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//===-- ValueObject.h -------------------------------------------*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "lldb/Core/Value.h"
#include "lldb/Symbol/CompilerType.h"
#include "lldb/Symbol/Type.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Process.h"
#include "lldb/Utility/ConstString.h"
#include "lldb/Utility/DataExtractor.h"
#include "lldb/Utility/SharedCluster.h"
#include "lldb/Utility/Status.h"
#include "lldb/Utility/UserID.h"
#include "lldb/lldb-defines.h"
#include "lldb/lldb-enumerations.h"
#include "lldb/lldb-forward.h"
#include "lldb/lldb-private-enumerations.h"
#include "lldb/lldb-types.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include <functional>
#include <initializer_list>
#include <map>
#include <mutex>
#include <string>
#include <utility>
#include <cstddef>
#include <cstdint>
namespace lldb_private {
class Declaration;
class DumpValueObjectOptions;
class EvaluateExpressionOptions;
class ExecutionContextScope;
class Log;
class Scalar;
class Stream;
class SymbolContextScope;
class TypeFormatImpl;
class TypeSummaryImpl;
class TypeSummaryOptions;
/// ValueObject:
/// This abstract class provides an interface to a particular value, be it a
/// register, a local or global variable,
/// that is evaluated in some particular scope. The ValueObject also has the
/// capability of being the "child" of
/// some other variable object, and in turn of having children.
/// If a ValueObject is a root variable object - having no parent - then it must
/// be constructed with respect to some
/// particular ExecutionContextScope. If it is a child, it inherits the
/// ExecutionContextScope from its parent.
/// The ValueObject will update itself if necessary before fetching its value,
/// summary, object description, etc.
/// But it will always update itself in the ExecutionContextScope with which it
/// was originally created.
/// A brief note on life cycle management for ValueObjects. This is a little
/// tricky because a ValueObject can contain
/// various other ValueObjects - the Dynamic Value, its children, the
/// dereference value, etc. Any one of these can be
/// handed out as a shared pointer, but for that contained value object to be
/// valid, the root object and potentially other
/// of the value objects need to stay around.
/// We solve this problem by handing out shared pointers to the Value Object and
/// any of its dependents using a shared
/// ClusterManager. This treats each shared pointer handed out for the entire
/// cluster as a reference to the whole
/// cluster. The whole cluster will stay around until the last reference is
/// released.
/// The ValueObject mostly handle this automatically, if a value object is made
/// with a Parent ValueObject, then it adds
/// itself to the ClusterManager of the parent.
/// It does mean that external to the ValueObjects we should only ever make
/// available ValueObjectSP's, never ValueObjects
/// or pointers to them. So all the "Root level" ValueObject derived
/// constructors should be private, and
/// should implement a Create function that new's up object and returns a Shared
/// Pointer that it gets from the GetSP() method.
/// However, if you are making an derived ValueObject that will be contained in
/// a parent value object, you should just
/// hold onto a pointer to it internally, and by virtue of passing the parent
/// ValueObject into its constructor, it will
/// be added to the ClusterManager for the parent. Then if you ever hand out a
/// Shared Pointer to the contained ValueObject,
/// just do so by calling GetSP() on the contained object.
class ValueObject {
enum GetExpressionPathFormat {
eGetExpressionPathFormatDereferencePointers = 1,
enum ValueObjectRepresentationStyle {
eValueObjectRepresentationStyleValue = 1,
enum ExpressionPathScanEndReason {
/// Out of data to parse.
eExpressionPathScanEndReasonEndOfString = 1,
/// Child element not found.
/// (Synthetic) child element not found.
/// [] only allowed for arrays.
/// . used when -> should be used.
/// -> used when . should be used.
/// ObjC ivar expansion not allowed.
/// [] not allowed by options.
/// [] not valid on objects other than scalars, pointers or arrays.
/// [] is good for arrays, but I cannot parse it.
/// [] is good for bitfields, but I cannot parse after it.
/// Something is malformed in he expression.
