/*	$OpenBSD: unifdef.c,v 1.6 2002/10/04 20:27:16 deraadt Exp $	*/
/*	$NetBSD: unifdef.c,v 1.6 1998/10/08 01:31:59 wsanchez Exp $	*/

/*
 * Copyright (c) 1985, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Dave Yost.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1985, 1993\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif				/* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)unifdef.c	8.1 (Berkeley) 6/6/93";
#endif
static char rcsid[] = "$OpenBSD: unifdef.c,v 1.6 2002/10/04 20:27:16 deraadt Exp $";
#endif				/* not lint */

/*
 * unifdef - remove ifdef'ed lines
 *
 *  Warning: will not work correctly if input contains null characters.
 *
 *  Wishlist:
 *      provide an option which will append the name of the
 *        appropriate symbol after #else's and #endif's
 *      provide an option which will check symbols after
 *        #else's and #endif's to see that they match their
 *        corresponding #ifdef or #ifndef
 */

#include <stdio.h>
#include <ctype.h>

FILE   *input;
#ifndef YES
#define YES 1
#define NO  0
#endif				/* YES */
#define C_COMMENT   1
#define CXX_COMMENT 2
typedef int Bool;

char   *progname;
char   *filename;
char text;			/* -t option in effect: this is a text file */
char lnblank;			/* -l option in effect: blank deleted lines */
char complement;		/* -c option in effect: complement the
				 * operation */

#define MAXSYMS 100
char   *symname[MAXSYMS];	/* symbol name */
char    true[MAXSYMS];		/* -Dsym */
char    ignore[MAXSYMS];	/* -iDsym or -iUsym */
char    insym[MAXSYMS];		/* state: false, inactive, true */
#define SYM_INACTIVE 0		/* symbol is currently inactive */
#define SYM_FALSE    1		/* symbol is currently false */
#define SYM_TRUE     2		/* symbol is currently true  */

char nsyms;
char incomment;			/* inside C comment */

#define QUOTE_NONE   0
#define QUOTE_SINGLE 1
#define QUOTE_DOUBLE 2
char inquote;			/* inside single or double quotes */
int exitstat;

int error(int, int, int);
int findsym(char *);
void flushline(Bool);
int getlin(char *, int, FILE *, int);
void pfile(void);
void prname(void);
char   *skipcomment(char *);
char   *skipquote(char *, int);

int
main(argc, argv)
	int     argc;
	char  **argv;
{
	char  **curarg;
	char *cp;
	char *cp1;
	char    ignorethis;

	progname = argv[0][0] ? argv[0] : "unifdef";

	for (curarg = &argv[1]; --argc > 0; curarg++) {
		if (*(cp1 = cp = *curarg) != '-')
			break;
		if (*++cp1 == 'i') {
			ignorethis = YES;
			cp1++;
		} else
			ignorethis = NO;
		if ((*cp1 == 'D'
			|| *cp1 == 'U'
		    )
		    && cp1[1] != '\0'
		    ) {
			int symind;

			if ((symind = findsym(&cp1[1])) < 0) {
				if (nsyms >= MAXSYMS) {
					prname();
					fprintf(stderr, "too many symbols.\n");
					exit(2);
				}
				symind = nsyms++;
				symname[symind] = &cp1[1];
				insym[symind] = SYM_INACTIVE;
			}
			ignore[symind] = ignorethis;
			true[symind] = *cp1 == 'D' ? YES : NO;
		} else
			if (ignorethis)
				goto unrec;
			else
				if (strcmp(&cp[1], "t") == 0)
					text = YES;
				else
					if (strcmp(&cp[1], "l") == 0)
						lnblank = YES;
					else
						if (strcmp(&cp[1], "c") == 0)
							complement = YES;
						else {
					unrec:
							prname();
							fprintf(stderr, "unrecognized option: %s\n", cp);
							goto usage;
						}
	}
	if (nsyms == 0) {
usage:
		fprintf(stderr, "\
Usage: %s [-l] [-t] [-c] [[-Dsym] [-Usym] [-iDsym] [-iUsym]]... [file]\n\
    At least one arg from [-D -U -iD -iU] is required\n", progname);
		exit(2);
	}
	if (argc > 1) {
		prname();
		fprintf(stderr, "can only do one file.\n");
	} else
		if (argc == 1) {
			filename = *curarg;
			if ((input = fopen(filename, "r")) != NULL) {
				pfile();
				(void) fclose(input);
			} else {
				prname();
				fprintf(stderr, "can't open ");
				perror(*curarg);
			}
		} else {
			filename = "[stdin]";
			input = stdin;
			pfile();
		}

