[Lldb-commits] [lldb] [LLDB] Add MSVC STL initializer_list formatter (PR #178712)
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lldb-commits at lists.llvm.org
Wed Aug 19 01:03:28 PDT 2026
https://github.com/Nerixyz updated https://github.com/llvm/llvm-project/pull/178712
>From b152b20bb4c4620095edaa0ebbade353c9ad6c89 Mon Sep 17 00:00:00 2001
From: Nerixyz <nerixdev at outlook.de>
Date: Mon, 12 Jan 2026 20:23:03 +0100
Subject: [PATCH] [LLDB] Add MSVC STL initializer_list formatter
---
.../CPlusPlus/GenericInitializerList.cpp | 73 ++++++++++++++-----
.../TestDataFormatterStdInitializerList.py | 7 ++
2 files changed, 62 insertions(+), 18 deletions(-)
diff --git a/lldb/source/Plugins/Language/CPlusPlus/GenericInitializerList.cpp b/lldb/source/Plugins/Language/CPlusPlus/GenericInitializerList.cpp
index 7f012b7fc8aa6..3f63a8dc6170b 100644
--- a/lldb/source/Plugins/Language/CPlusPlus/GenericInitializerList.cpp
+++ b/lldb/source/Plugins/Language/CPlusPlus/GenericInitializerList.cpp
@@ -9,9 +9,9 @@
#include "lldb/DataFormatters/FormattersHelpers.h"
#include "lldb/Utility/ConstString.h"
#include "lldb/ValueObject/ValueObject.h"
+#include "llvm/ADT/STLForwardCompat.h"
#include <cstddef>
#include <optional>
-#include <type_traits>
using namespace lldb;
using namespace lldb_private;
@@ -21,12 +21,13 @@ template <class T>
using size_func = decltype(T::GetSizeMember(std::declval<ValueObject &>()));
template <class T>
using start_func = decltype(T::GetStartMember(std::declval<ValueObject &>()));
-namespace {
-template <typename...> struct check_func : std::true_type {};
-} // namespace
+template <class T>
+using end_func = decltype(T::GetEndMember(std::declval<ValueObject &>()));
template <typename T>
-using has_functions = check_func<size_func<T>, start_func<T>>;
+using has_start_function = llvm::is_detected<start_func, T>;
+template <typename T> using has_size_function = llvm::is_detected<size_func, T>;
+template <typename T> using has_end_function = llvm::is_detected<end_func, T>;
} // namespace generic_check
struct LibCxx {
@@ -49,14 +50,24 @@ struct LibStdcpp {
}
};
+struct MsvcStl {
+ static ValueObjectSP GetStartMember(ValueObject &backend) {
+ return backend.GetChildMemberWithName("_First");
+ }
+
+ static ValueObjectSP GetEndMember(ValueObject &backend) {
+ return backend.GetChildMemberWithName("_Last");
+ }
+};
+
namespace lldb_private::formatters {
template <class StandardImpl>
class GenericInitializerListSyntheticFrontEnd
: public SyntheticChildrenFrontEnd {
public:
- static_assert(generic_check::has_functions<StandardImpl>::value,
- "Missing Required Functions.");
+ static_assert(generic_check::has_start_function<StandardImpl>::value,
+ "Missing start function.");
GenericInitializerListSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
: SyntheticChildrenFrontEnd(*valobj_sp), m_element_type() {
@@ -71,16 +82,11 @@ class GenericInitializerListSyntheticFrontEnd
}
llvm::Expected<uint32_t> CalculateNumChildren() override {
- m_num_elements = 0;
-
- const ValueObjectSP size_sp(StandardImpl::GetSizeMember(m_backend));
- if (size_sp)
- m_num_elements = size_sp->GetValueAsUnsigned(0);
return m_num_elements;
}
lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override {
- if (!m_start)
+ if (!m_start || idx >= m_num_elements)
return {};
uint64_t offset = static_cast<uint64_t>(idx) * m_element_size;
@@ -95,18 +101,46 @@ class GenericInitializerListSyntheticFrontEnd
lldb::ChildCacheState Update() override {
m_start = nullptr;
m_num_elements = 0;
- m_element_type = m_backend.GetCompilerType().GetTypeTemplateArgument(0);
- if (!m_element_type.IsValid())
+ // Store raw pointers or end up with a circular dependency.
