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2 - 1 
#include "e.h"
2 
#include "y.tab.h"
3 
#include <ctype.h>
4 
#include <errno.h>
5 
 
6 
Infile	infile[10];
7 
Infile	*curfile = infile;
8 
 
9 
#define	MAXSRC	50
10 
Src	src[MAXSRC];	/* input source stack */
11 
Src	*srcp	= src;
12 
 
13 
extern int getarg(char *);
14 
extern	void eprint(void);
15 
 
16 
void pushsrc(int type, char *ptr)	/* new input source */
17 
{
18 
	if (++srcp >= src + MAXSRC)
19 
		ERROR "inputs nested too deep" FATAL;
20 
	srcp->type = type;
21 
	srcp->sp = ptr;
22 
	if (dbg > 1) {
23 
		printf("\n%3d ", srcp - src);
24 
		switch (srcp->type) {
25 
		case File:
26 
			printf("push file %s\n", ((Infile *)ptr)->fname);
27 
			break;
28 
		case Macro:
29 
			printf("push macro <%s>\n", ptr);
30 
			break;
31 
		case Char:
32 
			printf("push char <%c>\n", *ptr);
33 
			break;
34 
		case String:
35 
			printf("push string <%s>\n", ptr);
36 
			break;
37 
		case Free:
38 
			printf("push free <%s>\n", ptr);
39 
			break;
40 
		default:
41 
			ERROR "pushed bad type %d\n", srcp->type FATAL;
42 
		}
43 
	}
44 
}
45 
 
46 
void popsrc(void)	/* restore an old one */
47 
{
48 
	if (srcp <= src)
49 
		ERROR "too many inputs popped" FATAL;
50 
	if (dbg > 1) {
51 
		printf("%3d ", srcp - src);
52 
		switch (srcp->type) {
53 
		case File:
54 
			printf("pop file\n");
55 
			break;
56 
		case Macro:
57 
			printf("pop macro\n");
58 
			break;
59 
		case Char:
60 
			printf("pop char <%c>\n", *srcp->sp);
61 
			break;
62 
		case String:
63 
			printf("pop string\n");
64 
			break;
65 
		case Free:
66 
			printf("pop free\n");
67 
			break;
68 
		default:
69 
			ERROR "pop weird input %d\n", srcp->type FATAL;
70 
		}
71 
	}
72 
	srcp--;
73 
}
74 
 
75 
Arg	args[10];	/* argument frames */
76 
Arg	*argfp = args;	/* frame pointer */
77 
int	argcnt;		/* number of arguments seen so far */
78 
 
79 
void dodef(tbl *stp)	/* collect args and switch input to defn */
80 
{
81 
	int i, len;
82 
	char *p;
83 
	Arg *ap;
84 
 
85 
	ap = argfp+1;
86 
	if (ap >= args+10)
87 
		ERROR "more than arguments\n" FATAL;
88 
	argcnt = 0;
89 
	if (input() != '(')
90 
		ERROR "disaster in dodef\n"FATAL;
91 
	if (ap->argval == 0)
92 
		ap->argval = malloc(1000);
93 
	for (p = ap->argval; (len = getarg(p)) != -1; p += len) {
94 
		ap->argstk[argcnt++] = p;
95 
		if (input() == ')')
96 
			break;
97 
	}
98 
	for (i = argcnt; i < MAXARGS; i++)
99 
		ap->argstk[i] = "";
100 
	if (dbg)
101 
		for (i = 0; i < argcnt; i++)
102 
			printf("arg %d.%d = <%s>\n", ap-args, i+1, ap->argstk[i]);
103 
	argfp = ap;
104 
	pushsrc(Macro, stp->cval);
105 
}
106 
 
107 
getarg(char *p)	/* pick up single argument, store in p, return length */
108 
{
109 
	int n, c, npar;
110 
 
111 
	n = npar = 0;
112 
	for ( ;; ) {
113 
		c = input();
114 
		if (c == EOF)
115 
			ERROR "end of file in getarg!\n" FATAL;
116 
		if (npar == 0 && (c == ',' || c == ')'))
117 
			break;
118 
		if (c == '"')	/* copy quoted stuff intact */
119 
			do {
120 
				*p++ = c;
121 
				n++;
122 
			} while ((c = input()) != '"' && c != EOF);
123 
		else if (c == '(')
124 
			npar++;
125 
		else if (c == ')')
126 
			npar--;
127 
		n++;
128 
		*p++ = c;
129 
	}
130 
	*p = 0;
131 
	unput(c);
132 
	return(n + 1);
133 
}
134 
 
135 
#define	PBSIZE	2000
136 
char	pbuf[PBSIZE];		/* pushback buffer */
137 
char	*pb	= pbuf-1;	/* next pushed back character */
138 
 
139 
char	ebuf[200];		/* collect input here for error reporting */
140 
char	*ep	= ebuf;
141 
 
