plan9port

input.c (11496B)

---

 #include <u.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
 #include <errno.h>
 #include "grap.h"
 #include "y.tab.h"
 
 Infile	infile[10];
 Infile	*curfile = infile;
 
 #define	MAXSRC	50
 Src	src[MAXSRC];	/* input source stack */
 Src	*srcp	= src;
 
 void pushsrc(int type, char *ptr)	/* new input source */
 {
 	if (++srcp >= src + MAXSRC)
 		ERROR "inputs nested too deep" FATAL;
 	srcp->type = type;
 	srcp->sp = ptr;
 	if (dbg) {
 		printf("\n%3ld ", (long)(srcp - src));
 		switch (srcp->type) {
 		case File:
 			printf("push file %s\n", ptr);
 			break;
 		case Macro:
 			printf("push macro <%s>\n", ptr);
 			break;
 		case Char:
 			printf("push char <%c>\n", *ptr);
 			break;
 		case Thru:
 			printf("push thru\n");
 			break;
 		case String:
 			printf("push string <%s>\n", ptr);
 			break;
 		case Free:
 			printf("push free <%s>\n", ptr);
 			break;
 		default:
 			ERROR "pushed bad type %d", srcp->type FATAL;
 		}
 	}
 }
 
 void popsrc(void)	/* restore an old one */
 {
 	if (srcp <= src)
 		ERROR "too many inputs popped" FATAL;
 	if (dbg) {
 		printf("%3ld ", (long)(srcp - src));
 		switch (srcp->type) {
 		case File:
 			printf("pop file\n");
 			break;
 		case Macro:
 			printf("pop macro\n");
 			break;
 		case Char:
 			printf("pop char <%c>\n", *srcp->sp);
 			break;
 		case Thru:
 			printf("pop thru\n");
 			break;
 		case String:
 			printf("pop string\n");
 			break;
 		case Free:
 			printf("pop free\n");
 			break;
 		default:
 			ERROR "pop weird input %d", srcp->type FATAL;
 		}
 	}
 	srcp--;
 }
 
 void definition(char *s)	/* collect definition for s and install */
 				/* definitions picked up lexically */
 {
 	char *p;
 	Obj *stp;
 
 	p = delimstr("definition");
 	stp = lookup(s, 0);
 	if (stp != NULL) {	/* it's there before */
 		if (stp->type != DEFNAME) {
 			ERROR "%s used as variable and definition", s WARNING;
 			return;
 		}
 		free(stp->val);
 	} else {
 		stp = lookup(s, 1);
 		stp->type = DEFNAME;
 	}
 	stp->val = p;
 	dprintf("installing %s as `%s'\n", s, p);
 }
 
 char *delimstr(char *s)	/* get body of X ... X */
 			/* message if too big */
 {
 	int c, delim, rdelim, n, deep;
 	static char *buf = NULL;
 	static int nbuf = 0;
 	char *p;
 
 	if (buf == NULL)
 		buf = grow(buf, "buf", nbuf += 1000, sizeof(buf[0]));
 	while ((delim = input()) == ' ' || delim == '\t' || delim == '\n')
 		;
 	rdelim = baldelim(delim, "{}");		/* could be "(){}[]`'" */
 	deep = 1;
 	for (p = buf; ; ) {
 		c = input();
 		if (c == rdelim)
 			if (--deep == 0)
 				break;
 		if (c == delim)
 			deep++;
 		if (p >= buf + nbuf) {
 			n = p - buf;
 			buf = grow(buf, "buf", nbuf += 1000, sizeof(buf[0]));
 			p = buf + n;
 		}
 		if (c == EOF)
 			ERROR "end of file in %s %c %.20s... %c", s, delim, buf, delim FATAL;
 		*p++ = c;
 	}
 	*p = '\0';
 	dprintf("delimstr %s %c <%s> %c\n", s, delim, buf, delim);
 	return tostring(buf);
 }
 
 int
 baldelim(int c, char *s)	/* replace c by balancing entry in s */
 {
 	for ( ; *s; s += 2)
 		if (*s == c)
 			return s[1];
 	return c;
 }
 
