Move Courgette...

third_party/courgette/image_info.cc

Index: third_party/courgette/image_info.cc
===================================================================
--- third_party/courgette/image_info.cc	(revision 15668)
+++ third_party/courgette/image_info.cc	(working copy)
@@ -1,392 +0,0 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "third_party/courgette/image_info.h"
-
-#include <memory.h>
-#include <algorithm>
-#include <map>
-#include <set>
-#include <sstream>
-#include <vector>
-
-#include "base/logging.h"
-
-namespace courgette {
-
-std::string SectionName(const Section* section) {
-  if (section == NULL)
-    return "<none>";
-  char name[9];
-  memcpy(name, section->name, 8);
-  name[8] = '\0';  // Ensure termination.
-  return name;
-}
-
-PEInfo::PEInfo()
-  : failure_reason_("uninitialized"),
-    start_(0), end_(0), length_(0),
-    is_PE32_plus_(0), file_length_(0), has_text_section_(false) {
-}
-
-void PEInfo::Init(const void* start, size_t length) {
-  start_ = reinterpret_cast<const uint8*>(start);
-  length_ = length;
-  end_ = start_ + length_;
-  failure_reason_ = "unparsed";
-}
-
-// DescribeRVA is for debugging only.  I would put it under #ifdef DEBUG except
-// that during development I'm finding I need to call it when compiled in
-// Release mode.  Hence:
-// TODO(sra): make this compile only for debug mode.
-std::string PEInfo::DescribeRVA(RVA rva) const {
-  const Section* section = RVAToSection(rva);
-  std::ostringstream s;
-  s << std::hex << rva;
-  if (section) {
-    s << " (";
-    s << SectionName(section) << "+"
-      << std::hex << (rva - section->virtual_address)
-      << ")";
-  }
-  return s.str();
-}
-
-const Section* PEInfo::FindNextSection(uint32 fileOffset) const {
-  const Section* best = 0;
-  for (int i = 0; i < number_of_sections_; i++) {
-    const Section* section = &sections_[i];
-    if (fileOffset <= section->file_offset_of_raw_data) {
-      if (best == 0 ||
-          section->file_offset_of_raw_data < best->file_offset_of_raw_data) {
-        best = section;
-      }
-    }
-  }
-  return best;
-}
-
-const Section* PEInfo::RVAToSection(RVA rva) const {
-  for (int i = 0; i < number_of_sections_; i++) {
-    const Section* section = &sections_[i];
-    uint32 offset = rva - section->virtual_address;
-    if (offset < section->virtual_size) {
-      return section;
-    }
-  }
-  return NULL;
-}
-
-int PEInfo::RVAToFileOffset(RVA rva) const {
-  const Section* section = RVAToSection(rva);
-  if (section) {
-    uint32 offset = rva - section->virtual_address;
-    if (offset < section->size_of_raw_data) {
-      return section->file_offset_of_raw_data + offset;
-    } else {
-      return kNoOffset;  // In section but not in file (e.g. uninit data).
-    }
-  }
-
-  // Small RVA values point into the file header in the loaded image.
-  // RVA 0 is the module load address which Windows uses as the module handle.
-  // RVA 2 sometimes occurs, I'm not sure what it is, but it would map into the
-  // DOS header.
-  if (rva == 0 || rva == 2)
-    return rva;
-
-  NOTREACHED();
-  return kNoOffset;
-}
-
-const uint8* PEInfo::RVAToPointer(RVA rva) const {
-  int file_offset = RVAToFileOffset(rva);
-  if (file_offset == kNoOffset)
-    return NULL;
-  else
-    return start_ + file_offset;
-}
-
-RVA PEInfo::FileOffsetToRVA(uint32 file_offset) const {
-  for (int i = 0; i < number_of_sections_; i++) {
-    const Section* section = &sections_[i];
-    uint32 offset = file_offset - section->file_offset_of_raw_data;
-    if (offset < section->size_of_raw_data) {
-      return section->virtual_address + offset;
-    }
-  }
-  return 0;
-}
-
-////////////////////////////////////////////////////////////////////////////////
-
-namespace {
-
-// Constants and offsets gleaned from WINNT.H and various articles on the
-// format of Windows PE executables.
-
-// This is FIELD_OFFSET(IMAGE_DOS_HEADER, e_lfanew):
-const size_t kOffsetOfFileAddressOfNewExeHeader = 0x3c;
-
-const uint16 kImageNtOptionalHdr32Magic = 0x10b;
-const uint16 kImageNtOptionalHdr64Magic = 0x20b;
-
-const size_t kSizeOfCoffHeader = 20;
-const size_t kOffsetOfDataDirectoryFromImageOptionalHeader32 = 96;
-const size_t kOffsetOfDataDirectoryFromImageOptionalHeader64 = 112;
-
-// These helper functions avoid the need for casts in the main code.
