Shafik Yaghmour 28c878aeb2 [LLDB] Applying clang-tidy modernize-use-default-member-init over LLDB
Applied modernize-use-default-member-init clang-tidy check over LLDB.
It appears in many files we had already switched to in class member init but
never updated the constructors to reflect that. This check is already present in
the lldb/.clang-tidy config.

Differential Revision: https://reviews.llvm.org/D121481
2022-03-14 13:32:03 -07:00

434 lines
12 KiB
C++

//===-- LibCxxList.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 "LibCxx.h"
#include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
#include "lldb/Core/ValueObject.h"
#include "lldb/Core/ValueObjectConstResult.h"
#include "lldb/DataFormatters/FormattersHelpers.h"
#include "lldb/Target/Target.h"
#include "lldb/Utility/DataBufferHeap.h"
#include "lldb/Utility/Endian.h"
#include "lldb/Utility/Status.h"
#include "lldb/Utility/Stream.h"
using namespace lldb;
using namespace lldb_private;
using namespace lldb_private::formatters;
namespace {
class ListEntry {
public:
ListEntry() = default;
ListEntry(ValueObjectSP entry_sp) : m_entry_sp(std::move(entry_sp)) {}
ListEntry(ValueObject *entry)
: m_entry_sp(entry ? entry->GetSP() : ValueObjectSP()) {}
ListEntry next() {
static ConstString g_next("__next_");
if (!m_entry_sp)
return ListEntry();
return ListEntry(m_entry_sp->GetChildMemberWithName(g_next, true));
}
ListEntry prev() {
static ConstString g_prev("__prev_");
if (!m_entry_sp)
return ListEntry();
return ListEntry(m_entry_sp->GetChildMemberWithName(g_prev, true));
}
uint64_t value() const {
if (!m_entry_sp)
return 0;
return m_entry_sp->GetValueAsUnsigned(0);
}
bool null() { return (value() == 0); }
explicit operator bool() { return GetEntry() && !null(); }
ValueObjectSP GetEntry() { return m_entry_sp; }
void SetEntry(ValueObjectSP entry) { m_entry_sp = entry; }
bool operator==(const ListEntry &rhs) const { return value() == rhs.value(); }
bool operator!=(const ListEntry &rhs) const { return !(*this == rhs); }
private:
ValueObjectSP m_entry_sp;
};
class ListIterator {
public:
ListIterator() = default;
ListIterator(ListEntry entry) : m_entry(std::move(entry)) {}
ListIterator(ValueObjectSP entry) : m_entry(std::move(entry)) {}
ListIterator(ValueObject *entry) : m_entry(entry) {}
ValueObjectSP value() { return m_entry.GetEntry(); }
ValueObjectSP advance(size_t count) {
if (count == 0)
return m_entry.GetEntry();
if (count == 1) {
next();
return m_entry.GetEntry();
}
while (count > 0) {
next();
count--;
if (m_entry.null())
return lldb::ValueObjectSP();
}
return m_entry.GetEntry();
}
bool operator==(const ListIterator &rhs) const {
return (rhs.m_entry == m_entry);
}
protected:
void next() { m_entry = m_entry.next(); }
void prev() { m_entry = m_entry.prev(); }
private:
ListEntry m_entry;
};
class AbstractListFrontEnd : public SyntheticChildrenFrontEnd {
public:
size_t GetIndexOfChildWithName(ConstString name) override {
return ExtractIndexFromString(name.GetCString());
}
bool MightHaveChildren() override { return true; }
bool Update() override;
protected:
AbstractListFrontEnd(ValueObject &valobj)
: SyntheticChildrenFrontEnd(valobj) {}
size_t m_count;
ValueObject *m_head;
static constexpr bool g_use_loop_detect = true;
size_t m_loop_detected; // The number of elements that have had loop detection
// run over them.