142 
input(void)
143 
{
144 
	register int c = 0;
145 
 
146 
  loop:
147 
	switch (srcp->type) {
148 
	case File:
149 
		c = getc(curfile->fin);
150 
		if (c == EOF) {
151 
			if (curfile == infile)
152 
				break;
153 
			if (curfile->fin != stdin) {
154 
				fclose(curfile->fin);
155 
				free(curfile->fname);	/* assumes allocated */
156 
			}
157 
			curfile--;
158 
			printf(".lf %d %s\n", curfile->lineno, curfile->fname);
159 
			popsrc();
160 
			goto loop;
161 
		}
162 
		if (c == '\n')
163 
			curfile->lineno++;
164 
		break;
165 
	case Char:
166 
		if (pb >= pbuf) {
167 
			c = *pb--;
168 
			popsrc();
169 
			break;
170 
		} else {	/* can't happen? */
171 
			popsrc();
172 
			goto loop;
173 
		}
174 
	case String:
175 
		c = *srcp->sp++;
176 
		if (c == '\0') {
177 
			popsrc();
178 
			goto loop;
179 
		} else {
180 
			if (*srcp->sp == '\0')	/* empty, so pop */
181 
				popsrc();
182 
			break;
183 
		}
184 
	case Macro:
185 
		c = *srcp->sp++;
186 
		if (c == '\0') {
187 
			if (--argfp < args)
188 
				ERROR "argfp underflow" FATAL;
189 
			popsrc();
190 
			goto loop;
191 
		} else if (c == '$' && isdigit(*srcp->sp)) {
192 
			int n = 0;
193 
			while (isdigit(*srcp->sp))
194 
				n = 10 * n + *srcp->sp++ - '0';
195 
			if (n > 0 && n <= MAXARGS)
196 
				pushsrc(String, argfp->argstk[n-1]);
197 
			goto loop;
198 
		}
199 
		break;
200 
	case Free:	/* free string */
201 
		free(srcp->sp);
202 
		popsrc();
203 
		goto loop;
204 
	}
205 
	if (ep >= ebuf + sizeof ebuf)
206 
		ep = ebuf;
207 
	*ep++ = c;
208 
	return c;
209 
}
210 
 
211 
 
212 
unput(int c)
213 
{
214 
	if (++pb >= pbuf + sizeof pbuf)
215 
		ERROR "pushback overflow\n"FATAL;
216 
	if (--ep < ebuf)
217 
		ep = ebuf + sizeof(ebuf) - 1;
218 
	*pb = c;
219 
	pushsrc(Char, pb);
220 
	return c;
221 
}
222 
 
223 
void pbstr(char *s)
224 
{
225 
	pushsrc(String, s);
226 
}
227 
 
228 
void error(int die, char *s)
229 
{
230 
	extern char *cmdname;
231 
 
232 
	if (synerr)
233 
		return;
234 
	fprintf(stderr, "%s: ", cmdname);
235 
	fprintf(stderr, s);
236 
	if (errno > 0)
237 
		perror("???");
238 
	if (curfile->fin)
239 
		fprintf(stderr, " near %s:%d",
240 
			curfile->fname, curfile->lineno+1);
241 
	fprintf(stderr, "\n");
242 
	eprint();
243 
	synerr = 1;
244 
	errno = 0;
245 
	if (die) {
246 
		if (dbg)
247 
			abort();
248 
		else
249 
			exit(1);
250 
	}
251 
}
252 
 
253 
void yyerror(char *s)
254 
{
255 
	error(0, s);	/* temporary */
256 
}
257 
 
258 
char errbuf[200];
259 
 
260 
void eprint(void)	/* try to print context around error */
261 
{
262 
	char *p, *q;
263 
 
264 
	if (ep == ebuf)
265 
		return;				/* no context */
266 
	p = ep - 1;
267 
	if (p > ebuf && *p == '\n')
268 
		p--;
269 
	for ( ; p >= ebuf && *p != '\n'; p--)
270 
		;
271 
	while (*p == '\n')
272 
		p++;
273 
	fprintf(stderr, " context is\n\t");
274 
	for (q=ep-1; q>=p && *q!=' ' && *q!='\t' && *q!='\n'; q--)
275 
		;
276 
	while (p < q)
277 
		putc(*p++, stderr);
278 
	fprintf(stderr, " >>> ");
279 
	while (p < ep)
280 
		putc(*p++, stderr);
281 
	fprintf(stderr, " <<< ");
282 
	while (pb >= pbuf)
283 
		putc(*pb--, stderr);
284 
	if (curfile->fin)
285 
		fgets(ebuf, sizeof ebuf, curfile->fin);
286 
	fprintf(stderr, "%s", ebuf);
287 
	pbstr("\n.EN\n");	/* safety first */
288 
	ep = ebuf;
289 
}