[Lldb-commits] [lldb] [LLDB] Add formatters for MSVC STL std::tuple (PR #148548)
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lldb-commits at lists.llvm.org
Mon Jul 14 10:03:26 PDT 2025
https://github.com/Nerixyz updated https://github.com/llvm/llvm-project/pull/148548
>From d8983cbdd12b9c3b7730e9a42960705f89eecc7b Mon Sep 17 00:00:00 2001
From: Nerixyz <nerixdev at outlook.de>
Date: Sun, 13 Jul 2025 22:46:23 +0200
Subject: [PATCH] [LLDB] Add formatters for MSVC STL std::tuple
---
.../Plugins/Language/CPlusPlus/CMakeLists.txt | 1 +
.../Language/CPlusPlus/CPlusPlusLanguage.cpp | 32 ++++--
.../Plugins/Language/CPlusPlus/MsvcStl.h | 6 +
.../Language/CPlusPlus/MsvcStlTuple.cpp | 105 ++++++++++++++++++
.../tuple/TestDataFormatterStdTuple.py | 6 +
.../data-formatter-stl/generic/tuple/main.cpp | 1 +
6 files changed, 139 insertions(+), 12 deletions(-)
create mode 100644 lldb/source/Plugins/Language/CPlusPlus/MsvcStlTuple.cpp
diff --git a/lldb/source/Plugins/Language/CPlusPlus/CMakeLists.txt b/lldb/source/Plugins/Language/CPlusPlus/CMakeLists.txt
index 296159ea28407..ea86b6b4327be 100644
--- a/lldb/source/Plugins/Language/CPlusPlus/CMakeLists.txt
+++ b/lldb/source/Plugins/Language/CPlusPlus/CMakeLists.txt
@@ -35,6 +35,7 @@ add_lldb_library(lldbPluginCPlusPlusLanguage PLUGIN
LibStdcppUniquePointer.cpp
MsvcStl.cpp
MsvcStlSmartPointer.cpp
+ MsvcStlTuple.cpp
MSVCUndecoratedNameParser.cpp
LINK_COMPONENTS
diff --git a/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp b/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp
index 9a869f3ea0289..31350d3737ad2 100644
--- a/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp
+++ b/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp
@@ -1507,10 +1507,6 @@ static void LoadLibStdcppFormatters(lldb::TypeCategoryImplSP cpp_category_sp) {
"^std::((__debug::)?|(__cxx11::)?)list<.+>(( )?&)?$",
stl_summary_flags, true);
- AddCXXSummary(cpp_category_sp, ContainerSizeSummaryProvider,
- "libstdc++ std::tuple summary provider",
- "^std::tuple<.*>(( )?&)?$", stl_summary_flags, true);
-
cpp_category_sp->AddTypeSummary(
"^std::((__debug::)?|(__cxx11::)?)forward_list<.+>(( )?&)?$",
eFormatterMatchRegex,
@@ -1540,11 +1536,6 @@ static void LoadLibStdcppFormatters(lldb::TypeCategoryImplSP cpp_category_sp) {
lldb_private::formatters::LibStdcppUniquePtrSyntheticFrontEndCreator,
"std::unique_ptr synthetic children", "^std::unique_ptr<.+>(( )?&)?$",
stl_synth_flags, true);
- AddCXXSynthetic(
- cpp_category_sp,
- lldb_private::formatters::LibStdcppTupleSyntheticFrontEndCreator,
- "std::tuple synthetic children", "^std::tuple<.*>(( )?&)?$",
- stl_synth_flags, true);
static constexpr const char *const libstdcpp_std_coroutine_handle_regex =
"^std::coroutine_handle<.+>(( )?&)?$";
@@ -1611,6 +1602,17 @@ static bool GenericUniquePtrSummaryProvider(ValueObject &valobj, Stream &stream,
if (IsMsvcStlUniquePtr(valobj))
return MsvcStlUniquePtrSummaryProvider(valobj, stream, options);
return LibStdcppUniquePointerSummaryProvider(valobj, stream, options);
+ }
+
+ static SyntheticChildrenFrontEnd*
+GenericTupleSyntheticFrontEndCreator(CXXSyntheticChildren *children,
+ lldb::ValueObjectSP valobj_sp) {
+ if (!valobj_sp)
+ return nullptr;
+
+ if (IsMsvcStlTuple(*valobj_sp))
+ return MsvcStlTupleSyntheticFrontEndCreator(children, valobj_sp);
+ return LibStdcppTupleSyntheticFrontEndCreator(children, valobj_sp);
}
/// Load formatters that are formatting types from more than one STL
@@ -1656,9 +1658,6 @@ static void LoadCommonStlFormatters(lldb::TypeCategoryImplSP cpp_category_sp) {
},
"MSVC STL/libstdc++ std::wstring summary provider"));
- stl_summary_flags.SetDontShowChildren(false);
- stl_summary_flags.SetSkipPointers(false);
-
AddCXXSynthetic(cpp_category_sp, GenericSmartPointerSyntheticFrontEndCreator,
