Add defines for the size of wchar_t to build_config.h. Use this in places where we currently have an OS-specific check.

Remove all WIN32 ifdefs from base and replace them with proper defined(OS...).

I also fixed random style bits when I encountered them. I made major style fixes to string16.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@524 0039d316-1c4b-4281-b951-d872f2087c98

14 files changed, 220 insertions, 218 deletions

diff --git a/base/build/base.vcproj b/base/build/base.vcproj
index 7a45722..a5257cb 100644
--- a/base/build/base.vcproj
+++ b/base/build/base.vcproj
@@ -654,6 +654,10 @@
 			>
 		</File>
 		<File
+			RelativePath="..\sys_string_conversions.h"
+			>
+		</File>
+		<File
 			RelativePath="..\sys_string_conversions_win.cc"
 			>
 		</File>
diff --git a/base/debug_on_start.h b/base/debug_on_start.h
index b260122..63fc5dc 100644
--- a/base/debug_on_start.h
+++ b/base/debug_on_start.h
@@ -31,11 +31,13 @@
 // line argument. When the command line argument is detected, it invokes the
 // debugger, if no system-wide debugger is registered, a debug break is done.
 
-#ifndef BASE_DEBUG_ON_START_H__
-#define BASE_DEBUG_ON_START_H__
+#ifndef BASE_DEBUG_ON_START_H_
+#define BASE_DEBUG_ON_START_H_
+
+#include "base/basictypes.h"
 
 // This only works on Windows.
-#ifdef _WIN32
+#if defined(OS_WIN)
 
 #ifndef DECLSPEC_SELECTANY
 #define DECLSPEC_SELECTANY  __declspec(selectany)
@@ -85,6 +87,6 @@ DECLSPEC_SELECTANY DebugOnStart::PIFV debug_on_start = &DebugOnStart::Init;
 #pragma data_seg(pop)
 
 #endif  // _WIN64
-#endif  // _WIN32
+#endif  // defined(OS_WIN)
 
-#endif  // BASE_DEBUG_ON_START_H__
+#endif  // BASE_DEBUG_ON_START_H_
diff --git a/base/file_util.h b/base/file_util.h
index 579e81c..f74ff97 100644
--- a/base/file_util.h
+++ b/base/file_util.h
@@ -30,14 +30,15 @@
 // This file contains utility functions for dealing with the local
 // filesystem.
 
-#ifndef BASE_FILE_UTIL_H__
-#define BASE_FILE_UTIL_H__
+#ifndef BASE_FILE_UTIL_H_
+#define BASE_FILE_UTIL_H_
 
 #include "build/build_config.h"
 
-#ifdef OS_WIN
+#if defined(OS_WIN)
 #include <windows.h>
 #endif
+
 #include <stack>
 #include <string>
 
@@ -120,13 +121,13 @@ void ReplaceExtension(std::wstring* file_name, const std::wstring& extension);
 //-----------------------------------------------------------------------------
 // Functions that involve filesystem access or modification:
 
-#ifdef OS_WIN
+#if defined(OS_WIN)
 // Returns the number of files matching the current path that were
 // created on or after the given FILETIME.  Doesn't count ".." or ".".
 // Filetime is UTC filetime, not LocalFiletime.
 int CountFilesCreatedAfter(const std::wstring& path,
                            const FILETIME& file_time);
-#endif
+#endif  // defined(OS_WIN)
 
 // Deletes the given path, whether it's a file or a directory.
 // If it's a directory, it's perfectly happy to delete all of the
@@ -162,7 +163,7 @@ bool PathExists(const std::wstring& path);
 // Returns true if the given path is writable by the user, false otherwise.
 bool PathIsWritable(const std::wstring& path);
 
-#ifdef OS_WIN
+#if defined(OS_WIN)
 // Gets the creation time of the given file (expressed in the local timezone),
 // and returns it via the creation_time parameter.  Returns true if successful,
 // false otherwise.
@@ -172,7 +173,7 @@ bool GetFileCreationLocalTime(const std::wstring& filename,
 // Same as above, but takes a previously-opened file handle instead of a name.
 bool GetFileCreationLocalTimeFromHandle(HANDLE file_handle,
                                         LPSYSTEMTIME creation_time);
-#endif
+#endif  // defined(OS_WIN)
 
 // Returns true if the contents of the two files given are equal, false
 // otherwise.  If either file can't be read, returns false.
@@ -299,10 +300,10 @@ class FileEnumerator {
   // enumerate in the breadth-first search.
   std::stack<std::wstring> pending_paths_;
 
