TLA  Line data    Source code

       1                 : /*-------------------------------------------------------------------------
       2                 :  *
       3                 :  * c_keywords.c
       4                 :  *    lexical token lookup for reserved words in postgres embedded SQL
       5                 :  *
       6                 :  * src/interfaces/ecpg/preproc/c_keywords.c
       7                 :  *
       8                 :  *-------------------------------------------------------------------------
       9                 :  */
      10                 : #include "postgres_fe.h"
      11                 : 
      12                 : /* ScanKeywordList lookup data for C keywords */
      13                 : #include "c_kwlist_d.h"
      14                 : #include "preproc_extern.h"
      15                 : #include "preproc.h"
      16                 : 
      17                 : /* Token codes for C keywords */
      18                 : #define PG_KEYWORD(kwname, value) value,
      19                 : 
      20                 : static const uint16 ScanCKeywordTokens[] = {
      21                 : #include "c_kwlist.h"
      22                 : };
      23                 : 
      24                 : #undef PG_KEYWORD
      25                 : 
      26                 : 
      27                 : /*
      28                 :  * ScanCKeywordLookup - see if a given word is a keyword
      29                 :  *
      30                 :  * Returns the token value of the keyword, or -1 if no match.
      31                 :  *
      32                 :  * Do a hash search using plain strcmp() comparison.  This is much like
      33                 :  * ScanKeywordLookup(), except we want case-sensitive matching.
      34                 :  */
      35                 : int
      36 GNC        9865 : ScanCKeywordLookup(const char *text)
      37                 : {
      38                 :     size_t      len;
      39                 :     int         h;
      40                 :     const char *kw;
      41                 : 
      42                 :     /*
      43                 :      * Reject immediately if too long to be any keyword.  This saves useless
      44                 :      * hashing work on long strings.
      45                 :      */
      46            9865 :     len = strlen(text);
      47 CBC        9865 :     if (len > ScanCKeywords.max_kw_len)
      48            1348 :         return -1;
      49                 : 
      50                 :     /*
      51                 :      * Compute the hash function.  Since it's a perfect hash, we need only
      52                 :      * match to the specific keyword it identifies.
      53                 :      */
      54 GNC        8517 :     h = ScanCKeywords_hash_func(text, len);
      55                 : 
      56                 :     /* An out-of-range result implies no match */
      57 CBC        8517 :     if (h < 0 || h >= ScanCKeywords.num_keywords)
      58            4813 :         return -1;
      59                 : 
      60            3704 :     kw = GetScanKeyword(h, &ScanCKeywords);
      61                 : 
      62 GNC        3704 :     if (strcmp(kw, text) == 0)
      63 CBC         908 :         return ScanCKeywordTokens[h];
      64                 : 
      65            2796 :     return -1;
      66                 : }