simplify regular expression locale global variables

From 817a47ac865a0aa3a99a79d9bc2bec951d6f2a6e Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Mon, 21 Oct 2024 07:24:50 +0200
Subject: [PATCH v2] Remove pg_regex_collation and pg_regex_strategy

We don't need three global variables to describe the locale strategy
for regular expressions.  We only need to keep pg_regex_locale.  This
works now because pg_locale_t now contains all the required
information (such as a ctype_is_c field).  This allows us to structure
the locale-using regular expression code more similar to other
locale-using code, mainly by provider, avoiding another layer that is
specific only to the regular expression code.

Discussion: https://www.postgresql.org/message-id/flat/b1b92ae1-2e06-4619-a87a-4b4858e547ec%40eisentraut.org
---
 src/backend/regex/regc_pg_locale.c | 430 +++++++++++++----------------
 src/tools/pgindent/typedefs.list   |   1 -
 2 files changed, 185 insertions(+), 246 deletions(-)

diff --git a/src/backend/regex/regc_pg_locale.c b/src/backend/regex/regc_pg_locale.c
index b75784b6ce5..4691e796385 100644
--- a/src/backend/regex/regc_pg_locale.c
+++ b/src/backend/regex/regc_pg_locale.c
@@ -63,18 +63,7 @@
  * NB: the coding here assumes pg_wchar is an unsigned type.
  */
 
-typedef enum
-{
-	PG_REGEX_STRATEGY_C,		/* C locale (encoding independent) */
-	PG_REGEX_STRATEGY_BUILTIN,	/* built-in Unicode semantics */
-	PG_REGEX_STRATEGY_LIBC_WIDE,	/* Use locale_t <wctype.h> functions */
-	PG_REGEX_STRATEGY_LIBC_1BYTE,	/* Use locale_t <ctype.h> functions */
-	PG_REGEX_STRATEGY_ICU,		/* Use ICU uchar.h functions */
-} PG_Locale_Strategy;
-
-static PG_Locale_Strategy pg_regex_strategy;
 static pg_locale_t pg_regex_locale;
-static Oid	pg_regex_collation;
 
 /*
  * Hard-wired character properties for C locale
@@ -232,7 +221,6 @@ void
 pg_set_regex_collation(Oid collation)
 {
 	pg_locale_t locale = 0;
-	PG_Locale_Strategy strategy;
 
 	if (!OidIsValid(collation))
 	{
@@ -253,8 +241,9 @@ pg_set_regex_collation(Oid collation)
 		 * catalog access is available, so we can't call
 		 * pg_newlocale_from_collation().
 		 */
-		strategy = PG_REGEX_STRATEGY_C;
-		collation = C_COLLATION_OID;
+		static struct pg_locale_struct dummy_locale = {.ctype_is_c = true};
+
+		locale = &dummy_locale;
 	}
 	else
 	{
@@ -264,121 +253,80 @@ pg_set_regex_collation(Oid collation)
 			ereport(ERROR,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 					 errmsg("nondeterministic collations are not supported for regular expressions")));
-
-		if (locale->ctype_is_c)
-		{
-			/*
-			 * C/POSIX collations use this path regardless of database
-			 * encoding
-			 */
-			strategy = PG_REGEX_STRATEGY_C;
-			locale = 0;
-			collation = C_COLLATION_OID;
-		}
-		else if (locale->provider == COLLPROVIDER_BUILTIN)
-		{
-			Assert(GetDatabaseEncoding() == PG_UTF8);
-			strategy = PG_REGEX_STRATEGY_BUILTIN;
-		}
-#ifdef USE_ICU
-		else if (locale->provider == COLLPROVIDER_ICU)
-		{
-			strategy = PG_REGEX_STRATEGY_ICU;
-		}
-#endif
-		else
-		{
-			Assert(locale->provider == COLLPROVIDER_LIBC);
-			if (GetDatabaseEncoding() == PG_UTF8)
-				strategy = PG_REGEX_STRATEGY_LIBC_WIDE;
-			else
-				strategy = PG_REGEX_STRATEGY_LIBC_1BYTE;
-		}
 	}
 
