tinput.c - plan9port - [fork] Plan 9 from user space
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tinput.c (5436B)
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1 #include "e.h"
2 #include "y.tab.h"
3 #include <ctype.h>
4
5 Infile infile[10];
6 Infile *curfile = infile;
7
8 #define MAXSRC 50
9 Src src[MAXSRC]; /* input source stack */
10 Src *srcp = src;
11
12 extern int getarg(char *);
13 extern void eprint(void);
14
15 void pushsrc(int type, char *ptr) /* new input source */
16 {
17 if (++srcp >= src + MAXSRC)
18 ERROR "inputs nested too deep" FATAL;
19 srcp->type = type;
20 srcp->sp = ptr;
21 if (dbg > 1) {
22 printf("\n%3ld ", (long)(srcp - src));
23 switch (srcp->type) {
24 case File:
25 printf("push file %s\n", ((Infile *)ptr)->fname);
26 break;
27 case Macro:
28 printf("push macro <%s>\n", ptr);
29 break;
30 case Char:
31 printf("push char <%c>\n", *ptr);
32 break;
33 case String:
34 printf("push string <%s>\n", ptr);
35 break;
36 case Free:
37 printf("push free <%s>\n", ptr);
38 break;
39 default:
40 ERROR "pushed bad type %d\n", srcp->type FATAL;
41 }
42 }
43 }
44
45 void popsrc(void) /* restore an old one */
46 {
47 if (srcp <= src)
48 ERROR "too many inputs popped" FATAL;
49 if (dbg > 1) {
50 printf("%3ld ", (long)(srcp - src));
51 switch (srcp->type) {
52 case File:
53 printf("pop file\n");
54 break;
55 case Macro:
56 printf("pop macro\n");
57 break;
58 case Char:
59 printf("pop char <%c>\n", *srcp->sp);
60 break;
61 case String:
62 printf("pop string\n");
63 break;
64 case Free:
65 printf("pop free\n");
66 break;
67 default:
68 ERROR "pop weird input %d\n", srcp->type FATAL;
69 }
70 }
71 srcp--;
72 }
73
74 Arg args[10]; /* argument frames */
75 Arg *argfp = args; /* frame pointer */
76 int argcnt; /* number of arguments seen so far */
77
78 void dodef(tbl *stp) /* collect args and switch input to defn */
79 {
80 int i, len;
81 char *p;
82 Arg *ap;
83
84 ap = argfp+1;
85 if (ap >= args+10)
86 ERROR "more than arguments\n" FATAL;
87 argcnt = 0;
88 if (input() != '(')
89 ERROR "disaster in dodef\n"FATAL;
90 if (ap->argval == 0)
91 ap->argval = malloc(1000);
92 for (p = ap->argval; (len = getarg(p)) != -1; p += len) {
93 ap->argstk[argcnt++] = p;
94 if (input() == ')')
95 break;
96 }
97 for (i = argcnt; i < MAXARGS; i++)
98 ap->argstk[i] = "";
99 if (dbg)
100 for (i = 0; i < argcnt; i++)
101 printf("arg %ld.%d = <%s>\n", (long)(ap-args), i+1, ap->argstk[i]);
102 argfp = ap;
103 pushsrc(Macro, stp->cval);
104 }
105
106 int
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 int
143 input(void)
144 {
145 register int c = 0;
146
147 loop:
148 switch (srcp->type) {
149 case File:
150 c = getc(curfile->fin);
151 if (c == EOF) {
152 if (curfile == infile)
153 break;
154 if (curfile->fin != stdin) {
155 fclose(curfile->fin);
156 free(curfile->fname); /* assumes allocated */
157 }
158 curfile--;
159 printf(".lf %d %s\n", curfile->lineno, curfile->fname);
160 popsrc();
161 goto loop;
162 }
163 if (c == '\n')
164 curfile->lineno++;
165 break;
166 case Char:
167 if (pb >= pbuf) {
168 c = *pb--;
169 popsrc();
170 break;
171 } else { /* can't happen? */
172 popsrc();
173 goto loop;
174 }
175 case String:
176 c = *srcp->sp++;
177 if (c == '\0') {
178 popsrc();
179 goto loop;
180 } else {
181 if (*srcp->sp == '\0') /* empty, so pop */
182 popsrc();
183 break;
184 }
185 case Macro:
186 c = *srcp->sp++;
187 if (c == '\0') {
188 if (--argfp < args)
189 ERROR "argfp underflow" FATAL;
190 popsrc();
191 goto loop;
192 } else if (c == '$' && isdigit((unsigned char)*srcp->sp)) {
193 int n = 0;
194 while (isdigit((unsigned char)*srcp->sp))
195 n = 10 * n + *srcp->sp++ - '0';
196 if (n > 0 && n <= MAXARGS)
197 pushsrc(String, argfp->argstk[n-1]);
198 goto loop;
199 }
200 break;
201 case Free: /* free string */
202 free(srcp->sp);
203 popsrc();
204 goto loop;
205 }
206 if (ep >= ebuf + sizeof ebuf)
207 ep = ebuf;
208 *ep++ = c;
209 return c;
210 }
211
212 int
213 unput(int c)
214 {
215 if (++pb >= pbuf + sizeof pbuf)
216 ERROR "pushback overflow\n"FATAL;
217 if (--ep < ebuf)
218 ep = ebuf + sizeof(ebuf) - 1;
219 *pb = c;
220 pushsrc(Char, pb);
221 return c;
222 }
223
224 void pbstr(char *s)
225 {
226 pushsrc(String, s);
227 }
228
229 void error(int die, char *s)
230 {
231 extern char *cmdname;
232
233 if (synerr)
234 return;
235 fprintf(stderr, "%s: %s", cmdname, 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[2000];
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 }