contrib/llvm/tools/lldb/include/lldb/Utility/ProcessStructReader.h

   1 //===---------------------ProcessStructReader.h ------------------*- 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 #ifndef utility_ProcessStructReader_h_
  11 #define utility_ProcessStructReader_h_
  12
  13 #include "lldb/lldb-defines.h"
  14 #include "lldb/lldb-types.h"
  15
  16 #include "lldb/Core/ConstString.h"
  17 #include "lldb/Core/DataExtractor.h"
  18 #include "lldb/Core/Error.h"
  19 #include "lldb/Symbol/ClangASTType.h"
  20 #include "lldb/Target/Process.h"
  21
  22 #include <initializer_list>
  23 #include <map>
  24 #include <string>
  25
  26 namespace lldb_private {
  27     class ProcessStructReader
  28     {
  29     protected:
  30         struct FieldImpl
  31         {
  32             ClangASTType type;
  33             size_t offset;
  34             size_t size;
  35         };
  36
  37         std::map<ConstString, FieldImpl> m_fields;
  38         DataExtractor m_data;
  39         lldb::ByteOrder m_byte_order;
  40         size_t m_addr_byte_size;
  41
  42     public:
  43         ProcessStructReader (Process *process, lldb::addr_t base_addr, ClangASTType struct_type)
  44         {
  45             if (!process)
  46                 return;
  47             if (base_addr == 0 || base_addr == LLDB_INVALID_ADDRESS)
  48                 return;
  49             m_byte_order = process->GetByteOrder();
  50             m_addr_byte_size = process->GetAddressByteSize();
  51
  52             for (size_t idx = 0; idx < struct_type.GetNumFields(); idx++)
  53             {
  54                 std::string name;
  55                 uint64_t bit_offset;
  56                 uint32_t bitfield_bit_size;
  57                 bool is_bitfield;
  58                 ClangASTType field_type = struct_type.GetFieldAtIndex(idx,name,&bit_offset,&bitfield_bit_size,&is_bitfield);
  59                 // no support for bitfields in here (yet)
  60                 if (is_bitfield)
  61                     return;
  62                 auto size = field_type.GetByteSize();
  63                 // no support for things larger than a uint64_t (yet)
  64                 if (size > 8)
  65                     return;
  66                 ConstString const_name = ConstString(name.c_str());
  67                 size_t byte_index = static_cast<size_t>(bit_offset / 8);
  68                 m_fields[const_name] = FieldImpl{field_type, byte_index, static_cast<size_t>(size)};
  69             }
  70             size_t total_size = struct_type.GetByteSize();
  71             lldb::DataBufferSP buffer_sp(new DataBufferHeap(total_size,0));
  72             Error error;
  73             process->ReadMemoryFromInferior(base_addr,
  74                                             buffer_sp->GetBytes(),
  75                                             total_size,
  76                                             error);
  77             if (error.Fail())
  78                 return;
  79             m_data = DataExtractor(buffer_sp,m_byte_order,m_addr_byte_size);
  80         }
  81
  82         template<typename RetType>
  83         RetType
  84         GetField (ConstString name, RetType fail_value = RetType())
  85         {
  86             auto iter = m_fields.find(name), end = m_fields.end();
  87             if (iter == end)
  88                 return fail_value;
  89             auto size = iter->second.size;
  90             if (sizeof(RetType) < size)
  91                 return fail_value;
  92             lldb::offset_t offset = iter->second.offset;
  93             if (offset + size > m_data.GetByteSize())
  94                 return fail_value;
  95             return (RetType)(m_data.GetMaxU64(&offset, size));
  96         }
  97     };
  98 }
  99
 100 #endif // utility_ProcessStructReader_h_