-	pg_regex_strategy = strategy;
 	pg_regex_locale = locale;
-	pg_regex_collation = collation;
 }
 
 static int
 pg_wc_isdigit(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
+		return (c <= (pg_wchar) 127 && (pg_char_properties[c] & PG_ISDIGIT));
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return pg_u_isdigit(c, true);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
 	{
-		case PG_REGEX_STRATEGY_C:
-			return (c <= (pg_wchar) 127 &&
-					(pg_char_properties[c] & PG_ISDIGIT));
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return pg_u_isdigit(c, true);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return iswdigit_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return iswdigit_l((wint_t) c, pg_regex_locale->info.lt);
+		else
 			return (c <= (pg_wchar) UCHAR_MAX &&
 					isdigit_l((unsigned char) c, pg_regex_locale->info.lt));
-			break;
-		case PG_REGEX_STRATEGY_ICU:
+	}
 #ifdef USE_ICU
-			return u_isdigit(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_isdigit(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
 static int
 pg_wc_isalpha(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
+		return (c <= (pg_wchar) 127 && (pg_char_properties[c] & PG_ISALPHA));
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return pg_u_isalpha(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
 	{
-		case PG_REGEX_STRATEGY_C:
-			return (c <= (pg_wchar) 127 &&
-					(pg_char_properties[c] & PG_ISALPHA));
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return pg_u_isalpha(c);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return iswalpha_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return iswalpha_l((wint_t) c, pg_regex_locale->info.lt);
+		else
 			return (c <= (pg_wchar) UCHAR_MAX &&
 					isalpha_l((unsigned char) c, pg_regex_locale->info.lt));
-			break;
-		case PG_REGEX_STRATEGY_ICU:
+	}
 #ifdef USE_ICU
-			return u_isalpha(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_isalpha(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
 static int
 pg_wc_isalnum(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
+		return (c <= (pg_wchar) 127 && (pg_char_properties[c] & PG_ISALNUM));
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return pg_u_isalnum(c, true);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
 	{
-		case PG_REGEX_STRATEGY_C:
-			return (c <= (pg_wchar) 127 &&
-					(pg_char_properties[c] & PG_ISALNUM));
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return pg_u_isalnum(c, true);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return iswalnum_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return iswalnum_l((wint_t) c, pg_regex_locale->info.lt);
+		else
 			return (c <= (pg_wchar) UCHAR_MAX &&
 					isalnum_l((unsigned char) c, pg_regex_locale->info.lt));
-			break;
-		case PG_REGEX_STRATEGY_ICU:
+	}
 #ifdef USE_ICU
-			return u_isalnum(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_isalnum(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
@@ -394,218 +342,206 @@ pg_wc_isword(pg_wchar c)
 static int
 pg_wc_isupper(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
+		return (c <= (pg_wchar) 127 && (pg_char_properties[c] & PG_ISUPPER));
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return pg_u_isupper(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
 	{
-		case PG_REGEX_STRATEGY_C:
-			return (c <= (pg_wchar) 127 &&
-					(pg_char_properties[c] & PG_ISUPPER));
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return pg_u_isupper(c);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return iswupper_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return iswupper_l((wint_t) c, pg_regex_locale->info.lt);
+		else
 			return (c <= (pg_wchar) UCHAR_MAX &&
 					isupper_l((unsigned char) c, pg_regex_locale->info.lt));
-			break;
-		case PG_REGEX_STRATEGY_ICU:
+	}
 #ifdef USE_ICU
-			return u_isupper(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_isupper(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
 static int
 pg_wc_islower(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
+		return (c <= (pg_wchar) 127 && (pg_char_properties[c] & PG_ISLOWER));
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return pg_u_islower(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
 	{
-		case PG_REGEX_STRATEGY_C:
-			return (c <= (pg_wchar) 127 &&
-					(pg_char_properties[c] & PG_ISLOWER));
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return pg_u_islower(c);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return iswlower_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return iswlower_l((wint_t) c, pg_regex_locale->info.lt);
+		else
 			return (c <= (pg_wchar) UCHAR_MAX &&
 					islower_l((unsigned char) c, pg_regex_locale->info.lt));
-			break;
-		case PG_REGEX_STRATEGY_ICU:
+	}
 #ifdef USE_ICU
-			return u_islower(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_islower(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
 static int
 pg_wc_isgraph(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
+		return (c <= (pg_wchar) 127 && (pg_char_properties[c] & PG_ISGRAPH));
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return pg_u_isgraph(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
 	{
-		case PG_REGEX_STRATEGY_C:
-			return (c <= (pg_wchar) 127 &&
-					(pg_char_properties[c] & PG_ISGRAPH));
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return pg_u_isgraph(c);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return iswgraph_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return iswgraph_l((wint_t) c, pg_regex_locale->info.lt);
+		else
 			return (c <= (pg_wchar) UCHAR_MAX &&
 					isgraph_l((unsigned char) c, pg_regex_locale->info.lt));
-			break;
-		case PG_REGEX_STRATEGY_ICU:
+	}
 #ifdef USE_ICU
-			return u_isgraph(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_isgraph(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
 static int
 pg_wc_isprint(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
+		return (c <= (pg_wchar) 127 && (pg_char_properties[c] & PG_ISPRINT));
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return pg_u_isprint(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
 	{
-		case PG_REGEX_STRATEGY_C:
-			return (c <= (pg_wchar) 127 &&
-					(pg_char_properties[c] & PG_ISPRINT));
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return pg_u_isprint(c);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return iswprint_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return iswprint_l((wint_t) c, pg_regex_locale->info.lt);
+		else
 			return (c <= (pg_wchar) UCHAR_MAX &&
 					isprint_l((unsigned char) c, pg_regex_locale->info.lt));
-			break;
-		case PG_REGEX_STRATEGY_ICU:
+	}
 #ifdef USE_ICU
-			return u_isprint(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_isprint(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
 static int
 pg_wc_ispunct(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
+		return (c <= (pg_wchar) 127 && (pg_char_properties[c] & PG_ISPUNCT));
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return pg_u_ispunct(c, true);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
 	{
-		case PG_REGEX_STRATEGY_C:
-			return (c <= (pg_wchar) 127 &&
-					(pg_char_properties[c] & PG_ISPUNCT));
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return pg_u_ispunct(c, true);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return iswpunct_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return iswpunct_l((wint_t) c, pg_regex_locale->info.lt);
+		else
 			return (c <= (pg_wchar) UCHAR_MAX &&
 					ispunct_l((unsigned char) c, pg_regex_locale->info.lt));
-			break;
-		case PG_REGEX_STRATEGY_ICU:
+	}
 #ifdef USE_ICU
-			return u_ispunct(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_ispunct(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
 static int
 pg_wc_isspace(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
+		return (c <= (pg_wchar) 127 && (pg_char_properties[c] & PG_ISSPACE));
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return pg_u_isspace(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
 	{
-		case PG_REGEX_STRATEGY_C:
-			return (c <= (pg_wchar) 127 &&
-					(pg_char_properties[c] & PG_ISSPACE));
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return pg_u_isspace(c);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return iswspace_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return iswspace_l((wint_t) c, pg_regex_locale->info.lt);
+		else
 			return (c <= (pg_wchar) UCHAR_MAX &&
 					isspace_l((unsigned char) c, pg_regex_locale->info.lt));
-			break;
-		case PG_REGEX_STRATEGY_ICU:
+	}
 #ifdef USE_ICU
-			return u_isspace(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_isspace(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
 static pg_wchar
 pg_wc_toupper(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
 	{
-		case PG_REGEX_STRATEGY_C:
-			if (c <= (pg_wchar) 127)
-				return pg_ascii_toupper((unsigned char) c);
-			return c;
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return unicode_uppercase_simple(c);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return towupper_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (c <= (pg_wchar) 127)
+			return pg_ascii_toupper((unsigned char) c);
+		return c;
+	}
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return unicode_uppercase_simple(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
+	{
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return towupper_l((wint_t) c, pg_regex_locale->info.lt);
+		else
+		{
 			if (c <= (pg_wchar) UCHAR_MAX)
 				return toupper_l((unsigned char) c, pg_regex_locale->info.lt);
 			return c;
-		case PG_REGEX_STRATEGY_ICU:
+		}
+	}
 #ifdef USE_ICU
-			return u_toupper(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_toupper(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
 static pg_wchar
 pg_wc_tolower(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
 	{
-		case PG_REGEX_STRATEGY_C:
-			if (c <= (pg_wchar) 127)
-				return pg_ascii_tolower((unsigned char) c);
-			return c;
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return unicode_lowercase_simple(c);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return towlower_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (c <= (pg_wchar) 127)
+			return pg_ascii_tolower((unsigned char) c);
+		return c;
+	}
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return unicode_lowercase_simple(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
+	{
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return towlower_l((wint_t) c, pg_regex_locale->info.lt);
+		else
+		{
 			if (c <= (pg_wchar) UCHAR_MAX)
 				return tolower_l((unsigned char) c, pg_regex_locale->info.lt);
 			return c;
-		case PG_REGEX_STRATEGY_ICU:
+		}
+	}
 #ifdef USE_ICU
-			return u_tolower(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_tolower(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
@@ -628,7 +564,7 @@ typedef int (*pg_wc_probefunc) (pg_wchar c);
 typedef struct pg_ctype_cache
 {
 	pg_wc_probefunc probefunc;	/* pg_wc_isalpha or a sibling */
-	Oid			collation;		/* collation this entry is for */
+	pg_locale_t locale;			/* locale this entry is for */
 	struct cvec cv;				/* cache entry contents */
 	struct pg_ctype_cache *next;	/* chain link */
 } pg_ctype_cache;
@@ -697,7 +633,7 @@ pg_ctype_get_cache(pg_wc_probefunc probefunc, int cclasscode)
 	for (pcc = pg_ctype_cache_list; pcc != NULL; pcc = pcc->next)
 	{
 		if (pcc->probefunc == probefunc &&
-			pcc->collation == pg_regex_collation)
+			pcc->locale == pg_regex_locale)
 			return &pcc->cv;
 	}
 
