Files
clang-p2996/lldb/source/ValueObject/ValueObjectChild.cpp
Jonas Devlieghere b852fb1ec5 [lldb] Move ValueObject into its own library (NFC) (#113393)
ValueObject is part of lldbCore for historical reasons, but conceptually
it deserves to be its own library. This does introduce a (link-time) circular
dependency between lldbCore and lldbValueObject, which is unfortunate
but probably unavoidable because so many things in LLDB rely on
ValueObject. We already have cycles and these libraries are never built
as dylibs so while this doesn't improve the situation, it also doesn't
make things worse.

The header includes were updated with the following command:

```
find . -type f -exec sed -i.bak "s%include \"lldb/Core/ValueObject%include \"lldb/ValueObject/ValueObject%" '{}' \;
```
2024-10-24 20:20:48 -07:00

226 lines
8.3 KiB
C++

//===-- ValueObjectChild.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 "lldb/ValueObject/ValueObjectChild.h"
#include "lldb/Core/Value.h"
#include "lldb/Symbol/CompilerType.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Process.h"
#include "lldb/Utility/Flags.h"
#include "lldb/Utility/Scalar.h"
#include "lldb/Utility/Status.h"
#include "lldb/lldb-forward.h"
#include <functional>
#include <memory>
#include <vector>
#include <cstdio>
#include <cstring>
using namespace lldb_private;
ValueObjectChild::ValueObjectChild(
ValueObject &parent, const CompilerType &compiler_type, ConstString name,
uint64_t byte_size, int32_t byte_offset, uint32_t bitfield_bit_size,
uint32_t bitfield_bit_offset, bool is_base_class, bool is_deref_of_parent,
AddressType child_ptr_or_ref_addr_type, uint64_t language_flags)
: ValueObject(parent), m_compiler_type(compiler_type),
m_byte_size(byte_size), m_byte_offset(byte_offset),
m_bitfield_bit_size(bitfield_bit_size),
m_bitfield_bit_offset(bitfield_bit_offset),
m_is_base_class(is_base_class), m_is_deref_of_parent(is_deref_of_parent),
m_can_update_with_invalid_exe_ctx() {
m_name = name;
SetAddressTypeOfChildren(child_ptr_or_ref_addr_type);
SetLanguageFlags(language_flags);
}
ValueObjectChild::~ValueObjectChild() = default;
lldb::ValueType ValueObjectChild::GetValueType() const {
return m_parent->GetValueType();
}
llvm::Expected<uint32_t> ValueObjectChild::CalculateNumChildren(uint32_t max) {
ExecutionContext exe_ctx(GetExecutionContextRef());
auto children_count = GetCompilerType().GetNumChildren(true, &exe_ctx);
if (!children_count)
return children_count;
return *children_count <= max ? *children_count : max;
}
static void AdjustForBitfieldness(ConstString &name,
uint8_t bitfield_bit_size) {
if (name && bitfield_bit_size)
name.SetString(llvm::formatv("{0}:{1}", name, bitfield_bit_size).str());
}
ConstString ValueObjectChild::GetTypeName() {
if (m_type_name.IsEmpty()) {
m_type_name = GetCompilerType().GetTypeName();
AdjustForBitfieldness(m_type_name, m_bitfield_bit_size);
}
return m_type_name;
}
ConstString ValueObjectChild::GetQualifiedTypeName() {
ConstString qualified_name = GetCompilerType().GetTypeName();
AdjustForBitfieldness(qualified_name, m_bitfield_bit_size);
return qualified_name;
}
ConstString ValueObjectChild::GetDisplayTypeName() {
ConstString display_name = GetCompilerType().GetDisplayTypeName();
AdjustForBitfieldness(display_name, m_bitfield_bit_size);
return display_name;
}
LazyBool ValueObjectChild::CanUpdateWithInvalidExecutionContext() {
if (m_can_update_with_invalid_exe_ctx)
return *m_can_update_with_invalid_exe_ctx;
if (m_parent) {
ValueObject *opinionated_parent =
m_parent->FollowParentChain([](ValueObject *valobj) -> bool {
return (valobj->CanUpdateWithInvalidExecutionContext() ==
eLazyBoolCalculate);
});
if (opinionated_parent)
return *(m_can_update_with_invalid_exe_ctx =
opinionated_parent->CanUpdateWithInvalidExecutionContext());
}
return *(m_can_update_with_invalid_exe_ctx =
this->ValueObject::CanUpdateWithInvalidExecutionContext());
