contrib/llvm-project/lldb/include/lldb/Target/ProcessStructReader.h

   1 //===---------------------ProcessStructReader.h ------------------*- C++-*-===//
   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 #ifndef LLDB_TARGET_PROCESSSTRUCTREADER_H
  10 #define LLDB_TARGET_PROCESSSTRUCTREADER_H
  11
  12 #include "lldb/lldb-defines.h"
  13 #include "lldb/lldb-types.h"
  14
  15 #include "lldb/Symbol/CompilerType.h"
  16 #include "lldb/Target/Process.h"
  17 #include "lldb/Utility/ConstString.h"
  18 #include "lldb/Utility/DataBufferHeap.h"
  19 #include "lldb/Utility/DataExtractor.h"
  20 #include "lldb/Utility/Status.h"
  21
  22 #include <initializer_list>
  23 #include <map>
  24 #include <string>
  25
  26 namespace lldb_private {
  27 class ProcessStructReader {
  28 protected:
  29   struct FieldImpl {
  30     CompilerType type;
  31     size_t offset;
  32     size_t size;
  33   };
  34
  35   std::map<ConstString, FieldImpl> m_fields;
  36   DataExtractor m_data;
  37   lldb::ByteOrder m_byte_order;
  38   size_t m_addr_byte_size;
  39
  40 public:
  41   ProcessStructReader(Process *process, lldb::addr_t base_addr,
  42                       CompilerType struct_type) {
  43     if (!process)
  44       return;
  45     if (base_addr == 0 || base_addr == LLDB_INVALID_ADDRESS)
  46       return;
  47     m_byte_order = process->GetByteOrder();
  48     m_addr_byte_size = process->GetAddressByteSize();
  49
  50     for (size_t idx = 0; idx < struct_type.GetNumFields(); idx++) {
  51       std::string name;
  52       uint64_t bit_offset;
  53       uint32_t bitfield_bit_size;
  54       bool is_bitfield;
  55       CompilerType field_type = struct_type.GetFieldAtIndex(
  56           idx, name, &bit_offset, &bitfield_bit_size, &is_bitfield);
  57       // no support for bitfields in here (yet)
  58       if (is_bitfield)
  59         return;
  60       auto size = field_type.GetByteSize(nullptr);
  61       // no support for things larger than a uint64_t (yet)
  62       if (!size || *size > 8)
  63         return;
  64       ConstString const_name = ConstString(name.c_str());
  65       size_t byte_index = static_cast<size_t>(bit_offset / 8);
  66       m_fields[const_name] =
  67           FieldImpl{field_type, byte_index, static_cast<size_t>(*size)};
  68     }
  69     auto total_size = struct_type.GetByteSize(nullptr);
  70     if (!total_size)
  71       return;
  72     lldb::DataBufferSP buffer_sp(new DataBufferHeap(*total_size, 0));
  73     Status error;
  74     process->ReadMemoryFromInferior(base_addr, buffer_sp->GetBytes(),
  75                                     *total_size, error);
  76     if (error.Fail())
  77       return;
  78     m_data = DataExtractor(buffer_sp, m_byte_order, m_addr_byte_size);
  79   }
  80
  81   template <typename RetType>
  82   RetType GetField(ConstString name, RetType fail_value = RetType()) {
  83     auto iter = m_fields.find(name), end = m_fields.end();
  84     if (iter == end)
  85       return fail_value;
  86     auto size = iter->second.size;
  87     if (sizeof(RetType) < size)
  88       return fail_value;
  89     lldb::offset_t offset = iter->second.offset;
  90     if (offset + size > m_data.GetByteSize())
  91       return fail_value;
  92     return (RetType)(m_data.GetMaxU64(&offset, size));
  93   }
  94
  95   size_t GetOffsetOf(ConstString name, size_t fail_value = SIZE_MAX) {
  96     auto iter = m_fields.find(name), end = m_fields.end();
  97     if (iter == end)
  98       return fail_value;
  99     return iter->second.offset;
 100   }
 101 };
 102 }
 103
 104 #endif // utility_ProcessStructReader_h_