@@ -708,7 +644,7 @@ pg_ctype_get_cache(pg_wc_probefunc probefunc, int cclasscode)
 	if (pcc == NULL)
 		return NULL;
 	pcc->probefunc = probefunc;
-	pcc->collation = pg_regex_collation;
+	pcc->locale = pg_regex_locale;
 	pcc->cv.nchrs = 0;
 	pcc->cv.chrspace = 128;
 	pcc->cv.chrs = (chr *) malloc(pcc->cv.chrspace * sizeof(chr));
@@ -732,37 +668,41 @@ pg_ctype_get_cache(pg_wc_probefunc probefunc, int cclasscode)
 	 * would always be true for production values of MAX_SIMPLE_CHR, but it's
 	 * useful to allow it to be small for testing purposes.)
 	 */
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
 	{
-		case PG_REGEX_STRATEGY_C:
 #if MAX_SIMPLE_CHR >= 127
-			max_chr = (pg_wchar) 127;
-			pcc->cv.cclasscode = -1;
+		max_chr = (pg_wchar) 127;
+		pcc->cv.cclasscode = -1;
 #else
-			max_chr = (pg_wchar) MAX_SIMPLE_CHR;
+		max_chr = (pg_wchar) MAX_SIMPLE_CHR;
 #endif
-			break;
-		case PG_REGEX_STRATEGY_BUILTIN:
-			max_chr = (pg_wchar) MAX_SIMPLE_CHR;
-			break;
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
+	}
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+	{
+		max_chr = (pg_wchar) MAX_SIMPLE_CHR;
+	}
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
+	{
+		if (GetDatabaseEncoding() == PG_UTF8)
 			max_chr = (pg_wchar) MAX_SIMPLE_CHR;
-			break;
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		else
+		{
 #if MAX_SIMPLE_CHR >= UCHAR_MAX
 			max_chr = (pg_wchar) UCHAR_MAX;
 			pcc->cv.cclasscode = -1;
 #else
 			max_chr = (pg_wchar) MAX_SIMPLE_CHR;
 #endif
-			break;
-		case PG_REGEX_STRATEGY_ICU:
-			max_chr = (pg_wchar) MAX_SIMPLE_CHR;
-			break;
-		default:
-			Assert(false);
-			max_chr = 0;		/* can't get here, but keep compiler quiet */
-			break;
+		}
+	}
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+	{
+		max_chr = (pg_wchar) MAX_SIMPLE_CHR;
+	}
+	else
+	{
+		Assert(false);
+		max_chr = 0;			/* can't get here, but keep compiler quiet */
 	}
 