-#ifdef OS_WIN
+#if defined(OS_WIN)
   WIN32_FIND_DATA find_data_;
   HANDLE find_handle_;
-#endif
+#endif  // defined(OS_WIN)
 
   DISALLOW_EVIL_CONSTRUCTORS(FileEnumerator);
 };
@@ -315,4 +316,4 @@ bool RenameFileAndResetSecurityDescriptor(
 
 }  // namespace file_util
 
-#endif  // BASE_FILE_UTIL_H__
+#endif  // BASE_FILE_UTIL_H_
diff --git a/base/logging.h b/base/logging.h
index 40c176f..6bfb34e 100644
--- a/base/logging.h
+++ b/base/logging.h
@@ -27,8 +27,8 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#ifndef BASE_LOGGING_H__
-#define BASE_LOGGING_H__
+#ifndef BASE_LOGGING_H_
+#define BASE_LOGGING_H_
 
 #include <string>
 #include <cstring>
@@ -143,10 +143,10 @@ enum OldFileDeletionState { DELETE_OLD_LOG_FILE, APPEND_TO_OLD_LOG_FILE };
 // The default log file is initialized to "debug.log" in the application
 // directory. You probably don't want this, especially since the program
 // directory may not be writable on an enduser's system.
-#if defined(WIN32)
+#if defined(OS_WIN)
 void InitLogging(const wchar_t* log_file, LoggingDestination logging_dest,
                  LogLockingState lock_log, OldFileDeletionState delete_old);
-#else
+#elif defined(OS_POSIX)
 // TODO(avi): do we want to do a unification of character types here?
 void InitLogging(const char* log_file, LoggingDestination logging_dest,
                  LogLockingState lock_log, OldFileDeletionState delete_old);
@@ -483,7 +483,7 @@ class LogMessage {
   size_t message_start_;  // Offset of the start of the message (past prefix
                           // info).
 
-  DISALLOW_EVIL_CONSTRUCTORS(LogMessage);
+  DISALLOW_COPY_AND_ASSIGN(LogMessage);
 };
 
 // A non-macro interface to the log facility; (useful
@@ -509,16 +509,17 @@ class LogMessageVoidify {
 //       after this call.
 void CloseLogFile();
 
-} // namespace Logging
+}  // namespace logging
 
 // These functions are provided as a convenience for logging, which is where we
 // use streams (it is against Google style to use streams in other places). It
 // is designed to allow you to emit non-ASCII Unicode strings to the log file,
 // which is normally ASCII. It is relatively slow, so try not to use it for
-// common cases. Non-ASCII characters will be converted to UTF-8 by these operators.
+// common cases. Non-ASCII characters will be converted to UTF-8 by these
+// operators.
 std::ostream& operator<<(std::ostream& out, const wchar_t* wstr);
 inline std::ostream& operator<<(std::ostream& out, const std::wstring& wstr) {
   return out << wstr.c_str();
 }
 
-#endif  // BASE_LOGGING_H__
+#endif  // BASE_LOGGING_H_
diff --git a/base/platform_thread.cc b/base/platform_thread.cc
index 3cb8f39..6b24b3d 100644
--- a/base/platform_thread.cc
+++ b/base/platform_thread.cc
@@ -27,19 +27,19 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#ifndef WIN32
+#include "base/platform_thread.h"
+
+#if defined(OS_POSIX)
 #include <sched.h>
 #endif
 
-#include "base/platform_thread.h"
-
 // static
 PlatformThread PlatformThread::Current() {
   PlatformThread thread;
 
-#ifdef WIN32
+#if defined(OS_WIN)
   thread.thread_ = GetCurrentThread();
-#else
+#elif defined(OS_POSIX)
   thread.thread_ = pthread_self();
 #endif
 
@@ -48,17 +48,17 @@ PlatformThread PlatformThread::Current() {
 
 // static
 void PlatformThread::YieldCurrentThread() {
-#ifdef WIN32
+#if defined(OS_WIN)
   ::Sleep(0);
-#else
+#elif defined(OS_POSIX)
   sched_yield();
 #endif
 }
 
 bool PlatformThread::operator==(const PlatformThread& other_thread) {
-#ifdef WIN32
+#if defined(OS_WIN)
   return thread_ == other_thread.thread_;
-#else
+#elif defined(OS_POSIX)
   return pthread_equal(thread_, other_thread.thread_);
 #endif
 }
diff --git a/base/platform_thread.h b/base/platform_thread.h
index 7f887d2..2dca402 100644
--- a/base/platform_thread.h
+++ b/base/platform_thread.h
@@ -27,16 +27,22 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#ifndef BASE_PLATFORM_THREAD_H__
-#define BASE_PLATFORM_THREAD_H__
+#ifndef BASE_PLATFORM_THREAD_H_
+#define BASE_PLATFORM_THREAD_H_
+
+#include "build/build_config.h"
+
+#if defined(OS_WIN)
 
