1 #include	<stdio.h>
2 #include	<ctype.h>
3 #include	"pic.h"
4 #include	"y.tab.h"
5 
6 YYSTYPE
7 getvar(char *s)	/* return value of variable s (usually pointer) */
8 {
9 	struct symtab *p;
10 	static YYSTYPE bug;
11 
12 	p = lookup(s);
13 	if (p == NULL) {
14 		if (islower(s[0]))
15 			ERROR "no such variable as %s", s WARNING;
16 		else
17 			ERROR "no such place as %s", s WARNING;
18 		return(bug);
19 	}
20 	return(p->s_val);
21 }
22 
23 double
24 getfval(char *s)	/* return float value of variable s */
25 {
26 	YYSTYPE y;
27 
28 	y = getvar(s);
29 	return y.f;
30 }
31 
32 void
33 setfval(char *s, double f)	/* set variable s to f */
34 {
35 	struct symtab *p;
36 
37 	if ((p = lookup(s)) != NULL)
38 		p->s_val.f = f;
39 }
40 
41 struct symtab*
42 makevar(char *s, int t, YYSTYPE v)	/* make variable named s in table */
43 		/* assumes s is static or from tostring */
44 {
45 	struct symtab *p;
46 
47 	for (p = stack[nstack].p_symtab; p != NULL; p = p->s_next)
48 		if (strcmp(s, p->s_name) == 0)
49 			break;
50 	if (p == NULL) {	/* it's a new one */
51 		p = (struct symtab *) malloc(sizeof(struct symtab));
52 		if (p == NULL)
53 			ERROR "out of symtab space with %s", s FATAL;
54 		p->s_next = stack[nstack].p_symtab;
55 		stack[nstack].p_symtab = p;	/* stick it at front */
56 	}
57 	p->s_name = s;
58 	p->s_type = t;
59 	p->s_val = v;
60 	return(p);
61 }
62 
63 struct symtab*
64 lookup(char *s)	/* find s in symtab */
65 {
66 	int i;
67 	struct symtab *p;
68 
69 	for (i = nstack; i >= 0; i--)	/* look in each active symtab */
70 		for (p = stack[i].p_symtab; p != NULL; p = p->s_next)
71 			if (strcmp(s, p->s_name) == 0)
72 				return(p);
73 	return(NULL);
74 }
75 
76 void
77 freesymtab(struct symtab *p)	/* free space used by symtab at p */
78 {
79 	struct symtab *q;
80 
81 	for ( ; p != NULL; p = q) {
82 		q = p->s_next;
83 		free(p->s_name);	/* assumes done with tostring */
84 		free((char *)p);
85 	}
86 }
87 
88 void
89 freedef(char *s)	/* free definition for string s */
90 {
91 	struct symtab *p, *q, *op;
92 
93 	for (p = op = q = stack[nstack].p_symtab; p != NULL; p = p->s_next) {
94 		if (strcmp(s, p->s_name) == 0) { 	/* got it */
95 			if (p->s_type != DEFNAME)
96 				break;
97 			if (p == op)	/* 1st elem */
98 				stack[nstack].p_symtab = p->s_next;
99 			else
100 				q->s_next = p->s_next;
101 			free(p->s_name);
102 			free(p->s_val.p);
103 			free((char *)p);
104 			return;
105 		}
106 		q = p;
107 	}
108 	/* ERROR "%s is not defined at this point", s WARNING; */
109 }