//===-- 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/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/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 in_value.IsPossibleCPlusPlusDynamicType(); } 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)) { // FIXME: Can we get the Clang Type and ask it if the thing is really virtual? That would avoid false positives, // at the cost of not looking for the dynamic type of objects if DWARF->Clang gets it wrong. // 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, true); if (original_ptr == LLDB_INVALID_ADDRESS) return false; Target *target = in_value.GetUpdatePoint().GetTarget(); Process *process = in_value.GetUpdatePoint().GetProcess(); 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) { // 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); TypeList class_types; uint32_t num_matches = target->GetImages().FindTypes (sc, ConstString(class_name), true, UINT32_MAX, class_types); if (num_matches == 1) { class_type_or_name.SetTypeSP(class_types.GetTypeAtIndex(0)); } else if (num_matches > 1) { for (size_t i = 0; i < num_matches; i++) { lldb::TypeSP this_type(class_types.GetTypeAtIndex(i)); if (this_type) { if (ClangASTContext::IsCXXClassType(this_type->GetClangFullType())) { // 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: clang::ASTContext *in_ast_ctx = in_value.GetClangAST (); clang::ASTContext *this_ast_ctx = this_type->GetClangAST (); if (in_ast_ctx != this_ast_ctx || !ClangASTContext::AreTypesSame (in_ast_ctx, in_value.GetClangType(), this_type->GetClangFullType())) { class_type_or_name.SetTypeSP (this_type); return true; } return false; } } } } else 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.SetOffset(dynamic_addr); dynamic_address.SetSection(NULL); } 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 //------------------------------------------------------------------ lldb_private::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; } void ItaniumABILanguageRuntime::SetExceptionBreakpoints () { if (!m_process) return; if (!m_cxx_exception_bp_sp) m_cxx_exception_bp_sp = m_process->GetTarget().CreateBreakpoint (NULL, "__cxa_throw", eFunctionNameTypeBase, true); else m_cxx_exception_bp_sp->SetEnabled (true); if (!m_cxx_exception_alloc_bp_sp) m_cxx_exception_alloc_bp_sp = m_process->GetTarget().CreateBreakpoint (NULL, "__cxa_allocate", eFunctionNameTypeBase, true); else m_cxx_exception_alloc_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); } if (m_cxx_exception_alloc_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(); lldb::BreakpointSiteSP bp_site_sp = m_process->GetBreakpointSiteList().FindByID(break_site_id); if (!bp_site_sp) return false; uint32_t num_owners = bp_site_sp->GetNumberOfOwners(); bool check_cxx_exception = false; break_id_t cxx_exception_bid; bool check_cxx_exception_alloc = false; break_id_t cxx_exception_alloc_bid; if (m_cxx_exception_bp_sp) { check_cxx_exception = true; cxx_exception_bid = m_cxx_exception_bp_sp->GetID(); } if (m_cxx_exception_alloc_bp_sp) { check_cxx_exception_alloc = true; cxx_exception_alloc_bid = m_cxx_exception_alloc_bp_sp->GetID(); } for (uint32_t i = 0; i < num_owners; i++) { break_id_t bid = bp_site_sp->GetOwnerAtIndex(i)->GetBreakpoint().GetID(); if ((check_cxx_exception && (bid == cxx_exception_bid)) || (check_cxx_exception_alloc && (bid == cxx_exception_alloc_bid))) return true; } return false; }