lex.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static char	*sccsid = " @(#)lex.c	1.3	(ULTRIX)	1/15/86";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1986 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

/************************************************************************
*
*			Modification History
*
*	David Metsky		14-Jan-86
*
* 001	Replaced old version with BSD 4.3 version as part of upgrade.
*
*	Based on:	lex.c		5.2		8/29/85
*
*************************************************************************/

/*
 * lex.c
 *
 * Lexical scanner routines for the f77 compiler, pass 1, 4.2 BSD.
 *
 * University of Utah CS Dept modification history:
 *
 * $Log:	lex.c,v $
 * Revision 5.2  85/08/10  04:45:41  donn
 * Jerry Berkman's changes to ifdef 66 code and handle -r8/double flag.
 * 
 * Revision 5.1  85/08/10  03:48:20  donn
 * 4.3 alpha
 * 
 * Revision 1.2  84/10/27  02:20:09  donn
 * Fixed bug where the input file and the name field of the include file
 * structure shared -- when the input file name was freed, the include file
 * name got stomped on, leading to peculiar error messages.
 * 
 */

#include "defs.h"
#include "tokdefs.h"

# define BLANK	' '
# define MYQUOTE (2)
# define SEOF 0

/* card types */

# define STEOF 1
# define STINITIAL 2
# define STCONTINUE 3

/* lex states */

#define NEWSTMT	1
#define FIRSTTOKEN	2
#define OTHERTOKEN	3
#define RETEOS	4


LOCAL int stkey;
LOCAL int lastend = 1;
ftnint yystno;
flag intonly;
LOCAL long int stno;
LOCAL long int nxtstno;
LOCAL int parlev;
LOCAL int expcom;
LOCAL int expeql;
LOCAL char *nextch;
LOCAL char *lastch;
LOCAL char *nextcd 	= NULL;
LOCAL char *endcd;
LOCAL int prevlin;
LOCAL int thislin;
LOCAL int code;
LOCAL int lexstate	= NEWSTMT;
LOCAL char s[1390];
LOCAL char *send	= s+20*66;
LOCAL int nincl	= 0;
LOCAL char *newname = NULL;

struct Inclfile
	{
	struct Inclfile *inclnext;
	FILEP inclfp;
	char *inclname;
	int incllno;
	char *incllinp;
	int incllen;
	int inclcode;
	ftnint inclstno;
	} ;

LOCAL struct Inclfile *inclp	=  NULL;
LOCAL struct Keylist { char *keyname; int keyval; char notinf66; } ;
LOCAL struct Punctlist { char punchar; int punval; };
LOCAL struct Fmtlist { char fmtchar; int fmtval; };
LOCAL struct Dotlist { char *dotname; int dotval; };
LOCAL struct Keylist *keystart[26], *keyend[26];




inilex(name)
char *name;
{
nincl = 0;
inclp = NULL;
doinclude(name);
lexstate = NEWSTMT;
return(NO);
}



/* throw away the rest of the current line */
flline()
{
lexstate = RETEOS;
}



char *lexline(n)
int *n;
{
*n = (lastch - nextch) + 1;
return(nextch);
}





doinclude(name)
char *name;
{
FILEP fp;
struct Inclfile *t;
char temp[100];
register char *lastslash, *s;

if(inclp)
	{
	inclp->incllno = thislin;
	inclp->inclcode = code;
	inclp->inclstno = nxtstno;
	if(nextcd)
		inclp->incllinp = copyn(inclp->incllen = endcd-nextcd , nextcd);
	else
		inclp->incllinp = 0;
	}
nextcd = NULL;

if(++nincl >= MAXINCLUDES)
	fatal("includes nested too deep");
if(name[0] == '\0')
	fp = stdin;
else if(name[0]=='/' || inclp==NULL)
	fp = fopen(name, "r");
else	{
	lastslash = NULL;
	for(s = inclp->inclname ; *s ; ++s)
		if(*s == '/')
			lastslash = s;
	if(lastslash)
		{
		*lastslash = '\0';
		sprintf(temp, "%s/%s", inclp->inclname, name);
		*lastslash = '/';
		}
	else
		strcpy(temp, name);