 	/*
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 57de1acff3a..bbc1ac179e8 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1821,7 +1821,6 @@ PGTargetServerType
 PGTernaryBool
 PGTransactionStatusType
 PGVerbosity
-PG_Locale_Strategy
 PG_Lock_Status
 PG_init_t
 PGcancel

base-commit: 57a36e890d3d60e6408bf6805e91c82f7b370873
-- 
2.47.0

From ab19b4d7ab03ba8c515da3e4b389d41941c5ab27 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Tue, 3 Dec 2024 16:58:38 +0100
Subject: [PATCH v3 1/2] Remove pg_regex_collation

We can also use the existing pg_regex_locale as the cache key, which
is the only use of this variable.

Discussion: https://www.postgresql.org/message-id/flat/b1b92ae1-2e06-4619-a87a-4b4858e547ec%40eisentraut.org
---
 src/backend/regex/regc_pg_locale.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/src/backend/regex/regc_pg_locale.c b/src/backend/regex/regc_pg_locale.c
index b75784b6ce5..e07d4a8868c 100644
--- a/src/backend/regex/regc_pg_locale.c
+++ b/src/backend/regex/regc_pg_locale.c
@@ -74,7 +74,6 @@ typedef enum
 
 static PG_Locale_Strategy pg_regex_strategy;
 static pg_locale_t pg_regex_locale;
-static Oid	pg_regex_collation;
 