/// Impossible to apply & operator.
/// Impossible to apply * operator.
/// [] was expanded into a VOList.
/// getting the synthetic children failed.
eExpressionPathScanEndReasonUnknown = 0xFFFF
enum ExpressionPathEndResultType {
/// Anything but...
eExpressionPathEndResultTypePlain = 1,
/// A bitfield.
/// A range [low-high].
/// A range [].
/// Several items in a VOList.
eExpressionPathEndResultTypeInvalid = 0xFFFF
enum ExpressionPathAftermath {
/// Just return it.
eExpressionPathAftermathNothing = 1,
/// Dereference the target.
/// Take target's address.
enum ClearUserVisibleDataItems {
eClearUserVisibleDataItemsNothing = 1u << 0,
eClearUserVisibleDataItemsValue = 1u << 1,
eClearUserVisibleDataItemsSummary = 1u << 2,
eClearUserVisibleDataItemsLocation = 1u << 3,
eClearUserVisibleDataItemsDescription = 1u << 4,
eClearUserVisibleDataItemsSyntheticChildren = 1u << 5,
eClearUserVisibleDataItemsAllStrings =
eClearUserVisibleDataItemsValue | eClearUserVisibleDataItemsSummary |
eClearUserVisibleDataItemsLocation |
eClearUserVisibleDataItemsAll = 0xFFFF
struct GetValueForExpressionPathOptions {
enum class SyntheticChildrenTraversal {
bool m_check_dot_vs_arrow_syntax;
bool m_no_fragile_ivar;
bool m_allow_bitfields_syntax;
SyntheticChildrenTraversal m_synthetic_children_traversal;
bool dot = false, bool no_ivar = false, bool bitfield = true,
SyntheticChildrenTraversal synth_traverse =
: m_check_dot_vs_arrow_syntax(dot), m_no_fragile_ivar(no_ivar),
m_synthetic_children_traversal(synth_traverse) {}
GetValueForExpressionPathOptions &DoCheckDotVsArrowSyntax() {
m_check_dot_vs_arrow_syntax = true;
return *this;
GetValueForExpressionPathOptions &DontCheckDotVsArrowSyntax() {
m_check_dot_vs_arrow_syntax = false;
return *this;
GetValueForExpressionPathOptions &DoAllowFragileIVar() {
m_no_fragile_ivar = false;
return *this;
GetValueForExpressionPathOptions &DontAllowFragileIVar() {
m_no_fragile_ivar = true;
return *this;
GetValueForExpressionPathOptions &DoAllowBitfieldSyntax() {
m_allow_bitfields_syntax = true;
return *this;
GetValueForExpressionPathOptions &DontAllowBitfieldSyntax() {
m_allow_bitfields_syntax = false;
return *this;
GetValueForExpressionPathOptions &
SetSyntheticChildrenTraversal(SyntheticChildrenTraversal traverse) {
m_synthetic_children_traversal = traverse;
return *this;
static const GetValueForExpressionPathOptions DefaultOptions() {
static GetValueForExpressionPathOptions g_default_options;
return g_default_options;
class EvaluationPoint {
EvaluationPoint(ExecutionContextScope *exe_scope,
bool use_selected = false);
EvaluationPoint(const EvaluationPoint &rhs);
const ExecutionContextRef &GetExecutionContextRef() const {
return m_exe_ctx_ref;
void SetIsConstant() {
bool IsConstant() const { return !m_mod_id.IsValid(); }
ProcessModID GetModID() const { return m_mod_id; }
void SetUpdateID(ProcessModID new_id) { m_mod_id = new_id; }
void SetNeedsUpdate() { m_needs_update = true; }
void SetUpdated();
bool NeedsUpdating(bool accept_invalid_exe_ctx) {
return m_needs_update;
bool IsValid() {
const bool accept_invalid_exe_ctx = false;
if (!m_mod_id.IsValid())
return false;
else if (SyncWithProcessState(accept_invalid_exe_ctx)) {
if (!m_mod_id.IsValid())
return false;
return true;
void SetInvalid() {
// Use the stop id to mark us as invalid, leave the thread id and the
// stack id around for logging and history purposes.