	if( (fp = fopen(temp, "r")) == NULL )
		{
		sprintf(temp, "/usr/include/%s", name);
		fp = fopen(temp, "r");
		}
	if(fp)
		name = copys(temp);
	}

if( fp )
	{
	t = inclp;
	inclp = ALLOC(Inclfile);
	inclp->inclnext = t;
	prevlin = thislin = 0;
	inclp->inclname = name;
	infname = copys(name);
	infile = inclp->inclfp = fp;
	}
else
	{
	fprintf(diagfile, "Cannot open file %s", name);
	done(1);
	}
}




LOCAL popinclude()
{
struct Inclfile *t;
register char *p;
register int k;

if(infile != stdin)
	clf(&infile);
free(infname);

--nincl;
t = inclp->inclnext;
free(inclp->inclname);
free( (charptr) inclp);
inclp = t;
if(inclp == NULL)
	return(NO);

infile = inclp->inclfp;
infname = copys(inclp->inclname);
prevlin = thislin = inclp->incllno;
code = inclp->inclcode;
stno = nxtstno = inclp->inclstno;
if(inclp->incllinp)
	{
	endcd = nextcd = s;
	k = inclp->incllen;
	p = inclp->incllinp;
	while(--k >= 0)
		*endcd++ = *p++;
	free( (charptr) (inclp->incllinp) );
	}
else
	nextcd = NULL;
return(YES);
}




yylex()
{
static int  tokno;

	switch(lexstate)
	{
case NEWSTMT :	/* need a new statement */
	if(getcds() == STEOF)
		return(SEOF);
	lastend =  stkey == SEND;
	crunch();
	tokno = 0;
	lexstate = FIRSTTOKEN;
	yystno = stno;
	stno = nxtstno;
	toklen = 0;
	return(SLABEL);

first:
case FIRSTTOKEN :	/* first step on a statement */
	analyz();
	lexstate = OTHERTOKEN;
	tokno = 1;
	return(stkey);

case OTHERTOKEN :	/* return next token */
	if(nextch > lastch)
		goto reteos;
	++tokno;
	if( (stkey==SLOGIF || stkey==SELSEIF) && parlev==0 && tokno>3)
		goto first;

	if(stkey==SASSIGN && tokno==3 && nextch<lastch &&
		nextch[0]=='t' && nextch[1]=='o')
			{
			nextch+=2;
			return(STO);
			}
	return(gettok());

reteos:
case RETEOS:
	lexstate = NEWSTMT;
	return(SEOS);
	}
fatali("impossible lexstate %d", lexstate);
/* NOTREACHED */
}

LOCAL getcds()
{
register char *p, *q;

	if (newname)
		{
		free(infname);
		infname = newname;
		newname = NULL;
		}

top:
	if(nextcd == NULL)
		{
		code = getcd( nextcd = s );
		stno = nxtstno;
		if (newname)
			{
			free(infname);
			infname = newname;
			newname = NULL;
			}
		prevlin = thislin;
		}
	if(code == STEOF)
		if( popinclude() )
			goto top;
		else
			return(STEOF);

	if(code == STCONTINUE)
		{
		if (newname)
			{
			free(infname);
			infname = newname;
			newname = NULL;
			}
		lineno = thislin;
		err("illegal continuation card ignored");
		nextcd = NULL;
		goto top;
		}

	if(nextcd > s)
		{
		q = nextcd;
		p = s;
		while(q < endcd)
			*p++ = *q++;
		endcd = p;
		}
	for(nextcd = endcd ;
		nextcd+66<=send && (code = getcd(nextcd))==STCONTINUE ;
		nextcd = endcd )
			;
	nextch = s;
	lastch = nextcd - 1;
	if(nextcd >= send)
		nextcd = NULL;
	lineno = prevlin;
	prevlin = thislin;
	return(STINITIAL);
}

