xref: /csrg-svn/usr.sbin/sendmail/src/stab.c (revision 4151)
1 # include "sendmail.h"
2 
3 static char SccsId[] = "@(#)stab.c	3.7	08/17/81";
4 
5 /*
6 **  STAB -- manage the symbol table
7 **
8 **	Parameters:
9 **		name -- the name to be looked up or inserted.
10 **		type -- the type of symbol.
11 **		op -- what to do:
12 **			ST_ENTER -- enter the name if not
13 **				already present.
14 **			ST_FIND -- find it only.
15 **
16 **	Returns:
17 **		pointer to a STAB entry for this name.
18 **		NULL if not found and not entered.
19 **
20 **	Side Effects:
21 **		can update the symbol table.
22 */
23 
24 # define STABSIZE	400
25 
26 static STAB	*SymTab[STABSIZE];
27 
28 STAB *
29 stab(name, type, op)
30 	char *name;
31 	int type;
32 	int op;
33 {
34 	register STAB *s;
35 	register STAB **ps;
36 	extern bool sameword();
37 	register int hfunc;
38 	register char *p;
39 
40 # ifdef DEBUG
41 	if (Debug > 4)
42 		printf("STAB: %s %d ", name, type);
43 # endif DEBUG
44 
45 	/*
46 	**  Compute the hashing function
47 	**
48 	**	We could probably do better....
49 	*/
50 
51 	hfunc = type;
52 	for (p = name; *p != '\0'; p++)
53 		hfunc = ((hfunc << 7) | lower(*p)) % STABSIZE;
54 
55 # ifdef DEBUG
56 	if (Debug > 15)
57 		printf("(hfunc=%d) ", hfunc);
58 # endif DEBUG
59 
60 	ps = &SymTab[hfunc];
61 	while ((s = *ps) != NULL && (!sameword(name, s->s_name) || s->s_type != type))
62 	{
63 		ps = &s->s_next;
64 		s = s->s_next;
65 	}
66 
67 	/*
68 	**  Dispose of the entry.
69 	*/
70 
71 	if (s != NULL || op == ST_FIND)
72 	{
73 # ifdef DEBUG
74 		if (Debug > 4)
75 		{
76 			if (s == NULL)
77 				printf("not found\n");
78 			else
79 				printf("type %d val %x\n", s->s_type, s->s_class);
80 		}
81 # endif DEBUG
82 		return (s);
83 	}
84 
85 	/*
86 	**  Make a new entry and link it in.
87 	*/
88 
89 # ifdef DEBUG
90 	if (Debug > 4)
91 		printf("entered\n");
92 # endif DEBUG
93 
94 	/* make new entry */
95 	s = (STAB *) xalloc(sizeof *s);
96 	clear((char *) s, sizeof *s);
97 	s->s_name = newstr(name);
98 	makelower(s->s_name);
99 	s->s_type = type;
100 
101 	/* link it in */
102 	*ps = s;
103 
104 	return (s);
105 }
106