Add collation support on Windows (MSVC build)

There is not yet support in initdb to populate the pg_collation
catalog, but if that is done manually, the rest should work.

src/backend/utils/adt/pg_locale.c

@@ -971,8 +971,12 @@ pg_newlocale_from_collation(Oid collid)
 		if (strcmp(collcollate, collctype) == 0)
 		{
 			/* Normal case where they're the same */
+#ifndef WIN32
 			result = newlocale(LC_COLLATE_MASK | LC_CTYPE_MASK, collcollate,
 							   NULL);
+#else
+			result = _create_locale(LC_ALL, collcollate);
+#endif
 			if (!result)
 				ereport(ERROR,
 						(errcode_for_file_access(),
@@ -981,6 +985,7 @@ pg_newlocale_from_collation(Oid collid)
 		}
 		else
 		{
+#ifndef WIN32
 			/* We need two newlocale() steps */
 			locale_t loc1;
 
@@ -996,6 +1001,16 @@ pg_newlocale_from_collation(Oid collid)
 						(errcode_for_file_access(),
 						 errmsg("could not create locale \"%s\": %m",
 								collctype)));
+#else
+			/*
+			 * XXX The _create_locale() API doesn't appear to support
+			 * this.  Could perhaps be worked around by changing
+			 * pg_locale_t to contain two separate fields.
+			 */
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("collations with different collate and ctype values are not supported on this platform")));
+#endif
 		}
 
 		cache_entry->locale = result;

src/backend/utils/adt/varlena.c

@@ -1374,6 +1374,11 @@ varstr_cmp(char *arg1, int len1, char *arg2, int len2, Oid collid)
 			((LPWSTR) a2p)[r] = 0;
 
 			errno = 0;
+#ifdef HAVE_LOCALE_T
+			if (mylocale)
+				result = wcscoll_l((LPWSTR) a1p, (LPWSTR) a2p, mylocale);
+			else
+#endif
 			result = wcscoll((LPWSTR) a1p, (LPWSTR) a2p);
 			if (result == 2147483647)	/* _NLSCMPERROR; missing from mingw
 										 * headers */

src/bin/initdb/initdb.c

@@ -1571,7 +1571,7 @@ setup_collation(void)
 	fputs(_("creating collations ... "), stdout);
 	fflush(stdout);
 
-#ifdef HAVE_LOCALE_T
+#if defined(HAVE_LOCALE_T) && !defined(WIN32)
 	snprintf(cmd, sizeof(cmd),
 			 "\"%s\" %s template1 >%s",
 			 backend_exec, backend_options,

src/include/pg_config.h.win32

@@ -5,7 +5,7 @@
  * changes to be valid for Visual C++ (and compatible):
  *
  * HAVE_CBRT, HAVE_FUNCNAME_FUNC, HAVE_GETOPT, HAVE_GETOPT_H,
- * HAVE_GETOPT_LONG, HAVE_RINT, HAVE_STRINGS_H, HAVE_STRTOLL,
+ * HAVE_GETOPT_LONG, HAVE_LOCALE_T, HAVE_RINT, HAVE_STRINGS_H, HAVE_STRTOLL,
  * HAVE_STRTOULL, HAVE_STRUCT_OPTION, ENABLE_THREAD_SAFETY,
  * USE_INLINE, inline
  */
@@ -244,6 +244,9 @@
 #define HAVE_LL_CONSTANTS 1
 #endif
 
+/* Define to 1 if the system has the type `locale_t'. */
+#define HAVE_LOCALE_T 1
+
 /* Define to 1 if `long int' works and is 64 bits. */
 /* #undef HAVE_LONG_INT_64 */
 
@@ -547,6 +550,9 @@
 /* Define to build with Kerberos 5 support. (--with-krb5) */
 /* #undef KRB5 */
 
+/* Define to 1 if `locale_t' requires <xlocale.h>. */
+/* #undef LOCALE_T_IN_XLOCALE */
+
 /* Define to the location of locale files. */
 /* #undef LOCALEDIR */
 

src/include/port/win32.h

@@ -275,6 +275,20 @@ typedef int pid_t;
 #define EBADFD WSAENOTSOCK
 #define EOPNOTSUPP WSAEOPNOTSUPP
 
+/*
+ * Extended locale functions with gratuitous underscore prefixes.
+ * (These APIs are nevertheless fully documented by Microsoft.)
+ */
+#define locale_t _locale_t
+#define tolower_l _tolower_l
+#define toupper_l _toupper_l
+#define towlower_l _towlower_l
+#define towupper_l _towupper_l
+#define isalnum_l _isalnum_l
+#define iswalnum_l _iswalnum_l
+#define strcoll_l _strcoll_l
+#define wcscoll_l _wcscoll_l
+
 
 /* In backend/port/win32/signal.c */
 extern PGDLLIMPORT volatile int pg_signal_queue;