 /*
  * Hard-wired character properties for C locale
@@ -254,7 +253,7 @@ pg_set_regex_collation(Oid collation)
 		 * pg_newlocale_from_collation().
 		 */
 		strategy = PG_REGEX_STRATEGY_C;
-		collation = C_COLLATION_OID;
+		locale = 0;
 	}
 	else
 	{
@@ -273,7 +272,6 @@ pg_set_regex_collation(Oid collation)
 			 */
 			strategy = PG_REGEX_STRATEGY_C;
 			locale = 0;
-			collation = C_COLLATION_OID;
 		}
 		else if (locale->provider == COLLPROVIDER_BUILTIN)
 		{
@@ -298,7 +296,6 @@ pg_set_regex_collation(Oid collation)
 
 	pg_regex_strategy = strategy;
 	pg_regex_locale = locale;
-	pg_regex_collation = collation;
 }
 
 static int
@@ -628,7 +625,7 @@ typedef int (*pg_wc_probefunc) (pg_wchar c);
 typedef struct pg_ctype_cache
 {
 	pg_wc_probefunc probefunc;	/* pg_wc_isalpha or a sibling */
-	Oid			collation;		/* collation this entry is for */
+	pg_locale_t locale;			/* locale this entry is for */
 	struct cvec cv;				/* cache entry contents */
 	struct pg_ctype_cache *next;	/* chain link */
 } pg_ctype_cache;
@@ -697,7 +694,7 @@ pg_ctype_get_cache(pg_wc_probefunc probefunc, int cclasscode)
 	for (pcc = pg_ctype_cache_list; pcc != NULL; pcc = pcc->next)
 	{
 		if (pcc->probefunc == probefunc &&
-			pcc->collation == pg_regex_collation)
+			pcc->locale == pg_regex_locale)
 			return &pcc->cv;
 	}
 
@@ -708,7 +705,7 @@ pg_ctype_get_cache(pg_wc_probefunc probefunc, int cclasscode)
 	if (pcc == NULL)
 		return NULL;
 	pcc->probefunc = probefunc;
-	pcc->collation = pg_regex_collation;
+	pcc->locale = pg_regex_locale;
 	pcc->cv.nchrs = 0;
 	pcc->cv.chrspace = 128;
 	pcc->cv.chrs = (chr *) malloc(pcc->cv.chrspace * sizeof(chr));

base-commit: 1ba0782ce90cb4261098de59b49ae5cb2326566b
-- 
2.47.1

From 3406390429bbb27931b1e99f9be410213fe05da4 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Tue, 3 Dec 2024 16:59:51 +0100
Subject: [PATCH v3 2/2] Remove pg_regex_strategy

We only need to keep pg_regex_locale.  This works now because
pg_locale_t now contains all the required information (such as a
ctype_is_c field).  This allows us to structure the locale-using
regular expression code more similar to other locale-using code,
mainly by provider, avoiding another layer that is specific only to
the regular expression code.

Discussion: https://www.postgresql.org/message-id/flat/b1b92ae1-2e06-4619-a87a-4b4858e547ec%40eisentraut.org
---
 src/backend/regex/regc_pg_locale.c | 421 +++++++++++++----------------
 src/tools/pgindent/typedefs.list   |   1 -
 2 files changed, 182 insertions(+), 240 deletions(-)

diff --git a/src/backend/regex/regc_pg_locale.c b/src/backend/regex/regc_pg_locale.c
index e07d4a8868c..4691e796385 100644
--- a/src/backend/regex/regc_pg_locale.c
+++ b/src/backend/regex/regc_pg_locale.c
@@ -63,16 +63,6 @@
  * NB: the coding here assumes pg_wchar is an unsigned type.
  */
 
-typedef enum
-{
-	PG_REGEX_STRATEGY_C,		/* C locale (encoding independent) */
-	PG_REGEX_STRATEGY_BUILTIN,	/* built-in Unicode semantics */
-	PG_REGEX_STRATEGY_LIBC_WIDE,	/* Use locale_t <wctype.h> functions */
-	PG_REGEX_STRATEGY_LIBC_1BYTE,	/* Use locale_t <ctype.h> functions */
-	PG_REGEX_STRATEGY_ICU,		/* Use ICU uchar.h functions */
-} PG_Locale_Strategy;
-
-static PG_Locale_Strategy pg_regex_strategy;
 static pg_locale_t pg_regex_locale;
 