+ m_start = StandardImpl::GetStartMember(m_backend).get();
+ if (!m_start)
return lldb::ChildCacheState::eRefetch;
+ m_element_type = m_backend.GetCompilerType().GetTypeTemplateArgument(0);
+ if (!m_element_type) {
+ // PDB doesn't have template types, so get the element type from the start
+ // pointer.
+ m_element_type = m_start->GetCompilerType().GetPointeeType();
+ if (!m_element_type)
+ return lldb::ChildCacheState::eRefetch;
+ }
+
llvm::Expected<uint64_t> size_or_err = m_element_type.GetByteSize(nullptr);
if (!size_or_err)
LLDB_LOG_ERRORV(GetLog(LLDBLog::DataFormatters), size_or_err.takeError(),
"{0}");
- else {
+ else
m_element_size = *size_or_err;
- // Store raw pointers or end up with a circular dependency.
- m_start = StandardImpl::GetStartMember(m_backend).get();
+
+ if (m_element_size == 0)
+ return lldb::ChildCacheState::eRefetch;
+
+ if constexpr (generic_check::has_size_function<StandardImpl>::value) {
+ const ValueObjectSP size_sp(StandardImpl::GetSizeMember(m_backend));
+ if (size_sp)
+ m_num_elements = size_sp->GetValueAsUnsigned(0);
+ } else {
+ static_assert(generic_check::has_end_function<StandardImpl>::value,
+ "Must have size or end function");
+ ValueObjectSP end_sp = StandardImpl::GetEndMember(m_backend);
+ if (!end_sp)
+ return lldb::ChildCacheState::eRefetch;
+
+ uint64_t start = m_start->GetValueAsUnsigned(0);
+ uint64_t end = end_sp->GetValueAsUnsigned(0);
+ if (end < start)
+ return lldb::ChildCacheState::eRefetch;
+ m_num_elements = (end - start) / m_element_size;
}
return lldb::ChildCacheState::eRefetch;
@@ -140,6 +174,9 @@ SyntheticChildrenFrontEnd *GenericInitializerListSyntheticFrontEndCreator(
if (LibCxx::GetStartMember(*valobj_sp) != nullptr)
return new GenericInitializerListSyntheticFrontEnd<LibCxx>(valobj_sp);
+ if (MsvcStl::GetStartMember(*valobj_sp) != nullptr)
+ return new GenericInitializerListSyntheticFrontEnd<MsvcStl>(valobj_sp);
+
return new GenericInitializerListSyntheticFrontEnd<LibStdcpp>(valobj_sp);
}
} // namespace lldb_private::formatters
diff --git a/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/initializer_list/TestDataFormatterStdInitializerList.py b/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/initializer_list/TestDataFormatterStdInitializerList.py
index 38d8cdb01ba90..40ab53ea601d2 100644
--- a/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/initializer_list/TestDataFormatterStdInitializerList.py
+++ b/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/initializer_list/TestDataFormatterStdInitializerList.py
@@ -10,6 +10,8 @@
class InitializerListTestCase(TestBase):
+ TEST_WITH_PDB_DEBUG_INFO = True
+
def do_test(self):
self.runCmd("file " + self.getBuildArtifact("a.out"), CURRENT_EXECUTABLE_SET)
@@ -50,3 +52,8 @@ def test_libcxx(self):
def test_libstdcpp(self):
self.build(dictionary={"USE_LIBSTDCPP": 1})
self.do_test()
+
+ @add_test_categories(["msvcstl"])
+ def test_msvcstd(self):
+ self.build()
+ self.do_test()
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