// Can't update an invalid state.
m_needs_update = false;
bool SyncWithProcessState(bool accept_invalid_exe_ctx);
ProcessModID m_mod_id; // This is the stop id when this ValueObject was last
// evaluated.
ExecutionContextRef m_exe_ctx_ref;
bool m_needs_update = true;
virtual ~ValueObject();
const EvaluationPoint &GetUpdatePoint() const { return m_update_point; }
EvaluationPoint &GetUpdatePoint() { return m_update_point; }
const ExecutionContextRef &GetExecutionContextRef() const {
return m_update_point.GetExecutionContextRef();
lldb::TargetSP GetTargetSP() const {
return m_update_point.GetExecutionContextRef().GetTargetSP();
lldb::ProcessSP GetProcessSP() const {
return m_update_point.GetExecutionContextRef().GetProcessSP();
lldb::ThreadSP GetThreadSP() const {
return m_update_point.GetExecutionContextRef().GetThreadSP();
lldb::StackFrameSP GetFrameSP() const {
return m_update_point.GetExecutionContextRef().GetFrameSP();
void SetNeedsUpdate();
CompilerType GetCompilerType() { return MaybeCalculateCompleteType(); }
// this vends a TypeImpl that is useful at the SB API layer
virtual TypeImpl GetTypeImpl() { return TypeImpl(GetCompilerType()); }
virtual bool CanProvideValue();
// Subclasses must implement the functions below.
virtual llvm::Optional<uint64_t> GetByteSize() = 0;
virtual lldb::ValueType GetValueType() const = 0;
// Subclasses can implement the functions below.
virtual ConstString GetTypeName() { return GetCompilerType().GetTypeName(); }
virtual ConstString GetDisplayTypeName() { return GetTypeName(); }
virtual ConstString GetQualifiedTypeName() {
return GetCompilerType().GetTypeName();
virtual lldb::LanguageType GetObjectRuntimeLanguage() {
return GetCompilerType().GetMinimumLanguage();
virtual uint32_t
GetTypeInfo(CompilerType *pointee_or_element_compiler_type = nullptr) {
return GetCompilerType().GetTypeInfo(pointee_or_element_compiler_type);
virtual bool IsPointerType() { return GetCompilerType().IsPointerType(); }
virtual bool IsArrayType() { return GetCompilerType().IsArrayType(); }
virtual bool IsScalarType() { return GetCompilerType().IsScalarType(); }
virtual bool IsPointerOrReferenceType() {
return GetCompilerType().IsPointerOrReferenceType();
virtual bool IsPossibleDynamicType();
bool IsNilReference();
bool IsUninitializedReference();
virtual bool IsBaseClass() { return false; }
bool IsBaseClass(uint32_t &depth);
virtual bool IsDereferenceOfParent() { return false; }
bool IsIntegerType(bool &is_signed) {
return GetCompilerType().IsIntegerType(is_signed);
virtual void GetExpressionPath(
Stream &s,
GetExpressionPathFormat = eGetExpressionPathFormatDereferencePointers);
lldb::ValueObjectSP GetValueForExpressionPath(
llvm::StringRef expression,
ExpressionPathScanEndReason *reason_to_stop = nullptr,
ExpressionPathEndResultType *final_value_type = nullptr,
const GetValueForExpressionPathOptions &options =
ExpressionPathAftermath *final_task_on_target = nullptr);
virtual bool IsInScope() { return true; }
virtual lldb::offset_t GetByteOffset() { return 0; }
virtual uint32_t GetBitfieldBitSize() { return 0; }
virtual uint32_t GetBitfieldBitOffset() { return 0; }
bool IsBitfield() {
return (GetBitfieldBitSize() != 0) || (GetBitfieldBitOffset() != 0);
virtual bool IsArrayItemForPointer() {
return m_flags.m_is_array_item_for_pointer;
virtual const char *GetValueAsCString();
virtual bool GetValueAsCString(const lldb_private::TypeFormatImpl &format,
std::string &destination);
bool GetValueAsCString(lldb::Format format, std::string &destination);
virtual uint64_t GetValueAsUnsigned(uint64_t fail_value,
bool *success = nullptr);
virtual int64_t GetValueAsSigned(int64_t fail_value, bool *success = nullptr);
virtual bool SetValueFromCString(const char *value_str, Status &error);
/// Return the module associated with this value object in case the value is
/// from an executable file and might have its data in sections of the file.