-inline uint16 ReadU16(const uint8* address, size_t offset) {
-  return *reinterpret_cast<const uint16*>(address + offset);
-}
-
-inline uint32 ReadU32(const uint8* address, size_t offset) {
-  return *reinterpret_cast<const uint32*>(address + offset);
-}
-
-inline uint64 ReadU64(const uint8* address, size_t offset) {
-  return *reinterpret_cast<const uint64*>(address + offset);
-}
-
-}  // namespace
-
-// ParseHeader attempts to match up the buffer with the Windows data
-// structures that exist within a Windows 'Portable Executable' format file.
-// Returns 'true' if the buffer matches, and 'false' if the data looks
-// suspicious.  Rather than try to 'map' the buffer to the numerous windows
-// structures, we extract the information we need into the courgette::PEInfo
-// structure.
-//
-bool PEInfo::ParseHeader() {
-  if (length_ < kOffsetOfFileAddressOfNewExeHeader + 4 /*size*/)
-    return Bad("Too small");
-
-  // Have 'MZ' magic for a DOS header?
-  if (start_[0] != 'M' || start_[1] != 'Z')
-    return Bad("Not MZ");
-
-  // offset from DOS header to PE header is stored in DOS header.
-  uint32 offset = ReadU32(start_, kOffsetOfFileAddressOfNewExeHeader);
-
-  const uint8* const pe_header = start_ + offset;
-  const size_t kMinPEHeaderSize = 4 /*signature*/ + kSizeOfCoffHeader;
-  if (pe_header <= start_  ||  pe_header >= end_ - kMinPEHeaderSize)
-    return Bad("Bad offset to PE header");
-
-  if (offset % 8 != 0)
-    return Bad("Misaligned PE header");
-
-  // The 'PE' header is an IMAGE_NT_HEADERS structure as defined in WINNT.H.
-  // See http://msdn.microsoft.com/en-us/library/ms680336(VS.85).aspx
-  //
-  // The first field of the IMAGE_NT_HEADERS is the signature.
-  if (!(pe_header[0] == 'P' &&
-        pe_header[1] == 'E' &&
-        pe_header[2] == 0 &&
-        pe_header[3] == 0))
-    return Bad("no PE signature");
-
-  // The second field of the IMAGE_NT_HEADERS is the COFF header.
-  // The COFF header is also called an IMAGE_FILE_HEADER
-  //   http://msdn.microsoft.com/en-us/library/ms680313(VS.85).aspx
-  const uint8* const coff_header = pe_header + 4;
-  machine_type_       = ReadU16(coff_header, 0);
-  number_of_sections_ = ReadU16(coff_header, 2);
-  size_of_optional_header_ = ReadU16(coff_header, 16);
-
-  // The rest of the IMAGE_NT_HEADERS is the IMAGE_OPTIONAL_HEADER(32|64)
-  const uint8* const optional_header = coff_header + kSizeOfCoffHeader;
-  optional_header_ = optional_header;
-
-  if (optional_header + size_of_optional_header_ >= end_)
-    return Bad("optional header past end of file");
-
-  // Check we can read the magic.
-  if (size_of_optional_header_ < 2)
-    return Bad("optional header no magic");
-
-  uint16 magic = ReadU16(optional_header, 0);
-
-  if (magic == kImageNtOptionalHdr32Magic) {
-    is_PE32_plus_ = false;
-    offset_of_data_directories_ =
-      kOffsetOfDataDirectoryFromImageOptionalHeader32;
-  } else if (magic == kImageNtOptionalHdr64Magic) {
-    is_PE32_plus_ = true;
-    offset_of_data_directories_ =
-      kOffsetOfDataDirectoryFromImageOptionalHeader64;
-  } else {
-    return Bad("unrecognized magic");
-  }
-
-  // Check that we can read the rest of the the fixed fields.  Data directories
-  // directly follow the fixed fields of the IMAGE_OPTIONAL_HEADER.
-  if (size_of_optional_header_ < offset_of_data_directories_)
-    return Bad("optional header too short");
-
-  // The optional header is either an IMAGE_OPTIONAL_HEADER32 or
-  // IMAGE_OPTIONAL_HEADER64
-  // http://msdn.microsoft.com/en-us/library/ms680339(VS.85).aspx
-  //
-  // Copy the fields we care about.
-  size_of_code_               = ReadU32(optional_header, 4);
-  size_of_initialized_data_   = ReadU32(optional_header, 8);
-  size_of_uninitialized_data_ = ReadU32(optional_header, 12);
-  base_of_code_               = ReadU32(optional_header, 20);
-  if (is_PE32_plus_) {
-    base_of_data_ = 0;
-    image_base_  = ReadU64(optional_header, 24);
-  } else {
-    base_of_data_ = ReadU32(optional_header, 24);
-    image_base_   = ReadU32(optional_header, 28);
-  }
-  size_of_image_ = ReadU32(optional_header, 56);
-  number_of_data_directories_ =
-    ReadU32(optional_header, (is_PE32_plus_ ? 108 : 92));
-
-  if (size_of_code_ >= length_ ||
-      size_of_initialized_data_ >= length_ ||
-      size_of_code_ + size_of_initialized_data_ >= length_) {
-    // This validation fires on some perfectly fine executables.
