Move Courgette...

courgette/image_info.h

Index: courgette/image_info.h
===================================================================
--- courgette/image_info.h	(revision 0)
+++ courgette/image_info.h	(revision 0)
@@ -0,0 +1,199 @@
+// 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.
+
+#ifndef COURGETTE_IMAGE_INFO_H_
+#define COURGETTE_IMAGE_INFO_H_
+
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+
+namespace courgette {
+
+// A Relative Virtual Address is the address in the image file after it is
+// loaded into memory relative to the image load address.
+typedef uint32 RVA;
+
+// PE file section header.  This struct has the same layout as the
+// IMAGE_SECTION_HEADER structure from WINNT.H
+// http://msdn.microsoft.com/en-us/library/ms680341(VS.85).aspx
+//
+#pragma pack(push, 1)  // Supported by MSVC and GCC. Ensures no gaps in packing.
+struct Section {
+  char name[8];
+  uint32 virtual_size;
+  uint32 virtual_address;
+  uint32 size_of_raw_data;
+  uint32 file_offset_of_raw_data;
+  uint32 pointer_to_relocations;   // Always zero in an image.
+  uint32 pointer_to_line_numbers;  // Always zero in an image.
+  uint16 number_of_relocations;    // Always zero in an image.
+  uint16 number_of_line_numbers;   // Always zero in an image.
+  uint32 characteristics;
+};
+#pragma pack(pop)
+
+COMPILE_ASSERT(sizeof(Section) == 40, section_is_40_bytes);
+
+// Returns the name of a section, solving the problem that the name is not
+// always properly NUL-terminated.  Used only for debugging.
+std::string SectionName(const Section* section);
+
+// ImageDataDirectory has same layout as IMAGE_DATA_DIRECTORY structure from
+// WINNT.H
+// http://msdn.microsoft.com/en-us/library/ms680305(VS.85).aspx
+//
+class ImageDataDirectory {
+ public:
+  ImageDataDirectory() : address_(0), size_(0) {}
+  RVA address_;
+  uint32 size_;
+};
+
+COMPILE_ASSERT(sizeof(ImageDataDirectory) == 8,
+               image_data_directory_is_8_bytes);
+
+//
+//  PEInfo holds information about a single Windows 'Portable Executable' format
+//  file in the on-disk format.
+//
+//  Imagine you had concatenated a bunch of 'original' files into one 'big'
+//  file and read the big file into memory.  You could find the executables
+//  from the original files by calling PEInfo::Init with different addresses.
+//  If PEInfo::TryParseHeader returns true, then Init was passed the address
+//  of the first byte of one of the original executables, and PEIinfo::length
+//  will tell how long the file was.
+//
+class PEInfo {
+ public:
+  PEInfo();
+
+  // ok() may always be called but returns 'true' only after ParseHeader
+  // succeeds.
+  bool ok() const { return failure_reason_ == NULL; }
+
+  // Initialize with buffer.  This just sets up the region of memory that
+  // potentially contains the bytes from an executable file.  The caller
+  // continues to own 'start'.
+  void Init(const void* start, size_t length);
+
+  // Returns 'true' if the buffer appears to point to a Windows 32 bit
+  // executable, 'false' otherwise.  If ParseHeader() succeeds, other member
+  // functions may be called.
+  bool ParseHeader();
+
+  // Returns 'true' if the base relocation table can be parsed.
+  // Output is a vector of the RVAs corresponding to locations within executable
+  // that are listed in the base relocation table.
+  bool ParseRelocs(std::vector<RVA> *addresses);
+
+  // Returns the length of the image.  Valid only if ParseHeader succeeded.
+  uint32 length() const { return file_length_; }
+
+  bool has_text_section() const { return has_text_section_; }
+
+  uint32 size_of_code() const { return size_of_code_; }
+
+  bool is_32bit() const { return !is_PE32_plus_; }
+
+  // Most addresses are represented as 32-bit RVAs.  The one address we can't
+  // do this with is the image base address.  'image_base' is valid only for
+  // 32-bit executables. 'image_base_64' is valid for 32- and 64-bit executable.
