//===-- ItaniumABILanguageRuntime.cpp -------------------------------------===//

//

// 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 "ItaniumABILanguageRuntime.h"

#include "Plugins/TypeSystem/Clang/TypeSystemClang.h"

#include "lldb/Breakpoint/BreakpointLocation.h"

#include "lldb/Core/Mangled.h"

#include "lldb/Core/Module.h"

#include "lldb/Core/PluginManager.h"

#include "lldb/Core/ValueObject.h"

#include "lldb/Core/ValueObjectMemory.h"

#include "lldb/DataFormatters/FormattersHelpers.h"

#include "lldb/Expression/DiagnosticManager.h"

#include "lldb/Expression/FunctionCaller.h"

#include "lldb/Interpreter/CommandObject.h"

#include "lldb/Interpreter/CommandObjectMultiword.h"

#include "lldb/Interpreter/CommandReturnObject.h"

#include "lldb/Symbol/Symbol.h"

#include "lldb/Symbol/SymbolFile.h"

#include "lldb/Symbol/TypeList.h"

#include "lldb/Target/Process.h"

#include "lldb/Target/RegisterContext.h"

#include "lldb/Target/SectionLoadList.h"

#include "lldb/Target/StopInfo.h"

#include "lldb/Target/Target.h"

#include "lldb/Target/Thread.h"

#include "lldb/Utility/ConstString.h"

#include "lldb/Utility/LLDBLog.h"

#include "lldb/Utility/Log.h"

#include "lldb/Utility/Scalar.h"

#include "lldb/Utility/Status.h"

#include <vector>

using namespace lldb;

using namespace lldb_private;

LLDB_PLUGIN_DEFINE_ADV(ItaniumABILanguageRuntime, CXXItaniumABI)

static const char *vtable_demangled_prefix = "vtable for ";

char ItaniumABILanguageRuntime::ID = 0;

bool ItaniumABILanguageRuntime::CouldHaveDynamicValue(ValueObject &in_value) {

  const bool check_cxx = true;

  const bool check_objc = false;

  return in_value.GetCompilerType().IsPossibleDynamicType(nullptr, check_cxx,

                                                          check_objc);

}

TypeAndOrName ItaniumABILanguageRuntime::GetTypeInfoFromVTableAddress(

    ValueObject &in_value, lldb::addr_t original_ptr,

    lldb::addr_t vtable_load_addr) {

  if (m_process && vtable_load_addr != LLDB_INVALID_ADDRESS) {

    // Find the symbol that contains the "vtable_load_addr" address

    Address vtable_addr;

    Target &target = m_process->GetTarget();

    if (!target.GetSectionLoadList().IsEmpty()) {

      if (target.GetSectionLoadList().ResolveLoadAddress(vtable_load_addr,

                                                         vtable_addr)) {

        // See if we have cached info for this type already

        TypeAndOrName type_info = GetDynamicTypeInfo(vtable_addr);

        if (type_info)

          return type_info;

        SymbolContext sc;

        target.GetImages().ResolveSymbolContextForAddress(

            vtable_addr, eSymbolContextSymbol, sc);

        Symbol *symbol = sc.symbol;

        if (symbol != nullptr) {

          const char *name =

              symbol->GetMangled().GetDemangledName().AsCString();

          if (name && strstr(name, vtable_demangled_prefix) == name) {

            Log *log = GetLog(LLDBLog::Object);

            LLDB_LOGF(log,

                      "0x%16.16" PRIx64

                      ": 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);

            // 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);

            type_info.SetName(class_name);

            const bool exact_match = true;

            TypeList class_types;

            // First look in the module that the vtable symbol came from and

            // look for a single exact match.

            llvm::DenseSet<SymbolFile *> searched_symbol_files;

            if (sc.module_sp)

              sc.module_sp->FindTypes(ConstString(lookup_name), exact_match, 1,

                                      searched_symbol_files, 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 (class_types.Empty())

              target.GetImages().FindTypes(nullptr, ConstString(lookup_name),

                                           exact_match, UINT32_MAX,

                                           searched_symbol_files, class_types);

            lldb::TypeSP type_sp;

            if (class_types.Empty()) {

              LLDB_LOGF(log, "0x%16.16" PRIx64 ": is not dynamic\n",

                        original_ptr);

              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",

                      original_ptr, 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",

                        original_ptr, 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",

                        original_ptr, in_value.GetTypeName().AsCString(),

                        type_sp->GetID(), type_sp->GetName().GetCString());

                    type_info.SetTypeSP(type_sp);

                  }

                }

              }

              if (log) {

                LLDB_LOGF(log,

                          "0x%16.16" PRIx64

                          ": static-type = '%s' has multiple matching dynamic "

                          "types, didn't find a C++ match\n",

                          original_ptr, in_value.GetTypeName().AsCString());

              }

            }

            if (type_info)

              SetDynamicTypeInfo(vtable_addr, type_info);

            return type_info;

          }

        }

      }

    }

  }

  return TypeAndOrName();

}

bool ItaniumABILanguageRuntime::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.

