eec98bef84
Adds synthetic children for MSVC STL's
[`std::tuple`](313964b78a/stl/inc/tuple).
A `tuple` is a chain of base classes:
```cpp
template <>
class tuple<> {};
template <class _This, class... _Rest>
class tuple<_This, _Rest...> : private tuple<_Rest...> {
_Tuple_val<_This> _Myfirst;
};
```
So the provider walks the base classes to the desired one.
The implementation makes it hard to detect if the empty tuple is from
this STL. Fortunately, libstdc++'s synthetic children provider works for
empty MSVC STL tuples as well.
Towards #24834.
106 lines
3.3 KiB
C++
106 lines
3.3 KiB
C++
//===-- MsvcStlTuple.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 "MsvcStl.h"
|
|
#include "lldb/DataFormatters/FormattersHelpers.h"
|
|
|
|
using namespace lldb;
|
|
using namespace lldb_private;
|
|
|
|
namespace {
|
|
|
|
class TupleFrontEnd : public SyntheticChildrenFrontEnd {
|
|
public:
|
|
TupleFrontEnd(ValueObject &valobj) : SyntheticChildrenFrontEnd(valobj) {
|
|
Update();
|
|
}
|
|
|
|
llvm::Expected<size_t> GetIndexOfChildWithName(ConstString name) override {
|
|
auto optional_idx = formatters::ExtractIndexFromString(name.GetCString());
|
|
if (!optional_idx) {
|
|
return llvm::createStringError("Type has no child named '%s'",
|
|
name.AsCString());
|
|
}
|
|
return *optional_idx;
|
|
}
|
|
|
|
lldb::ChildCacheState Update() override;
|
|
llvm::Expected<uint32_t> CalculateNumChildren() override {
|
|
return m_elements.size();
|
|
}
|
|
ValueObjectSP GetChildAtIndex(uint32_t idx) override;
|
|
|
|
private:
|
|
// The lifetime of a ValueObject and all its derivative ValueObjects
|
|
// (children, clones, etc.) is managed by a ClusterManager. These
|
|
// objects are only destroyed when every shared pointer to any of them
|
|
// is destroyed, so we must not store a shared pointer to any ValueObject
|
|
// derived from our backend ValueObject (since we're in the same cluster).
|
|
std::vector<ValueObject *> m_elements;
|
|
};
|
|
|
|
} // namespace
|
|
|
|
lldb::ChildCacheState TupleFrontEnd::Update() {
|
|
m_elements.clear();
|
|
|
|
size_t n_elements = 0;
|
|
for (CompilerType ty = m_backend.GetCompilerType();
|
|
ty.GetNumDirectBaseClasses() > 0;
|
|
ty = ty.GetDirectBaseClassAtIndex(0, nullptr))
|
|
++n_elements;
|
|
|
|
m_elements.assign(n_elements, nullptr);
|
|
return lldb::ChildCacheState::eRefetch;
|
|
}
|
|
|
|
ValueObjectSP TupleFrontEnd::GetChildAtIndex(uint32_t idx) {
|
|
if (idx >= m_elements.size())
|
|
return nullptr;
|
|
if (m_elements[idx])
|
|
return m_elements[idx]->GetSP();
|
|
|
|
CompilerType holder_ty = m_backend.GetCompilerType();
|
|
for (uint32_t i = 0; i < idx; i++) {
|
|
holder_ty = holder_ty.GetDirectBaseClassAtIndex(0, nullptr);
|
|
if (!holder_ty.IsValid())
|
|
return nullptr;
|
|
}
|
|
|
|
ValueObjectSP holder_sp = m_backend.Cast(holder_ty);
|
|
if (!holder_sp)
|
|
return nullptr;
|
|
holder_sp = holder_sp->GetChildMemberWithName("_Myfirst");
|
|
|
|
if (!holder_sp)
|
|
return nullptr;
|
|
|
|
ValueObjectSP val_sp = holder_sp->GetChildMemberWithName("_Val");
|
|
if (!val_sp)
|
|
return nullptr;
|
|
|
|
m_elements[idx] =
|
|
val_sp->Clone(ConstString(llvm::formatv("[{0}]", idx).str())).get();
|
|
return m_elements[idx]->GetSP();
|
|
}
|
|
|
|
bool formatters::IsMsvcStlTuple(ValueObject &valobj) {
|
|
// This returns false for empty tuples, but the libstdc++ formatter handles
|
|
// this correctly.
|
|
if (auto valobj_sp = valobj.GetNonSyntheticValue())
|
|
return valobj_sp->GetChildMemberWithName("_Myfirst") != nullptr;
|
|
return false;
|
|
}
|
|
|
|
SyntheticChildrenFrontEnd *formatters::MsvcStlTupleSyntheticFrontEndCreator(
|
|
CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
|
|
if (valobj_sp)
|
|
return new TupleFrontEnd(*valobj_sp);
|
|
return nullptr;
|
|
}
|