-#ifdef WIN32
 #include <windows.h>
 typedef HANDLE PlatformThreadHandle;
-#else
+
+#elif defined(OS_POSIX)
+
 #include <pthread.h>
 typedef pthread_t PlatformThreadHandle;
-#endif
+
+#endif  // defined(OS_POSIX)
 
 class PlatformThread {
  public:
@@ -49,8 +55,7 @@ class PlatformThread {
   bool operator==(const PlatformThread& other_thread);
 
  private:
-
   PlatformThreadHandle thread_;
 };
 
-#endif  // BASE_PLATFORM_THREAD_H__
+#endif  // BASE_PLATFORM_THREAD_H_
diff --git a/base/shared_memory.h b/base/shared_memory.h
index 00b51f9..3fb7298 100644
--- a/base/shared_memory.h
+++ b/base/shared_memory.h
@@ -27,17 +27,18 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#ifndef BASE_SHARED_MEMORY_H__
-#define BASE_SHARED_MEMORY_H__
+#ifndef BASE_SHARED_MEMORY_H_
+#define BASE_SHARED_MEMORY_H_
 
+#include "base/basictypes.h"
 #include "base/process_util.h"
 
 // SharedMemoryHandle is a platform specific type which represents
 // the underlying OS handle to a shared memory segment.
-#ifdef WIN32
+#if defined(OS_WIN)
 typedef HANDLE SharedMemoryHandle;
 typedef HANDLE SharedMemoryLock;
-#else
+#elif defined(OS_POSIX)
 typedef int SharedMemoryHandle;
 typedef int SharedMemoryLock;
 #endif
@@ -166,4 +167,4 @@ class SharedMemoryAutoLock {
 };
 
 
-#endif  // BASE_SHARED_MEMORY_H__
+#endif  // BASE_SHARED_MEMORY_H_
diff --git a/base/string16.h b/base/string16.h
index 2466028..41b0804 100644
--- a/base/string16.h
+++ b/base/string16.h
@@ -26,30 +26,10 @@
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are met:
-//
-//  1. Redistributions of source code must retain the above copyright notice,
-//     this list of conditions and the following disclaimer.
-//  2. Redistributions in binary form must reproduce the above copyright notice,
-//     this list of conditions and the following disclaimer in the documentation
-//     and/or other materials provided with the distribution.
-//  3. Neither the name of Google Inc. nor the names of its contributors may be
-//     used to endorse or promote products derived from this software without
-//     specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
-// WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
-// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
-// EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
-// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
-// OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
-// WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
-// OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
-// ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-//
+
+#ifndef BASE_STRING16_H_
+#define BASE_STRING16_H_
+
 // WHAT:
 // A version of std::basic_string that works even on Linux when 2-byte wchar_t
 // values (-fshort-wchar) are used. You can access this class as std::string16.
@@ -69,77 +49,81 @@
 // for us, std::wstring uses mostly *inline* wchar_t-based functions (like
 // wmemcmp) that are defined in .h files and do not need to be overridden.
 
-#ifndef BASE_STRING16_H__
-#define BASE_STRING16_H__
-
 #include <string>
 
-#ifdef WIN32
+#include "build/build_config.h"
+
+#ifdef WCHAR_T_IS_UTF16
 
 typedef wchar_t char16;
 
 namespace std {
-  typedef wstring string16;
+typedef wstring string16;
 }
 
-#else
+#else  // !WCHAR_T_IS_UTF16
 
 typedef unsigned short char16;
 
 namespace std {
-  typedef basic_string<char16> string16;
+typedef basic_string<char16> string16;
 }
 
 
 // Define char16 versions of functions required below in char_traits<char16>
 extern "C" {
 
-  inline char16 *char16_wmemmove(char16 *s1, const char16 *s2, size_t n) {
-    return (char16 *)memmove(s1, s2, n * sizeof(char16));
-  }
+inline char16 *char16_wmemmove(char16 *s1, const char16 *s2, size_t n) {
+  return reinterpret_cast<char16*>(memmove(s1, s2, n * sizeof(char16)));
+}
 
-  inline char16 *char16_wmemcpy(char16 *s1, const char16 *s2, size_t n) {
-    return (char16 *)memcpy(s1, s2, n * sizeof(char16));
-  }
+inline char16 *char16_wmemcpy(char16 *s1, const char16 *s2, size_t n) {
+  return reinterpret_cast<char16*>(memcpy(s1, s2, n * sizeof(char16)));
+}
 
