//===-- ItaniumABILanguageRuntime.cpp --------------------------------------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// #include "ItaniumABILanguageRuntime.h" #include "lldb/Breakpoint/BreakpointLocation.h" #include "lldb/Core/ConstString.h" #include "lldb/Core/Error.h" #include "lldb/Core/Log.h" #include "lldb/Core/Module.h" #include "lldb/Core/PluginManager.h" #include "lldb/Core/Scalar.h" #include "lldb/Core/ValueObject.h" #include "lldb/Core/ValueObjectMemory.h" #include "lldb/Symbol/ClangASTContext.h" #include "lldb/Symbol/Symbol.h" #include "lldb/Symbol/TypeList.h" #include "lldb/Target/Process.h" #include "lldb/Target/RegisterContext.h" #include "lldb/Target/StopInfo.h" #include "lldb/Target/Target.h" #include "lldb/Target/Thread.h" #include using namespace lldb; using namespace lldb_private; static const char *pluginName = "ItaniumABILanguageRuntime"; static const char *pluginDesc = "Itanium ABI for the C++ language"; static const char *pluginShort = "language.itanium"; static const char *vtable_demangled_prefix = "vtable for "; bool ItaniumABILanguageRuntime::CouldHaveDynamicValue (ValueObject &in_value) { return ClangASTContext::IsPossibleDynamicType(in_value.GetClangAST(), in_value.GetClangType(), NULL, true, // check for C++ false); // do not check for ObjC } bool ItaniumABILanguageRuntime::GetDynamicTypeAndAddress (ValueObject &in_value, lldb::DynamicValueType use_dynamic, TypeAndOrName &class_type_or_name, Address &dynamic_address) { // 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. // // Only a pointer or reference type can have a different dynamic and static type: if (CouldHaveDynamicValue (in_value)) { // First job, pull out the address at 0 offset from the object. AddressType address_type; lldb::addr_t original_ptr = in_value.GetPointerValue(&address_type); if (original_ptr == LLDB_INVALID_ADDRESS) return false; ExecutionContext exe_ctx (in_value.GetExecutionContextRef()); Target *target = exe_ctx.GetTargetPtr(); Process *process = exe_ctx.GetProcessPtr(); char memory_buffer[16]; DataExtractor data(memory_buffer, sizeof(memory_buffer), process->GetByteOrder(), process->GetAddressByteSize()); size_t address_byte_size = process->GetAddressByteSize(); Error error; size_t bytes_read = process->ReadMemory (original_ptr, memory_buffer, address_byte_size, error); if (!error.Success() || (bytes_read != address_byte_size)) { return false; } uint32_t offset_ptr = 0; lldb::addr_t vtable_address_point = data.GetAddress (&offset_ptr); if (offset_ptr == 0) return false; // Now find the symbol that contains this address: SymbolContext sc; Address address_point_address; if (target && !target->GetSectionLoadList().IsEmpty()) { if (target->GetSectionLoadList().ResolveLoadAddress (vtable_address_point, address_point_address)) { target->GetImages().ResolveSymbolContextForAddress (address_point_address, eSymbolContextSymbol, sc); Symbol *symbol = sc.symbol; if (symbol != NULL) { const char *name = symbol->GetMangled().GetDemangledName().AsCString(); if (strstr(name, vtable_demangled_prefix) == name) { LogSP log (lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_OBJECT)); if (log) log->Printf ("0x%16.16llx: static-type = '%s' has vtable symbol '%s'\n", original_ptr, in_value.GetTypeName().GetCString(), name); // We are a C++ class, that's good. Get the class name and look it up: const char *class_name = name + strlen(vtable_demangled_prefix); class_type_or_name.SetName (class_name); const bool exact_match = true; TypeList class_types; uint32_t num_matches = 0; // First look in the module that the vtable symbol came from // and look