ListEntry m_slow_runner; // Used for loop detection
ListEntry m_fast_runner; // Used for loop detection
size_t m_list_capping_size;
CompilerType m_element_type;
std::map<size_t, ListIterator> m_iterators;
bool HasLoop(size_t count);
ValueObjectSP GetItem(size_t idx);
};
class ForwardListFrontEnd : public AbstractListFrontEnd {
public:
ForwardListFrontEnd(ValueObject &valobj);
size_t CalculateNumChildren() override;
ValueObjectSP GetChildAtIndex(size_t idx) override;
bool Update() override;
};
class ListFrontEnd : public AbstractListFrontEnd {
public:
ListFrontEnd(lldb::ValueObjectSP valobj_sp);
~ListFrontEnd() override = default;
size_t CalculateNumChildren() override;
lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
bool Update() override;
private:
lldb::addr_t m_node_address = 0;
ValueObject *m_tail = nullptr;
};
} // end anonymous namespace
bool AbstractListFrontEnd::Update() {
m_loop_detected = 0;
m_count = UINT32_MAX;
m_head = nullptr;
m_list_capping_size = 0;
m_slow_runner.SetEntry(nullptr);
m_fast_runner.SetEntry(nullptr);
m_iterators.clear();
if (m_backend.GetTargetSP())
m_list_capping_size =
m_backend.GetTargetSP()->GetMaximumNumberOfChildrenToDisplay();
if (m_list_capping_size == 0)
m_list_capping_size = 255;
CompilerType list_type = m_backend.GetCompilerType();
if (list_type.IsReferenceType())
list_type = list_type.GetNonReferenceType();
if (list_type.GetNumTemplateArguments() == 0)
return false;
m_element_type = list_type.GetTypeTemplateArgument(0);
return false;
}
bool AbstractListFrontEnd::HasLoop(size_t count) {
if (!g_use_loop_detect)
return false;
// don't bother checking for a loop if we won't actually need to jump nodes
if (m_count < 2)
return false;
if (m_loop_detected == 0) {
// This is the first time we are being run (after the last update). Set up
// the loop invariant for the first element.
m_slow_runner = ListEntry(m_head).next();
m_fast_runner = m_slow_runner.next();
m_loop_detected = 1;
}
// Loop invariant:
// Loop detection has been run over the first m_loop_detected elements. If
// m_slow_runner == m_fast_runner then the loop has been detected after
// m_loop_detected elements.
const size_t steps_to_run = std::min(count, m_count);
while (m_loop_detected < steps_to_run && m_slow_runner && m_fast_runner &&
m_slow_runner != m_fast_runner) {
m_slow_runner = m_slow_runner.next();
m_fast_runner = m_fast_runner.next().next();
m_loop_detected++;
}
if (count <= m_loop_detected)
return false; // No loop in the first m_loop_detected elements.
if (!m_slow_runner || !m_fast_runner)
return false; // Reached the end of the list. Definitely no loops.
return m_slow_runner == m_fast_runner;
}
ValueObjectSP AbstractListFrontEnd::GetItem(size_t idx) {
size_t advance = idx;
ListIterator current(m_head);
if (idx > 0) {
auto cached_iterator = m_iterators.find(idx - 1);
if (cached_iterator != m_iterators.end()) {
current = cached_iterator->second;
advance = 1;
}
}
ValueObjectSP value_sp = current.advance(advance);
m_iterators[idx] = current;
return value_sp;
}
ForwardListFrontEnd::ForwardListFrontEnd(ValueObject &valobj)
: AbstractListFrontEnd(valobj) {
Update();
}
size_t ForwardListFrontEnd::CalculateNumChildren() {
if (m_count != UINT32_MAX)
return m_count;
ListEntry current(m_head);
m_count = 0;
while (current && m_count < m_list_capping_size) {
++m_count;
current = current.next();
}
return m_count;
}
ValueObjectSP ForwardListFrontEnd::GetChildAtIndex(size_t idx) {
if (idx >= CalculateNumChildren())
return nullptr;
if (!m_head)
return nullptr;
if (HasLoop(idx + 1))
return nullptr;
ValueObjectSP current_sp = GetItem(idx);
if (!current_sp)
return nullptr;
current_sp = current_sp->GetChildAtIndex(1, true); // get the __value_ child
if (!current_sp)
return nullptr;
// we need to copy current_sp into a new object otherwise we will end up with
// all items named __value_
DataExtractor data;
Status error;
current_sp->GetData(data, error);
if (error.Fail())
return nullptr;
return CreateValueObjectFromData(llvm::formatv("[{0}]", idx).str(), data,