/// This can be used for variables.
virtual lldb::ModuleSP GetModule();
ValueObject *GetRoot();
/// Given a ValueObject, loop over itself and its parent, and its parent's
/// parent, .. until either the given callback returns false, or you end up at
/// a null pointer
ValueObject *FollowParentChain(std::function<bool(ValueObject *)>);
virtual bool GetDeclaration(Declaration &decl);
// The functions below should NOT be modified by subclasses
const Status &GetError();
ConstString GetName() const { return m_name; }
/// Returns a unique id for this ValueObject.
lldb::user_id_t GetID() const { return m_id.GetID(); }
virtual lldb::ValueObjectSP GetChildAtIndex(size_t idx, bool can_create);
// this will always create the children if necessary
lldb::ValueObjectSP GetChildAtIndexPath(llvm::ArrayRef<size_t> idxs,
size_t *index_of_error = nullptr);
GetChildAtIndexPath(llvm::ArrayRef<std::pair<size_t, bool>> idxs,
size_t *index_of_error = nullptr);
// this will always create the children if necessary
lldb::ValueObjectSP GetChildAtNamePath(llvm::ArrayRef<ConstString> names,
ConstString *name_of_error = nullptr);
GetChildAtNamePath(llvm::ArrayRef<std::pair<ConstString, bool>> names,
ConstString *name_of_error = nullptr);
virtual lldb::ValueObjectSP GetChildMemberWithName(ConstString name,
bool can_create);
virtual size_t GetIndexOfChildWithName(ConstString name);
size_t GetNumChildren(uint32_t max = UINT32_MAX);
const Value &GetValue() const { return m_value; }
Value &GetValue() { return m_value; }
virtual bool ResolveValue(Scalar &scalar);
// return 'false' whenever you set the error, otherwise callers may assume
// true means everything is OK - this will break breakpoint conditions among
// potentially a few others
virtual bool IsLogicalTrue(Status &error);
virtual const char *GetLocationAsCString() {
return GetLocationAsCStringImpl(m_value, m_data);
const char *
GetSummaryAsCString(lldb::LanguageType lang = lldb::eLanguageTypeUnknown);
GetSummaryAsCString(TypeSummaryImpl *summary_ptr, std::string &destination,
lldb::LanguageType lang = lldb::eLanguageTypeUnknown);
bool GetSummaryAsCString(std::string &destination,
const TypeSummaryOptions &options);
bool GetSummaryAsCString(TypeSummaryImpl *summary_ptr,
std::string &destination,
const TypeSummaryOptions &options);
const char *GetObjectDescription();
bool HasSpecialPrintableRepresentation(
ValueObjectRepresentationStyle val_obj_display,
lldb::Format custom_format);
enum class PrintableRepresentationSpecialCases : bool {
eDisable = false,
eAllow = true
DumpPrintableRepresentation(Stream &s,
ValueObjectRepresentationStyle val_obj_display =
lldb::Format custom_format = lldb::eFormatInvalid,
PrintableRepresentationSpecialCases special =
bool do_dump_error = true);
bool GetValueIsValid() const { return m_flags.m_value_is_valid; }
// If you call this on a newly created ValueObject, it will always return
// false.
bool GetValueDidChange() { return m_flags.m_value_did_change; }
bool UpdateValueIfNeeded(bool update_format = true);
bool UpdateFormatsIfNeeded();
lldb::ValueObjectSP GetSP() { return m_manager->GetSharedPointer(this); }
/// Change the name of the current ValueObject. Should *not* be used from a
/// synthetic child provider as it would change the name of the non synthetic
/// child as well.