	(void) fflush(stdout);
	exit(exitstat);
}
/* types of input lines: */
typedef int Linetype;
#define LT_PLAIN       0	/* ordinary line */
#define LT_TRUE        1	/* a true  #ifdef of a symbol known to us */
#define LT_FALSE       2	/* a false #ifdef of a symbol known to us */
#define LT_OTHER       3	/* an #ifdef of a symbol not known to us */
#define LT_IF          4	/* an #ifdef of a symbol not known to us */
#define LT_ELSE        5	/* #else */
#define LT_ENDIF       6	/* #endif */
#define LT_LEOF        7	/* end of file */
Linetype checkline(int *);

typedef int Reject_level;
Reject_level reject;		/* 0 or 1: pass thru; 1 or 2: ignore comments */
#define REJ_NO          0
#define REJ_IGNORE      1
#define REJ_YES         2
int doif(int, int, Reject_level, int);

int linenum;			/* current line number */
int stqcline;			/* start of current coment or quote */
char   *errs[] = {
#define NO_ERR      0
	"",
#define END_ERR     1
	"",
#define ELSE_ERR    2
	"Inappropriate else",
#define ENDIF_ERR   3
	"Inappropriate endif",
#define IEOF_ERR    4
	"Premature EOF in ifdef",
#define CEOF_ERR    5
	"Premature EOF in comment",
#define Q1EOF_ERR   6
	"Premature EOF in quoted character",
#define Q2EOF_ERR   7
	"Premature EOF in quoted string"
};
/* States for inif arg to doif */
#define IN_NONE 0
#define IN_IF   1
#define IN_ELSE 2

void
pfile()
{
	reject = REJ_NO;
	(void) doif(-1, IN_NONE, reject, 0);
	return;
}

int
doif(thissym, inif, prevreject, depth)
	int thissym;	/* index of the symbol who was last ifdef'ed */
	int     inif;		/* YES or NO we are inside an ifdef */
	Reject_level prevreject;/* previous value of reject */
	int     depth;		/* depth of ifdef's */
{
	Linetype lineval;
	Reject_level thisreject;
	int     doret;		/* tmp return value of doif */
	int     cursym;		/* index of the symbol returned by checkline */
	int     stline;		/* line number when called this time */

	stline = linenum;
	for (;;) {
		switch (lineval = checkline(&cursym)) {
		case LT_PLAIN:
			flushline(YES);
			break;

		case LT_TRUE:
		case LT_FALSE:
			thisreject = reject;
			if (lineval == LT_TRUE)
				insym[cursym] = SYM_TRUE;
			else {
				if (reject != REJ_YES)
					reject = ignore[cursym] ? REJ_IGNORE : REJ_YES;
				insym[cursym] = SYM_FALSE;
			}
			if (ignore[cursym])
				flushline(YES);
			else {
				exitstat = 1;
				flushline(NO);
			}
			if ((doret = doif(cursym, IN_IF, thisreject, depth + 1)) != NO_ERR)
				return error(doret, stline, depth);
			break;

		case LT_IF:
		case LT_OTHER:
			flushline(YES);
			if ((doret = doif(-1, IN_IF, reject, depth + 1)) != NO_ERR)
				return error(doret, stline, depth);
			break;

		case LT_ELSE:
			if (inif != IN_IF)
				return error(ELSE_ERR, linenum, depth);
			inif = IN_ELSE;
			if (thissym >= 0) {
				if (insym[thissym] == SYM_TRUE) {
					reject = ignore[thissym] ? REJ_IGNORE : REJ_YES;
					insym[thissym] = SYM_FALSE;
				} else {	/* (insym[thissym] ==
						 * SYM_FALSE) */
					reject = prevreject;
					insym[thissym] = SYM_TRUE;
				}
				if (!ignore[thissym]) {
					flushline(NO);
					break;
				}
			}
			flushline(YES);
			break;

		case LT_ENDIF:
			if (inif == IN_NONE)
				return error(ENDIF_ERR, linenum, depth);
			if (thissym >= 0) {
				insym[thissym] = SYM_INACTIVE;
				reject = prevreject;
				if (!ignore[thissym]) {
					flushline(NO);
					return NO_ERR;
				}
			}
			flushline(YES);
			return NO_ERR;

		case LT_LEOF:{
				int     err;
				err = incomment
				    ? CEOF_ERR
				    : inquote == QUOTE_SINGLE
				    ? Q1EOF_ERR
				    : inquote == QUOTE_DOUBLE
				    ? Q2EOF_ERR
				    : NO_ERR;
				if (inif != IN_NONE) {
					if (err != NO_ERR)
						(void) error(err, stqcline, depth);
					return error(IEOF_ERR, stline, depth);
				} else
					if (err != NO_ERR)
						return error(err, stqcline, depth);
					else
						return NO_ERR;
			}
		}
	}
}
#define endsym(c) (!isalpha (c) && !isdigit (c) && c != '_')

#define MAXLINE 256
char    tline[MAXLINE];

