llvm-project/lldb/source/ValueObject/ValueObjectCast.cpp
Adrian Prantl 878a64f94a
[lldb] Upgrade CompilerType::GetBitSize to return llvm::Expected (#129601)
This patch pushes the error handling boundary for the GetBitSize()
methods from Runtime into the Type and CompilerType APIs. This makes it
easier to diagnose problems thanks to more meaningful error messages
being available. GetBitSize() is often the first thing LLDB asks about a
type, so this method is particularly important for a better user
experience.

rdar://145667239
2025-03-05 10:21:19 -08:00

94 lines
3.2 KiB
C++

//===-- ValueObjectCast.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/ValueObjectCast.h"
#include "lldb/Core/Value.h"
#include "lldb/Symbol/CompilerType.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Utility/Scalar.h"
#include "lldb/Utility/Status.h"
#include "lldb/ValueObject/ValueObject.h"
#include <optional>
namespace lldb_private {
class ConstString;
}
using namespace lldb_private;
lldb::ValueObjectSP ValueObjectCast::Create(ValueObject &parent,
ConstString name,
const CompilerType &cast_type) {
ValueObjectCast *cast_valobj_ptr =
new ValueObjectCast(parent, name, cast_type);
return cast_valobj_ptr->GetSP();
}
ValueObjectCast::ValueObjectCast(ValueObject &parent, ConstString name,
const CompilerType &cast_type)
: ValueObject(parent), m_cast_type(cast_type) {
SetName(name);
m_value.SetCompilerType(cast_type);
}
ValueObjectCast::~ValueObjectCast() = default;
CompilerType ValueObjectCast::GetCompilerTypeImpl() { return m_cast_type; }
llvm::Expected<uint32_t> ValueObjectCast::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;
}
llvm::Expected<uint64_t> ValueObjectCast::GetByteSize() {
ExecutionContext exe_ctx(GetExecutionContextRef());
return m_value.GetValueByteSize(nullptr, &exe_ctx);
}
lldb::ValueType ValueObjectCast::GetValueType() const {
// Let our parent answer global, local, argument, etc...
return m_parent->GetValueType();
}
bool ValueObjectCast::UpdateValue() {
SetValueIsValid(false);
m_error.Clear();
if (m_parent->UpdateValueIfNeeded(false)) {
Value old_value(m_value);
m_update_point.SetUpdated();
m_value = m_parent->GetValue();
CompilerType compiler_type(GetCompilerType());
m_value.SetCompilerType(compiler_type);
SetAddressTypeOfChildren(m_parent->GetAddressTypeOfChildren());
if (!CanProvideValue()) {
// this value object represents an aggregate type whose children have
// values, but this object does not. So we say we are changed if our
// location has changed.
SetValueDidChange(m_value.GetValueType() != old_value.GetValueType() ||
m_value.GetScalar() != old_value.GetScalar());
}
ExecutionContext exe_ctx(GetExecutionContextRef());
m_error = m_value.GetValueAsData(&exe_ctx, m_data, GetModule().get());
SetValueDidChange(m_parent->GetValueDidChange());
return true;
}
// The dynamic value failed to get an error, pass the error along
if (m_error.Success() && m_parent->GetError().Fail())
m_error = m_parent->GetError().Clone();
SetValueIsValid(false);
return false;
}
bool ValueObjectCast::IsInScope() { return m_parent->IsInScope(); }