%" PRIx64 | |
| "}, type-name='%s'\n", | |
| in_value.GetPointerValue().address, | |
| in_value.GetTypeName().AsCString(""), type_sp->GetID(), | |
| type_sp->GetName().GetCString()); | |
| type_info.SetTypeSP(type_sp); | |
| } | |
| } | |
| } else { | |
| size_t i; | |
| if (log) { | |
| for (i = 0; i < class_types.GetSize(); i++) { | |
| type_sp = class_types.GetTypeAtIndex(i); | |
| if (type_sp) { | |
| LLDB_LOGF(log, | |
| "0x%16.16" PRIx64 | |
| ": static-type = '%s' has multiple matching dynamic " | |
| "types: uid={0x%" PRIx64 "}, type-name='%s'\n", | |
| in_value.GetPointerValue().address, | |
| in_value.GetTypeName().AsCString(""), type_sp->GetID(), | |
| type_sp->GetName().GetCString()); | |
| } | |
| } | |
| } | |
| for (i = 0; i < class_types.GetSize(); i++) { | |
| type_sp = class_types.GetTypeAtIndex(i); | |
| if (type_sp) { | |
| if (TypeSystemClang::IsCXXClassType( | |
| type_sp->GetForwardCompilerType())) { | |
| LLDB_LOGF(log, | |
| "0x%16.16" PRIx64 ": static-type = '%s' has multiple " | |
| "matching dynamic types, picking " | |
| "this one: uid={0x%" PRIx64 "}, type-name='%s'\n", | |
| in_value.GetPointerValue().address, | |
| in_value.GetTypeName().AsCString(""), type_sp->GetID(), | |
| type_sp->GetName().GetCString()); | |
| type_info.SetTypeSP(type_sp); | |
| } | |
| } | |
| } | |
| LLDB_LOGF(log, | |
| "0x%16.16" PRIx64 | |
| ": static-type = '%s' has multiple matching dynamic " | |
| "types, didn't find a C++ match\n", | |
| in_value.GetPointerValue().address, | |
| in_value.GetTypeName().AsCString("")); | |
| } | |
| if (type_info) | |
| SetDynamicTypeInfo(vtable_info.addr, type_info); | |
| return type_info; | |
| } | |
| } | |
| return TypeAndOrName(); | |
| } | |
| llvm::Error ItaniumABIRuntime::TypeHasVTable(CompilerType type) { | |
| // Check to make sure the class has a vtable. | |
| CompilerType original_type = type; | |
| if (type.IsPointerOrReferenceType()) { | |
| CompilerType pointee_type = type.GetPointeeType(); | |
| if (pointee_type) | |
| type = pointee_type; | |
| } | |
| // Make sure this is a class or a struct first by checking the type class | |
| // bitfield that gets returned. | |
| if ((type.GetTypeClass() & (eTypeClassStruct | eTypeClassClass)) == 0) { | |
| return llvm::createStringError( | |
| std::errc::invalid_argument, | |
| "type \"%s\" is not a class or struct or a pointer to one", | |
| original_type.GetTypeName().AsCString("<invalid>")); | |
| } | |
| // Check if the type has virtual functions by asking it if it is polymorphic. | |
| if (!type.IsPolymorphicClass()) { | |
| return llvm::createStringError(std::errc::invalid_argument, | |
| "type \"%s\" doesn't have a vtable", | |
| type.GetTypeName().AsCString("<invalid>")); | |
| } | |
| return llvm::Error::success(); | |
| } | |
| // This function can accept both pointers or references to classes as well as | |
| // instances of classes. If you are using this function during dynamic type | |
| // detection, only valid ValueObjects that return true to | |
| // CouldHaveDynamicValue(...) should call this function and \a check_type | |
| // should be set to false. This function is also used by ValueObjectVTable | |
| // and is can pass in instances of classes which is not suitable for dynamic | |
| // type detection, these cases should pass true for \a check_type. | |
| llvm::Expected<LanguageRuntime::VTableInfo> | |
| ItaniumABIRuntime::GetVTableInfo(ValueObject &in_value, bool check_type) { | |
| CompilerType type = in_value.GetCompilerType(); | |
| if (check_type) { | |
| if (llvm::Error err = TypeHasVTable(type)) | |