void SetName(ConstString name) { m_name = name; }
virtual lldb::addr_t GetAddressOf(bool scalar_is_load_address = true,
AddressType *address_type = nullptr);
lldb::addr_t GetPointerValue(AddressType *address_type = nullptr);
lldb::ValueObjectSP GetSyntheticChild(ConstString key) const;
lldb::ValueObjectSP GetSyntheticArrayMember(size_t index, bool can_create);
lldb::ValueObjectSP GetSyntheticBitFieldChild(uint32_t from, uint32_t to,
bool can_create);
lldb::ValueObjectSP GetSyntheticExpressionPathChild(const char *expression,
bool can_create);
virtual lldb::ValueObjectSP
GetSyntheticChildAtOffset(uint32_t offset, const CompilerType &type,
bool can_create,
ConstString name_const_str = ConstString());
virtual lldb::ValueObjectSP
GetSyntheticBase(uint32_t offset, const CompilerType &type, bool can_create,
ConstString name_const_str = ConstString());
virtual lldb::ValueObjectSP GetDynamicValue(lldb::DynamicValueType valueType);
lldb::DynamicValueType GetDynamicValueType();
virtual lldb::ValueObjectSP GetStaticValue() { return GetSP(); }
virtual lldb::ValueObjectSP GetNonSyntheticValue() { return GetSP(); }
lldb::ValueObjectSP GetSyntheticValue();
virtual bool HasSyntheticValue();
virtual bool IsSynthetic() { return false; }
GetQualifiedRepresentationIfAvailable(lldb::DynamicValueType dynValue,
bool synthValue);
virtual lldb::ValueObjectSP CreateConstantValue(ConstString name);
virtual lldb::ValueObjectSP Dereference(Status &error);
/// Creates a copy of the ValueObject with a new name and setting the current
/// ValueObject as its parent. It should be used when we want to change the
/// name of a ValueObject without modifying the actual ValueObject itself
/// (e.g. sythetic child provider).
virtual lldb::ValueObjectSP Clone(ConstString new_name);
virtual lldb::ValueObjectSP AddressOf(Status &error);
virtual lldb::addr_t GetLiveAddress() { return LLDB_INVALID_ADDRESS; }
virtual void SetLiveAddress(lldb::addr_t addr = LLDB_INVALID_ADDRESS,
AddressType address_type = eAddressTypeLoad) {}
virtual lldb::ValueObjectSP Cast(const CompilerType &compiler_type);
virtual lldb::ValueObjectSP CastPointerType(const char *name,
CompilerType &ast_type);
virtual lldb::ValueObjectSP CastPointerType(const char *name,
lldb::TypeSP &type_sp);
// The backing bits of this value object were updated, clear any descriptive
// string, so we know we have to refetch them.
virtual void ValueUpdated() {
ClearUserVisibleData(eClearUserVisibleDataItemsValue |
eClearUserVisibleDataItemsSummary |
virtual bool IsDynamic() { return false; }
virtual bool DoesProvideSyntheticValue() { return false; }
virtual bool IsSyntheticChildrenGenerated() {
return m_flags.m_is_synthetic_children_generated;
virtual void SetSyntheticChildrenGenerated(bool b) {
m_flags.m_is_synthetic_children_generated = b;
virtual SymbolContextScope *GetSymbolContextScope();
void Dump(Stream &s);
void Dump(Stream &s, const DumpValueObjectOptions &options);
static lldb::ValueObjectSP
CreateValueObjectFromExpression(llvm::StringRef name,
llvm::StringRef expression,
const ExecutionContext &exe_ctx);
static lldb::ValueObjectSP
CreateValueObjectFromExpression(llvm::StringRef name,
llvm::StringRef expression,
const ExecutionContext &exe_ctx,
const EvaluateExpressionOptions &options);
static lldb::ValueObjectSP
CreateValueObjectFromAddress(llvm::StringRef name, uint64_t address,
const ExecutionContext &exe_ctx,
CompilerType type);
static lldb::ValueObjectSP
CreateValueObjectFromData(llvm::StringRef name, const DataExtractor &data,
const ExecutionContext &exe_ctx, CompilerType type);
lldb::ValueObjectSP Persist();
/// Returns true if this is a char* or a char[] if it is a char* and
/// check_pointer is true, it also checks that the pointer is valid.
