diff options
Diffstat (limited to 'src/backend')
| -rw-r--r-- | src/backend/parser/gram.y | 16 | ||||
| -rw-r--r-- | src/backend/utils/adt/regexp.c | 85 |
2 files changed, 79 insertions, 22 deletions
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index c97bb367f8e..a954acf509e 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -13073,15 +13073,15 @@ a_expr: c_expr { $$ = $1; } | a_expr SIMILAR TO a_expr %prec SIMILAR { - FuncCall *n = makeFuncCall(SystemFuncName("similar_escape"), - list_make2($4, makeNullAConst(-1)), + FuncCall *n = makeFuncCall(SystemFuncName("similar_to_escape"), + list_make1($4), @2); $$ = (Node *) makeSimpleA_Expr(AEXPR_SIMILAR, "~", $1, (Node *) n, @2); } | a_expr SIMILAR TO a_expr ESCAPE a_expr %prec SIMILAR { - FuncCall *n = makeFuncCall(SystemFuncName("similar_escape"), + FuncCall *n = makeFuncCall(SystemFuncName("similar_to_escape"), list_make2($4, $6), @2); $$ = (Node *) makeSimpleA_Expr(AEXPR_SIMILAR, "~", @@ -13089,15 +13089,15 @@ a_expr: c_expr { $$ = $1; } } | a_expr NOT_LA SIMILAR TO a_expr %prec NOT_LA { - FuncCall *n = makeFuncCall(SystemFuncName("similar_escape"), - list_make2($5, makeNullAConst(-1)), + FuncCall *n = makeFuncCall(SystemFuncName("similar_to_escape"), + list_make1($5), @2); $$ = (Node *) makeSimpleA_Expr(AEXPR_SIMILAR, "!~", $1, (Node *) n, @2); } | a_expr NOT_LA SIMILAR TO a_expr ESCAPE a_expr %prec NOT_LA { - FuncCall *n = makeFuncCall(SystemFuncName("similar_escape"), + FuncCall *n = makeFuncCall(SystemFuncName("similar_to_escape"), list_make2($5, $7), @2); $$ = (Node *) makeSimpleA_Expr(AEXPR_SIMILAR, "!~", @@ -14323,9 +14323,9 @@ subquery_Op: | NOT_LA ILIKE { $$ = list_make1(makeString("!~~*")); } /* cannot put SIMILAR TO here, because SIMILAR TO is a hack. - * the regular expression is preprocessed by a function (similar_escape), + * the regular expression is preprocessed by a function (similar_to_escape), * and the ~ operator for posix regular expressions is used. - * x SIMILAR TO y -> x ~ similar_escape(y) + * x SIMILAR TO y -> x ~ similar_to_escape(y) * this transformation is made on the fly by the parser upwards. * however the SubLink structure which handles any/some/all stuff * is not ready for such a thing. diff --git a/src/backend/utils/adt/regexp.c b/src/backend/utils/adt/regexp.c index 90a9197792e..3d38aef820c 100644 --- a/src/backend/utils/adt/regexp.c +++ b/src/backend/utils/adt/regexp.c @@ -654,15 +654,18 @@ textregexreplace(PG_FUNCTION_ARGS) } /* - * similar_escape() - * Convert a SQL:2008 regexp pattern to POSIX style, so it can be used by - * our regexp engine. + * similar_to_escape(), similar_escape() + * + * Convert a SQL "SIMILAR TO" regexp pattern to POSIX style, so it can be + * used by our regexp engine. + * + * similar_escape_internal() is the common workhorse for three SQL-exposed + * functions. esc_text can be passed as NULL to select the default escape + * (which is '\'), or as an empty string to select no escape character. */ -Datum -similar_escape(PG_FUNCTION_ARGS) +static text * +similar_escape_internal(text *pat_text, text *esc_text) { - text *pat_text; - text *esc_text; text *result; char *p, *e, @@ -673,13 +676,9 @@ similar_escape(PG_FUNCTION_ARGS) bool incharclass = false; int nquotes = 0; - /* This function is not strict, so must test explicitly */ - if (PG_ARGISNULL(0)) - PG_RETURN_NULL(); - pat_text = PG_GETARG_TEXT_PP(0); p = VARDATA_ANY(pat_text); plen = VARSIZE_ANY_EXHDR(pat_text); - if (PG_ARGISNULL(1)) + if (esc_text == NULL) { /* No ESCAPE clause provided; default to backslash as escape */ e = "\\"; @@ -687,12 +686,11 @@ similar_escape(PG_FUNCTION_ARGS) } else { - esc_text = PG_GETARG_TEXT_PP(1); e = VARDATA_ANY(esc_text); elen = VARSIZE_ANY_EXHDR(esc_text); if (elen == 0) e = NULL; /* no escape character */ - else + else if (elen > 1) { int escape_mblen = pg_mbstrlen_with_len(e, elen); @@ -898,6 +896,65 @@ similar_escape(PG_FUNCTION_ARGS) SET_VARSIZE(result, r - ((char *) result)); + return result; +} + +/* + * similar_to_escape(pattern, escape) + */ +Datum +similar_to_escape_2(PG_FUNCTION_ARGS) +{ + text *pat_text = PG_GETARG_TEXT_PP(0); + text *esc_text = PG_GETARG_TEXT_PP(1); + text *result; + + result = similar_escape_internal(pat_text, esc_text); + + PG_RETURN_TEXT_P(result); +} + +/* + * similar_to_escape(pattern) + * Inserts a default escape character. + */ +Datum +similar_to_escape_1(PG_FUNCTION_ARGS) +{ + text *pat_text = PG_GETARG_TEXT_PP(0); + text *result; + + result = similar_escape_internal(pat_text, NULL); + + PG_RETURN_TEXT_P(result); +} + +/* + * similar_escape(pattern, escape) + * + * Legacy function for compatibility with views stored using the + * pre-v13 expansion of SIMILAR TO. Unlike the above functions, this + * is non-strict, which leads to not-per-spec handling of "ESCAPE NULL". + */ +Datum +similar_escape(PG_FUNCTION_ARGS) +{ + text *pat_text; + text *esc_text; + text *result; + + /* This function is not strict, so must test explicitly */ + if (PG_ARGISNULL(0)) + PG_RETURN_NULL(); + pat_text = PG_GETARG_TEXT_PP(0); + + if (PG_ARGISNULL(1)) + esc_text = NULL; /* use default escape character */ + else + esc_text = PG_GETARG_TEXT_PP(1); + + result = similar_escape_internal(pat_text, esc_text); + PG_RETURN_TEXT_P(result); } |