[Lldb-commits] [lldb] [lldb][libc++] Adds valarray data formatters. (PR #80609)

[Michael Buch via lldb-commits]

================
@@ -0,0 +1,140 @@
+//===-- LibCxxValarray.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 "lldb/Core/ValueObject.h"
+#include "lldb/DataFormatters/FormattersHelpers.h"
+#include <optional>
+
+using namespace lldb;
+using namespace lldb_private;
+using namespace lldb_private::formatters;
+
+namespace lldb_private {
+namespace formatters {
+class LibcxxStdValarraySyntheticFrontEnd : public SyntheticChildrenFrontEnd {
+public:
+  LibcxxStdValarraySyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
+
+  ~LibcxxStdValarraySyntheticFrontEnd() override;
+
+  size_t CalculateNumChildren() override;
+
+  lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
+
+  bool Update() override;
+
+  bool MightHaveChildren() override;
+
+  size_t GetIndexOfChildWithName(ConstString name) override;
+
+private:
+  ValueObject *m_start = nullptr;
+  ValueObject *m_finish = nullptr;
+  CompilerType m_element_type;
+  uint32_t m_element_size = 0;
+};
+
+} // namespace formatters
+} // namespace lldb_private
+
+lldb_private::formatters::LibcxxStdValarraySyntheticFrontEnd::
+    LibcxxStdValarraySyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
+    : SyntheticChildrenFrontEnd(*valobj_sp), m_element_type() {
+  if (valobj_sp)
+    Update();
+}
+
+lldb_private::formatters::LibcxxStdValarraySyntheticFrontEnd::
+    ~LibcxxStdValarraySyntheticFrontEnd() {
+  // these need to stay around because they are child objects who will follow
+  // their parent's life cycle
+  // delete m_start;
+  // delete m_finish;
+}
+
+size_t lldb_private::formatters::LibcxxStdValarraySyntheticFrontEnd::
+    CalculateNumChildren() {
+  if (!m_start || !m_finish)
+    return 0;
+  uint64_t start_val = m_start->GetValueAsUnsigned(0);
+  uint64_t finish_val = m_finish->GetValueAsUnsigned(0);
+
+  if (start_val == 0 || finish_val == 0)
+    return 0;
+
+  if (start_val >= finish_val)
+    return 0;
+
+  size_t num_children = (finish_val - start_val);
+  if (num_children % m_element_size)
+    return 0;
+  return num_children / m_element_size;
+}
+
+lldb::ValueObjectSP
+lldb_private::formatters::LibcxxStdValarraySyntheticFrontEnd::GetChildAtIndex(
+    size_t idx) {
+  if (!m_start || !m_finish)
+    return lldb::ValueObjectSP();
+
+  uint64_t offset = idx * m_element_size;
+  offset = offset + m_start->GetValueAsUnsigned(0);
+  StreamString name;
+  name.Printf("[%" PRIu64 "]", (uint64_t)idx);
+  return CreateValueObjectFromAddress(name.GetString(), offset,
+                                      m_backend.GetExecutionContextRef(),
+                                      m_element_type);
+}
+
+bool lldb_private::formatters::LibcxxStdValarraySyntheticFrontEnd::Update() {
----------------
Michael137 wrote:

The return type of `Update` changed in https://github.com/llvm/llvm-project/pull/80167. So you'll have some conflicts when rebasing. The `return false;` should be `return ChildCacheState::eRefetch` instead.

https://github.com/llvm/llvm-project/pull/80609