| return std::move(err); | |
| } | |
| ExecutionContext exe_ctx(in_value.GetExecutionContextRef()); | |
| Process *process = exe_ctx.GetProcessPtr(); | |
| if (process == nullptr) | |
| return llvm::createStringError(std::errc::invalid_argument, | |
| "invalid process"); | |
| auto [original_ptr, address_type] = | |
| type.IsPointerOrReferenceType() | |
| ? in_value.GetPointerValue() | |
| : in_value.GetAddressOf(/*scalar_is_load_address=*/true); | |
| if (original_ptr == LLDB_INVALID_ADDRESS || address_type != eAddressTypeLoad) | |
| return llvm::createStringError(std::errc::invalid_argument, | |
| "failed to get the address of the value"); | |
| Status error; | |
| lldb::addr_t vtable_load_addr = | |
| process->ReadPointerFromMemory(original_ptr, error); | |
| if (!error.Success() || vtable_load_addr == LLDB_INVALID_ADDRESS) | |
| return llvm::createStringError( | |
| std::errc::invalid_argument, | |
| "failed to read vtable pointer from memory at 0x%" PRIx64, | |
| original_ptr); | |
| // The vtable load address can have authentication bits with | |
| // AArch64 targets on Darwin. | |
| vtable_load_addr = process->FixDataAddress(vtable_load_addr); | |
| // Find the symbol that contains the "vtable_load_addr" address | |
| Address vtable_addr; | |
| if (!process->GetTarget().ResolveLoadAddress(vtable_load_addr, vtable_addr)) | |
| return llvm::createStringError(std::errc::invalid_argument, | |
| "failed to resolve vtable pointer 0x%" PRIx64 | |
| "to a section", | |
| vtable_load_addr); | |
| // Check our cache first to see if we already have this info | |
| { | |
| std::lock_guard<std::mutex> locker(m_mutex); | |
| auto pos = m_vtable_info_map.find(vtable_addr); | |
| if (pos != m_vtable_info_map.end()) | |
| return pos->second; | |
| } | |
| Symbol *symbol = vtable_addr.CalculateSymbolContextSymbol(); | |
| if (symbol == nullptr) | |
| return llvm::createStringError(std::errc::invalid_argument, | |
| "no symbol found for 0x%" PRIx64, | |
| vtable_load_addr); | |
| llvm::StringRef name = symbol->GetMangled().GetDemangledName().GetStringRef(); | |
| if (name.starts_with(vtable_demangled_prefix)) { | |
| LanguageRuntime::VTableInfo info = {vtable_addr, symbol}; | |
| std::lock_guard<std::mutex> locker(m_mutex); | |
| auto pos = m_vtable_info_map[vtable_addr] = info; | |
| return info; | |
| } | |
| return llvm::createStringError(std::errc::invalid_argument, | |
| "symbol found that contains 0x%" PRIx64 | |
| " is not a vtable symbol", | |
| vtable_load_addr); | |
| } | |
| bool ItaniumABIRuntime::GetDynamicTypeAndAddress( | |
| ValueObject &in_value, lldb::DynamicValueType use_dynamic, | |
| TypeAndOrName &class_type_or_name, Address &dynamic_address, | |
| Value::ValueType &value_type) { | |
| // For Itanium, if the type has a vtable pointer in the object, it will be at | |
| // offset 0 in the object. That will point to the "address point" within the | |
| // vtable (not the beginning of the vtable.) We can then look up the symbol | |
| // containing this "address point" and that symbol's name demangled will | |
| // contain the full class name. The second pointer above the "address point" | |
| // is the "offset_to_top". We'll use that to get the start of the value | |
| // object which holds the dynamic type. | |
| // Check if we have a vtable pointer in this value. If we don't it will | |
| // return an error, else it will return a valid resolved address. We don't | |
| // want GetVTableInfo to check the type since we accept void * as a possible | |
