PDP-10.its/c20/lex/lex.old

/*
 * Copyright (c) 1978 Charles H. Forsyth
 */

/*
 * lex -- initialisation, allocation, set creation
 *
 * Revised for PDP-11 (Decus) C by Martin Minow
 */

/* Modified 02-Dec-80 Bob Denny -- Conditionalized debug code for smaller size
 *			     01	-- Moved calls to dfa build, min, print, write
 *				    and to stat, and code for ending() into
 *				    this module so that 'ytab' could be put
 *				    into overlay region.
 *          29-May-81 Bob Denny -- More extern hacking for RSX overlaying.
 * More     19-Mar-82 Bob Denny -- New C library & compiler
 * More     03-May-82 Bob Denny -- Final touches, remove unreferenced autos
 *          28-Aug-82 Bob Denny -- Add "-s" switch to supress references to
 *                                  "stdio.h" in generated code.  Add switch
 *                                  comments in code. Add -e for "easy" com-
 *				    mand line. "lex -e file" is the short way
 *				    of saying:
 *					"lex -i file.lxi -o file.c -t file"
 * More(!)  30-Oct-82 Bob Denny -- Fix RSX ODL to put lots of FCS junk into
 *				    overlay, pick up (badly needed) 3KW for
 *				    NFA nodes, etc.  Change static allocations
 *				    in LEXLEX.H for RSX so can do non-trivial
 *				    things.  Task is now big on RSX and grows
 *				    from big to huge as it runs.
 *				   Fix "-s" support so it is again possible
 *				    to do a lexswitch() (dumb!).
 */


/*)BUILD	$(PROGRAM)	= lex
		$(INCLUDE)	= { lexlex.h ytab.h }
		$(FILES)	= { base dfa eclosu lex impure
                                    min out1 out2 lexsrt ytab }
		$(STACK)	= 4000
		$(TKBOPTIONS)	= {
			STACK = 3000
			TASK  = ...LEX
			;DON'T TRY TO USE FCSRES (RBD)
		}
		$(ODL)		= {
;
; ODL FOR BUILDING LEX ON RSX11M.
; BOB DENNY  29-MAY-81
; BOB DENNY  19-MAR-82
; BOB DENNY  03-MAY-82
; BOB DENNY  30-OCT-82   PUT SOME FCS JUNK IN OVERLAY. REORGANIZE FOR
;			 SIMPLICITY.
;
	.NAME	OVR1
	.NAME   FCSJNK
	.NAME	LXPROC
	.NAME	PARSER
	.ROOT	L0,L1
;
L0:	.FCTR	LEX-IMPURE-OUT2-LB:[1,1]C/LB
;
L1:	.FCTR	OVR1-*(FCS,STAT,PARS)
;
FCS:	.FCTR	FCSJNK-(F1,F2)
;
F1:	.FCTR	LB:[1,1]SYSLIB/LB:.CSI1:.CSI2
F2:	.FCTR	LB:[1,1]SYSLIB/LB:OPEN-(OP1,OP2)
;
OP1:	.FCTR	LB:[1,1]SYSLIB/LB:CREATE:CLOSE:DEL:FINIT:MKDL:OPFNB:RQLCB
OP2:	.FCTR	LB:[1,1]SYSLIB/LB:PARSE
;
STAT:	.FCTR	LXPROC-LEXSRT-DFA-BASE-ECLOSU-MIN-OUT1-LB:[1,1]C/LB
;
PARS:	.FCTR	PARSER-YTAB-LB:[1,1]C/LB
;
	.END
		}
		$(OVR)		= {
		LEX
		LEXSRT
		IMPURE
		$(SUPORT)
		$(RTLIB)
		DFA/O:1
		MIN/O:1
		OUT1/O:1
		YTAB/O:1
		BASE/O:2
		OUT2/O:2
		ECLOSU/O:2
		}
*/