for a single exact match. if (sc.module_sp) { num_matches = sc.module_sp->FindTypes (sc, ConstString(class_name), exact_match, 1, class_types); } // 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 (num_matches == 0) { num_matches = target->GetImages().FindTypes (sc, ConstString(class_name), exact_match, UINT32_MAX, class_types); } lldb::TypeSP type_sp; if (num_matches == 0) { if (log) log->Printf("0x%16.16llx: is not dynamic\n", original_ptr); return false; } if (num_matches == 1) { type_sp = class_types.GetTypeAtIndex(0); if (log) log->Printf ("0x%16.16llx: static-type = '%s' has dynamic type: uid={0x%llx}, type-name='%s'\n", original_ptr, in_value.GetTypeName().AsCString(), type_sp->GetID(), type_sp->GetName().GetCString()); class_type_or_name.SetTypeSP(class_types.GetTypeAtIndex(0)); } else if (num_matches > 1) { size_t i; if (log) { for (i = 0; i < num_matches; i++) { type_sp = class_types.GetTypeAtIndex(i); if (type_sp) { if (log) log->Printf ("0x%16.16llx: static-type = '%s' has multiple matching dynamic types: uid={0x%llx}, type-name='%s'\n", original_ptr, in_value.GetTypeName().AsCString(), type_sp->GetID(), type_sp->GetName().GetCString()); } } } for (i = 0; i < num_matches; i++) { type_sp = class_types.GetTypeAtIndex(i); if (type_sp) { if (ClangASTContext::IsCXXClassType(type_sp->GetClangFullType())) { if (log) log->Printf ("0x%16.16llx: static-type = '%s' has multiple matching dynamic types, picking this one: uid={0x%llx}, type-name='%s'\n", original_ptr, in_value.GetTypeName().AsCString(), type_sp->GetID(), type_sp->GetName().GetCString()); class_type_or_name.SetTypeSP(type_sp); break; } } } if (i == num_matches) { if (log) log->Printf ("0x%16.16llx: static-type = '%s' has multiple matching dynamic types, didn't find a C++ match\n", original_ptr, in_value.GetTypeName().AsCString()); return false; } } // 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_sp) { clang::ASTContext *in_ast_ctx = in_value.GetClangAST (); clang::ASTContext *this_ast_ctx = type_sp->GetClangAST (); if (in_ast_ctx == this_ast_ctx) { if (ClangASTContext::AreTypesSame (in_ast_ctx, in_value.GetClangType(), type_sp->GetClangFullType())) { // 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 address. Address offset_to_top_address = address_point_address; int64_t slide = -2 * ((int64_t) target->GetArchitecture().GetAddressByteSize()); offset_to_top_address.Slide (slide); Error error; lldb::addr_t offset_to_top_location = offset_to_top_address.GetLoadAddress(target); size_t bytes_read = process->ReadMemory (offset_to_top_location, memory_buffer, address_byte_size, error); if (!error.Success() || (bytes_read != address_byte_size)) { return false; } offset_ptr = 0; int64_t offset_to_top = data.GetMaxS64(&offset_ptr, process->GetAddressByteSize()); // So the dynamic type is a value that starts at offset_to_top // above the original address. lldb::addr_t dynamic_addr = original_ptr + offset_to_top; if (!target->GetSectionLoadList().ResolveLoadAddress (dynamic_addr, dynamic_address)) { dynamic_address.SetRawAddress(dynamic_addr); } return true; } } } } } } return false; } bool ItaniumABILanguageRuntime::IsVTableName (const char *name) { if (name == NULL) return false; // Can we maybe ask Clang about this? if (strstr (name, "_vptr$") == name) return true; else return false; } //------------------------------------------------------------------ // Static Functions //------------------------------------------------------------------ LanguageRuntime * ItaniumABILanguageRuntime::CreateInstance (Process *process, lldb::LanguageType language) { // FIXME: We have to check