LOCAL getcd(b)
register char *b;
{
register int c;
register char *p, *bend;
int speclin;
static char a[6];
static char *aend	= a+6;
int num;

top:
	endcd = b;
	bend = b+66;
	speclin = NO;

	if( (c = getc(infile)) == '&')
		{
		a[0] = BLANK;
		a[5] = 'x';
		speclin = YES;
		bend = send;
		}
	else if(c=='c' || c=='C' || c=='*')
		{
		while( (c = getc(infile)) != '\n')
			if(c == EOF)
				return(STEOF);
		++thislin;
		goto top;
		}
	else if(c == '#')
		{
		c = getc(infile);
		while (c == BLANK || c == '\t')
			c = getc(infile);

		num = 0;
		while (isdigit(c))
			{
			num = 10*num + c - '0';
			c = getc(infile);
			}
		thislin = num - 1;

		while (c == BLANK || c == '\t')
			c = getc(infile);

		if (c == '"')
			{
			char fname[1024];
			int len = 0;

			c = getc(infile);
			while (c != '"' && c != '\n')
				{
				fname[len++] = c;
				c = getc(infile);
				}
			fname[len++] = '\0';

			if (newname)
				free(newname);
			newname = (char *) ckalloc(len);
			strcpy(newname, fname);
			}

		while (c != '\n')
			if (c == EOF)
				return (STEOF);
			else
				c = getc(infile);
		goto top;
		}

	else if(c != EOF)
		{
		/* a tab in columns 1-6 skips to column 7 */
		ungetc(c, infile);
		for(p=a; p<aend && (c=getc(infile)) != '\n' && c!=EOF; )
			if(c == '\t')
				{
				while(p < aend)
					*p++ = BLANK;
				speclin = YES;
				bend = send;
				}
			else
				*p++ = c;
		}
	if(c == EOF)
		return(STEOF);
	if(c == '\n')
		{
		while(p < aend)
			*p++ = BLANK;
		if( ! speclin )
			while(endcd < bend)
				*endcd++ = BLANK;
		}
	else	{	/* read body of line */
		while( endcd<bend && (c=getc(infile)) != '\n' && c!=EOF )
			*endcd++ = c;
		if(c == EOF)
			return(STEOF);
		if(c != '\n')
			{
			while( (c=getc(infile)) != '\n')
				if(c == EOF)
					return(STEOF);
			}

		if( ! speclin )
			while(endcd < bend)
				*endcd++ = BLANK;
		}
	++thislin;
	if( !isspace(a[5]) && a[5]!='0')
		return(STCONTINUE);
	for(p=a; p<aend; ++p)
		if( !isspace(*p) ) goto initline;
	for(p = b ; p<endcd ; ++p)
		if( !isspace(*p) ) goto initline;
	goto top;

initline:
	nxtstno = 0;
	for(p = a ; p<a+5 ; ++p)
		if( !isspace(*p) )
			if(isdigit(*p))
				nxtstno = 10*nxtstno + (*p - '0');
			else	{
				if (newname)
					{
					free(infname);
					infname = newname;
					newname = NULL;
					}
				lineno = thislin;
				err("nondigit in statement number field");
				nxtstno = 0;
				break;
				}
	return(STINITIAL);
}

LOCAL crunch()
{
register char *i, *j, *j0, *j1, *prvstr;
int ten, nh, quote;

/* i is the next input character to be looked at
j is the next output character */
parlev = 0;
expcom = 0;	/* exposed ','s */
expeql = 0;	/* exposed equal signs */
j = s;
prvstr = s;
for(i=s ; i<=lastch ; ++i)
	{
	if(isspace(*i) )
		continue;
	if(*i=='\'' ||  *i=='"')
		{