 Arg	args[10];	/* argument frames */
 Arg	*argfp = args;	/* frame pointer */
 int	argcnt;		/* number of arguments seen so far */
 
 void dodef(Obj *stp)	/* collect args and switch input to defn */
 {
 	int i, len;
 	char *p;
 	Arg *ap;
 
 	ap = argfp+1;
 	if (ap >= args+10)
 		ERROR "arguments too deep" FATAL;
 	argcnt = 0;
 	if (input() != '(')
 		ERROR "disaster in dodef" FATAL;
 	if (ap->argval == 0)
 		ap->argval = malloc(1000);
 	for (p = ap->argval; (len = getarg(p)) != -1; p += len) {
 		ap->argstk[argcnt++] = p;
 		if (input() == ')')
 			break;
 	}
 	for (i = argcnt; i < MAXARGS; i++)
 		ap->argstk[i] = "";
 	if (dbg)
 		for (i = 0; i < argcnt; i++)
 			printf("arg %ld.%d = <%s>\n", (long)(ap-args), i+1, ap->argstk[i]);
 	argfp = ap;
 	pushsrc(Macro, stp->val);
 }
 
 int
 getarg(char *p)	/* pick up single argument, store in p, return length */
 {
 	int n, c, npar;
 
 	n = npar = 0;
 	for ( ;; ) {
 		c = input();
 		if (c == EOF)
 			ERROR "end of file in getarg!" FATAL;
 		if (npar == 0 && (c == ',' || c == ')'))
 			break;
 		if (c == '"')	/* copy quoted stuff intact */
 			do {
 				*p++ = c;
 				n++;
 			} while ((c = input()) != '"' && c != EOF);
 		else if (c == '(')
 			npar++;
 		else if (c == ')')
 			npar--;
 		n++;
 		*p++ = c;
 	}
 	*p = 0;
 	unput(c);
 	return(n + 1);
 }
 
 #define	PBSIZE	2000
 char	pbuf[PBSIZE];		/* pushback buffer */
 char	*pb	= pbuf-1;	/* next pushed back character */
 
 char	ebuf[200];		/* collect input here for error reporting */
 char	*ep	= ebuf;
 
 int	begin	= 0;
 extern	int	thru;
 extern	Obj	*thrudef;
 extern	char	*untilstr;
 
 int
 input(void)
 {
 	register int c;
 
 	if (thru && begin) {
 		do_thru();
 		begin = 0;
 	}
 	c = nextchar();
 	dprintf(" <%c>", c);
 	if (ep >= ebuf + sizeof ebuf)
 		ep = ebuf;
 	return *ep++ = c;
 }
 
 int
 nextchar(void)
 {
 	register int c;
 
 	c = 0; /* gcc */
 
   loop:
 	switch (srcp->type) {
 	case Free:	/* free string */
 		free(srcp->sp);
 		popsrc();
 		goto loop;
 	case Thru:	/* end of pushed back line */
 		begin = 1;
 		popsrc();
 		c = '\n';
 		break;
 	case Char:
 		if (pb >= pbuf) {
 			c = *pb--;
 			popsrc();
 			break;
 		} else {	/* can't happen? */
 			popsrc();
 			goto loop;
 		}
 	case String:
 		c = *srcp->sp++;
 		if (c == '\0') {
 			popsrc();
 			goto loop;
 		} else {
 			if (*srcp->sp == '\0')	/* empty, so pop */
 				popsrc();
 			break;
 		}
 	case Macro:
 		c = *srcp->sp++;
 		if (c == '\0') {
 			if (--argfp < args)
 				ERROR "argfp underflow" FATAL;
 			popsrc();
 			goto loop;
 		} else if (c == '$' && isdigit((uchar)*srcp->sp)) {	/* $3 */
 			int n = 0;
 			while (isdigit((uchar)*srcp->sp))
 				n = 10 * n + *srcp->sp++ - '0';
 			if (n > 0 && n <= MAXARGS)
 				pushsrc(String, argfp->argstk[n-1]);
 			goto loop;
 		}
 		break;
 	case File:
 		c = getc(curfile->fin);
 		if (c == EOF) {
 			if (curfile == infile)
 				ERROR "end of file inside .G1/.G2" FATAL;
 			if (curfile->fin != stdin) {
 				fclose(curfile->fin);
 				free(curfile->fname);	/* assumes allocated */
 			}
 			curfile--;
 			printf(".lf %d %s\n", curfile->lineno, curfile->fname);
 			popsrc();
 			thru = 0;	/* chicken out */
 			thrudef = 0;
 			if (untilstr) {
 				free(untilstr);
 				untilstr = 0;
 			}
 			goto loop;
 		}
 		if (c == '\n')
 			curfile->lineno++;
 		break;
 	}
 	return c;
 }
 
