from http://sourceforge.net/p/cygwin-ports/pkg-config/ci/e7b7d2d257a42ede81242e5afe0ef3e182b239ff/tree/glib-cygwin.patch

pkg-config_0.27.1-cygwin.patch

--- a/glib/glib/gatomic.c	2012-07-14 17:03:45.000000000 -0500
+++ b/glib/glib/gatomic.c	2013-03-08 14:56:54.644462500 -0600
@@ -464,7 +464,7 @@ gsize
   return g_atomic_pointer_xor ((volatile gpointer *) atomic, val);
 }
 
-#elif defined (G_PLATFORM_WIN32)
+#elif defined (G_OS_WIN32)
 
 #include <windows.h>
 #if !defined(_M_AMD64) && !defined (_M_IA64) && !defined(_M_X64)
--- a/glib/glib/gcharset.c	2012-07-14 17:03:45.000000000 -0500
+++ b/glib/glib/gcharset.c	2013-03-08 14:58:07.538631800 -0600
@@ -496,7 +496,7 @@ guess_category_value (const gchar *categ
   if ((retval != NULL) && (retval[0] != '\0'))
     return retval;
 
-#ifdef G_PLATFORM_WIN32
+#ifdef G_OS_WIN32
   /* g_win32_getlocale() first checks for LC_ALL, LC_MESSAGES and
    * LANG, which we already did above. Oh well. The main point of
    * calling g_win32_getlocale() is to get the thread's locale as used
--- a/glib/glib/gconvert.c	2012-07-14 17:03:45.000000000 -0500
+++ b/glib/glib/gconvert.c	2013-03-08 14:58:07.549632500 -0600
@@ -33,9 +33,6 @@
 
 #ifdef G_OS_WIN32
 #include "win_iconv.c"
-#endif
-
-#ifdef G_PLATFORM_WIN32
 #define STRICT
 #include <windows.h>
 #undef STRICT
@@ -1262,7 +1259,7 @@ g_locale_from_utf8 (const gchar *utf8str
 		      charset, "UTF-8", bytes_read, bytes_written, error);
 }
 
-#ifndef G_PLATFORM_WIN32
+#ifndef G_OS_WIN32
 
 typedef struct _GFilenameCharsetCache GFilenameCharsetCache;
 
@@ -1378,7 +1375,7 @@ g_get_filename_charsets (const gchar ***
   return cache->is_utf8;
 }
 
-#else /* G_PLATFORM_WIN32 */
+#else /* G_OS_WIN32 */
 
 gboolean
 g_get_filename_charsets (const gchar ***filename_charsets) 
@@ -1407,7 +1404,7 @@ g_get_filename_charsets (const gchar ***
 #endif
 }
 
-#endif /* G_PLATFORM_WIN32 */
+#endif /* G_OS_WIN32 */
 
 static gboolean
 get_filename_charset (const gchar **filename_charset)
--- a/glib/glib/gfileutils.c	2012-08-22 08:03:52.000000000 -0500
+++ b/glib/glib/gfileutils.c	2013-03-08 14:58:07.565633400 -0600
@@ -2175,7 +2175,7 @@ g_path_skip_root (const gchar *file_name
 {
   g_return_val_if_fail (file_name != NULL, NULL);
 
-#ifdef G_PLATFORM_WIN32
+#ifdef G_OS_WIN32
   /* Skip \\server\share or //server/share */
   if (G_IS_DIR_SEPARATOR (file_name[0]) &&
       G_IS_DIR_SEPARATOR (file_name[1]) &&
@@ -2185,7 +2185,6 @@ g_path_skip_root (const gchar *file_name
       gchar *p;
       p = strchr (file_name + 2, G_DIR_SEPARATOR);
 
-#ifdef G_OS_WIN32
       {
         gchar *q;
 
