128 lines
3.5 KiB
C
128 lines
3.5 KiB
C
/*-------------------------------------------------------------------------
|
|
*
|
|
* scansup.c
|
|
* scanner support routines used by the core lexer
|
|
*
|
|
* Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
|
|
* Portions Copyright (c) 1994, Regents of the University of California
|
|
*
|
|
*
|
|
* IDENTIFICATION
|
|
* src/backend/parser/scansup.c
|
|
*
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
#include "postgres.h"
|
|
|
|
#include <ctype.h>
|
|
|
|
#include "mb/pg_wchar.h"
|
|
#include "parser/scansup.h"
|
|
|
|
|
|
/*
|
|
* downcase_truncate_identifier() --- do appropriate downcasing and
|
|
* truncation of an unquoted identifier. Optionally warn of truncation.
|
|
*
|
|
* Returns a palloc'd string containing the adjusted identifier.
|
|
*
|
|
* Note: in some usages the passed string is not null-terminated.
|
|
*
|
|
* Note: the API of this function is designed to allow for downcasing
|
|
* transformations that increase the string length, but we don't yet
|
|
* support that. If you want to implement it, you'll need to fix
|
|
* SplitIdentifierString() in utils/adt/varlena.c.
|
|
*/
|
|
char *
|
|
downcase_truncate_identifier(const char *ident, int len, bool warn)
|
|
{
|
|
return downcase_identifier(ident, len, warn, true);
|
|
}
|
|
|
|
/*
|
|
* a workhorse for downcase_truncate_identifier
|
|
*/
|
|
char *
|
|
downcase_identifier(const char *ident, int len, bool warn, bool truncate)
|
|
{
|
|
char *result;
|
|
int i;
|
|
bool enc_is_single_byte;
|
|
|
|
result = palloc(len + 1);
|
|
enc_is_single_byte = pg_database_encoding_max_length() == 1;
|
|
|
|
/*
|
|
* SQL99 specifies Unicode-aware case normalization, which we don't yet
|
|
* have the infrastructure for. Instead we use tolower() to provide a
|
|
* locale-aware translation. However, there are some locales where this
|
|
* is not right either (eg, Turkish may do strange things with 'i' and
|
|
* 'I'). Our current compromise is to use tolower() for characters with
|
|
* the high bit set, as long as they aren't part of a multi-byte
|
|
* character, and use an ASCII-only downcasing for 7-bit characters.
|
|
*/
|
|
for (i = 0; i < len; i++)
|
|
{
|
|
unsigned char ch = (unsigned char) ident[i];
|
|
|
|
if (ch >= 'A' && ch <= 'Z')
|
|
ch += 'a' - 'A';
|
|
else if (enc_is_single_byte && IS_HIGHBIT_SET(ch) && isupper(ch))
|
|
ch = tolower(ch);
|
|
result[i] = (char) ch;
|
|
}
|
|
result[i] = '\0';
|
|
|
|
if (i >= NAMEDATALEN && truncate)
|
|
truncate_identifier(result, i, warn);
|
|
|
|
return result;
|
|
}
|
|
|
|
|
|
/*
|
|
* truncate_identifier() --- truncate an identifier to NAMEDATALEN-1 bytes.
|
|
*
|
|
* The given string is modified in-place, if necessary. A warning is
|
|
* issued if requested.
|
|
*
|
|
* We require the caller to pass in the string length since this saves a
|
|
* strlen() call in some common usages.
|
|
*/
|
|
void
|
|
truncate_identifier(char *ident, int len, bool warn)
|
|
{
|
|
if (len >= NAMEDATALEN)
|
|
{
|
|
len = pg_mbcliplen(ident, len, NAMEDATALEN - 1);
|
|
if (warn)
|
|
ereport(NOTICE,
|
|
(errcode(ERRCODE_NAME_TOO_LONG),
|
|
errmsg("identifier \"%s\" will be truncated to \"%.*s\"",
|
|
ident, len, ident)));
|
|
ident[len] = '\0';
|
|
}
|
|
}
|
|
|
|
/*
|
|
* scanner_isspace() --- return true if flex scanner considers char whitespace
|
|
*
|
|
* This should be used instead of the potentially locale-dependent isspace()
|
|
* function when it's important to match the lexer's behavior.
|
|
*
|
|
* In principle we might need similar functions for isalnum etc, but for the
|
|
* moment only isspace seems needed.
|
|
*/
|
|
bool
|
|
scanner_isspace(char ch)
|
|
{
|
|
/* This must match scan.l's list of {space} characters */
|
|
if (ch == ' ' ||
|
|
ch == '\t' ||
|
|
ch == '\n' ||
|
|
ch == '\r' ||
|
|
ch == '\f')
|
|
return true;
|
|
return false;
|
|
}
|