 /*
@@ -231,7 +221,6 @@ void
 pg_set_regex_collation(Oid collation)
 {
 	pg_locale_t locale = 0;
-	PG_Locale_Strategy strategy;
 
 	if (!OidIsValid(collation))
 	{
@@ -252,8 +241,9 @@ pg_set_regex_collation(Oid collation)
 		 * catalog access is available, so we can't call
 		 * pg_newlocale_from_collation().
 		 */
-		strategy = PG_REGEX_STRATEGY_C;
-		locale = 0;
+		static struct pg_locale_struct dummy_locale = {.ctype_is_c = true};
+
+		locale = &dummy_locale;
 	}
 	else
 	{
@@ -263,119 +253,80 @@ pg_set_regex_collation(Oid collation)
 			ereport(ERROR,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 					 errmsg("nondeterministic collations are not supported for regular expressions")));
-
-		if (locale->ctype_is_c)
-		{
-			/*
-			 * C/POSIX collations use this path regardless of database
-			 * encoding
-			 */
-			strategy = PG_REGEX_STRATEGY_C;
-			locale = 0;
-		}
-		else if (locale->provider == COLLPROVIDER_BUILTIN)
-		{
-			Assert(GetDatabaseEncoding() == PG_UTF8);
-			strategy = PG_REGEX_STRATEGY_BUILTIN;
-		}
-#ifdef USE_ICU
-		else if (locale->provider == COLLPROVIDER_ICU)
-		{
-			strategy = PG_REGEX_STRATEGY_ICU;
-		}
-#endif
-		else
-		{
-			Assert(locale->provider == COLLPROVIDER_LIBC);
-			if (GetDatabaseEncoding() == PG_UTF8)
-				strategy = PG_REGEX_STRATEGY_LIBC_WIDE;
-			else
-				strategy = PG_REGEX_STRATEGY_LIBC_1BYTE;
-		}
 	}
 