#ifdef	DOCUMENTATION

title	lex	A Lexical Analyser Generator
index		A Lexical Analyser Generator

synopsis

	lex [-options] [-i grammar] [-o outfile] [-t table]

description

	Lex compiles a lexical analyser from a grammar and description of
	actions.  It is described more fully in lex.doc: only usage is
	described.  The following options are available:
	.lm +16
	.s.i-16;-a		Disable recognition of non-ASCII characters
	(codes > 177 octal) for exception character classes (form [^ ...]).
	.s.i-16;-d		Enable debugging code within lex.  Normally
	needed only for debugging lex.
	.s.i-16;-e		"Easy" command line. Saying "lex#-e#name" is the
	same as saying:
	.s.i 4;"lex -i name.lxi -o name.c -t name"
	.s
	Do not include devices or an extension on "name" or make it longer
	than 8 characters, or you'll get several error messages.
	.s.i-16;-i file		Read the grammar from the file.  If "-i" is not
	specified, input will be read from the standard input.
	.s.i-16;-m		Enable state minimization. Currently not
	implemented, switch is a no-op.
	.s.i-16;-o file		Write the output to the file.  If "-o" is not
	specified, output will be written to file "lextab.c".
	.s.i-16;-s		"Stand-alone" switch.  Supresses the line
	"#include <stdio.h>" normally generated in the lex output.  Use this
	if LEX is generating a module to be used in a program which does not
	use the "standard I/O" package.
	.s.i-16;-t table	Name the recognizer "table" instead of the
	default "lextab".  If -o is not given, output will be written to file
	"table.c".
	.s.i-16;-v [file]	Verify -- write internal tables to the
	indicated file.  If "-v" is given without a file name argument,
	tables will be written to "lex.out".
	.lm -16

diagnostics

	The following error messages may occur on invocation.  See lex
	documentation for information on compilation errors.
	.lm +8
	.s.i -8;Can't create ...
	.s.i -8;Cannot open ...
	.s.i -8;Illegal option.
	.s.i -8;Illegal switch combination.
	.s
	"-i", "-o" or "-t" given with "-e" or vice-versa
	.s.i -8;Table name too long.
	.s
	The table name (argument to "-t") must not be longer than 8 bytes.
	.s.i -8;Missing table name.
	.s.i -8;Missing input file.
	.s.i -8;Missing output file.
	.s.i -8;Missing name.
	.lm -8

author

	Charles Forsyth
	Modified by Bob Denny
bugs

#endif


#include <stdio.h>
#include "lexlex.h"

extern char *lalloc();
extern char *tolower();

struct	nfa	nfa[MAXNFA];
struct	nfa	*nfap = &nfa[1];

struct	xset	sets[NCHARS];
char	insets[NCHARS];

struct	trans	trans[NTRANS];
struct	trans	*transp = &trans[0];

char	ccls[NCCLS][(NCHARS+1)/NBPC];
int	nccls;

int	ndfa;
struct	dfa	dfa[MAXDFA];
struct	move	move[NNEXT];

char	*tabname = "lextab";
char	tabfile[15];
char	*infile		= NULL;
char	*outfile	= NULL;

#ifdef DEBUG
char	*dumpfile	= "lex.out";
int	lldebug	= 0;
#endif

int	llnxtmax = 0;

FILE	*llout;
FILE	*lexin;
FILE	*lexlog;

/*
 * Flags.  Allow globals only for
 * those requiring same. Some only
 * used for checking for bad combos.
 */
	int	aflag = 0;	/* Ignore non-ASCII in [^ ...] */
static	int	eflag = 0;	/* Easy command line */
static	int	iflag = 0;	/* "-i" given */
	int	mflag = 0;	/* Enable state minimization (not imp.) */
static	int	oflag = 0;	/* "-o" given */
	int	sflag = 0;	/* Supress "#include <stdio.h>" in output */
static	int	tflag = 0;	/* "-t" given */

struct	set	*setlist = 0;

main(argc, argv)
char **argv;
{
	register char *cp, *cp2;

#ifdef DEBUG
	int vflag;
	vflag = 0;
#endif

	for (; argc>1 && *argv[1]=='-'; argv++, argc--)
	switch (tolower(argv[1][1])) {

#ifdef DEBUG
	/*
	 * Create "verification" file, describing the
	 * scanner.
	 */
	case 'v':				/* -v => lex.out	*/
		vflag++;			/* -v x.out => x.out	*/
		if (argc > 2 && argv[2][1] != '1') {
			--argc;
			dumpfile = (++argv)[1];
		}
		break;

	/*
	 * Enable debug displays
	 */
	case 'd':
		lldebug++;
		break;
#endif
	/*
	 * Enable state minimization. Currently not
	 * implemented.
	 */
	case 'm':
		mflag++;
		break;

	/*
	 * Disable matching of non-ASCII characters (codes > 177(8))
	 * for exception character classes (form "[^ ...]").
	 */
	case 'a':
		aflag++;
		break;

	/*
	 * Supress "#include <stdio.h>" in generated
	 * code for programs not using standard I/O.
	 */
	case 's':
		sflag++;
		break;