}
bool ValueObjectChild::UpdateValue() {
m_error.Clear();
SetValueIsValid(false);
ValueObject *parent = m_parent;
if (parent) {
if (parent->UpdateValueIfNeeded(false)) {
m_value.SetCompilerType(GetCompilerType());
CompilerType parent_type(parent->GetCompilerType());
// Copy the parent scalar value and the scalar value type
m_value.GetScalar() = parent->GetValue().GetScalar();
m_value.SetValueType(parent->GetValue().GetValueType());
Flags parent_type_flags(parent_type.GetTypeInfo());
const bool is_instance_ptr_base =
((m_is_base_class) &&
(parent_type_flags.AnySet(lldb::eTypeInstanceIsPointer)));
if (parent->GetCompilerType().ShouldTreatScalarValueAsAddress()) {
m_value.GetScalar() = parent->GetPointerValue();
switch (parent->GetAddressTypeOfChildren()) {
case eAddressTypeFile: {
lldb::ProcessSP process_sp(GetProcessSP());
if (process_sp && process_sp->IsAlive())
m_value.SetValueType(Value::ValueType::LoadAddress);
else
m_value.SetValueType(Value::ValueType::FileAddress);
} break;
case eAddressTypeLoad:
m_value.SetValueType(is_instance_ptr_base
? Value::ValueType::Scalar
: Value::ValueType::LoadAddress);
break;
case eAddressTypeHost:
m_value.SetValueType(Value::ValueType::HostAddress);
break;
case eAddressTypeInvalid:
// TODO: does this make sense?
m_value.SetValueType(Value::ValueType::Scalar);
break;
}
}
switch (m_value.GetValueType()) {
case Value::ValueType::Invalid:
break;
case Value::ValueType::LoadAddress:
case Value::ValueType::FileAddress:
case Value::ValueType::HostAddress: {
lldb::addr_t addr = m_value.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
if (addr == LLDB_INVALID_ADDRESS) {
m_error = Status::FromErrorString("parent address is invalid.");
} else if (addr == 0) {
m_error = Status::FromErrorString("parent is NULL");
} else {
// If a bitfield doesn't fit into the child_byte_size'd window at
// child_byte_offset, move the window forward until it fits. The
// problem here is that Value has no notion of bitfields and thus the
// Value's DataExtractor is sized like the bitfields CompilerType; a
// sequence of bitfields, however, can be larger than their underlying
// type.
if (m_bitfield_bit_offset) {
const bool thread_and_frame_only_if_stopped = true;
ExecutionContext exe_ctx(GetExecutionContextRef().Lock(
thread_and_frame_only_if_stopped));
if (auto type_bit_size = GetCompilerType().GetBitSize(
exe_ctx.GetBestExecutionContextScope())) {
uint64_t bitfield_end =
m_bitfield_bit_size + m_bitfield_bit_offset;
if (bitfield_end > *type_bit_size) {
uint64_t overhang_bytes =
(bitfield_end - *type_bit_size + 7) / 8;
m_byte_offset += overhang_bytes;
m_bitfield_bit_offset -= overhang_bytes * 8;
}
}
}
// Set this object's scalar value to the address of its value by
// adding its byte offset to the parent address
m_value.GetScalar() += m_byte_offset;
}
} break;
case Value::ValueType::Scalar:
// try to extract the child value from the parent's scalar value
{
Scalar scalar(m_value.GetScalar());
scalar.ExtractBitfield(8 * m_byte_size, 8 * m_byte_offset);
m_value.GetScalar() = scalar;
}
break;
}
if (m_error.Success()) {
const bool thread_and_frame_only_if_stopped = true;
ExecutionContext exe_ctx(
GetExecutionContextRef().Lock(thread_and_frame_only_if_stopped));
if (GetCompilerType().GetTypeInfo() & lldb::eTypeHasValue) {
Value &value = is_instance_ptr_base ? m_parent->GetValue() : m_value;
m_error = value.GetValueAsData(&exe_ctx, m_data, GetModule().get());
} else {
m_error.Clear(); // No value so nothing to read...
}
}
} else {
m_error = Status::FromErrorStringWithFormat(
"parent failed to evaluate: %s", parent->GetError().AsCString());
}
} else {
m_error = Status::FromErrorString(
"ValueObjectChild has a NULL parent ValueObject.");
}
return m_error.Success();
}
bool ValueObjectChild::IsInScope() {
ValueObject *root(GetRoot());
if (root)
return root->IsInScope();
return false;
}