-	pg_regex_strategy = strategy;
 	pg_regex_locale = locale;
 }
 
 static int
 pg_wc_isdigit(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
+		return (c <= (pg_wchar) 127 && (pg_char_properties[c] & PG_ISDIGIT));
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return pg_u_isdigit(c, true);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
 	{
-		case PG_REGEX_STRATEGY_C:
-			return (c <= (pg_wchar) 127 &&
-					(pg_char_properties[c] & PG_ISDIGIT));
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return pg_u_isdigit(c, true);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return iswdigit_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return iswdigit_l((wint_t) c, pg_regex_locale->info.lt);
+		else
 			return (c <= (pg_wchar) UCHAR_MAX &&
 					isdigit_l((unsigned char) c, pg_regex_locale->info.lt));
-			break;
-		case PG_REGEX_STRATEGY_ICU:
+	}
 #ifdef USE_ICU
-			return u_isdigit(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_isdigit(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
 static int
 pg_wc_isalpha(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
+		return (c <= (pg_wchar) 127 && (pg_char_properties[c] & PG_ISALPHA));
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return pg_u_isalpha(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
 	{
-		case PG_REGEX_STRATEGY_C:
-			return (c <= (pg_wchar) 127 &&
-					(pg_char_properties[c] & PG_ISALPHA));
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return pg_u_isalpha(c);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return iswalpha_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return iswalpha_l((wint_t) c, pg_regex_locale->info.lt);
+		else
 			return (c <= (pg_wchar) UCHAR_MAX &&
 					isalpha_l((unsigned char) c, pg_regex_locale->info.lt));
-			break;
-		case PG_REGEX_STRATEGY_ICU:
+	}
 #ifdef USE_ICU
-			return u_isalpha(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_isalpha(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
 static int
 pg_wc_isalnum(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
+		return (c <= (pg_wchar) 127 && (pg_char_properties[c] & PG_ISALNUM));
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return pg_u_isalnum(c, true);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
 	{
-		case PG_REGEX_STRATEGY_C:
-			return (c <= (pg_wchar) 127 &&
-					(pg_char_properties[c] & PG_ISALNUM));
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return pg_u_isalnum(c, true);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return iswalnum_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return iswalnum_l((wint_t) c, pg_regex_locale->info.lt);
+		else
 			return (c <= (pg_wchar) UCHAR_MAX &&
 					isalnum_l((unsigned char) c, pg_regex_locale->info.lt));
-			break;
-		case PG_REGEX_STRATEGY_ICU:
+	}
 #ifdef USE_ICU
-			return u_isalnum(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_isalnum(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
@@ -391,218 +342,206 @@ pg_wc_isword(pg_wchar c)
 static int
 pg_wc_isupper(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
+		return (c <= (pg_wchar) 127 && (pg_char_properties[c] & PG_ISUPPER));
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return pg_u_isupper(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
 	{
-		case PG_REGEX_STRATEGY_C:
-			return (c <= (pg_wchar) 127 &&
-					(pg_char_properties[c] & PG_ISUPPER));
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return pg_u_isupper(c);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return iswupper_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return iswupper_l((wint_t) c, pg_regex_locale->info.lt);
+		else
 			return (c <= (pg_wchar) UCHAR_MAX &&
 					isupper_l((unsigned char) c, pg_regex_locale->info.lt));
-			break;
-		case PG_REGEX_STRATEGY_ICU:
+	}
 #ifdef USE_ICU
-			return u_isupper(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_isupper(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
 static int
 pg_wc_islower(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
+		return (c <= (pg_wchar) 127 && (pg_char_properties[c] & PG_ISLOWER));
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return pg_u_islower(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
 	{
-		case PG_REGEX_STRATEGY_C:
-			return (c <= (pg_wchar) 127 &&
-					(pg_char_properties[c] & PG_ISLOWER));
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return pg_u_islower(c);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return iswlower_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return iswlower_l((wint_t) c, pg_regex_locale->info.lt);
+		else
 			return (c <= (pg_wchar) UCHAR_MAX &&
 					islower_l((unsigned char) c, pg_regex_locale->info.lt));
-			break;
-		case PG_REGEX_STRATEGY_ICU:
+	}
 #ifdef USE_ICU
-			return u_islower(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_islower(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
 static int
 pg_wc_isgraph(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
+		return (c <= (pg_wchar) 127 && (pg_char_properties[c] & PG_ISGRAPH));
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return pg_u_isgraph(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
 	{
-		case PG_REGEX_STRATEGY_C:
-			return (c <= (pg_wchar) 127 &&
-					(pg_char_properties[c] & PG_ISGRAPH));
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return pg_u_isgraph(c);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return iswgraph_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return iswgraph_l((wint_t) c, pg_regex_locale->info.lt);
+		else
 			return (c <= (pg_wchar) UCHAR_MAX &&
 					isgraph_l((unsigned char) c, pg_regex_locale->info.lt));
-			break;
-		case PG_REGEX_STRATEGY_ICU:
+	}
 #ifdef USE_ICU
-			return u_isgraph(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_isgraph(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
 static int
 pg_wc_isprint(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
+		return (c <= (pg_wchar) 127 && (pg_char_properties[c] & PG_ISPRINT));
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return pg_u_isprint(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
 	{
-		case PG_REGEX_STRATEGY_C:
-			return (c <= (pg_wchar) 127 &&
-					(pg_char_properties[c] & PG_ISPRINT));
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return pg_u_isprint(c);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return iswprint_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return iswprint_l((wint_t) c, pg_regex_locale->info.lt);
+		else
 			return (c <= (pg_wchar) UCHAR_MAX &&
 					isprint_l((unsigned char) c, pg_regex_locale->info.lt));
-			break;
-		case PG_REGEX_STRATEGY_ICU:
+	}
 #ifdef USE_ICU
-			return u_isprint(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_isprint(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
 static int
 pg_wc_ispunct(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
+		return (c <= (pg_wchar) 127 && (pg_char_properties[c] & PG_ISPUNCT));
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return pg_u_ispunct(c, true);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
 	{
-		case PG_REGEX_STRATEGY_C:
-			return (c <= (pg_wchar) 127 &&
-					(pg_char_properties[c] & PG_ISPUNCT));
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return pg_u_ispunct(c, true);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return iswpunct_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return iswpunct_l((wint_t) c, pg_regex_locale->info.lt);
+		else
 			return (c <= (pg_wchar) UCHAR_MAX &&
 					ispunct_l((unsigned char) c, pg_regex_locale->info.lt));
-			break;
-		case PG_REGEX_STRATEGY_ICU:
+	}
 #ifdef USE_ICU
-			return u_ispunct(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_ispunct(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
 static int
 pg_wc_isspace(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
+		return (c <= (pg_wchar) 127 && (pg_char_properties[c] & PG_ISSPACE));
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return pg_u_isspace(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
 	{
-		case PG_REGEX_STRATEGY_C:
-			return (c <= (pg_wchar) 127 &&
-					(pg_char_properties[c] & PG_ISSPACE));
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return pg_u_isspace(c);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return iswspace_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return iswspace_l((wint_t) c, pg_regex_locale->info.lt);
+		else
 			return (c <= (pg_wchar) UCHAR_MAX &&
 					isspace_l((unsigned char) c, pg_regex_locale->info.lt));
-			break;
-		case PG_REGEX_STRATEGY_ICU:
+	}
 #ifdef USE_ICU
-			return u_isspace(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_isspace(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
 static pg_wchar
 pg_wc_toupper(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
 	{
-		case PG_REGEX_STRATEGY_C:
-			if (c <= (pg_wchar) 127)
-				return pg_ascii_toupper((unsigned char) c);
-			return c;
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return unicode_uppercase_simple(c);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return towupper_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (c <= (pg_wchar) 127)
+			return pg_ascii_toupper((unsigned char) c);
+		return c;
+	}
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return unicode_uppercase_simple(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
+	{
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return towupper_l((wint_t) c, pg_regex_locale->info.lt);
+		else
+		{
 			if (c <= (pg_wchar) UCHAR_MAX)
 				return toupper_l((unsigned char) c, pg_regex_locale->info.lt);
 			return c;
-		case PG_REGEX_STRATEGY_ICU:
+		}
+	}
 #ifdef USE_ICU
-			return u_toupper(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_toupper(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
 static pg_wchar
 pg_wc_tolower(pg_wchar c)
 {
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
 	{
-		case PG_REGEX_STRATEGY_C:
-			if (c <= (pg_wchar) 127)
-				return pg_ascii_tolower((unsigned char) c);
-			return c;
-		case PG_REGEX_STRATEGY_BUILTIN:
-			return unicode_lowercase_simple(c);
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
-			if (sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF)
-				return towlower_l((wint_t) c, pg_regex_locale->info.lt);
-			/* FALL THRU */
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		if (c <= (pg_wchar) 127)
+			return pg_ascii_tolower((unsigned char) c);
+		return c;
+	}
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+		return unicode_lowercase_simple(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
+	{
+		if (GetDatabaseEncoding() == PG_UTF8 &&
+			(sizeof(wchar_t) >= 4 || c <= (pg_wchar) 0xFFFF))
+			return towlower_l((wint_t) c, pg_regex_locale->info.lt);
+		else
+		{
 			if (c <= (pg_wchar) UCHAR_MAX)
 				return tolower_l((unsigned char) c, pg_regex_locale->info.lt);
 			return c;
-		case PG_REGEX_STRATEGY_ICU:
+		}
+	}
 #ifdef USE_ICU
-			return u_tolower(c);
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+		return u_tolower(c);
 #endif
-			break;
-	}
+
 	return 0;					/* can't get here, but keep compiler quiet */
 }
 