@@ -2193,7 +2192,6 @@ g_path_skip_root (const gchar *file_name
         if (p == NULL || (q != NULL && q < p))
         p = q;
       }
-#endif
 
       if (p && p > file_name + 2 && p[1])
         {
--- a/glib/glib/glib.h	2012-08-22 07:53:31.000000000 -0500
+++ b/glib/glib/glib.h	2013-03-08 14:58:07.577634100 -0600
@@ -95,7 +95,7 @@
 #include <glib/gvariant.h>
 #include <glib/gversion.h>
 #include <glib/gversionmacros.h>
-#ifdef G_PLATFORM_WIN32
+#ifdef G_OS_WIN32
 #include <glib/gwin32.h>
 #endif
 
--- a/glib/glib/gutf8.c	2012-08-22 08:03:52.000000000 -0500
+++ b/glib/glib/gutf8.c	2013-03-08 14:58:07.591634900 -0600
@@ -27,7 +27,7 @@
 #endif
 #include <string.h>
 
-#ifdef G_PLATFORM_WIN32
+#ifdef G_OS_WIN32
 #include <stdio.h>
 #define STRICT
 #include <windows.h>
--- a/glib/glib/gutils.c	2012-08-22 08:03:52.000000000 -0500
+++ b/glib/glib/gutils.c	2013-03-08 14:58:07.594635000 -0600
@@ -71,7 +71,7 @@
 #include "garray.h"
 #include "glibintl.h"
 
-#ifdef G_PLATFORM_WIN32
+#ifdef G_OS_WIN32
 #include "gconvert.h"
 #include "gwin32.h"
 #endif
@@ -85,16 +85,13 @@
  * These are portable utility functions.
  */
 
-#ifdef G_PLATFORM_WIN32
+#ifdef G_OS_WIN32
 #  include <windows.h>
 #  ifndef GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS
 #    define GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT 2
 #    define GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS 4
 #  endif
 #  include <lmcons.h>		/* For UNLEN */
-#endif /* G_PLATFORM_WIN32 */
-
-#ifdef G_OS_WIN32
 #  include <direct.h>
 #  include <shlobj.h>
    /* older SDK (e.g. msvc 5.0) does not have these*/
@@ -130,7 +127,7 @@
 #include <langinfo.h>
 #endif
 
-#ifdef G_PLATFORM_WIN32
+#ifdef G_OS_WIN32
 
 gchar *
 _glib_get_dll_directory (void)
--- a/glib/glib/gutils.h	2012-08-22 08:03:52.000000000 -0500
+++ b/glib/glib/gutils.h	2013-03-08 14:58:07.597635200 -0600
@@ -342,7 +342,7 @@ G_END_DECLS
  * On non-Windows platforms, expands to nothing.
  */
 
-#ifndef G_PLATFORM_WIN32
+#ifndef G_OS_WIN32
 # define G_WIN32_DLLMAIN_FOR_DLL_NAME(static, dll_name)
 #else
 # define G_WIN32_DLLMAIN_FOR_DLL_NAME(static, dll_name)			\
@@ -370,6 +370,6 @@ DllMain (HINSTANCE hinstDLL,						\
 
 #endif	/* !G_DISABLE_DEPRECATED */
 
-#endif /* G_PLATFORM_WIN32 */
+#endif /* G_OS_WIN32 */
 
 #endif /* __G_UTILS_H__ */
--- a/glib/glib/gwin32.h	2012-07-14 17:03:45.000000000 -0500
+++ b/glib/glib/gwin32.h	2013-03-08 14:58:07.600635400 -0600
@@ -33,7 +33,7 @@
 
 #include <glib/gtypes.h>
 
-#ifdef G_PLATFORM_WIN32
+#ifdef G_OS_WIN32
 
 G_BEGIN_DECLS
 
@@ -41,8 +41,6 @@ G_BEGIN_DECLS
 #define MAXPATHLEN 1024
 #endif
 
-#ifdef G_OS_WIN32
-
 /*
  * To get prototypes for the following POSIXish functions, you have to
  * include the indicated non-POSIX headers. The functions are defined
@@ -67,7 +65,6 @@ G_BEGIN_DECLS
  */
 gint		g_win32_ftruncate	(gint		 f,
 					 guint		 size);
-#endif /* G_OS_WIN32 */
 