-  inline int char16_wmemcmp(const char16 *s1, const char16 *s2, size_t n) {
-    // we cannot call memcmp because that changes the semantics.
-    while (n > 0) {
-      if (*s1 != *s2) {
-        // we cannot use (*s1 - *s2) because char16 is unsigned
-        return ((*s1 < *s2) ? -1 : 1);
-      }
-      ++s1; ++s2; --n;
+inline int char16_wmemcmp(const char16 *s1, const char16 *s2, size_t n) {
+  // We cannot call memcmp because that changes the semantics.
+  while (n > 0) {
+    if (*s1 != *s2) {
+      // We cannot use (*s1 - *s2) because char16 is unsigned.
+      return ((*s1 < *s2) ? -1 : 1);
     }
-    return 0;
+    ++s1;
+    ++s2;
+    --n;
   }
+  return 0;
+}
 
-  inline const char16 *char16_wmemchr(const char16 *s, char16 c, size_t n) {
-    while (n > 0) {
-      if (*s == c) {
-        return s;
-      }
-      ++s; --n;
+inline const char16 *char16_wmemchr(const char16 *s, char16 c, size_t n) {
+  while (n > 0) {
+    if (*s == c) {
+      return s;
     }
-    return 0;
+    ++s;
+    --n;
   }
+  return 0;
+}
 
-  inline char16 *char16_wmemset(char16 *s, char16 c, size_t n) {
-    char16 *s_orig = s;
-    while (n > 0) {
-      *s = c;
-      ++s; --n;
-    }
-    return s_orig;
+inline char16 *char16_wmemset(char16 *s, char16 c, size_t n) {
+  char16 *s_orig = s;
+  while (n > 0) {
+    *s = c;
+    ++s;
+    --n;
   }
+  return s_orig;
+}
 
-  inline size_t char16_wcslen(const char16 *s) {
-    const char16 *s_orig = s;
-    while (*s) { ++s; }
-    return (s - s_orig);
-  }
+inline size_t char16_wcslen(const char16 *s) {
+  const char16 *s_orig = s;
+  while (*s)
+    ++s;
+  return (s - s_orig);
+}
 
-} // END: extern "C"
+}  // extern "C"
 
 
 // Definition of char_traits<char16>, which enables basic_string<char16>
@@ -147,71 +131,69 @@ extern "C" {
 // This is a slightly modified version of char_traits<wchar_t> from gcc 3.2.2
 namespace std {
 
-  template<>
-    struct char_traits<char16>
-    {
-      typedef char16 		char_type;
-      typedef wint_t 		int_type;
-      typedef streamoff 	off_type;
-      typedef wstreampos 	pos_type;
-      typedef mbstate_t 	state_type;
+template<> struct char_traits<char16> {
+  typedef char16 char_type;
+  typedef wint_t int_type;
+  typedef streamoff off_type;
+  typedef wstreampos pos_type;
+  typedef mbstate_t state_type;
 
-      static void
-      assign(char_type& __c1, const char_type& __c2)
-      { __c1 = __c2; }
-
-      static bool
-      eq(const char_type& __c1, const char_type& __c2)
-      { return __c1 == __c2; }
-
-      static bool
-      lt(const char_type& __c1, const char_type& __c2)
-      { return __c1 < __c2; }
-
-      static int
-      compare(const char_type* __s1, const char_type* __s2, size_t __n)
-      { return char16_wmemcmp(__s1, __s2, __n); }
-
-      static size_t
-      length(const char_type* __s)
-      { return char16_wcslen(__s); }
+  static void assign(char_type& c1, const char_type& c2) {
+    c1 = c2;
+  }
 
-      static const char_type*
-      find(const char_type* __s, size_t __n, const char_type& __a)
-      { return char16_wmemchr(__s, __a, __n); }
+  static bool eq(const char_type& c1, const char_type& c2) {
+    return c1 == c2;
+  }
+  static bool lt(const char_type& c1, const char_type& c2) {
+    return c1 < c2;
+  }
 
-      static char_type*
-      move(char_type* __s1, const char_type* __s2, int_type __n)
-      { return char16_wmemmove(__s1, __s2, __n); }
+  static int compare(const char_type* s1, const char_type* s2, size_t n) {
+    return char16_wmemcmp(s1, s2, n);
+  }
 