  //

  class_type_or_name.Clear();

  value_type = Value::ValueType::Scalar;

  // Only a pointer or reference type can have a different dynamic and static

  // type:

  if (!CouldHaveDynamicValue(in_value))

    return false;

  // 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());

  Process *process = exe_ctx.GetProcessPtr();

  if (process == nullptr)

    return false;

  Status error;

  const lldb::addr_t vtable_address_point =

      process->ReadPointerFromMemory(original_ptr, error);

  if (!error.Success() || 
vtable_address_point == 274
LLDB_INVALID_ADDRESS274
)

    return false;

  class_type_or_name = GetTypeInfoFromVTableAddress(in_value, original_ptr,

                                                    vtable_address_point);

  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.

  const uint32_t addr_byte_size = process->GetAddressByteSize();

  const lldb::addr_t offset_to_top_location =

      vtable_address_point - 2 * addr_byte_size;

  // Watch for underflow, offset_to_top_location should be less than

  // vtable_address_point

  if (offset_to_top_location >= vtable_address_point)

    return false;

  const int64_t offset_to_top = process->ReadSignedIntegerFromMemory(

      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 = original_ptr + offset_to_top;

  if (!process->GetTarget().GetSectionLoadList().ResolveLoadAddress(

          dynamic_addr, dynamic_address)) {

    dynamic_address.SetRawAddress(dynamic_addr);

  }

  return true;

}

TypeAndOrName ItaniumABILanguageRuntime::FixUpDynamicType(

    const TypeAndOrName &type_and_or_name, ValueObject &static_value) {

  CompilerType static_type(static_value.GetCompilerType());

  Flags static_type_flags(static_type.GetTypeInfo());

  TypeAndOrName ret(type_and_or_name);

  if (type_and_or_name.HasType()) {

    // The type will always be the type of the dynamic object.  If our parent's

    // type was a pointer, then our type should be a pointer to the type of the

    // dynamic object.  If a reference, then the original type should be

    // okay...

    CompilerType orig_type = type_and_or_name.GetCompilerType();

    CompilerType corrected_type = orig_type;

    if (static_type_flags.AllSet(eTypeIsPointer))

      corrected_type = orig_type.GetPointerType();

    else if (static_type_flags.AllSet(eTypeIsReference))

      corrected_type = orig_type.GetLValueReferenceType();

    ret.SetCompilerType(corrected_type);

  } else {

    // If we are here we need to adjust our dynamic type name to include the

    // correct & or * symbol

    std::string corrected_name(type_and_or_name.GetName().GetCString());

    if (static_type_flags.AllSet(eTypeIsPointer))

      corrected_name.append(" *");

    else if (static_type_flags.AllSet(eTypeIsReference))

      corrected_name.append(" &");

    // the parent type should be a correctly pointer'ed or referenc'ed type

    ret.SetCompilerType(static_type);

    ret.SetName(corrected_name.c_str());

  }

  return ret;

}

// 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 ||

      
language == eLanguageTypeC_plus_plus_03401k
 ||

      
language == eLanguageTypeC_plus_plus_11401k
 ||

      
language == eLanguageTypeC_plus_plus_14400k
)

    return new ItaniumABILanguageRuntime(process);

  else

    return nullptr;

}

class CommandObjectMultiwordItaniumABI_Demangle : public CommandObjectParsed {

public:

  CommandObjectMultiwordItaniumABI_Demangle(CommandInterpreter &interpreter)

      : CommandObjectParsed(

            interpreter, "demangle", "Demangle a C++ mangled name.",

            "language cplusplus demangle [<mangled-name> ...]") {

    CommandArgumentEntry arg;

    CommandArgumentData index_arg;

    // Define the first (and only) variant of this arg.

    index_arg.arg_type = eArgTypeSymbol;

    index_arg.arg_repetition = eArgRepeatPlus;

    // There is only one variant this argument could be; put it into the

    // argument entry.

    arg.push_back(index_arg);

    // Push the data for the first argument into the m_arguments vector.

    m_arguments.push_back(arg);

  }

  ~CommandObjectMultiwordItaniumABI_Demangle() override = default;

protected:

  bool DoExecute(Args &command, CommandReturnObject &result) override {

    bool demangled_any = false;

    bool error_any = false;

    for (auto &entry : command.entries()) {

      if (entry.ref().empty())

        continue;

      // the actual Mangled class should be strict about this, but on the

      // command line if you're copying mangled names out of 'nm' on Darwin,

      // they will come out with an extra underscore - be willing to strip this

      // on behalf of the user.   This is the moral equivalent of the -_/-n

      // options to c++filt

      auto name = entry.ref();

      if (name.startswith("__Z"))

        name = name.drop_front();

      Mangled mangled(name);

      if (mangled.GuessLanguage() == lldb::eLanguageTypeC_plus_plus) {

        ConstString demangled(mangled.GetDisplayDemangledName());

        demangled_any = true;

        result.AppendMessageWithFormat("%s ---> %s\n", entry.c_str(),

                                       demangled.GetCString());