@@ -729,37 +668,41 @@ pg_ctype_get_cache(pg_wc_probefunc probefunc, int cclasscode)
 	 * would always be true for production values of MAX_SIMPLE_CHR, but it's
 	 * useful to allow it to be small for testing purposes.)
 	 */
-	switch (pg_regex_strategy)
+	if (pg_regex_locale->ctype_is_c)
 	{
-		case PG_REGEX_STRATEGY_C:
 #if MAX_SIMPLE_CHR >= 127
-			max_chr = (pg_wchar) 127;
-			pcc->cv.cclasscode = -1;
+		max_chr = (pg_wchar) 127;
+		pcc->cv.cclasscode = -1;
 #else
-			max_chr = (pg_wchar) MAX_SIMPLE_CHR;
+		max_chr = (pg_wchar) MAX_SIMPLE_CHR;
 #endif
-			break;
-		case PG_REGEX_STRATEGY_BUILTIN:
-			max_chr = (pg_wchar) MAX_SIMPLE_CHR;
-			break;
-		case PG_REGEX_STRATEGY_LIBC_WIDE:
+	}
+	else if (pg_regex_locale->provider == COLLPROVIDER_BUILTIN)
+	{
+		max_chr = (pg_wchar) MAX_SIMPLE_CHR;
+	}
+	else if (pg_regex_locale->provider == COLLPROVIDER_LIBC)
+	{
+		if (GetDatabaseEncoding() == PG_UTF8)
 			max_chr = (pg_wchar) MAX_SIMPLE_CHR;
-			break;
-		case PG_REGEX_STRATEGY_LIBC_1BYTE:
+		else
+		{
 #if MAX_SIMPLE_CHR >= UCHAR_MAX
 			max_chr = (pg_wchar) UCHAR_MAX;
 			pcc->cv.cclasscode = -1;
 #else
 			max_chr = (pg_wchar) MAX_SIMPLE_CHR;
 #endif
-			break;
-		case PG_REGEX_STRATEGY_ICU:
-			max_chr = (pg_wchar) MAX_SIMPLE_CHR;
-			break;
-		default:
-			Assert(false);
-			max_chr = 0;		/* can't get here, but keep compiler quiet */
-			break;
+		}
+	}
+	else if (pg_regex_locale->provider == COLLPROVIDER_ICU)
+	{
+		max_chr = (pg_wchar) MAX_SIMPLE_CHR;
+	}
+	else
+	{
+		Assert(false);
+		max_chr = 0;			/* can't get here, but keep compiler quiet */
 	}
 
 	/*
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 2d4c870423a..94b041ec9e9 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1823,7 +1823,6 @@ PGTargetServerType
 PGTernaryBool
 PGTransactionStatusType
 PGVerbosity
-PG_Locale_Strategy
 PG_Lock_Status
 PG_init_t
 PGcancel
-- 
2.47.1