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 // C Includes
  11 // C++ Includes
  12 // Other libraries and framework includes
  13 // Project includes
  14 #include "LibCxx.h"
  15
  16 #include "lldb/Core/ConstString.h"
  17 #include "lldb/Core/ValueObject.h"
  18 #include "lldb/DataFormatters/FormattersHelpers.h"
  19
  20 using namespace lldb;
  21 using namespace lldb_private;
  22 using namespace lldb_private::formatters;
  23
  24 namespace lldb_private {
  25 namespace formatters {
  26 class LibcxxInitializerListSyntheticFrontEnd
  27     : public SyntheticChildrenFrontEnd {
  28 public:
  29   LibcxxInitializerListSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
  30
  31   ~LibcxxInitializerListSyntheticFrontEnd() override;
  32
  33   size_t CalculateNumChildren() override;
  34
  35   lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
  36
  37   bool Update() override;
  38
  39   bool MightHaveChildren() override;
  40
  41   size_t GetIndexOfChildWithName(const ConstString &name) override;
  42
  43 private:
  44   ValueObject *m_start;
  45   CompilerType m_element_type;
  46   uint32_t m_element_size;
  47   size_t m_num_elements;
  48 };
  49 } // namespace formatters
  50 } // namespace lldb_private
  51
  52 lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
  53     LibcxxInitializerListSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
  54     : SyntheticChildrenFrontEnd(*valobj_sp), m_start(nullptr), m_element_type(),
  55       m_element_size(0), m_num_elements(0) {
  56   if (valobj_sp)
  57     Update();
  58 }
  59
  60 lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
  61     ~LibcxxInitializerListSyntheticFrontEnd() {
  62   // this needs to stay around because it's a child object who will follow its
  63   // parent's life cycle
  64   // delete m_start;
  65 }
  66
  67 size_t lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
  68     CalculateNumChildren() {
  69   static ConstString g___size_("__size_");
  70   m_num_elements = 0;
  71   ValueObjectSP size_sp(m_backend.GetChildMemberWithName(g___size_, true));
  72   if (size_sp)
  73     m_num_elements = size_sp->GetValueAsUnsigned(0);
  74   return m_num_elements;
  75 }
  76
  77 lldb::ValueObjectSP lldb_private::formatters::
  78     LibcxxInitializerListSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
  79   if (!m_start)
  80     return lldb::ValueObjectSP();
  81
  82   uint64_t offset = idx * m_element_size;
  83   offset = offset + m_start->GetValueAsUnsigned(0);
  84   StreamString name;
  85   name.Printf("[%" PRIu64 "]", (uint64_t)idx);
  86   return CreateValueObjectFromAddress(name.GetString(), offset,
  87                                       m_backend.GetExecutionContextRef(),
  88                                       m_element_type);
  89 }
  90
  91 bool lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
  92     Update() {
  93   static ConstString g___begin_("__begin_");
  94
  95   m_start = nullptr;
  96   m_num_elements = 0;
  97   lldb::TemplateArgumentKind kind;
  98   m_element_type = m_backend.GetCompilerType().GetTemplateArgument(0, kind);
  99   if (kind != lldb::eTemplateArgumentKindType || !m_element_type.IsValid())
 100     return false;
 101
 102   m_element_size = m_element_type.GetByteSize(nullptr);
 103
 104   if (m_element_size > 0)
 105     m_start =
 106         m_backend.GetChildMemberWithName(g___begin_, true)
 107             .get(); // store raw pointers or end up with a circular dependency
 108
 109   return false;
 110 }
 111
 112 bool lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
 113     MightHaveChildren() {
 114   return true;
 115 }
 116
 117 size_t lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
 118     GetIndexOfChildWithName(const ConstString &name) {
 119   if (!m_start)
 120     return UINT32_MAX;
 121   return ExtractIndexFromString(name.GetCString());
 122 }
 123
 124 lldb_private::SyntheticChildrenFrontEnd *
 125 lldb_private::formatters::LibcxxInitializerListSyntheticFrontEndCreator(
 126     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
 127   return (valobj_sp ? new LibcxxInitializerListSyntheticFrontEnd(valobj_sp)
 128                     : nullptr);
 129 }