On Mon, 2025-04-14 at 13:44 -0700, Noah Misch wrote:
> v18 regc_pg_locale.c uses only the locale_t-extended forms, and it
> aims not to
> depend on LC_CTYPE. v17 used both tolower() and tolower_l(), but v18
> uses the
> latter only.
Fixed in v2-0001 by rewording the comment slightly.
>
> However, I think v17's
> concept of separate PG_REGEX_ symbols for the default-locale case is
> still the
> right thing for v18. In other words, this code should change to look
> more
> like v17, with the removal of non-locale_t calls being the main
> change.
I tried that in v2-0003, but I think it ended up worse. Most
pg_wc_xyz() functions don't care if it's the default collation or not,
so there are a lot of duplicate cases.
The previous approach is still there as v2-0002.
Regrads,
Jeff Davis
From 9724181f715ce3468e9342763fadde450db08d26 Mon Sep 17 00:00:00 2001
From: Jeff Davis <[email protected]>
Date: Tue, 15 Apr 2025 15:04:37 -0700
Subject: [PATCH v2 1/3] Improve comment in regc_pg_locale.c.
Reported-by: Noah Misch <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
src/backend/regex/regc_pg_locale.c | 29 +++++++++++++----------------
1 file changed, 13 insertions(+), 16 deletions(-)
diff --git a/src/backend/regex/regc_pg_locale.c b/src/backend/regex/regc_pg_locale.c
index ed7411df83d..31d8ba0322a 100644
--- a/src/backend/regex/regc_pg_locale.c
+++ b/src/backend/regex/regc_pg_locale.c
@@ -21,22 +21,22 @@
#include "utils/pg_locale.h"
/*
- * To provide as much functionality as possible on a variety of platforms,
- * without going so far as to implement everything from scratch, we use
- * several implementation strategies depending on the situation:
+ * For the libc provider, to provide as much functionality as possible on a
+ * variety of platforms without going so far as to implement everything from
+ * scratch, we use several implementation strategies depending on the
+ * situation:
*
* 1. In C/POSIX collations, we use hard-wired code. We can't depend on
* the <ctype.h> functions since those will obey LC_CTYPE. Note that these
* collations don't give a fig about multibyte characters.
*
- * 2. In the "default" collation (which is supposed to obey LC_CTYPE):
- *
- * 2a. When working in UTF8 encoding, we use the <wctype.h> functions.
+ * 2. When working in UTF8 encoding, we use the <wctype.h> functions.
* This assumes that every platform uses Unicode codepoints directly
- * as the wchar_t representation of Unicode. On some platforms
+ * as the wchar_t representation of Unicode. (XXX: ICU makes this assumption
+ * even for non-UTF8 encodings, which may be a problem.) On some platforms
* wchar_t is only 16 bits wide, so we have to punt for codepoints > 0xFFFF.
*
- * 2b. In all other encodings, we use the <ctype.h> functions for pg_wchar
+ * 3. In all other encodings, we use the <ctype.h> functions for pg_wchar
* values up to 255, and punt for values above that. This is 100% correct
* only in single-byte encodings such as LATINn. However, non-Unicode
* multibyte encodings are mostly Far Eastern character sets for which the
@@ -46,14 +46,11 @@
* the platform's wchar_t representation matches what we do in pg_wchar
* conversions.
*
- * 3. Here, we use the locale_t-extended forms of the <wctype.h> and <ctype.h>
- * functions, under exactly the same cases as #2.
- *
- * There is one notable difference between cases 2 and 3: in the "default"
- * collation we force ASCII letters to follow ASCII upcase/downcase rules,
- * while in a non-default collation we just let the library functions do what
- * they will. The case where this matters is treatment of I/i in Turkish,
- * and the behavior is meant to match the upper()/lower() SQL functions.
+ * As a special case, in the "default" collation we force ASCII letters to
+ * follow ASCII upcase/downcase rules, while in a non-default collation we
+ * just let the library functions do what they will. The case where this
+ * matters is treatment of I/i in Turkish, and the behavior is meant to match
+ * the upper()/lower() SQL functions.