-      static char_type*
-      copy(char_type* __s1, const char_type* __s2, size_t __n)
-      { return char16_wmemcpy(__s1, __s2, __n); }
+  static size_t length(const char_type* s) {
+    return char16_wcslen(s);
+  }
 
-      static char_type*
-      assign(char_type* __s, size_t __n, char_type __a)
-      { return char16_wmemset(__s, __a, __n); }
+  static const char_type* find(const char_type* s, size_t n,
+                               const char_type& a) {
+    return char16_wmemchr(s, a, n);
+  }
 
-      static char_type
-      to_char_type(const int_type& __c) { return char_type(__c); }
+  static char_type* move(char_type* s1, const char_type* s2, int_type n) {
+    return char16_wmemmove(s1, s2, n);
+  }
 
-      static int_type
-      to_int_type(const char_type& __c) { return int_type(__c); }
+  static char_type* copy(char_type* s1, const char_type* s2, size_t n) {
+    return char16_wmemcpy(s1, s2, n);
+  }
 
-      static bool
-      eq_int_type(const int_type& __c1, const int_type& __c2)
-      { return __c1 == __c2; }
+  static char_type* assign(char_type* s, size_t n, char_type a) {
+    return char16_wmemset(s, a, n);
+  }
 
-      static int_type
-      eof() { return static_cast<int_type>(WEOF); }
+  static char_type to_char_type(const int_type& c) {
+    return char_type(c);
+  }
+  static int_type to_int_type(const char_type& c) {
+    return int_type(c);
+  }
+  static bool eq_int_type(const int_type& c1, const int_type& c2) {
+    return c1 == c2;
+  }
 
-      static int_type
-      not_eof(const int_type& __c)
-      { return eq_int_type(__c, eof()) ? 0 : __c; }
-  };
+  static int_type eof() {
+    return static_cast<int_type>(WEOF);
+  }
+  static int_type not_eof(const int_type& c) {
+    return eq_int_type(c, eof()) ? 0 : c;
+  }
+};
 
-} // END: namespace std
+}  // namespace std
 
-#endif // END: WIN32
+#endif  // !WCHAR_T_IS_UTF16
 
-#endif // END: BASE_STRING16_H__
+#endif  // BASE_STRING16_H_
diff --git a/base/string_util.h b/base/string_util.h
index b89694f..4e52daf 100644
--- a/base/string_util.h
+++ b/base/string_util.h
@@ -29,8 +29,8 @@
 //
 // This file defines utility functions for working with strings.
 
-#ifndef BASE_STRING_UTIL_H__
-#define BASE_STRING_UTIL_H__
+#ifndef BASE_STRING_UTIL_H_
+#define BASE_STRING_UTIL_H_
 
 #include <string>
 #include <vector>
@@ -76,9 +76,9 @@ int SWPrintF(wchar_t* buffer, size_t size, const wchar_t* format, ...);
 
 // Some of these implementations need to be inlined.
 
-#if defined(WIN32)
+#if defined(OS_WIN)
 #include "base/string_util_win.h"
-#elif defined(__APPLE__)
+#elif defined(OS_MACOSX)
 #include "base/string_util_mac.h"
 #else
 #error Define string operations appropriately for your platform
@@ -532,4 +532,4 @@ std::wstring ReplaceStringPlaceholders(const std::wstring& format_string,
 bool MatchPattern(const std::wstring& string, const std::wstring& pattern);
 bool MatchPattern(const std::string& string, const std::string& pattern);
 
-#endif  // BASE_STRING_UTIL_H__
+#endif  // BASE_STRING_UTIL_H_
diff --git a/base/string_util_icu.cc b/base/string_util_icu.cc
index 1a84be3..534ca88 100644
--- a/base/string_util_icu.cc
+++ b/base/string_util_icu.cc
@@ -62,9 +62,8 @@ bool ReadUnicodeCharacter(const char* src, int32 src_len,
   return U_IS_UNICODE_CHAR(*code_point);
 }
 
-#ifdef WIN32
-// Reads a UTF-16 character for Windows. The usage is the same as the 8-bit
-// version above.
+#if defined(WCHAR_T_IS_UTF16)
+// Reads a UTF-16 character. The usage is the same as the 8-bit version above.
 bool ReadUnicodeCharacter(const wchar_t* src, int32 src_len,
                           int32* char_index, uint32* code_point) {
   if (U16_IS_SURROGATE(src[*char_index])) {
@@ -86,10 +85,9 @@ bool ReadUnicodeCharacter(const wchar_t* src, int32 src_len,
 
