courgette/disassembler_win32_x86.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "courgette/disassembler_win32_x86.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/logging.h"
  10 #include "courgette/assembly_program.h"
  11 #include "courgette/courgette.h"
  12 #include "courgette/rel32_finder_x86.h"
  13
  14 #if COURGETTE_HISTOGRAM_TARGETS
  15 #include <iostream>
  16 #endif
  17
  18 namespace courgette {
  19
  20 DisassemblerWin32X86::DisassemblerWin32X86(const uint8_t* start, size_t length)
  21     : DisassemblerWin32(start, length) {}
  22
  23 RVA DisassemblerWin32X86::PointerToTargetRVA(const uint8_t* p) const {
  24   return Address32ToRVA(Read32LittleEndian(p));
  25 }
  26
  27 RVA DisassemblerWin32X86::Address32ToRVA(uint32_t address) const {
  28   if (address < image_base() || address >= image_base() + size_of_image_)
  29     return kNoRVA;
  30   return static_cast<RVA>(address - image_base());
  31 }
  32
  33 CheckBool DisassemblerWin32X86::EmitAbs(Label* label,
  34                                         InstructionReceptor* receptor) const {
  35   return receptor->EmitAbs32(label);
  36 }
  37
  38 void DisassemblerWin32X86::ParseRel32RelocsFromSection(const Section* section) {
  39   // TODO(sra): use characteristic.
  40   bool isCode = strcmp(section->name, ".text") == 0;
  41   if (!isCode)
  42     return;
  43
  44   FileOffset start_file_offset = section->file_offset_of_raw_data;
  45   // |virtual_size < size_of_raw_data| is possible. In this case, disassembly
  46   // should not proceed beyond |virtual_size|, so rel32 location RVAs remain
  47   // translatable to file offsets.
  48   FileOffset end_file_offset =
  49       start_file_offset +
  50       std::min(section->virtual_size, section->size_of_raw_data);
  51
  52   const uint8_t* start_pointer = FileOffsetToPointer(start_file_offset);
  53   const uint8_t* end_pointer = FileOffsetToPointer(end_file_offset);
  54
  55   RVA start_rva = FileOffsetToRVA(start_file_offset);
  56   RVA end_rva = start_rva + section->virtual_size;
  57
  58   Rel32FinderX86 finder(
  59       base_relocation_table().address_,
  60       base_relocation_table().address_ + base_relocation_table().size_);
  61   finder.Find(start_pointer, end_pointer, start_rva, end_rva, abs32_locations_);
  62   finder.SwapRel32Locations(&rel32_locations_);
  63
  64 #if COURGETTE_HISTOGRAM_TARGETS
  65   DCHECK(rel32_target_rvas_.empty());
  66   finder.SwapRel32TargetRVAs(&rel32_target_rvas_);
  67 #endif
  68 }
  69
  70 }  // namespace courgette