bool IsCStringContainer(bool check_pointer = false);
std::pair<size_t, bool>
ReadPointedString(lldb::DataBufferSP &buffer_sp, Status &error,
uint32_t max_length = 0, bool honor_array = true,
lldb::Format item_format = lldb::eFormatCharArray);
virtual size_t GetPointeeData(DataExtractor &data, uint32_t item_idx = 0,
uint32_t item_count = 1);
virtual uint64_t GetData(DataExtractor &data, Status &error);
virtual bool SetData(DataExtractor &data, Status &error);
virtual bool GetIsConstant() const { return m_update_point.IsConstant(); }
bool NeedsUpdating() {
const bool accept_invalid_exe_ctx =
(CanUpdateWithInvalidExecutionContext() == eLazyBoolYes);
return m_update_point.NeedsUpdating(accept_invalid_exe_ctx);
void SetIsConstant() { m_update_point.SetIsConstant(); }
lldb::Format GetFormat() const;
virtual void SetFormat(lldb::Format format) {
if (format != m_format)
m_format = format;
virtual lldb::LanguageType GetPreferredDisplayLanguage();
void SetPreferredDisplayLanguage(lldb::LanguageType lt) {
m_preferred_display_language = lt;
lldb::TypeSummaryImplSP GetSummaryFormat() {
return m_type_summary_sp;
void SetSummaryFormat(lldb::TypeSummaryImplSP format) {
m_type_summary_sp = std::move(format);
void SetValueFormat(lldb::TypeFormatImplSP format) {
m_type_format_sp = std::move(format);
lldb::TypeFormatImplSP GetValueFormat() {
return m_type_format_sp;
void SetSyntheticChildren(const lldb::SyntheticChildrenSP &synth_sp) {
if (synth_sp.get() == m_synthetic_children_sp.get())
m_synthetic_children_sp = synth_sp;
lldb::SyntheticChildrenSP GetSyntheticChildren() {
return m_synthetic_children_sp;
// Use GetParent for display purposes, but if you want to tell the parent to
// update itself then use m_parent. The ValueObjectDynamicValue's parent is
// not the correct parent for displaying, they are really siblings, so for
// display it needs to route through to its grandparent.
virtual ValueObject *GetParent() { return m_parent; }
virtual const ValueObject *GetParent() const { return m_parent; }
ValueObject *GetNonBaseClassParent();
void SetAddressTypeOfChildren(AddressType at) {
m_address_type_of_ptr_or_ref_children = at;
AddressType GetAddressTypeOfChildren();
void SetHasCompleteType() {
m_flags.m_did_calculate_complete_objc_class_type = true;
/// Find out if a ValueObject might have children.
/// This call is much more efficient than CalculateNumChildren() as
/// it doesn't need to complete the underlying type. This is designed
/// to be used in a UI environment in order to detect if the
/// disclosure triangle should be displayed or not.
/// This function returns true for class, union, structure,
/// pointers, references, arrays and more. Again, it does so without
/// doing any expensive type completion.