*
* We store the active collation setting in static variables. In principle
* it could be passed down to here via the regex library's "struct vars" data
--
2.34.1
From d7e18174cb25fc981ba906101c3f4582fc41a826 Mon Sep 17 00:00:00 2001
From: Jeff Davis <[email protected]>
Date: Tue, 15 Apr 2025 15:05:08 -0700
Subject: [PATCH v2 2/3] Another unintentional behavior change in commit
e9931bfb75.
Reported-by: Noah Misch <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
src/backend/regex/regc_pg_locale.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/src/backend/regex/regc_pg_locale.c b/src/backend/regex/regc_pg_locale.c
index 31d8ba0322a..7377f459607 100644
--- a/src/backend/regex/regc_pg_locale.c
+++ b/src/backend/regex/regc_pg_locale.c
@@ -559,10 +559,16 @@ pg_wc_toupper(pg_wchar c)
case PG_REGEX_STRATEGY_BUILTIN:
return unicode_uppercase_simple(c);
case PG_REGEX_STRATEGY_LIBC_WIDE:
+ /* force C behavior for ASCII characters, per comments above */
+ if (pg_regex_locale->is_default && c <= (pg_wchar) 127)
+ return pg_ascii_toupper((unsigned char) c);
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:
+ /* force C behavior for ASCII characters, per comments above */
+ if (pg_regex_locale->is_default && c <= (pg_wchar) 127)
+ return pg_ascii_toupper((unsigned char) c);
if (c <= (pg_wchar) UCHAR_MAX)
return toupper_l((unsigned char) c, pg_regex_locale->info.lt);
return c;
@@ -587,10 +593,16 @@ pg_wc_tolower(pg_wchar c)
case PG_REGEX_STRATEGY_BUILTIN:
return unicode_lowercase_simple(c);
case PG_REGEX_STRATEGY_LIBC_WIDE:
+ /* force C behavior for ASCII characters, per comments above */
+ if (pg_regex_locale->is_default && c <= (pg_wchar) 127)
+ return pg_ascii_tolower((unsigned char) c);
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:
+ /* force C behavior for ASCII characters, per comments above */
+ if (pg_regex_locale->is_default && c <= (pg_wchar) 127)
+ return pg_ascii_tolower((unsigned char) c);
if (c <= (pg_wchar) UCHAR_MAX)
return tolower_l((unsigned char) c, pg_regex_locale->info.lt);
return c;
--
2.34.1
From 280929ad8f70106be7bc4d59d90957ecf86a421c Mon Sep 17 00:00:00 2001
From: Jeff Davis <[email protected]>
Date: Tue, 15 Apr 2025 15:49:44 -0700
Subject: [PATCH v2 3/3] alternative approach
---
src/backend/regex/regc_pg_locale.c | 60 +++++++++++++++++++++++++-----
1 file changed, 50 insertions(+), 10 deletions(-)
diff --git a/src/backend/regex/regc_pg_locale.c b/src/backend/regex/regc_pg_locale.c
index 7377f459607..ec9bb8e460b 100644
--- a/src/backend/regex/regc_pg_locale.c
+++ b/src/backend/regex/regc_pg_locale.c
@@ -64,6 +64,8 @@ typedef enum
{
PG_REGEX_STRATEGY_C, /* C locale (encoding independent) */
PG_REGEX_STRATEGY_BUILTIN, /* built-in Unicode semantics */
+ PG_REGEX_STRATEGY_DEF_WIDE, /* libc default, locale_t <wctype.h> functions */
+ PG_REGEX_STRATEGY_DEF_1BYTE, /* libc default, locale_t <ctype.h> functions */
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 */
@@ -285,9 +287,19 @@ pg_set_regex_collation(Oid collation)
{