| // dynamic type and that won't pass the type check. We already checked the | |
| // type above in CouldHaveDynamicValue(...). | |
| llvm::Expected<LanguageRuntime::VTableInfo> vtable_info_or_err = | |
| GetVTableInfo(in_value, /*check_type=*/false); | |
| if (!vtable_info_or_err) { | |
| llvm::consumeError(vtable_info_or_err.takeError()); | |
| return false; | |
| } | |
| const LanguageRuntime::VTableInfo &vtable_info = vtable_info_or_err.get(); | |
| class_type_or_name = GetTypeInfo(in_value, vtable_info); | |
| if (!class_type_or_name) | |
| return false; | |
| CompilerType type = class_type_or_name.GetCompilerType(); | |
| // There can only be one type with a given name, so we've just found | |
| // duplicate definitions, and this one will do as well as any other. We | |
| // don't consider something to have a dynamic type if it is the same as | |
| // the static type. So compare against the value we were handed. | |
| if (!type) | |
| return true; | |
| if (TypeSystemClang::AreTypesSame(in_value.GetCompilerType(), type)) { | |
| // The dynamic type we found was the same type, so we don't have a | |
| // dynamic type here... | |
| return false; | |
| } | |
| // The offset_to_top is two pointers above the vtable pointer. | |
| Target &target = m_process->GetTarget(); | |
| const addr_t vtable_load_addr = vtable_info.addr.GetLoadAddress(&target); | |
| if (vtable_load_addr == LLDB_INVALID_ADDRESS) | |
| return false; | |
| const uint32_t addr_byte_size = m_process->GetAddressByteSize(); | |
| const lldb::addr_t offset_to_top_location = | |
| vtable_load_addr - 2 * addr_byte_size; | |
| // Watch for underflow, offset_to_top_location should be less than | |
| // vtable_load_addr | |
| if (offset_to_top_location >= vtable_load_addr) | |
| return false; | |
| Status error; | |
| const int64_t offset_to_top = target.ReadSignedIntegerFromMemory( | |
| Address(offset_to_top_location), addr_byte_size, INT64_MIN, error); | |
| if (offset_to_top == INT64_MIN) | |
| return false; | |
| // So the dynamic type is a value that starts at offset_to_top above | |
| // the original address. | |
| lldb::addr_t dynamic_addr = | |
| in_value.GetPointerValue().address + offset_to_top; | |
| if (!m_process->GetTarget().ResolveLoadAddress(dynamic_addr, | |
| dynamic_address)) { | |
| dynamic_address.SetRawAddress(dynamic_addr); | |
| } | |
| return true; | |
| } | |
| void ItaniumABIRuntime::AppendExceptionBreakpointFunctions( | |
| std::vector<const char *> &names, bool catch_bp, bool throw_bp, | |
| bool for_expressions) { | |
| // One complication here is that most users DON'T want to stop at | |
| // __cxa_allocate_expression, but until we can do anything better with | |
| // predicting unwinding the expression parser does. So we have two forms of | |
| // the exception breakpoints, one for expressions that leaves out | |
| // __cxa_allocate_exception, and one that includes it. The | |
| // SetExceptionBreakpoints does the latter, the CreateExceptionBreakpoint in | |
| // the runtime the former. | |
| static const char *g_catch_name = "__cxa_begin_catch"; | |
| static const char *g_throw_name1 = "__cxa_throw"; | |
| static const char *g_throw_name2 = "__cxa_rethrow"; | |
| static const char *g_exception_throw_name = "__cxa_allocate_exception"; | |
| if (catch_bp) | |
| names.push_back(g_catch_name); | |
| if (throw_bp) { | |
| names.push_back(g_throw_name1); | |
| names.push_back(g_throw_name2); | |
| } | |
| if (for_expressions) | |
| names.push_back(g_exception_throw_name); | |
| } | |
| void ItaniumABIRuntime::AppendExceptionBreakpointFilterModules( | |