/// \return
/// Returns \b true if the ValueObject might have children, or \b
/// false otherwise.
virtual bool MightHaveChildren();
virtual lldb::VariableSP GetVariable() { return nullptr; }
virtual bool IsRuntimeSupportValue();
virtual uint64_t GetLanguageFlags() { return m_language_flags; }
virtual void SetLanguageFlags(uint64_t flags) { m_language_flags = flags; }
typedef ClusterManager<ValueObject> ValueObjectManager;
class ChildrenManager {
ChildrenManager() : m_mutex(), m_children() {}
bool HasChildAtIndex(size_t idx) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
return (m_children.find(idx) != m_children.end());
ValueObject *GetChildAtIndex(size_t idx) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
const auto iter = m_children.find(idx);
return ((iter == m_children.end()) ? nullptr : iter->second);
void SetChildAtIndex(size_t idx, ValueObject *valobj) {
// we do not need to be mutex-protected to make a pair
ChildrenPair pair(idx, valobj);
std::lock_guard<std::recursive_mutex> guard(m_mutex);
void SetChildrenCount(size_t count) { Clear(count); }
size_t GetChildrenCount() { return m_children_count; }
void Clear(size_t new_count = 0) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
m_children_count = new_count;
typedef std::map<size_t, ValueObject *> ChildrenMap;
typedef ChildrenMap::iterator ChildrenIterator;
typedef ChildrenMap::value_type ChildrenPair;
std::recursive_mutex m_mutex;
ChildrenMap m_children;
size_t m_children_count = 0;
// Classes that inherit from ValueObject can see and modify these
/// The parent value object, or nullptr if this has no parent.
ValueObject *m_parent = nullptr;
/// The root of the hierarchy for this ValueObject (or nullptr if never
/// calculated).
ValueObject *m_root = nullptr;
/// Stores both the stop id and the full context at which this value was last
/// updated. When we are asked to update the value object, we check whether
/// the context & stop id are the same before updating.
EvaluationPoint m_update_point;
/// The name of this object.
ConstString m_name;
/// A data extractor that can be used to extract the value.
DataExtractor m_data;
Value m_value;
/// An error object that can describe any errors that occur when updating
/// values.
Status m_error;
/// Cached value string that will get cleared if/when the value is updated.
std::string m_value_str;
/// Cached old value string from the last time the value was gotten
std::string m_old_value_str;
/// Cached location string that will get cleared if/when the value is updated.
std::string m_location_str;
/// Cached summary string that will get cleared if/when the value is updated.
std::string m_summary_str;
/// Cached result of the "object printer". This differs from the summary
/// in that the summary is consed up by us, the object_desc_string is builtin.
std::string m_object_desc_str;
/// If the type of the value object should be overridden, the type to impose.
CompilerType m_override_type;
/// This object is managed by the root object (any ValueObject that gets
/// created without a parent.) The manager gets passed through all the
/// generations of dependent objects, and will keep the whole cluster of
/// objects alive as long as a shared pointer to any of them has been handed
/// out. Shared pointers to value objects must always be made with the GetSP
/// method.
ValueObjectManager *m_manager = nullptr;
ChildrenManager m_children;
std::map<ConstString, ValueObject *> m_synthetic_children;
ValueObject *m_dynamic_value = nullptr;
ValueObject *m_synthetic_value = nullptr;
ValueObject *m_deref_valobj = nullptr;
/// We have to hold onto a shared pointer to this one because it is created
/// as an independent ValueObjectConstResult, which isn't managed by us.
lldb::ValueObjectSP m_addr_of_valobj_sp;
lldb::Format m_format = lldb::eFormatDefault;
lldb::Format m_last_format = lldb::eFormatDefault;
uint32_t m_last_format_mgr_revision = 0;
lldb::TypeSummaryImplSP m_type_summary_sp;
lldb::TypeFormatImplSP m_type_format_sp;
lldb::SyntheticChildrenSP m_synthetic_children_sp;
ProcessModID m_user_id_of_forced_summary;
AddressType m_address_type_of_ptr_or_ref_children = eAddressTypeInvalid;
llvm::SmallVector<uint8_t, 16> m_value_checksum;
lldb::LanguageType m_preferred_display_language = lldb::eLanguageTypeUnknown;
uint64_t m_language_flags = 0;
/// Unique identifier for every value object.
UserID m_id;
// Utility class for initializing all bitfields in ValueObject's constructors.