 void do_thru(void)	/* read one line, make into a macro expansion */
 {
 	int c, i;
 	char *p;
 	Arg *ap;
 
 	ap = argfp+1;
 	if (ap >= args+10)
 		ERROR "arguments too deep" FATAL;
 	if (ap->argval == NULL)
 		ap->argval = malloc(1000);
 	p = ap->argval;
 	argcnt = 0;
 	c = nextchar();
 	if (thru == 0) {	/* end of file was seen, so thru is done */
 		unput(c);
 		return;
 	}
 	for ( ; c != '\n' && c != EOF; ) {
 		if (c == ' ' || c == '\t') {
 			c = nextchar();
 			continue;
 		}
 		if (argcnt >= MAXARGS)
 			ERROR "too many fields on input line" FATAL;
 		ap->argstk[argcnt++] = p;
 		if (c == '"') {
 			do {
 				*p++ = c;
 				if ((c = nextchar()) == '\\') {
 					*p++ = c;
 					*p++ = nextchar();
 					c = nextchar();
 				}
 			} while (c != '"' && c != '\n' && c != EOF);
 			*p++ = '"';
 			if (c == '"')
 				c = nextchar();
 		} else {
 			do {
 				*p++ = c;
 			} while ((c = nextchar())!=' ' && c!='\t' && c!='\n' && c!=',' && c!=EOF);
 			if (c == ',')
 				c = nextchar();
 		}
 		*p++ = '\0';
 	}
 	if (c == EOF)
 		ERROR "unexpected end of file in do_thru" FATAL;
 	if (argcnt == 0) {	/* ignore blank line */
 		pushsrc(Thru, (char *) 0);
 		return;
 	}
 	for (i = argcnt; i < MAXARGS; i++)
 		ap->argstk[i] = "";
 	if (dbg)
 		for (i = 0; i < argcnt; i++)
 			printf("arg %ld.%d = <%s>\n", (long)(ap-args), i+1, ap->argstk[i]);
 	if (strcmp(ap->argstk[0], ".G2") == 0) {
 		thru = 0;
 		thrudef = 0;
 		pushsrc(String, "\n.G2\n");
 		return;
 	}
 	if (untilstr && strcmp(ap->argstk[0], untilstr) == 0) {
 		thru = 0;
 		thrudef = 0;
 		free(untilstr);
 		untilstr = 0;
 		return;
 	}
 	pushsrc(Thru, (char *) 0);
 	dprintf("do_thru pushing back <%s>\n", thrudef->val);
 	argfp = ap;
 	pushsrc(Macro, thrudef->val);
 }
 
 int
 unput(int c)
 {
 	if (++pb >= pbuf + sizeof pbuf)
 		ERROR "pushback overflow" FATAL;
 	if (--ep < ebuf)
 		ep = ebuf + sizeof(ebuf) - 1;
 	*pb = c;
 	pushsrc(Char, pb);
 	return c;
 }
 
 void pbstr(char *s)
 {
 	pushsrc(String, s);
 }
 
 double errcheck(double x, char *s)
 {
 	if (errno == EDOM) {
 		errno = 0;
 		ERROR "%s argument out of domain", s WARNING;
 	} else if (errno == ERANGE) {
 		errno = 0;
 		ERROR "%s result out of range", s WARNING;
 	}
 	return x;
 }
 
 char	errbuf[200];
 
 void yyerror(char *s)
 {
 	extern char *cmdname;
 	int ern = errno;	/* cause some libraries clobber it */
 
 	if (synerr)
 		return;
 	fflush(stdout);
 	fprintf(stderr, "%s: %s", cmdname, s);
 	if (ern > 0) {
 		errno = ern;
 		perror("???");
 	}
 	fprintf(stderr, " near %s:%d\n",
 		curfile->fname, curfile->lineno+1);
 	eprint();
 	synerr = 1;
 	errno = 0;
 }
 
 void eprint(void)	/* try to print context around error */
 {
 	char *p, *q;
 