the process and make sure we actually know that this process supports // the Itanium ABI. if (language == eLanguageTypeC_plus_plus) return new ItaniumABILanguageRuntime (process); else return NULL; } void ItaniumABILanguageRuntime::Initialize() { PluginManager::RegisterPlugin (pluginName, pluginDesc, CreateInstance); } void ItaniumABILanguageRuntime::Terminate() { PluginManager::UnregisterPlugin (CreateInstance); } //------------------------------------------------------------------ // PluginInterface protocol //------------------------------------------------------------------ const char * ItaniumABILanguageRuntime::GetPluginName() { return pluginName; } const char * ItaniumABILanguageRuntime::GetShortPluginName() { return pluginShort; } uint32_t ItaniumABILanguageRuntime::GetPluginVersion() { return 1; } static const char *exception_names[] = { "__cxa_begin_catch", "__cxa_throw", "__cxa_rethrow", "__cxa_allocate_exception"}; static const int num_throw_names = 3; static const int num_expression_throw_names = 1; BreakpointResolverSP ItaniumABILanguageRuntime::CreateExceptionResolver (Breakpoint *bkpt, bool catch_bp, bool throw_bp) { return CreateExceptionResolver (bkpt, catch_bp, throw_bp, false); } BreakpointResolverSP ItaniumABILanguageRuntime::CreateExceptionResolver (Breakpoint *bkpt, bool catch_bp, bool throw_bp, bool for_expressions) { BreakpointResolverSP resolver_sp; static const int total_expressions = sizeof (exception_names)/sizeof (char *); // 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. uint32_t num_expressions; if (catch_bp && throw_bp) { if (for_expressions) num_expressions = total_expressions; else num_expressions = total_expressions - num_expression_throw_names; resolver_sp.reset (new BreakpointResolverName (bkpt, exception_names, num_expressions, eFunctionNameTypeBase, eLazyBoolNo)); } else if (throw_bp) { if (for_expressions) num_expressions = num_throw_names - num_expression_throw_names; else num_expressions = num_throw_names; resolver_sp.reset (new BreakpointResolverName (bkpt, exception_names + 1, num_expressions, eFunctionNameTypeBase, eLazyBoolNo)); } else if (catch_bp) resolver_sp.reset (new BreakpointResolverName (bkpt, exception_names, total_expressions - num_throw_names, eFunctionNameTypeBase, eLazyBoolNo)); return resolver_sp; } void ItaniumABILanguageRuntime::SetExceptionBreakpoints () { if (!m_process) return; const bool catch_bp = false; const bool throw_bp = true; const bool is_internal = true; const bool for_expressions = true; // For the exception breakpoints set by the Expression parser, we'll be a little more aggressive and // stop at exception allocation as well. if (!m_cxx_exception_bp_sp) { Target &target = m_process->GetTarget(); BreakpointResolverSP exception_resolver_sp = CreateExceptionResolver (NULL, catch_bp, throw_bp, for_expressions); SearchFilterSP filter_sp = target.GetSearchFilterForModule(NULL); m_cxx_exception_bp_sp = target.CreateBreakpoint (filter_sp, exception_resolver_sp, is_internal); } else m_cxx_exception_bp_sp->SetEnabled (true); } void ItaniumABILanguageRuntime::ClearExceptionBreakpoints () { if (!m_process) return; if (m_cxx_exception_bp_sp.get()) { m_cxx_exception_bp_sp->SetEnabled (false); } } bool ItaniumABILanguageRuntime::ExceptionBreakpointsExplainStop (lldb::StopInfoSP stop_reason) { if (!m_process) return false; if (!stop_reason || stop_reason->GetStopReason() != eStopReasonBreakpoint) return false; uint64_t break_site_id = stop_reason->GetValue(); return m_process->GetBreakpointSiteList().BreakpointSiteContainsBreakpoint(break_site_id, m_cxx_exception_bp_sp->GetID()); }