Subversion Repositories planix.SVN

Rev

Rev 2 | Details | Compare with Previous | Last modification | View Log | RSS feed

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