	/*
	 * "Easy" command line
	 */
	case 'e':
		if(iflag || oflag || tflag) {
			error("Illegal switch combination\n");
			exit(1);
		}
		if (--argc <= 1) {
			error("Missing name\n");
			exit(1);
		}
		if (strlen(tabname = (++argv)[1]) > 8) {
			error("Name too long\n");
			exit(1);
		}
		infile = malloc(14);
		outfile = malloc(12);
		concat(infile, tabname, ".lxi", 0);
		if (freopen(infile, "r", stdin) == NULL) {
			error("Cannot open input \"%s\"\n", infile);
			exit(1);
		}
		concat(outfile, tabname, ".c", 0);
		break;

	/*
	 * Specify input file name. Default = terminal (stdin)
	 */
	case 'i':
		if (eflag) {
			error("Illegal switch combination\n");
			exit(1);
		}
		iflag++;
		if (--argc <= 1) {
			error("Missing input file\n");
			exit(1);
		}
		infile = (++argv)[1];
		if (freopen(infile, "r", stdin) == NULL) {
			error("Cannot open input \"%s\"\n", infile);
			exit(1);
		}
		break;

	/*
	 * Specify output file name. Default = "lextab.c"
	 */
	case 'o':
		if (eflag) {
			error("Illegal switch combination\n");
			exit(1);
		}
		oflag++;
		if (--argc <= 1) {
			error("Missing output file");
			exit(1);
		}
		outfile = (++argv)[1];
		break;

	/*
 	 * Specify table name.  Default = "lextab".  If "-o"
	 * not given, output will go to "tabname.c".
	 */
	case 't':
		if (eflag) {
			error("Illegal switch combination\n");
			exit(1);
		}
		tflag++;
		if (--argc <= 1) {
			error("Missing table name");
			exit(1);
		}
		if (strlen(tabname = (++argv)[1]) > 8) {
			error("Table name too long\n");
			exit(1);
		}
		break;

	default:
		error("Illegal option: %s\n", argv[1]);
		exit(1);
	}
	lexin = stdin;

#ifdef DEBUG
	cp = (vflag) ? dumpfile : "nl:";	/* Dec specific	*/
	if ((lexlog = fopen(cp, "w")) == NULL) {
		error("Cannot open \"%s\"", cp);
		exit(1);
	}
#endif

	if (infile == NULL) {
		infile = malloc(31);
		fgetname(lexin, infile);
	}
	cp = infile;			/* Fold infile to lower case */
	while(*cp)
		*cp++ = tolower(*cp);
	cp = tabname;			/* Fold tabname to lower case */
	while(*cp)
		*cp++ = tolower(*cp);
	if (outfile == NULL) {
		/*
		 * Typical hacker's idiom!
		 */
		for (cp = tabname, cp2 = tabfile; *cp2 = *cp++;)
			cp2++;
		for (cp = ".c"; *cp2++ = *cp++;)
			;
		outfile = tabfile;
	}
	if ((llout = freopen(outfile, "w", stdout))==NULL) {
		error("Can't create %s\n", outfile);
		exit(1);
	}
	heading();
	if (yyparse())
		error("Parse failed\n");
	dfabuild();						/* 01+ */
	dfamin();
	dfaprint();
	dfawrite();
#ifdef DEBUG
	stats();
#endif								/* 01- */
} /** END OF MAIN **/

/*
 * This module was moved here from out.c so it could be called from
 * ytab.c residing in same overlay region as out.c.
 * 02-Dec-80  Bob Denny.
 */
								/* 01+ */
ending()
{
	static int ended;

	if (ended++)
		return;
	fprintf(llout, "\t}\n\treturn(LEXSKIP);\n}\n");
	setline();
}
								/* 01- */

#ifdef DEBUG
stats()
{
	fprintf(lexlog, "\n");
	fprintf(lexlog, "%d/%d NFA states, %d/%d DFA states\n",
		nfap-nfa, MAXNFA, ndfa, MAXDFA);
	fprintf(lexlog, "%d/%d entries in move vectors\n", llnxtmax, NNEXT);
}

/*
 * Print a state set on { ... } form on lexlog.
 */
pset(t, nf)
register struct set *t;
{
	register i;

	fprintf(lexlog, "{");
	for (i = 0; i < t->s_len; i++)
		if (nf)
			fprintf(lexlog, " %d", t->s_els[i]-nfa); else
			fprintf(lexlog, " %d", t->s_els[i]);
	fprintf(lexlog, "}");
}