 	p = ep - 1;
 	if (p > ebuf && *p == '\n')
 		p--;
 	for ( ; p >= ebuf && *p != '\n'; p--)
 		;
 	while (*p == '\n')
 		p++;
 	fprintf(stderr, " context is\n\t");
 	for (q=ep-1; q>=p && *q!=' ' && *q!='\t' && *q!='\n'; q--)
 		;
 	for (; p < q; p++)
 		if (isprint((uchar)*p))
 			putc(*p, stderr);
 	fprintf(stderr, " >>> ");
 	for (; p < ep; p++)
 		if (isprint((uchar)*p))
 			putc(*p, stderr);
 	fprintf(stderr, " <<< ");
 	while (pb >= pbuf)
 		putc(*pb--, stderr);
 	fgets(ebuf, sizeof ebuf, curfile->fin);
 	fprintf(stderr, "%s", ebuf);
 	pbstr("\n.G2\n");	/* safety first */
 	ep = ebuf;
 }
 
 int yywrap(void) {return 1;}
 
 char	*newfile = 0;		/* filename for file copy */
 char	*untilstr = 0;		/* string that terminates a thru */
 int	thru	= 0;		/* 1 if copying thru macro */
 Obj	*thrudef = 0;		/* macro being used */
 
 void copyfile(char *s)	/* remember file to start reading from */
 {
 	newfile = s;
 }
 
 void copydef(Obj *p)	/* remember macro Obj */
 {
 	thrudef = p;
 }
 
 Obj *copythru(char *s)	/* collect the macro name or body for thru */
 {
 	Obj *p;
 	char *q;
 
 	p = lookup(s, 0);
 	if (p != NULL) {
 		if (p->type == DEFNAME) {
 			p->val = addnewline(p->val);
 			return p;
 		} else
 			ERROR "%s used as define and name", s FATAL;
 	}
 	/* have to collect the definition */
 	pbstr(s);	/* first char is the delimiter */
 	q = delimstr("thru body");
 	p = lookup("nameless", 1);
 	if (p != NULL)
 		if (p->val)
 			free(p->val);
 	p->type = DEFNAME;
 	p->val = q;
 	p->val = addnewline(p->val);
 	dprintf("installing nameless as `%s'\n", p->val);
 	return p;
 }
 
 char *addnewline(char *p)	/* add newline to end of p */
 {
 	int n;
 
 	n = strlen(p);
 	if (p[n-1] != '\n') {
 		p = realloc(p, n+2);
 		p[n] = '\n';
 		p[n+1] = '\0';
 	}
 	return p;
 }
 
 void copyuntil(char *s)	/* string that terminates a thru */
 {
 	untilstr = s;
 }
 
 void copy(void)	/* begin input from file, etc. */
 {
 	FILE *fin;
 
 	if (newfile) {
 		if ((fin = fopen(newfile, "r")) == NULL)
 			ERROR "can't open file %s", newfile FATAL;
 		curfile++;
 		curfile->fin = fin;
 		curfile->fname = tostring(newfile);
 		curfile->lineno = 0;
 		printf(".lf 1 %s\n", curfile->fname);
 		pushsrc(File, curfile->fname);
 		newfile = 0;
 	}
 	if (thrudef) {
 		thru = 1;
 		begin = 1;	/* wrong place */
 	}
 }
 
 char	shellbuf[1000], *shellp;
 
 void shell_init(void)	/* set up to interpret a shell command */
 {
 	fprintf(tfd, "# shell cmd...\n");
 	sprintf(shellbuf, "rc -c '");
 	shellp = shellbuf + strlen(shellbuf);
 }
 
 void shell_text(char *s)	/* add string to command being collected */
 {
 	/* fprintf(tfd, "#add <%s> to <%s>\n", s, shellbuf); */
 	while (*s) {
 		if (*s == '\'')	{	/* protect interior quotes */
 			*shellp++ = '\'';
 			*shellp++ = '\\';
 			*shellp++ = '\'';
 		}
 		*shellp++ = *s++;
 	}
 }
 
 void shell_exec(void)	/* do it */
 {
 	/* fprintf(tfd, "# run <%s>\n", shellbuf); */
 	*shellp++ = '\'';
 	*shellp = '\0';
 	system(shellbuf);
 }