m_backend.GetExecutionContextRef(),
m_element_type);
}
bool ForwardListFrontEnd::Update() {
AbstractListFrontEnd::Update();
Status err;
ValueObjectSP backend_addr(m_backend.AddressOf(err));
if (err.Fail() || !backend_addr)
return false;
ValueObjectSP impl_sp(
m_backend.GetChildMemberWithName(ConstString("__before_begin_"), true));
if (!impl_sp)
return false;
impl_sp = GetValueOfLibCXXCompressedPair(*impl_sp);
if (!impl_sp)
return false;
m_head = impl_sp->GetChildMemberWithName(ConstString("__next_"), true).get();
return false;
}
ListFrontEnd::ListFrontEnd(lldb::ValueObjectSP valobj_sp)
: AbstractListFrontEnd(*valobj_sp) {
if (valobj_sp)
Update();
}
size_t ListFrontEnd::CalculateNumChildren() {
if (m_count != UINT32_MAX)
return m_count;
if (!m_head || !m_tail || m_node_address == 0)
return 0;
ValueObjectSP size_alloc(
m_backend.GetChildMemberWithName(ConstString("__size_alloc_"), true));
if (size_alloc) {
ValueObjectSP value = GetValueOfLibCXXCompressedPair(*size_alloc);
if (value) {
m_count = value->GetValueAsUnsigned(UINT32_MAX);
}
}
if (m_count != UINT32_MAX) {
return m_count;
} else {
uint64_t next_val = m_head->GetValueAsUnsigned(0);
uint64_t prev_val = m_tail->GetValueAsUnsigned(0);
if (next_val == 0 || prev_val == 0)
return 0;
if (next_val == m_node_address)
return 0;
if (next_val == prev_val)
return 1;
uint64_t size = 2;
ListEntry current(m_head);
while (current.next() && current.next().value() != m_node_address) {
size++;
current = current.next();
if (size > m_list_capping_size)
break;
}
return m_count = (size - 1);
}
}
lldb::ValueObjectSP ListFrontEnd::GetChildAtIndex(size_t idx) {
static ConstString g_value("__value_");
static ConstString g_next("__next_");
if (idx >= CalculateNumChildren())
return lldb::ValueObjectSP();
if (!m_head || !m_tail || m_node_address == 0)
return lldb::ValueObjectSP();
if (HasLoop(idx + 1))
return lldb::ValueObjectSP();
ValueObjectSP current_sp = GetItem(idx);
if (!current_sp)
return lldb::ValueObjectSP();
current_sp = current_sp->GetChildAtIndex(1, true); // get the __value_ child
if (!current_sp)
return lldb::ValueObjectSP();
if (current_sp->GetName() == g_next) {
ProcessSP process_sp(current_sp->GetProcessSP());
if (!process_sp)
return lldb::ValueObjectSP();
// if we grabbed the __next_ pointer, then the child is one pointer deep-er
lldb::addr_t addr = current_sp->GetParent()->GetPointerValue();
addr = addr + 2 * process_sp->GetAddressByteSize();
ExecutionContext exe_ctx(process_sp);
current_sp =
CreateValueObjectFromAddress("__value_", addr, exe_ctx, m_element_type);
if (!current_sp)
return lldb::ValueObjectSP();
}
// we need to copy current_sp into a new object otherwise we will end up with
// all items named __value_
DataExtractor data;
Status error;
current_sp->GetData(data, error);
if (error.Fail())
return lldb::ValueObjectSP();
StreamString name;
name.Printf("[%" PRIu64 "]", (uint64_t)idx);
return CreateValueObjectFromData(name.GetString(), data,
m_backend.GetExecutionContextRef(),
m_element_type);
}
bool ListFrontEnd::Update() {
AbstractListFrontEnd::Update();
m_tail = nullptr;
m_node_address = 0;
Status err;
ValueObjectSP backend_addr(m_backend.AddressOf(err));
if (err.Fail() || !backend_addr)
return false;
m_node_address = backend_addr->GetValueAsUnsigned(0);
if (!m_node_address || m_node_address == LLDB_INVALID_ADDRESS)
return false;
ValueObjectSP impl_sp(
m_backend.GetChildMemberWithName(ConstString("__end_"), true));
if (!impl_sp)
return false;
m_head = impl_sp->GetChildMemberWithName(ConstString("__next_"), true).get();
m_tail = impl_sp->GetChildMemberWithName(ConstString("__prev_"), true).get();
return false;
}
SyntheticChildrenFrontEnd *formatters::LibcxxStdListSyntheticFrontEndCreator(
CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
return (valobj_sp ? new ListFrontEnd(valobj_sp) : nullptr);
}
SyntheticChildrenFrontEnd *
formatters::LibcxxStdForwardListSyntheticFrontEndCreator(
CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
return valobj_sp ? new ForwardListFrontEnd(*valobj_sp) : nullptr;
}