[Lldb-commits] [lldb] [lldb][libc++] Adds slice_array data formatters. (PR #85544)

[Michael Buch via lldb-commits]

================
@@ -0,0 +1,166 @@
+//===-- LibCxxSliceArray.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 {
+
+bool LibcxxStdSliceArraySummaryProvider(ValueObject &valobj, Stream &stream,
+                                        const TypeSummaryOptions &options) {
+  ValueObjectSP obj = valobj.GetNonSyntheticValue();
+  if (!obj)
+    return false;
+
+  ValueObjectSP ptr_sp = obj->GetChildMemberWithName("__size_");
+  if (!ptr_sp)
+    return false;
+  const size_t size = ptr_sp->GetValueAsUnsigned(0);
+
+  ptr_sp = obj->GetChildMemberWithName("__stride_");
+  if (!ptr_sp)
+    return false;
+  const size_t stride = ptr_sp->GetValueAsUnsigned(0);
+
+  stream.Printf("stride=%" PRIu64 " size=%" PRIu64, stride, size);
+
+  return true;
+}
+
+/// Data formatter for libc++'s std::slice_array.
+///
+/// A slice_array is created by using:
+///   operator[](std::slice slicearr);
+/// and std::slice is created by:
+///   slice(std::size_t start, std::size_t size, std::size_t stride);
+/// The std::slice_array has the following members:
+/// - __vp_ pointes to std::valarray::__begin_ + @a start
----------------
Michael137 wrote:

```suggestion
/// - __vp_ points to std::valarray::__begin_ + @a start
```

https://github.com/llvm/llvm-project/pull/85544