"std::shared_ptr synthetic children",
"^std::shared_ptr<.+>(( )?&)?$", stl_synth_flags, true);
@@ -1668,6 +1667,12 @@ static void LoadCommonStlFormatters(lldb::TypeCategoryImplSP cpp_category_sp) {
AddCXXSynthetic(cpp_category_sp, GenericUniquePtrSyntheticFrontEndCreator,
"std::unique_ptr synthetic children",
"^std::unique_ptr<.+>(( )?&)?$", stl_synth_flags, true);
+ AddCXXSynthetic(cpp_category_sp, GenericTupleSyntheticFrontEndCreator,
+ "std::tuple synthetic children", "^std::tuple<.*>(( )?&)?$",
+ stl_synth_flags, true);
+
+ stl_summary_flags.SetDontShowChildren(false);
+ stl_summary_flags.SetSkipPointers(false);
AddCXXSummary(cpp_category_sp, GenericSmartPointerSummaryProvider,
"MSVC STL/libstdc++ std::shared_ptr summary provider",
@@ -1678,6 +1683,9 @@ static void LoadCommonStlFormatters(lldb::TypeCategoryImplSP cpp_category_sp) {
AddCXXSummary(cpp_category_sp, GenericUniquePtrSummaryProvider,
"MSVC STL/libstdc++ std::unique_ptr summary provider",
"^std::unique_ptr<.+>(( )?&)?$", stl_summary_flags, true);
+ AddCXXSummary(cpp_category_sp, ContainerSizeSummaryProvider,
+ "MSVC STL/libstdc++ std::tuple summary provider",
+ "^std::tuple<.*>(( )?&)?$", stl_summary_flags, true);
}
static void LoadMsvcStlFormatters(lldb::TypeCategoryImplSP cpp_category_sp) {
diff --git a/lldb/source/Plugins/Language/CPlusPlus/MsvcStl.h b/lldb/source/Plugins/Language/CPlusPlus/MsvcStl.h
index fe75bf275f8e2..bad47701904bb 100644
--- a/lldb/source/Plugins/Language/CPlusPlus/MsvcStl.h
+++ b/lldb/source/Plugins/Language/CPlusPlus/MsvcStl.h
@@ -45,6 +45,12 @@ bool MsvcStlUniquePtrSummaryProvider(ValueObject &valobj, Stream &stream,
lldb_private::SyntheticChildrenFrontEnd *
MsvcStlUniquePtrSyntheticFrontEndCreator(lldb::ValueObjectSP valobj_sp);
+// MSVC STL std::tuple<>
+bool IsMsvcStlTuple(ValueObject &valobj);
+SyntheticChildrenFrontEnd *
+MsvcStlTupleSyntheticFrontEndCreator(CXXSyntheticChildren *,
+ lldb::ValueObjectSP valobj_sp);
+
} // namespace formatters
} // namespace lldb_private
diff --git a/lldb/source/Plugins/Language/CPlusPlus/MsvcStlTuple.cpp b/lldb/source/Plugins/Language/CPlusPlus/MsvcStlTuple.cpp
new file mode 100644
index 0000000000000..fe20b4c141a65
--- /dev/null
+++ b/lldb/source/Plugins/Language/CPlusPlus/MsvcStlTuple.cpp
@@ -0,0 +1,105 @@
+//===-- 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;
+}
diff --git a/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/tuple/TestDataFormatterStdTuple.py b/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/tuple/TestDataFormatterStdTuple.py
index ade502e12b928..b23d549fe4c18 100644
--- a/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/tuple/TestDataFormatterStdTuple.py
+++ b/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/tuple/TestDataFormatterStdTuple.py
@@ -74,3 +74,9 @@ def test_libcxx(self):
def test_libstdcxx(self):
self.build(dictionary={"USE_LIBSTDCPP": 1})
self.do_test()
+
+ @add_test_categories(["msvcstl"])
+ def test_msvcstl(self):
+ # No flags, because the "msvcstl" category checks that the MSVC STL is used by default.
+ self.build()
+ self.do_test()
diff --git a/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/tuple/main.cpp b/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/tuple/main.cpp
index d49dbe8a5f1af..53d0a4efd3865 100644
--- a/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/tuple/main.cpp
+++ b/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/tuple/main.cpp
@@ -6,5 +6,6 @@ int main() {
std::tuple<int> one_elt{47};
std::tuple<std::string> string_elt{"foobar"};
std::tuple<int, long, std::string> three_elts{1, 47l, "foo"};
+ auto *foo = ∅ // needed with MSVC STL to keep the variable
return 0; // break here
}
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