contrib/llvm/tools/lldb/source/Plugins/Language/CPlusPlus/LibCxxInitializerList.cpp

   1 //===-- LibCxxInitializerList.cpp -------------------------------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "LibCxx.h"
  11
  12 #include "lldb/Core/ValueObject.h"
  13 #include "lldb/DataFormatters/FormattersHelpers.h"
  14 #include "lldb/Utility/ConstString.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 class LibcxxInitializerListSyntheticFrontEnd
  23     : public SyntheticChildrenFrontEnd {
  24 public:
  25   LibcxxInitializerListSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
  26
  27   ~LibcxxInitializerListSyntheticFrontEnd() override;
  28
  29   size_t CalculateNumChildren() override;
  30
  31   lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
  32
  33   bool Update() override;
  34
  35   bool MightHaveChildren() override;
  36
  37   size_t GetIndexOfChildWithName(const ConstString &name) override;
  38
  39 private:
  40   ValueObject *m_start;
  41   CompilerType m_element_type;
  42   uint32_t m_element_size;
  43   size_t m_num_elements;
  44 };
  45 } // namespace formatters
  46 } // namespace lldb_private
  47
  48 lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
  49     LibcxxInitializerListSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
  50     : SyntheticChildrenFrontEnd(*valobj_sp), m_start(nullptr), m_element_type(),
  51       m_element_size(0), m_num_elements(0) {
  52   if (valobj_sp)
  53     Update();
  54 }
  55
  56 lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
  57     ~LibcxxInitializerListSyntheticFrontEnd() {
  58   // this needs to stay around because it's a child object who will follow its
  59   // parent's life cycle
  60   // delete m_start;
  61 }
  62
  63 size_t lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
  64     CalculateNumChildren() {
  65   static ConstString g___size_("__size_");
  66   m_num_elements = 0;
  67   ValueObjectSP size_sp(m_backend.GetChildMemberWithName(g___size_, true));
  68   if (size_sp)
  69     m_num_elements = size_sp->GetValueAsUnsigned(0);
  70   return m_num_elements;
  71 }
  72
  73 lldb::ValueObjectSP lldb_private::formatters::
  74     LibcxxInitializerListSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
  75   if (!m_start)
  76     return lldb::ValueObjectSP();
  77
  78   uint64_t offset = idx * m_element_size;
  79   offset = offset + m_start->GetValueAsUnsigned(0);
  80   StreamString name;
  81   name.Printf("[%" PRIu64 "]", (uint64_t)idx);
  82   return CreateValueObjectFromAddress(name.GetString(), offset,
  83                                       m_backend.GetExecutionContextRef(),
  84                                       m_element_type);
  85 }
  86
  87 bool lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
  88     Update() {
  89   static ConstString g___begin_("__begin_");
  90
  91   m_start = nullptr;
  92   m_num_elements = 0;
  93   m_element_type = m_backend.GetCompilerType().GetTypeTemplateArgument(0);
  94   if (!m_element_type.IsValid())
  95     return false;
  96
  97   if (llvm::Optional<uint64_t> size = m_element_type.GetByteSize(nullptr)) {
  98     m_element_size = *size;
  99     // Store raw pointers or end up with a circular dependency.
 100     m_start = m_backend.GetChildMemberWithName(g___begin_, true).get();
 101   }
 102
 103   return false;
 104 }
 105
 106 bool lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
 107     MightHaveChildren() {
 108   return true;
 109 }
 110
 111 size_t lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
 112     GetIndexOfChildWithName(const ConstString &name) {
 113   if (!m_start)
 114     return UINT32_MAX;
 115   return ExtractIndexFromString(name.GetCString());
 116 }
 117
 118 lldb_private::SyntheticChildrenFrontEnd *
 119 lldb_private::formatters::LibcxxInitializerListSyntheticFrontEndCreator(
 120     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
 121   return (valobj_sp ? new LibcxxInitializerListSyntheticFrontEnd(valobj_sp)
 122                     : nullptr);
 123 }