// FIXME: This could be done via default initializers once we have C++20.
struct Bitflags {
bool m_value_is_valid : 1, m_value_did_change : 1,
m_children_count_valid : 1, m_old_value_valid : 1,
m_is_deref_of_parent : 1, m_is_array_item_for_pointer : 1,
m_is_bitfield_for_scalar : 1, m_is_child_at_offset : 1,
m_is_getting_summary : 1, m_did_calculate_complete_objc_class_type : 1,
m_is_synthetic_children_generated : 1;
Bitflags() {
m_value_is_valid = false;
m_value_did_change = false;
m_children_count_valid = false;
m_old_value_valid = false;
m_is_deref_of_parent = false;
m_is_array_item_for_pointer = false;
m_is_bitfield_for_scalar = false;
m_is_child_at_offset = false;
m_is_getting_summary = false;
m_did_calculate_complete_objc_class_type = false;
m_is_synthetic_children_generated = false;
} m_flags;
friend class ValueObjectChild;
friend class ExpressionVariable; // For SetName
friend class Target; // For SetName
friend class ValueObjectConstResultImpl;
friend class ValueObjectSynthetic; // For ClearUserVisibleData
/// Use this constructor to create a "root variable object". The ValueObject
/// will be locked to this context through-out its lifespan.
ValueObject(ExecutionContextScope *exe_scope, ValueObjectManager &manager,
AddressType child_ptr_or_ref_addr_type = eAddressTypeLoad);
/// Use this constructor to create a ValueObject owned by another ValueObject.
/// It will inherit the ExecutionContext of its parent.
ValueObject(ValueObject &parent);
ValueObjectManager *GetManager() { return m_manager; }
virtual bool UpdateValue() = 0;
virtual LazyBool CanUpdateWithInvalidExecutionContext() {
return eLazyBoolCalculate;
virtual void CalculateDynamicValue(lldb::DynamicValueType use_dynamic);
virtual lldb::DynamicValueType GetDynamicValueTypeImpl() {
return lldb::eNoDynamicValues;
virtual bool HasDynamicValueTypeInfo() { return false; }
virtual void CalculateSyntheticValue();
/// Should only be called by ValueObject::GetChildAtIndex().
/// \return A ValueObject managed by this ValueObject's manager.
virtual ValueObject *CreateChildAtIndex(size_t idx,
bool synthetic_array_member,
int32_t synthetic_index);
/// Should only be called by ValueObject::GetNumChildren().
virtual size_t CalculateNumChildren(uint32_t max = UINT32_MAX) = 0;
void SetNumChildren(size_t num_children);
void SetValueDidChange(bool value_changed) {
m_flags.m_value_did_change = value_changed;
void SetValueIsValid(bool valid) { m_flags.m_value_is_valid = valid; }
void ClearUserVisibleData(
uint32_t items = ValueObject::eClearUserVisibleDataItemsAllStrings);
void AddSyntheticChild(ConstString key, ValueObject *valobj);
DataExtractor &GetDataExtractor();
void ClearDynamicTypeInformation();
// Subclasses must implement the functions below.
virtual CompilerType GetCompilerTypeImpl() = 0;
const char *GetLocationAsCStringImpl(const Value &value,
const DataExtractor &data);
bool IsChecksumEmpty() { return m_value_checksum.empty(); }
void SetPreferredDisplayLanguageIfNeeded(lldb::LanguageType);
virtual void DoUpdateChildrenAddressType(ValueObject &valobj) { return; };
virtual CompilerType MaybeCalculateCompleteType();
void UpdateChildrenAddressType() {
lldb::ValueObjectSP GetValueForExpressionPath_Impl(
llvm::StringRef expression_cstr,
ExpressionPathScanEndReason *reason_to_stop,
ExpressionPathEndResultType *final_value_type,
const GetValueForExpressionPathOptions &options,
ExpressionPathAftermath *final_task_on_target);
ValueObject(const ValueObject &) = delete;
const ValueObject &operator=(const ValueObject &) = delete;
} // namespace lldb_private