   return U_IS_UNICODE_CHAR(*code_point);
 }
-#else
-// Reads a 32-bit character for Mac and Linux systems. The usage is the same as
-// the 8-bit version above.
-bool ReadUnicodeCharacter(const wchar_t* src, in32 src_len,
+#elif defined(WCHAR_T_IS_UTF32)
+// Reads UTF-32 character. The usage is the same as the 8-bit version above.
+bool ReadUnicodeCharacter(const wchar_t* src, int32 src_len,
                           int32* char_index, uint32* code_point) {
   // Conversion is easy since the source is 32-bit.
   *code_point = src[*char_index];
@@ -97,7 +95,7 @@ bool ReadUnicodeCharacter(const wchar_t* src, in32 src_len,
   // Validate the value.
   return U_IS_UNICODE_CHAR(*code_point);
 }
-#endif
+#endif  // defined(WCHAR_T_IS_UTF32)
 
 // WriteUnicodeCharacter -------------------------------------------------------
 
@@ -120,9 +118,8 @@ void WriteUnicodeCharacter(uint32 code_point, std::basic_string<char>* output) {
   output->resize(char_offset);
 }
 
-#ifdef WIN32
-// Appends the given code point as a UTF-16 character to the STL string. On
-// Windows, wchar_t is UTF-16.
+#if defined(WCHAR_T_IS_UTF16)
+// Appends the given code point as a UTF-16 character to the STL string.
 void WriteUnicodeCharacter(uint32 code_point,
                            std::basic_string<wchar_t>* output) {
   if (U16_LENGTH(code_point) == 1) {
@@ -135,15 +132,14 @@ void WriteUnicodeCharacter(uint32 code_point,
     U16_APPEND_UNSAFE(&(*output)[0], char_offset, code_point);
   }
 }
-#else
-// Appends the given UCS-4 character to the given 32-bit string for Linux and
-// Mac where wchar_t is UCS-4.
+#elif defined(WCHAR_T_IS_UTF32)
+// Appends the given UTF-32 character to the given 32-bit string.
 inline void WriteUnicodeCharacter(uint32 code_point,
                                   std::basic_string<wchar_t>* output) {
   // This is the easy case, just append the character.
   output->push_back(code_point);
 }
-#endif
+#endif  // defined(WCHAR_T_IS_UTF32)
 
 // Generalized Unicode converter -----------------------------------------------
 
@@ -245,10 +241,10 @@ bool WideToCodepage(const std::wstring& wide,
 
   const UChar* uchar_src;
   int uchar_len;
-#ifdef U_WCHAR_IS_UTF16
+#if defined(WCHAR_T_IS_UTF16)
   uchar_src = wide.c_str();
   uchar_len = static_cast<int>(wide.length());
-#else  // U_WCHAR_IS_UTF16
+#elif defined(WCHAR_T_IS_UTF32)
   // When wchar_t is wider than UChar (16 bits), transform |wide| into a
   // UChar* string.  Size the UChar* buffer to be large enough to hold twice
   // as many UTF-16 code points as there are UCS-4 characters, in case each
@@ -259,7 +255,7 @@ bool WideToCodepage(const std::wstring& wide,
                wide.c_str(), wide.length(), &status);
   uchar_src = &wide_uchar[0];
   DCHECK(U_SUCCESS(status)) << "failed to convert wstring to UChar*";
-#endif  // U_WCHAR_IS_UTF16
+#endif  // defined(WCHAR_T_IS_UTF32)
 
   int encoded_max_length = UCNV_GET_MAX_BYTES_FOR_STRING(uchar_len,
     ucnv_getMaxCharSize(converter));
@@ -307,14 +303,14 @@ bool CodepageToWide(const std::string& encoded,
   size_t uchar_max_length = encoded.length() * 2 + 1;
 
   UChar* uchar_dst;
-#ifdef U_WCHAR_IS_UTF16
+#if defined(WCHAR_T_IS_UTF16)
   uchar_dst = WriteInto(wide, uchar_max_length);
-#else
+#elif defined(WCHAR_T_IS_UTF32)
   // When wchar_t is wider than UChar (16 bits), convert into a temporary
   // UChar* buffer.
   std::vector<UChar> wide_uchar(uchar_max_length);
   uchar_dst = &wide_uchar[0];
-#endif  // U_WCHAR_IS_UTF16
+#endif  // defined(WCHAR_T_IS_UTF32)
 
   // Setup our error handler.
   switch (on_error) {
@@ -342,7 +338,7 @@ bool CodepageToWide(const std::string& encoded,
     return false;
   }
 