+  uint32 image_base() const { return static_cast<uint32>(image_base_); }
+  uint64 image_base_64() const { return image_base_; }
+
+  const ImageDataDirectory& base_relocation_table() const {
+    return base_relocation_table_;
+  }
+
+  bool IsValidRVA(RVA rva) const { return rva < size_of_image_; }
+
+  // Returns description of the RVA, e.g. ".text+0x1243".  For debugging only.
+  std::string DescribeRVA(RVA rva) const;
+
+  // Returns a pointer into the memory copy of the file format.
+  // FileOffsetToPointer(0) returns a pointer to the start of the file format.
+  const uint8* FileOffsetToPointer(uint32 offset) const {
+    return start_ + offset;
+  }
+
+  // Finds the first section at file_offset or above.
+  const Section* FindNextSection(uint32 file_offset) const;
+  // Returns Section containing the relative virtual address, or NULL if none.
+  const Section* RVAToSection(RVA rva) const;
+
+  // There are 2 'coordinate systems' for reasoning about executables.
+  //   FileOffset - the the offset within a single .EXE or .DLL *file*.
+  //   RVA - relative virtual address (offset within *loaded image*)
+  // FileOffsetToRVA and RVAToFileOffset convert between these representations.
+
+  RVA FileOffsetToRVA(uint32 offset) const;
+
+  static const int kNoOffset = -1;
+  // Returns kNoOffset if there is no file offset corresponding to 'rva'.
+  int RVAToFileOffset(RVA rva) const;
+
+  // Returns same as FileOffsetToPointer(RVAToFileOffset(rva)) except that NULL
+  // is returned if there is no file offset corresponding to 'rva'.
+  const uint8* RVAToPointer(RVA rva) const;
+
+ protected:
+  //
+  // Fields that are always valid.
+  //
+  const char* failure_reason_;
+
+  //
+  // Basic information that is always valid after Init.
+  //
+  const uint8* start_;    // In current memory, base for 'file offsets'.
+  const uint8* end_;      // In current memory.
+  unsigned int length_;   // In current memory.
+
+  //
+  // Information that is valid after successful ParseHeader.
+  //
+  bool is_PE32_plus_;   // PE32_plus is for 64 bit executables.
+  uint32 file_length_;
+
+  // Location and size of IMAGE_OPTIONAL_HEADER in the buffer.
+  const uint8 *optional_header_;
+  uint16 size_of_optional_header_;
+  uint16 offset_of_data_directories_;
+
+  uint16 machine_type_;
+  uint16 number_of_sections_;
+  const Section *sections_;
+  bool has_text_section_;
+
+  uint32 size_of_code_;
+  uint32 size_of_initialized_data_;
+  uint32 size_of_uninitialized_data_;
+  RVA base_of_code_;
+  RVA base_of_data_;
+
+  uint64 image_base_;  // range limited to 32 bits for 32 bit executable
+  uint32 size_of_image_;
+  int number_of_data_directories_;
+
+  ImageDataDirectory export_table_;
+  ImageDataDirectory import_table_;
+  ImageDataDirectory resource_table_;
+  ImageDataDirectory exception_table_;
+  ImageDataDirectory base_relocation_table_;
+  ImageDataDirectory bound_import_table_;
+  ImageDataDirectory import_address_table_;
+  ImageDataDirectory delay_import_descriptor_;
+  ImageDataDirectory clr_runtime_header_;
+
+ private:
+  bool ReadDataDirectory(int index, ImageDataDirectory* dir);
+  bool Bad(const char *reason);
+
+  DISALLOW_COPY_AND_ASSIGN(PEInfo);
+};
+
+}  // namespace
+#endif  // COURGETTE_IMAGE_INFO_H_