-    //  return Bad("code or initialized data too big");
-  }
-
-  // TODO(sra): we can probably get rid of most of the data directories.
-  bool b = true;
-  // 'b &= ...' could be short circuit 'b = b && ...' but it is not necessary
-  // for correctness and it compiles smaller this way.
-  b &= ReadDataDirectory(0, &export_table_);
-  b &= ReadDataDirectory(1, &import_table_);
-  b &= ReadDataDirectory(2, &resource_table_);
-  b &= ReadDataDirectory(3, &exception_table_);
-  b &= ReadDataDirectory(5, &base_relocation_table_);
-  b &= ReadDataDirectory(11, &bound_import_table_);
-  b &= ReadDataDirectory(12, &import_address_table_);
-  b &= ReadDataDirectory(13, &delay_import_descriptor_);
-  b &= ReadDataDirectory(14, &clr_runtime_header_);
-  if (!b) {
-    return Bad("malformed data directory");
-  }
-
-  // Sections follow the optional header.
-  sections_ =
-      reinterpret_cast<const Section*>(optional_header +
-                                       size_of_optional_header_);
-  file_length_ = 0;
-
-  for (int i = 0;  i < number_of_sections_;  ++i) {
-    const Section* section = &sections_[i];
-
-    // TODO(sra): consider using the 'characteristics' field of the section
-    // header to see if the section contains instructions.
-    if (memcmp(section->name, ".text", 6) == 0)
-      has_text_section_ = true;
-
-    uint32 section_end =
-        section->file_offset_of_raw_data + section->size_of_raw_data;
-    if (section_end > file_length_)
-      file_length_ = section_end;
-  }
-
-  failure_reason_ = NULL;
-  return true;
-}
-
-bool PEInfo::ReadDataDirectory(int index, ImageDataDirectory* directory) {
-  if (index < number_of_data_directories_) {
-    size_t offset = index * 8 + offset_of_data_directories_;
-    if (offset >= size_of_optional_header_)
-      return Bad("number of data directories inconsistent");
-    const uint8* data_directory = optional_header_ + offset;
-    if (data_directory < start_ || data_directory + 8 >= end_)
-      return Bad("data directory outside image");
-    RVA rva = ReadU32(data_directory, 0);
-    size_t size  = ReadU32(data_directory, 4);
-    if (size > size_of_image_)
-      return Bad("data directory size too big");
-
-    // TODO(sra): validate RVA.
-    directory->address_ = rva;
-    directory->size_ = size;
-    return true;
-  } else {
-    directory->address_ = 0;
-    directory->size_ = 0;
-    return true;
-  }
-}
-
-bool PEInfo::Bad(const char* reason) {
-  failure_reason_ = reason;
-  return false;
-}
-
-////////////////////////////////////////////////////////////////////////////////
-
-bool PEInfo::ParseRelocs(std::vector<RVA> *relocs) {
-  relocs->clear();
-
-  size_t relocs_size = base_relocation_table_.size_;
-  if (relocs_size == 0)
-    return true;
-
-  // The format of the base relocation table is a sequence of variable sized
-  // IMAGE_BASE_RELOCATION blocks.  Search for
-  //   "The format of the base relocation data is somewhat quirky"
-  // at http://msdn.microsoft.com/en-us/library/ms809762.aspx
-
-  const uint8* start = RVAToPointer(base_relocation_table_.address_);
-  const uint8* end = start + relocs_size;
-
-  // Make sure entire base relocation table is within the buffer.
-  if (start < start_ ||
-      start >= end_ ||
-      end <= start_ ||
-      end > end_) {
-    return Bad(".relocs outside image");
-  }
-
-  const uint8* block = start;
-
-  // Walk the variable sized blocks.
-  while (block + 8 < end) {
-    RVA page_rva = ReadU32(block, 0);
-    uint32 size = ReadU32(block, 4);
-    if (size < 8 ||        // Size includes header ...
-        size % 4  !=  0)   // ... and is word aligned.
-      return Bad("unreasonable relocs block");
-
-    const uint8* end_entries = block + size;
-
-    if (end_entries <= block || end_entries <= start_ || end_entries > end_)
-      return Bad(".relocs block outside image");
-
-    // Walk through the two-byte entries.
-    for (const uint8* p = block + 8;  p < end_entries;  p += 2) {
-      uint16 entry = ReadU16(p, 0);
-      int type = entry >> 12;
-      int offset = entry & 0xFFF;
-
-      RVA rva = page_rva + offset;
-      if (type == 3) {         // IMAGE_REL_BASED_HIGHLOW
-        relocs->push_back(rva);
-      } else if (type == 0) {  // IMAGE_REL_BASED_ABSOLUTE
-        // Ignore, used as padding.
-      } else {
-        // Does not occur in Windows x86 executables.
-        return Bad("unknown type of reloc");
-      }
-    }
-
-    block += size;
-  }
-
-  std::sort(relocs->begin(), relocs->end());
-
-  return true;
-}
-
-}  // namespace courgette
-