source/Plugins/Language/CPlusPlus/LibCxxVector.cpp

   1 //===-- LibCxxVector.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 LibcxxStdVectorSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
  27 public:
  28   LibcxxStdVectorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
  29
  30   ~LibcxxStdVectorSyntheticFrontEnd() override;
  31
  32   size_t CalculateNumChildren() override;
  33
  34   lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
  35
  36   bool Update() override;
  37
  38   bool MightHaveChildren() override;
  39
  40   size_t GetIndexOfChildWithName(const ConstString &name) override;
  41
  42 private:
  43   ValueObject *m_start;
  44   ValueObject *m_finish;
  45   CompilerType m_element_type;
  46   uint32_t m_element_size;
  47 };
  48 } // namespace formatters
  49 } // namespace lldb_private
  50
  51 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::
  52     LibcxxStdVectorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
  53     : SyntheticChildrenFrontEnd(*valobj_sp), m_start(nullptr),
  54       m_finish(nullptr), m_element_type(), m_element_size(0) {
  55   if (valobj_sp)
  56     Update();
  57 }
  58
  59 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::
  60     ~LibcxxStdVectorSyntheticFrontEnd() {
  61   // these need to stay around because they are child objects who will follow
  62   // their parent's life cycle
  63   // delete m_start;
  64   // delete m_finish;
  65 }
  66
  67 size_t lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::
  68     CalculateNumChildren() {
  69   if (!m_start || !m_finish)
  70     return 0;
  71   uint64_t start_val = m_start->GetValueAsUnsigned(0);
  72   uint64_t finish_val = m_finish->GetValueAsUnsigned(0);
  73
  74   if (start_val == 0 || finish_val == 0)
  75     return 0;
  76
  77   if (start_val >= finish_val)
  78     return 0;
  79
  80   size_t num_children = (finish_val - start_val);
  81   if (num_children % m_element_size)
  82     return 0;
  83   return num_children / m_element_size;
  84 }
  85
  86 lldb::ValueObjectSP
  87 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::GetChildAtIndex(
  88     size_t idx) {
  89   if (!m_start || !m_finish)
  90     return lldb::ValueObjectSP();
  91
  92   uint64_t offset = idx * m_element_size;
  93   offset = offset + m_start->GetValueAsUnsigned(0);
  94   StreamString name;
  95   name.Printf("[%" PRIu64 "]", (uint64_t)idx);
  96   return CreateValueObjectFromAddress(name.GetString(), offset,
  97                                       m_backend.GetExecutionContextRef(),
  98                                       m_element_type);
  99 }
 100
 101 bool lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::Update() {
 102   m_start = m_finish = nullptr;
 103   ValueObjectSP data_type_finder_sp(
 104       m_backend.GetChildMemberWithName(ConstString("__end_cap_"), true));
 105   if (!data_type_finder_sp)
 106     return false;
 107   data_type_finder_sp = data_type_finder_sp->GetChildMemberWithName(
 108       ConstString("__first_"), true);
 109   if (!data_type_finder_sp)
 110     return false;
 111   m_element_type = data_type_finder_sp->GetCompilerType().GetPointeeType();
 112   m_element_size = m_element_type.GetByteSize(nullptr);
 113
 114   if (m_element_size > 0) {
 115     // store raw pointers or end up with a circular dependency
 116     m_start =
 117         m_backend.GetChildMemberWithName(ConstString("__begin_"), true).get();
 118     m_finish =
 119         m_backend.GetChildMemberWithName(ConstString("__end_"), true).get();
 120   }
 121   return false;
 122 }
 123
 124 bool lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::
 125     MightHaveChildren() {
 126   return true;
 127 }
 128
 129 size_t lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::
 130     GetIndexOfChildWithName(const ConstString &name) {
 131   if (!m_start || !m_finish)
 132     return UINT32_MAX;
 133   return ExtractIndexFromString(name.GetCString());
 134 }
 135
 136 lldb_private::SyntheticChildrenFrontEnd *
 137 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEndCreator(
 138     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
 139   return (valobj_sp ? new LibcxxStdVectorSyntheticFrontEnd(valobj_sp)
 140                     : nullptr);
 141 }