      } else {

        error_any = true;

        result.AppendErrorWithFormat("%s is not a valid C++ mangled name\n",

                                     entry.ref().str().c_str());

      }

    }

    result.SetStatus(

        error_any ? 
lldb::eReturnStatusFailed2

                  : 
(2
demangled_any2
 ? 
lldb::eReturnStatusSuccessFinishResult2

                                   : 
lldb::eReturnStatusSuccessFinishNoResult0
));

    return result.Succeeded();

  }

};

class CommandObjectMultiwordItaniumABI : public CommandObjectMultiword {

public:

  CommandObjectMultiwordItaniumABI(CommandInterpreter &interpreter)

      : CommandObjectMultiword(

            interpreter, "cplusplus",

            "Commands for operating on the C++ language runtime.",

            "cplusplus <subcommand> [<subcommand-options>]") {

    LoadSubCommand(

        "demangle",

        CommandObjectSP(

            new CommandObjectMultiwordItaniumABI_Demangle(interpreter)));

  }

  ~CommandObjectMultiwordItaniumABI() override = default;

};

void ItaniumABILanguageRuntime::Initialize() {

  PluginManager::RegisterPlugin(

      GetPluginNameStatic(), "Itanium ABI for the C++ language", CreateInstance,

      [](CommandInterpreter &interpreter) -> lldb::CommandObjectSP {

        return CommandObjectSP(

            new CommandObjectMultiwordItaniumABI(interpreter));

      });

}

void ItaniumABILanguageRuntime::Terminate() {

  PluginManager::UnregisterPlugin(CreateInstance);

}

BreakpointResolverSP ItaniumABILanguageRuntime::CreateExceptionResolver(

    const BreakpointSP &bkpt, bool catch_bp, bool throw_bp) {

  return CreateExceptionResolver(bkpt, catch_bp, throw_bp, false);

}

BreakpointResolverSP ItaniumABILanguageRuntime::CreateExceptionResolver(

    const BreakpointSP &bkpt, 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";

  std::vector<const char *> exception_names;

  exception_names.reserve(4);

  if (catch_bp)

    exception_names.push_back(g_catch_name);

  if (throw_bp) {

    exception_names.push_back(g_throw_name1);

    exception_names.push_back(g_throw_name2);

  }

  if (for_expressions)

    exception_names.push_back(g_exception_throw_name);

  BreakpointResolverSP resolver_sp(new BreakpointResolverName(

      bkpt, exception_names.data(), exception_names.size(),

      eFunctionNameTypeBase, eLanguageTypeUnknown, 0, eLazyBoolNo));

  return resolver_sp;

}

lldb::SearchFilterSP ItaniumABILanguageRuntime::CreateExceptionSearchFilter() {

  Target &target = m_process->GetTarget();

  FileSpecList filter_modules;

  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");

  }

  return target.GetSearchFilterForModuleList(&filter_modules);

}

lldb::BreakpointSP ItaniumABILanguageRuntime::CreateExceptionBreakpoint(

    bool catch_bp, bool throw_bp, bool for_expressions, bool is_internal) {

  Target &target = m_process->GetTarget();

  FileSpecList filter_modules;

  BreakpointResolverSP exception_resolver_sp =

      CreateExceptionResolver(nullptr, catch_bp, throw_bp, for_expressions);

  SearchFilterSP filter_sp(CreateExceptionSearchFilter());

  const bool hardware = false;

  const bool resolve_indirect_functions = false;

  return target.CreateBreakpoint(filter_sp, exception_resolver_sp, is_internal,

                                 hardware, resolve_indirect_functions);

}

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) {

    m_cxx_exception_bp_sp->SetEnabled(true);

  } else {

    m_cxx_exception_bp_sp = CreateExceptionBreakpoint(

        catch_bp, throw_bp, for_expressions, is_internal);

    if (m_cxx_exception_bp_sp)

      m_cxx_exception_bp_sp->SetBreakpointKind("c++ exception");

  }

}

void ItaniumABILanguageRuntime::ClearExceptionBreakpoints() {

  if (!m_process)

    return;

  if (m_cxx_exception_bp_sp) {

    m_cxx_exception_bp_sp->SetEnabled(false);

  }

}

bool ItaniumABILanguageRuntime::ExceptionBreakpointsAreSet() {

  return m_cxx_exception_bp_sp && 
m_cxx_exception_bp_sp->IsEnabled()2.37k
;

}

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());

}

ValueObjectSP ItaniumABILanguageRuntime::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 ItaniumABILanguageRuntime::GetDynamicTypeInfo(

    const lldb_private::Address &vtable_addr) {

  std::lock_guard<std::mutex> locker(m_dynamic_type_map_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 ItaniumABILanguageRuntime::SetDynamicTypeInfo(

    const lldb_private::Address &vtable_addr, const TypeAndOrName &type_info) {

  std::lock_guard<std::mutex> locker(m_dynamic_type_map_mutex);

  m_dynamic_type_map[vtable_addr] = type_info;

}