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1.1 root 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;
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 line %d, file %s",
240: curfile->lineno, curfile->fname);
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: }
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