lldb/source/Plugins/Language/CPlusPlus/LibCxxRangesRefView.cpp

   1 //===-- LibCxxRangesRefView.cpp -------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "LibCxx.h"
  10
  11 #include "lldb/DataFormatters/FormattersHelpers.h"
  12 #include "lldb/Utility/ConstString.h"
  13 #include "lldb/ValueObject/ValueObject.h"
  14 #include "llvm/ADT/APSInt.h"
  15
  16 using namespace lldb;
  17 using namespace lldb_private;
  18 using namespace lldb_private::formatters;
  19
  20 namespace lldb_private {
  21 namespace formatters {
  22
  23 class LibcxxStdRangesRefViewSyntheticFrontEnd
  24     : public SyntheticChildrenFrontEnd {
  25 public:
  26   LibcxxStdRangesRefViewSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
  27
  28   ~LibcxxStdRangesRefViewSyntheticFrontEnd() override = default;
  29
  30   llvm::Expected<uint32_t> CalculateNumChildren() override {
  31     // __range_ will be the sole child of this type
  32     return 1;
  33   }
  34
  35   lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override {
  36     // Since we only have a single child, return it
  37     assert(idx == 0);
  38     return m_range_sp;
  39   }
  40
  41   lldb::ChildCacheState Update() override;
  42
  43   bool MightHaveChildren() override { return true; }
  44
  45   size_t GetIndexOfChildWithName(ConstString name) override {
  46     // We only have a single child
  47     return 0;
  48   }
  49
  50 private:
  51   /// Pointer to the dereferenced __range_ member
  52   lldb::ValueObjectSP m_range_sp = nullptr;
  53 };
  54
  55 lldb_private::formatters::LibcxxStdRangesRefViewSyntheticFrontEnd::
  56     LibcxxStdRangesRefViewSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
  57     : SyntheticChildrenFrontEnd(*valobj_sp) {
  58   if (valobj_sp)
  59     Update();
  60 }
  61
  62 lldb::ChildCacheState
  63 lldb_private::formatters::LibcxxStdRangesRefViewSyntheticFrontEnd::Update() {
  64   ValueObjectSP range_ptr =
  65       GetChildMemberWithName(m_backend, {ConstString("__range_")});
  66   if (!range_ptr)
  67     return lldb::ChildCacheState::eRefetch;
  68
  69   lldb_private::Status error;
  70   m_range_sp = range_ptr->Dereference(error);
  71
  72   return error.Success() ? lldb::ChildCacheState::eReuse
  73                          : lldb::ChildCacheState::eRefetch;
  74 }
  75
  76 lldb_private::SyntheticChildrenFrontEnd *
  77 LibcxxStdRangesRefViewSyntheticFrontEndCreator(CXXSyntheticChildren *,
  78                                                lldb::ValueObjectSP valobj_sp) {
  79   if (!valobj_sp)
  80     return nullptr;
  81   CompilerType type = valobj_sp->GetCompilerType();
  82   if (!type.IsValid())
  83     return nullptr;
  84   return new LibcxxStdRangesRefViewSyntheticFrontEnd(valobj_sp);
  85 }
  86
  87 } // namespace formatters
  88 } // namespace lldb_private