 /* The MS setlocale uses locale names of the form "English_United
  * States.1252" etc. We want the Unixish standard form "en", "zh_TW"
@@ -113,6 +110,6 @@ gchar*          g_win32_locale_filename_
 
 G_END_DECLS
 
-#endif	 /* G_PLATFORM_WIN32 */
+#endif	 /* G_OS_WIN32 */
 
 #endif /* __G_WIN32_H__ */
--- a/glib/glib/libcharset/localcharset.c	2012-07-14 17:03:45.000000000 -0500
+++ b/glib/glib/libcharset/localcharset.c	2013-03-08 14:58:07.604635600 -0600
@@ -46,10 +46,6 @@
 #   include <locale.h>
 #  endif
 # endif
-# ifdef __CYGWIN__
-#  define WIN32_LEAN_AND_MEAN
-#  include <windows.h>
-# endif
 #elif defined WIN32_NATIVE
 # define WIN32_LEAN_AND_MEAN
 # include <windows.h>
@@ -111,7 +107,7 @@ _g_locale_get_charset_aliases (void)
   cp = charset_aliases;
   if (cp == NULL)
     {
-#if !(defined VMS || defined WIN32_NATIVE || defined __CYGWIN__)
+#if !(defined VMS || defined WIN32_NATIVE)
       FILE *fp;
       const char *dir;
       const char *base = "charset.alias";
@@ -237,7 +233,7 @@ _g_locale_get_charset_aliases (void)
 	   "DECKOREAN" "\0" "EUC-KR" "\0";
 # endif
 
-# if defined WIN32_NATIVE || defined __CYGWIN__
+# if defined WIN32_NATIVE
       /* To avoid the troubles of installing a separate file in the same
 	 directory as the DLL and of retrieving the DLL's directory at
 	 runtime, simply inline the aliases here.  */
@@ -292,53 +288,6 @@ _g_locale_charset_raw (void)
   /* Most systems support nl_langinfo (CODESET) nowadays.  */
   codeset = nl_langinfo (CODESET);
 
-#  ifdef __CYGWIN__
-  /* Cygwin 2006 does not have locales.  nl_langinfo (CODESET) always
-     returns "US-ASCII".  As long as this is not fixed, return the suffix
-     of the locale name from the environment variables (if present) or
-     the codepage as a number.  */
-  if (codeset != NULL && strcmp (codeset, "US-ASCII") == 0)
-    {
-      const char *locale;
-      static char buf[2 + 10 + 1];
-
-      locale = getenv ("LC_ALL");
-      if (locale == NULL || locale[0] == '\0')
-	{
-	  locale = getenv ("LC_CTYPE");
-	  if (locale == NULL || locale[0] == '\0')
-	    locale = getenv ("LANG");
-	}
-      if (locale != NULL && locale[0] != '\0')
-	{
-	  /* If the locale name contains an encoding after the dot, return
-	     it.  */
-	  const char *dot = strchr (locale, '.');
-
-	  if (dot != NULL)
-	    {
-	      const char *modifier;
-
-	      dot++;
-	      /* Look for the possible @... trailer and remove it, if any.  */
-	      modifier = strchr (dot, '@');
-	      if (modifier == NULL)
-		return dot;
-	      if (modifier - dot < sizeof (buf))
-		{
-		  memcpy (buf, dot, modifier - dot);
-		  buf [modifier - dot] = '\0';
-		  return buf;
-		}
-	    }
-	}
-
-      /* Woe32 has a function returning the locale's codepage as a number.  */
-      sprintf (buf, "CP%u", GetACP ());
-      codeset = buf;
-    }
-#  endif
-
 # else
 
   /* On old systems which lack it, use setlocale or getenv.  */