c_keywords.c

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/*-------------------------------------------------------------------------
 *
 * c_keywords.c
 *    lexical token lookup for reserved words in postgres embedded SQL
 *
 * src/interfaces/ecpg/preproc/c_keywords.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres_fe.h"
 
/* ScanKeywordList lookup data for C keywords */
#include "c_kwlist_d.h"
#include "preproc_extern.h"
#include "preproc.h"
 
/* Token codes for C keywords */
#define PG_KEYWORD(kwname, value) value,
 
static const uint16 ScanCKeywordTokens[] = {
#include "c_kwlist.h"
};
 
#undef PG_KEYWORD
 
 
/*
 * ScanCKeywordLookup - see if a given word is a keyword
 *
 * Returns the token value of the keyword, or -1 if no match.
 *
 * Do a hash search using plain strcmp() comparison.  This is much like
 * ScanKeywordLookup(), except we want case-sensitive matching.
 */
int
ScanCKeywordLookup(const char *text)
{
    size_t      len;
    int         h;
    const char *kw;
 
    /*
     * Reject immediately if too long to be any keyword.  This saves useless
     * hashing work on long strings.
     */
    len = strlen(text);
    if (len > ScanCKeywords.max_kw_len)
        return -1;
 
    /*
     * Compute the hash function.  Since it's a perfect hash, we need only
     * match to the specific keyword it identifies.
     */
    h = ScanCKeywords_hash_func(text, len);
 
    /* An out-of-range result implies no match */
    if (h < 0 || h >= ScanCKeywords.num_keywords)
        return -1;
 
    kw = GetScanKeyword(h, &ScanCKeywords);
 
    if (strcmp(kw, text) == 0)
        return ScanCKeywordTokens[h];
 
    return -1;
}