| FileSpecList &filter_modules, const Target &target) { | |
| if (target.GetArchitecture().GetTriple().getVendor() == llvm::Triple::Apple) { | |
| // Limit the number of modules that are searched for these breakpoints for | |
| // Apple binaries. | |
| filter_modules.EmplaceBack("libc++abi.dylib"); | |
| filter_modules.EmplaceBack("libSystem.B.dylib"); | |
| filter_modules.EmplaceBack("libc++abi.1.0.dylib"); | |
| filter_modules.EmplaceBack("libc++abi.1.dylib"); | |
| } | |
| } | |
| ValueObjectSP | |
| ItaniumABIRuntime::GetExceptionObjectForThread(ThreadSP thread_sp) { | |
| if (!thread_sp->SafeToCallFunctions()) | |
| return {}; | |
| TypeSystemClangSP scratch_ts_sp = | |
| ScratchTypeSystemClang::GetForTarget(m_process->GetTarget()); | |
| if (!scratch_ts_sp) | |
| return {}; | |
| CompilerType voidstar = | |
| scratch_ts_sp->GetBasicType(eBasicTypeVoid).GetPointerType(); | |
| DiagnosticManager diagnostics; | |
| ExecutionContext exe_ctx; | |
| EvaluateExpressionOptions options; | |
| options.SetUnwindOnError(true); | |
| options.SetIgnoreBreakpoints(true); | |
| options.SetStopOthers(true); | |
| options.SetTimeout(m_process->GetUtilityExpressionTimeout()); | |
| options.SetTryAllThreads(false); | |
| thread_sp->CalculateExecutionContext(exe_ctx); | |
| const ModuleList &modules = m_process->GetTarget().GetImages(); | |
| SymbolContextList contexts; | |
| SymbolContext context; | |
| modules.FindSymbolsWithNameAndType( | |
| ConstString("__cxa_current_exception_type"), eSymbolTypeCode, contexts); | |
| contexts.GetContextAtIndex(0, context); | |
| if (!context.symbol) { | |
| return {}; | |
| } | |
| Address addr = context.symbol->GetAddress(); | |
| Status error; | |
| FunctionCaller *function_caller = | |
| m_process->GetTarget().GetFunctionCallerForLanguage( | |
| eLanguageTypeC, voidstar, addr, ValueList(), "caller", error); | |
| ExpressionResults func_call_ret; | |
| Value results; | |
| func_call_ret = function_caller->ExecuteFunction(exe_ctx, nullptr, options, | |
| diagnostics, results); | |
| if (func_call_ret != eExpressionCompleted || !error.Success()) { | |
| return ValueObjectSP(); | |
| } | |
| size_t ptr_size = m_process->GetAddressByteSize(); | |
| addr_t result_ptr = results.GetScalar().ULongLong(LLDB_INVALID_ADDRESS); | |
| addr_t exception_addr = | |
| m_process->ReadPointerFromMemory(result_ptr - ptr_size, error); | |
| if (!error.Success()) { | |
| return ValueObjectSP(); | |
| } | |
| lldb_private::formatters::InferiorSizedWord exception_isw(exception_addr, | |
| *m_process); | |
| ValueObjectSP exception = ValueObject::CreateValueObjectFromData( | |
| "exception", exception_isw.GetAsData(m_process->GetByteOrder()), exe_ctx, | |
| voidstar); | |
| ValueObjectSP dyn_exception = | |
| exception->GetDynamicValue(eDynamicDontRunTarget); | |
| // If we succeed in making a dynamic value, return that: | |
| if (dyn_exception) | |
| return dyn_exception; | |
| return exception; | |
| } | |
| TypeAndOrName ItaniumABIRuntime::GetDynamicTypeInfo( | |
| const lldb_private::Address &vtable_addr) { | |
| std::lock_guard<std::mutex> locker(m_mutex); | |
| DynamicTypeCache::const_iterator pos = m_dynamic_type_map.find(vtable_addr); | |
| if (pos == m_dynamic_type_map.end()) | |
| return TypeAndOrName(); | |
| else | |
| return pos->second; | |
| } | |
| void ItaniumABIRuntime::SetDynamicTypeInfo( | |
| const lldb_private::Address &vtable_addr, const TypeAndOrName &type_info) { | |
| std::lock_guard<std::mutex> locker(m_mutex); | |
| m_dynamic_type_map[vtable_addr] = type_info; | |
| } |