util/opt/lookup.c

   1 #ifndef NORCSID
   2 static char rcsid[] = "$Id: lookup.c,v 2.7 1994/06/24 10:40:10 ceriel Exp $";
   3 #endif
   4
   5 #include "param.h"
   6 #include "types.h"
   7 #include "tes.h"
   8 #include "lookup.h"
   9 #include "alloc.h"
  10 #include "proinf.h"
  11
  12 /*
  13  * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
  14  * See the copyright notice in the ACK home directory, in the file "Copyright".
  15  *
  16  * Author: Hans van Staveren
  17  */
  18
  19 extern char *strncpy();
  20
  21 unsigned hash(string) char *string; {
  22         register char *p;
  23         register unsigned i,sum;
  24
  25         for (sum=i=0,p=string;*p;i += 3)
  26                 sum ^= (*p++)<<(i&07);
  27         return(sum);
  28 }
  29
  30 sym_p symlookup(name,status,flags) char *name; int status,flags; {
  31         register sym_p *spp,sp;
  32         register i;
  33         static short genfrag = 32767;
  34
  35         spp = &symhash[hash(name)%NSYMHASH];
  36         while (*spp != (sym_p) 0)
  37                 if (strncmp((*spp)->s_name,name,IDL)==0) {
  38                         sp = *spp;
  39                         if ((sp->s_flags^flags)&SYMPRO)
  40                                 error("%s is both proc and datalabel",name);
  41                         if (status == DEFINING) {
  42                                 if (sp->s_flags&SYMDEF)
  43                                         error("redefined symbol %s",name);
  44                                 sp->s_flags |= SYMDEF;
  45                         }
  46                         return(sp);
  47                 } else
  48                         spp = &(*spp)->s_next;
  49
  50         /*
  51          * symbol not found, enter in table
  52          */
  53
  54         i = strlen(name) + 1;
  55         if (i & 1)
  56                 i++;
  57         if (i > IDL)
  58                 i = IDL;
  59         *spp = sp = newsym(i);
  60         strncpy(sp->s_name,name,i);
  61         sp->s_flags = flags;
  62         if (status == DEFINING)
  63                 sp->s_flags |= SYMDEF;
  64         sp->s_frag = genfrag--;
  65         return(sp);
  66 }
  67
  68 num_p numlookup(number) unsigned number; {
  69         register num_p *npp, np;
  70
  71         npp = &curpro.numhash[number%NNUMHASH];
  72         while (*npp != (num_p) 0)
  73                 if ((*npp)->n_number == number)
  74                         return(*npp);
  75                 else
  76                         npp = &(*npp)->n_next;
  77
  78         /*
  79          * local label not found, enter in tabel
  80          */
  81
  82         *npp = np = newnum();
  83         np->n_number = number;
  84         np->n_repl = np;
  85         return(np);
  86 }