Assert(locale->provider == COLLPROVIDER_LIBC);
if (GetDatabaseEncoding() == PG_UTF8)
- strategy = PG_REGEX_STRATEGY_LIBC_WIDE;
+ {
+ if (locale->is_default)
+ strategy = PG_REGEX_STRATEGY_DEF_WIDE;
+ else
+ strategy = PG_REGEX_STRATEGY_LIBC_WIDE;
+ }
else
- strategy = PG_REGEX_STRATEGY_LIBC_1BYTE;
+ {
+ if (locale->is_default)
+ strategy = PG_REGEX_STRATEGY_DEF_1BYTE;
+ else
+ strategy = PG_REGEX_STRATEGY_LIBC_1BYTE;
+ }
}
}
@@ -305,10 +317,12 @@ pg_wc_isdigit(pg_wchar c)
(pg_char_properties[c] & PG_ISDIGIT));
case PG_REGEX_STRATEGY_BUILTIN:
return pg_u_isdigit(c, !pg_regex_locale->info.builtin.casemap_full);
+ case PG_REGEX_STRATEGY_DEF_WIDE:
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_DEF_1BYTE:
case PG_REGEX_STRATEGY_LIBC_1BYTE:
return (c <= (pg_wchar) UCHAR_MAX &&
isdigit_l((unsigned char) c, pg_regex_locale->info.lt));
@@ -332,10 +346,12 @@ pg_wc_isalpha(pg_wchar c)
(pg_char_properties[c] & PG_ISALPHA));
case PG_REGEX_STRATEGY_BUILTIN:
return pg_u_isalpha(c);
+ case PG_REGEX_STRATEGY_DEF_WIDE:
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_DEF_1BYTE:
case PG_REGEX_STRATEGY_LIBC_1BYTE:
return (c <= (pg_wchar) UCHAR_MAX &&
isalpha_l((unsigned char) c, pg_regex_locale->info.lt));
@@ -359,10 +375,12 @@ pg_wc_isalnum(pg_wchar c)
(pg_char_properties[c] & PG_ISALNUM));
case PG_REGEX_STRATEGY_BUILTIN:
return pg_u_isalnum(c, !pg_regex_locale->info.builtin.casemap_full);
+ case PG_REGEX_STRATEGY_DEF_WIDE:
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_DEF_1BYTE:
case PG_REGEX_STRATEGY_LIBC_1BYTE:
return (c <= (pg_wchar) UCHAR_MAX &&
isalnum_l((unsigned char) c, pg_regex_locale->info.lt));
@@ -395,10 +413,12 @@ pg_wc_isupper(pg_wchar c)
(pg_char_properties[c] & PG_ISUPPER));
case PG_REGEX_STRATEGY_BUILTIN:
return pg_u_isupper(c);
+ case PG_REGEX_STRATEGY_DEF_WIDE:
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_DEF_1BYTE:
case PG_REGEX_STRATEGY_LIBC_1BYTE:
return (c <= (pg_wchar) UCHAR_MAX &&
isupper_l((unsigned char) c, pg_regex_locale->info.lt));
@@ -422,10 +442,12 @@ pg_wc_islower(pg_wchar c)
(pg_char_properties[c] & PG_ISLOWER));
case PG_REGEX_STRATEGY_BUILTIN:
return pg_u_islower(c);
+ case PG_REGEX_STRATEGY_DEF_WIDE:
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_DEF_1BYTE:
case PG_REGEX_STRATEGY_LIBC_1BYTE:
return (c <= (pg_wchar) UCHAR_MAX &&
islower_l((unsigned char) c, pg_regex_locale->info.lt));
@@ -449,10 +471,12 @@ pg_wc_isgraph(pg_wchar c)
(pg_char_properties[c] & PG_ISGRAPH));
case PG_REGEX_STRATEGY_BUILTIN:
return pg_u_isgraph(c);
+ case PG_REGEX_STRATEGY_DEF_WIDE:
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_DEF_1BYTE:
case PG_REGEX_STRATEGY_LIBC_1BYTE:
return (c <= (pg_wchar) UCHAR_MAX &&
isgraph_l((unsigned char) c, pg_regex_locale->info.lt));
@@ -476,10 +500,12 @@ pg_wc_isprint(pg_wchar c)
(pg_char_properties[c] & PG_ISPRINT));
case PG_REGEX_STRATEGY_BUILTIN:
return pg_u_isprint(c);
+ case PG_REGEX_STRATEGY_DEF_WIDE:
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_DEF_1BYTE:
case PG_REGEX_STRATEGY_LIBC_1BYTE:
return (c <= (pg_wchar) UCHAR_MAX &&
isprint_l((unsigned char) c, pg_regex_locale->info.lt));
@@ -503,10 +529,12 @@ pg_wc_ispunct(pg_wchar c)
(pg_char_properties[c] & PG_ISPUNCT));
case PG_REGEX_STRATEGY_BUILTIN:
return pg_u_ispunct(c, !pg_regex_locale->info.builtin.casemap_full);
+ case PG_REGEX_STRATEGY_DEF_WIDE:
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_DEF_1BYTE:
case PG_REGEX_STRATEGY_LIBC_1BYTE:
return (c <= (pg_wchar) UCHAR_MAX &&
ispunct_l((unsigned char) c, pg_regex_locale->info.lt));
@@ -530,10 +558,12 @@ pg_wc_isspace(pg_wchar c)
(pg_char_properties[c] & PG_ISSPACE));
case PG_REGEX_STRATEGY_BUILTIN:
return pg_u_isspace(c);
+ case PG_REGEX_STRATEGY_DEF_WIDE:
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_DEF_1BYTE:
case PG_REGEX_STRATEGY_LIBC_1BYTE:
return (c <= (pg_wchar) UCHAR_MAX &&
isspace_l((unsigned char) c, pg_regex_locale->info.lt));
@@ -558,17 +588,21 @@ pg_wc_toupper(pg_wchar c)
return c;
case PG_REGEX_STRATEGY_BUILTIN:
return unicode_uppercase_simple(c);
- case PG_REGEX_STRATEGY_LIBC_WIDE:
+ case PG_REGEX_STRATEGY_DEF_WIDE:
/* force C behavior for ASCII characters, per comments above */
- if (pg_regex_locale->is_default && c <= (pg_wchar) 127)
+ if (c <= (pg_wchar) 127)
return pg_ascii_toupper((unsigned char) c);
+ /* FALL THRU */
+ 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:
+ case PG_REGEX_STRATEGY_DEF_1BYTE:
/* force C behavior for ASCII characters, per comments above */
- if (pg_regex_locale->is_default && c <= (pg_wchar) 127)
+ if (c <= (pg_wchar) 127)
return pg_ascii_toupper((unsigned char) c);
+ /* FALL THRU */
+ case PG_REGEX_STRATEGY_LIBC_1BYTE:
if (c <= (pg_wchar) UCHAR_MAX)
return toupper_l((unsigned char) c, pg_regex_locale->info.lt);
return c;
@@ -592,17 +626,21 @@ pg_wc_tolower(pg_wchar c)
return c;
case PG_REGEX_STRATEGY_BUILTIN:
return unicode_lowercase_simple(c);
- case PG_REGEX_STRATEGY_LIBC_WIDE:
+ case PG_REGEX_STRATEGY_DEF_WIDE:
/* force C behavior for ASCII characters, per comments above */
- if (pg_regex_locale->is_default && c <= (pg_wchar) 127)
+ if (c <= (pg_wchar) 127)
return pg_ascii_tolower((unsigned char) c);
+ /* FALL THRU */
+ 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:
+ case PG_REGEX_STRATEGY_DEF_1BYTE:
/* force C behavior for ASCII characters, per comments above */
- if (pg_regex_locale->is_default && c <= (pg_wchar) 127)
+ if (c <= (pg_wchar) 127)
return pg_ascii_tolower((unsigned char) c);
+ /* FALL THRU */
+ case PG_REGEX_STRATEGY_LIBC_1BYTE:
if (c <= (pg_wchar) UCHAR_MAX)
return tolower_l((unsigned char) c, pg_regex_locale->info.lt);
return c;
@@ -751,9 +789,11 @@ pg_ctype_get_cache(pg_wc_probefunc probefunc, int cclasscode)
case PG_REGEX_STRATEGY_BUILTIN:
max_chr = (pg_wchar) MAX_SIMPLE_CHR;
break;
+ case PG_REGEX_STRATEGY_DEF_WIDE:
case PG_REGEX_STRATEGY_LIBC_WIDE:
max_chr = (pg_wchar) MAX_SIMPLE_CHR;
break;
+ case PG_REGEX_STRATEGY_DEF_1BYTE:
case PG_REGEX_STRATEGY_LIBC_1BYTE:
#if MAX_SIMPLE_CHR >= UCHAR_MAX
max_chr = (pg_wchar) UCHAR_MAX;
--
2.34.1