-#ifndef U_WCHAR_IS_UTF16
+#ifdef WCHAR_T_IS_UTF32
   // When wchar_t is wider than UChar (16 bits), it's not possible to wind up
   // with any more wchar_t elements than UChar elements.  ucnv_toUChars
   // returns the number of UChar elements not including the NUL terminator, so
@@ -350,7 +346,7 @@ bool CodepageToWide(const std::string& encoded,
   u_strToWCS(WriteInto(wide, actual_size + 1), actual_size + 1, &actual_size,
              uchar_dst, actual_size, &status);
   DCHECK(U_SUCCESS(status)) << "failed to convert UChar* to wstring";
-#endif  // U_WCHAR_IS_UTF16
+#endif  // WCHAR_T_IS_UTF32
 
   wide->resize(actual_size);
   return true;
@@ -372,10 +368,10 @@ std::wstring FormatNumber(int64 number) {
   UnicodeString ustr;
   number_format->format(number, ustr);
 
-#ifdef U_WCHAR_IS_UTF16
+#if defined(WCHAR_T_IS_UTF16)
   return std::wstring(ustr.getBuffer(),
                       static_cast<std::wstring::size_type>(ustr.length()));
-#else  // U_WCHAR_IS_UTF16
+#elif defined(WCHAR_T_IS_UTF32)
   wchar_t buffer[64];  // A int64 is less than 20 chars long,  so 64 chars
                        // leaves plenty of room for formating stuff.
   int length = 0;
@@ -387,5 +383,5 @@ std::wstring FormatNumber(int64 number) {
     return StringPrintf(L"%lld", number);
   }
   return std::wstring(buffer, static_cast<std::wstring::size_type>(length));
-#endif  // U_WCHAR_IS_UTF16
+#endif  // defined(WCHAR_T_IS_UTF32)
 }
diff --git a/base/string_util_unittest.cc b/base/string_util_unittest.cc
index dcebddf..1112676 100644
--- a/base/string_util_unittest.cc
+++ b/base/string_util_unittest.cc
@@ -153,9 +153,9 @@ static const wchar_t* const kConvertRoundtripCases[] = {
 
   // Test a character that takes more than 16-bits. This will depend on whether
   // wchar_t is 16 or 32 bits.
-  #ifdef WIN32
+  #if defined(WCHAR_T_IS_UTF16)
     L"\xd800\xdf00",
-  #else
+  #elif defined(WCHAR_T_IS_UTF32)
     "\x10300,
   #endif
 };
@@ -207,9 +207,9 @@ TEST(StringUtilTest, ConvertUTF8ToWide) {
     // This UTF-8 character decodes to a UTF-16 surrogate, which is illegal.
     {"\xed\xb0\x80", L"", false},
     // Non-BMP character. The result will either be in UTF-16 or UCS-4.
-#ifdef WIN32
+#if defined(WCHAR_T_IS_UTF16)
     {"A\xF0\x90\x8C\x80z", L"A\xd800\xdf00z", true},
-#else
+#elif defined(WCHAR_T_IS_UTF32)
     {"A\xF0\x90\x8C\x80z", L"A\x10300z", true},
 #endif
   };
@@ -238,7 +238,7 @@ TEST(StringUtilTest, ConvertUTF8ToWide) {
   EXPECT_EQ('B', converted[0]);
 }
 
-#ifdef WIN32
+#if defined(WCHAR_T_IS_UTf16)
 // This test is only valid when wchar_t == UTF-16.
 TEST(StringUtilTest, ConvertUTF16ToUTF8) {
   struct UTF16ToUTF8Case {
@@ -269,7 +269,7 @@ TEST(StringUtilTest, ConvertUTF16ToUTF8) {
   }
 }
 
-#else
+#elif defined(WCHAR_T_IS_UTF32)
 // This test is only valid when wchar_t == UCS-4.
 TEST(StringUtilTest, ConvertUCS4ToUTF8) {
   struct UTF8ToWideCase {
@@ -298,7 +298,7 @@ TEST(StringUtilTest, ConvertUCS4ToUTF8) {
     EXPECT_EQ(expected, converted);
   }
 }
-#endif
+#endif  // defined(WCHAR_T_IS_UTF32)
 
 TEST(StringUtilTest, ConvertMultiString) {
   static wchar_t wmulti[] = {
@@ -467,7 +467,7 @@ TEST(StringUtilTest, ConvertBetweenCodepageAndWide) {
                              OnStringUtilConversionError::SKIP, &encoded));
   EXPECT_STREQ("Chinese", encoded.c_str());
 
