1 3ebbd193 2017-06-19 rsc #include <stdio.h>
 2 3ebbd193 2017-06-19 rsc #include <stdlib.h>
 3 3ebbd193 2017-06-19 rsc #include "pic.h"
 4 3ebbd193 2017-06-19 rsc #include "y.tab.h"
 5 3ebbd193 2017-06-19 rsc 
 6 3ebbd193 2017-06-19 rsc #define	SLOP	1.001
 7 3ebbd193 2017-06-19 rsc 
 8 3ebbd193 2017-06-19 rsc typedef struct {
 9 3ebbd193 2017-06-19 rsc 	char	*var;	/* index variable */
10 3ebbd193 2017-06-19 rsc 	double	to;	/* limit */
11 3ebbd193 2017-06-19 rsc 	double	by;
12 3ebbd193 2017-06-19 rsc 	int	op;	/* operator */
13 3ebbd193 2017-06-19 rsc 	char	*str;	/* string to push back */
14 3ebbd193 2017-06-19 rsc } For;
15 3ebbd193 2017-06-19 rsc 
16 3ebbd193 2017-06-19 rsc For	forstk[10];	/* stack of for loops */
17 3ebbd193 2017-06-19 rsc For	*forp = forstk;	/* pointer to current top */
18 3ebbd193 2017-06-19 rsc 
19 3ebbd193 2017-06-19 rsc void	setfval(char *, double);
20 3ebbd193 2017-06-19 rsc void	nextfor(void);
21 3ebbd193 2017-06-19 rsc 
22 3ebbd193 2017-06-19 rsc void forloop(char *var, double from, double to, int op,
23 3ebbd193 2017-06-19 rsc 	double by, char *str)	/* set up a for loop */
24 3ebbd193 2017-06-19 rsc {
25 3ebbd193 2017-06-19 rsc 	dprintf("# for %s from %g to %g by %c %g \n",
26 3ebbd193 2017-06-19 rsc 		var, from, to, op, by);
27 3ebbd193 2017-06-19 rsc 	if (++forp >= forstk+10)
28 3ebbd193 2017-06-19 rsc 		ERROR "for loop nested too deep" FATAL;
29 3ebbd193 2017-06-19 rsc 	forp->var = var;
30 3ebbd193 2017-06-19 rsc 	forp->to = to;
31 3ebbd193 2017-06-19 rsc 	forp->op = op;
32 3ebbd193 2017-06-19 rsc 	forp->by = by;
33 3ebbd193 2017-06-19 rsc 	forp->str = str;
34 3ebbd193 2017-06-19 rsc 	setfval(var, from);
35 3ebbd193 2017-06-19 rsc 	nextfor();
36 3ebbd193 2017-06-19 rsc 	unput('\n');
37 3ebbd193 2017-06-19 rsc }
38 3ebbd193 2017-06-19 rsc 
39 3ebbd193 2017-06-19 rsc void nextfor(void)	/* do one iteration of a for loop */
40 3ebbd193 2017-06-19 rsc {
41 3ebbd193 2017-06-19 rsc 	/* BUG:  this should depend on op and direction */
42 3ebbd193 2017-06-19 rsc 	if (getfval(forp->var) > SLOP * forp->to) {	/* loop is done */
43 3ebbd193 2017-06-19 rsc 		free(forp->str);
44 3ebbd193 2017-06-19 rsc 		if (--forp < forstk)
45 3ebbd193 2017-06-19 rsc 			ERROR "forstk popped too far" FATAL;
46 3ebbd193 2017-06-19 rsc 	} else {		/* another iteration */
47 3ebbd193 2017-06-19 rsc 		pushsrc(String, "\nEndfor\n");
48 3ebbd193 2017-06-19 rsc 		pushsrc(String, forp->str);
49 3ebbd193 2017-06-19 rsc 	}
50 3ebbd193 2017-06-19 rsc }
51 3ebbd193 2017-06-19 rsc 
52 3ebbd193 2017-06-19 rsc void endfor(void)	/* end one iteration of for loop */
53 3ebbd193 2017-06-19 rsc {
54 3ebbd193 2017-06-19 rsc 	struct symtab *p = lookup(forp->var);
55 3ebbd193 2017-06-19 rsc 
56 3ebbd193 2017-06-19 rsc 	switch (forp->op) {
57 3ebbd193 2017-06-19 rsc 	case '+':
58 3ebbd193 2017-06-19 rsc 	case ' ':
59 3ebbd193 2017-06-19 rsc 		p->s_val.f += forp->by;
60 3ebbd193 2017-06-19 rsc 		break;
61 3ebbd193 2017-06-19 rsc 	case '-':
62 3ebbd193 2017-06-19 rsc 		p->s_val.f -= forp->by;
63 3ebbd193 2017-06-19 rsc 		break;
64 3ebbd193 2017-06-19 rsc 	case '*':
65 3ebbd193 2017-06-19 rsc 		p->s_val.f *= forp->by;
66 3ebbd193 2017-06-19 rsc 		break;
67 3ebbd193 2017-06-19 rsc 	case '/':
68 3ebbd193 2017-06-19 rsc 		p->s_val.f /= forp->by;
69 3ebbd193 2017-06-19 rsc 		break;
70 3ebbd193 2017-06-19 rsc 	}
71 3ebbd193 2017-06-19 rsc 	nextfor();
72 3ebbd193 2017-06-19 rsc }
73 3ebbd193 2017-06-19 rsc 
74 3ebbd193 2017-06-19 rsc char *ifstat(double expr, char *thenpart, char *elsepart)
75 3ebbd193 2017-06-19 rsc {
76 3ebbd193 2017-06-19 rsc 	dprintf("if %g then <%s> else <%s>\n", expr, thenpart, elsepart? elsepart : "");
77 3ebbd193 2017-06-19 rsc 	if (expr) {
78 3ebbd193 2017-06-19 rsc 		unput('\n');
79 3ebbd193 2017-06-19 rsc 		pushsrc(Free, thenpart);
80 3ebbd193 2017-06-19 rsc 		pushsrc(String, thenpart);
81 3ebbd193 2017-06-19 rsc 		unput('\n');
82 3ebbd193 2017-06-19 rsc   		if (elsepart)
83 3ebbd193 2017-06-19 rsc 			free(elsepart);
84 3ebbd193 2017-06-19 rsc 		return thenpart;	/* to be freed later */
85 3ebbd193 2017-06-19 rsc 	} else {
86 3ebbd193 2017-06-19 rsc 		free(thenpart);
87 3ebbd193 2017-06-19 rsc 		if (elsepart) {
88 3ebbd193 2017-06-19 rsc 			unput('\n');
89 3ebbd193 2017-06-19 rsc 			pushsrc(Free, elsepart);
90 3ebbd193 2017-06-19 rsc 			pushsrc(String, elsepart);
91 3ebbd193 2017-06-19 rsc 			unput('\n');
92 3ebbd193 2017-06-19 rsc 		}
93 3ebbd193 2017-06-19 rsc 		return elsepart;
94 3ebbd193 2017-06-19 rsc 	}
95 3ebbd193 2017-06-19 rsc }