win: Make reading NT_IMAGE_HEADERS work cross-bitness

snapshot/win/pe_image_reader.h

 // Copyright 2015 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 84 matching lines @@
   bool GetCrashpadInfo(process_types::CrashpadInfo* crashpad_info) const;
 
   //! \brief Obtains information from the module's debug directory, if any.
   //!
   //! \param[out] uuid The unique identifier of the executable/PDB.
   //! \param[out] age The age field for the pdb (the number of times it's been
   //!     relinked).
   //! \param[out] pdbname Name of the pdb file.
   //! \return `true` on success, or `false` if the module has no debug directory
   //!     entry.
-  bool DebugDirectoryInformation(UUID* uuid, DWORD* age, std::string* pdbname);
+  bool DebugDirectoryInformation(UUID* uuid,
+                                 DWORD* age,
+                                 std::string* pdbname) const;
 
  private:
+  //! \brief Implementation helper for DebugDirectoryInformation() templated by
+  //!     `IMAGE_NT_HEADERS` type for different bitnesses.
+  template <class NtHeadersType>
+  bool ReadDebugDirectoryInformation(UUID* uuid,
+                                     DWORD* age,
+                                     std::string* pdbname) const;
+
   //! \brief Reads the `IMAGE_NT_HEADERS` from the beginning of the image.
+  template <class NtHeadersType>
   bool ReadNtHeaders(WinVMAddress* nt_header_address,
-                     IMAGE_NT_HEADERS* nt_headers) const;
+                     NtHeadersType* nt_headers) const;
 
   //! \brief Finds a given section by name in the image.
+  template <class NtHeadersType>
   bool GetSectionByName(const std::string& name,
                         IMAGE_SECTION_HEADER* section) const;
 
   //! \brief Reads memory from target process, first checking whether the range
   //!     requested falls inside module_range_.
   //!
   //! \return `true` on success, with \a into filled out, otherwise `false` and
   //!     a message will be logged.
   bool CheckedReadMemory(WinVMAddress address,
                          WinVMSize size,
                          void* into) const;
 
   ProcessReaderWin* process_reader_;  // weak
   CheckedWinAddressRange module_range_;
   std::string module_name_;
   InitializationStateDcheck initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(PEImageReader);
 };
 
 }  // namespace crashpad
 
 #endif  // CRASHPAD_SNAPSHOT_WIN_PE_IMAGE_READER_H_