/*
 * Print a character to lexlog in readable form.
 * Returns the number of characters generated.
 */
chprint(ch)
{
	register char *s;

	ch &= 0377;
	switch (ch) {
	case '\t':
		s = "\\t";
		break;
	case '\n':
		s = "\\n";
		break;
	case '\b':
		s = "\\b";
		break;
	case '\r':
		s = "\\r";
		break;
	default:
		if(ch<040 || ch>=0177)
			{
			fprintf(lexlog, "\\%03o", ch);
			return(4);
			}
		else
			{
			putc(ch, lexlog);
			return(1);
			}
	}
	fprintf(lexlog, s);
	return(2);
}
#endif

/*
 * The following functions simply
 * allocate various kinds of
 * structures.
 */
struct nfa *
newnfa(ch, nf1, nf2)
struct nfa *nf1, *nf2;
{
	register struct nfa *nf;

	if ((nf = nfap++) >= &nfa[MAXNFA]) {
		error("Too many NFA states");
		exit(1);
	}
	nf->n_char = ch;
	nf->n_succ[0] = nf1;
	nf->n_succ[1] = nf2;
	nf->n_trans = 0;
	nf->n_flag = 0;
	nf->n_look = 0;
	return(nf);
}

newdfa()
{
	register struct dfa *df;

	if ((df = &dfa[ndfa++]) >= &dfa[MAXDFA]) {
		error("Out of dfa states");
		exit(1);
	}
	return(df);
}

char *
newccl(ccl)
char *ccl;
{
	register char *p, *q;
	register i;
	int j;

	for (j = 0; j < nccls; j++) {
		p = ccl;
		q = ccls[j];
		for (i = sizeof(ccls[j]); i--;)
			if (*p++ != *q++)
				goto cont;
		return(ccls[j]);
	cont:;
	}
	if (nccls >= NCCLS) {
		error("Too many character classes");
		exit(1);
	}
	p = ccl;
	q = ccls[j = nccls++];
	for (i = sizeof(ccls[j]); i--;)
		*q++ = *p++;
	return(ccls[j]);
}

struct trans *
newtrans(st, en)
struct nfa *st, *en;
{
	register struct trans *tp;

	if ((tp = transp++) >= &trans[NTRANS]) {
		error("Too many translations");
		exit(1);
	}
	tp->t_start = st;
	tp->t_final = en;
	en->n_trans = tp;
	return(tp);
}

/*
 * create a new set.
 * `sf', if set, indicates
 * that the elements of the
 * set are states of an NFA).
 * If `sf' is not set, the
 * elements are state numbers of
 * a DFA.
 */
struct set *
newset(v, i, sf)
register struct nfa **v;
register i;
{
	register struct set *t;
	register k;
	int setcomp();

	qsort(v, i, sizeof(*v), setcomp);
	for (t = setlist; t; t = t->s_next)
		if (t->s_len==i && eqvec(t->s_els, v, i))
			return(t);
	t = lalloc(1, sizeof(*t)+i*sizeof(t->s_els[0]), "set nodes");
	t->s_next = setlist;
	setlist = t;
	t->s_final = 0;
	t->s_state =  0;
	t->s_flag = 0;
	t->s_len = i;
	t->s_group = 0;
	t->s_look = 0;
	for (v += i; i;) {
		--v;
		if (sf) {
			if ((*v)->n_char==FIN)
				t->s_final =  (*v)-nfa;
			if ((*v)->n_flag&LOOK)
				t->s_look |= 1<<(*v)->n_look;
		} else {
			k = *v;
			dfa[k].df_name->s_group = t;
		}
		t->s_els[--i] = *v;
	}
	return(t);
}

setcomp(n1p, n2p)
struct nfa **n1p, **n2p;
{
	register struct nfa *n1, *n2;

	n1 = *n1p;
	n2 = *n2p;
	if (n1 > n2)
		return(1);
	if (n1==n2)
		return(0);
	return(-1);
}

eqvec(a, b, i)
register *a, *b, i;
{
	if (i)
		do {
			if (*a++ != *b++)
				return(0);
		} while (--i);
	return(1);
}

/*
 * Ask for core, and
 * complain if there is no more.
 */
char *
lalloc(n, s, w)
char *w;
{
	register char *cp;

	if ((cp = calloc(n, s)) == NULL) {
		fprintf(stderr, "No space for %s", w);
#ifdef DEBUG
		if (lldebug)
			dfaprint();
#endif
		exit(1);
	}
	return(cp);
}