-#ifdef WIN32
+#if defined(WCHAR_T_IS_UTF16)
   // When we're in UTF-16 mode, test an invalid UTF-16 character in the input.
   EXPECT_FALSE(WideToCodepage(L"a\xd800z", "iso-8859-1",
                               OnStringUtilConversionError::FAIL, &encoded));
@@ -475,7 +475,7 @@ TEST(StringUtilTest, ConvertBetweenCodepageAndWide) {
   EXPECT_TRUE(WideToCodepage(L"a\xd800z", "iso-8859-1",
                              OnStringUtilConversionError::SKIP, &encoded));
   EXPECT_STREQ("az", encoded.c_str());
-#endif
+#endif  // WCHAR_T_IS_UTf16
 
   // Invalid characters should fail.
   EXPECT_TRUE(WideToCodepage(L"a\xffffz", "iso-8859-1",
diff --git a/base/sys_string_conversions.h b/base/sys_string_conversions.h
index 52317ab..f1dae58 100644
--- a/base/sys_string_conversions.h
+++ b/base/sys_string_conversions.h
@@ -46,13 +46,13 @@ std::wstring SysUTF8ToWide(const std::string& utf8);
 
 // Converts between wide and the system multi-byte representations of a string.
 // DANGER: This will lose information and can change (on Windows, this can
-// change between reboots), 
+// change between reboots).
 std::string SysWideToNativeMB(const std::wstring& wide);
 std::wstring SysNativeMBToWide(const std::string& native_mb);
 
 // Windows-specific ------------------------------------------------------------
 
-#ifdef WIN32
+#if defined(OS_WIN)
 
 // Converts between an 8-bit string into a wide string, using the given
 // code page. The code page identifier is one accepted by the Windows function
@@ -60,7 +60,7 @@ std::wstring SysNativeMBToWide(const std::string& native_mb);
 std::wstring SysMultiByteToWide(const std::string& mb, uint32 code_page);
 std::string SysWideToMultiByte(const std::wstring& wide, uint32 code_page);
 
-#endif  // WIN32
+#endif  // defined(OS_WIN)
 
 }  // namespace base
 
diff --git a/base/time.h b/base/time.h
index e0c806d..306a67c 100644
--- a/base/time.h
+++ b/base/time.h
@@ -44,19 +44,19 @@
 // These classes are represented as only a 64-bit value, so they can be
 // efficiently passed by value.
 
-#ifndef BASE_TIME_H__
-#define BASE_TIME_H__
+#ifndef BASE_TIME_H_
+#define BASE_TIME_H_
 
-#ifdef WIN32
+#include <time.h>
+#include "base/basictypes.h"
+#include "testing/gtest/include/gtest/gtest_prod.h"
+
+#if defined(OS_WIN)
 // For FILETIME in FromFileTime, until it moves to a new converter class.
 // See TODO(iyengar) below.
 #include <windows.h>
 #endif
 
-#include <time.h>
-#include "base/basictypes.h"
-#include "testing/gtest/include/gtest/gtest_prod.h"
-
 class Time;
 class TimeTicks;
 
@@ -236,7 +236,7 @@ class Time {
   // (Jan 1, 1970).  Webkit uses this format to represent time.
   double ToDoubleT() const;
 
-#ifdef WIN32
+#if defined(OS_WIN)
   static Time FromFileTime(FILETIME ft);
   FILETIME ToFileTime() const;
 #endif
@@ -455,7 +455,7 @@ class TimeTicks {
   // Tick count in microseconds.
   int64 ticks_;
 
-#ifdef WIN32
+#if defined(OS_WIN)
   // The function to use for counting ticks.
   typedef int (__stdcall *TickFunction)(void);
   static TickFunction tick_function_;
@@ -466,4 +466,4 @@ inline TimeTicks TimeDelta::operator+(TimeTicks t) const {
   return TimeTicks(t.ticks_ + delta_);
 }
 
-#endif  // BASE_TIME_H__
+#endif  // BASE_TIME_H_
diff --git a/build/build_config.h b/build/build_config.h
index 87dd259..d667951 100644
--- a/build/build_config.h
+++ b/build/build_config.h
@@ -80,4 +80,14 @@
 #error Please add support for your architecture in build/build_config.h
 #endif
 
+// Type detection for wchar_t.
+#if defined(OS_WIN)
+#define WCHAR_T_IS_UTF16
+#elif defined(OS_POSIX) && defined(COMPILER_GCC) && \
+    defined(__WCHAR_MAX__) && __WCHAR_MAX__ == 0x7fffffff
+#define WCHAR_T_IS_UTF32
+#else
+#error Please add support for your compiler in build/build_config.h
+#endif
+
 #endif  // BUILD_BUILD_CONFIG_H_