Linetype
checkline(cursym)
	int    *cursym;		/* if LT_TRUE or LT_FALSE returned, set this
				 * to sym index */
{
	char *cp;
	char *symp;
	char   *scp;
	Linetype retval;
#define KWSIZE 8
	char    keyword[KWSIZE];

	linenum++;
	if (getlin(tline, sizeof tline, input, NO) == EOF)
		return LT_LEOF;

	retval = LT_PLAIN;
	if (*(cp = tline) != '#'
	    || incomment
	    || inquote == QUOTE_SINGLE
	    || inquote == QUOTE_DOUBLE
	    )
		goto eol;

	cp = skipcomment(++cp);
	symp = keyword;
	while (!endsym(*cp)) {
		*symp = *cp++;
		if (++symp >= &keyword[KWSIZE])
			goto eol;
	}
	*symp = '\0';

	if (strcmp(keyword, "ifdef") == 0) {
		retval = YES;
		goto ifdef;
	} else
		if (strcmp(keyword, "ifndef") == 0) {
			retval = NO;
	ifdef:
			scp = cp = skipcomment(++cp);
			if (incomment) {
				retval = LT_PLAIN;
				goto eol;
			} {
				int     symind;

				if ((symind = findsym(scp)) >= 0)
					retval = (retval ^ true[*cursym = symind])
					    ? LT_FALSE : LT_TRUE;
				else
					retval = LT_OTHER;
			}
		} else
			if (strcmp(keyword, "if") == 0)
				retval = LT_IF;
			else
				if (strcmp(keyword, "else") == 0)
					retval = LT_ELSE;
				else
					if (strcmp(keyword, "endif") == 0)
						retval = LT_ENDIF;

eol:
	if (!text && reject != REJ_IGNORE)
		for (; *cp;) {
			if (incomment)
				cp = skipcomment(cp);
			else
				if (inquote == QUOTE_SINGLE)
					cp = skipquote(cp, QUOTE_SINGLE);
				else
					if (inquote == QUOTE_DOUBLE)
						cp = skipquote(cp, QUOTE_DOUBLE);
					else
						if (*cp == '/' && (cp[1] == '*' || cp[1] == '/'))
							cp = skipcomment(cp);
						else
							if (*cp == '\'')
								cp = skipquote(cp, QUOTE_SINGLE);
							else
								if (*cp == '"')
									cp = skipquote(cp, QUOTE_DOUBLE);
								else
									cp++;
		}
	return retval;
}
/*
 *  Skip over comments and stop at the next charaacter
 *  position that is not whitespace.
 */
char   *
skipcomment(cp)
	char *cp;
{
	if (incomment)
		goto inside;
	for (;; cp++) {
		while (*cp == ' ' || *cp == '\t')
			cp++;
		if (text)
			return cp;
		if (cp[0] != '/')
			return cp;

		if (cp[1] == '*') {
			if (!incomment) {
				incomment = C_COMMENT;
				stqcline = linenum;
			}
		} else if (cp[1] == '/') {
			if (!incomment) {
				incomment = CXX_COMMENT;
				stqcline = linenum;
			}
		} else
			return cp;

		cp += 2;
inside:
		if (incomment == C_COMMENT) {
			for (;;) {
				for (; *cp != '*'; cp++)
					if (*cp == '\0')
						return cp;
				if (*++cp == '/') {
					incomment = NO;
					break;
				}
			}
		}
		else if (incomment == CXX_COMMENT) {
			for (; *cp != '\n'; cp++)
				if (*cp == '\0')
					return cp;
			incomment = NO;
		}
	}
}
/*
 *  Skip over a quoted string or character and stop at the next charaacter
 *  position that is not whitespace.
 */
char   *
skipquote(cp, type)
	char *cp;
	int type;
{
	char qchar;

	qchar = type == QUOTE_SINGLE ? '\'' : '"';

	if (inquote == type)
		goto inside;
	for (;; cp++) {
		if (*cp != qchar)
			return cp;
		cp++;
		inquote = type;
		stqcline = linenum;
inside:
		for (;; cp++) {
			if (*cp == qchar)
				break;
			if (*cp == '\0' || (*cp == '\\' && *++cp == '\0'))
				return cp;
		}
		inquote = QUOTE_NONE;
	}
}
/*
 *  findsym - look for the symbol in the symbol table.
 *            if found, return symbol table index,
 *            else return -1.
 */
int
findsym(str)
	char   *str;
{
	char *cp;
	char *symp;
	int symind;
	char chr;

	for (symind = 0; symind < nsyms; ++symind) {
		if (insym[symind] == SYM_INACTIVE) {
			for (symp = symname[symind], cp = str
			    ; *symp && *cp == *symp
			    ; cp++, symp++
			    )
				continue;
			chr = *cp;
			if (*symp == '\0' && endsym(chr))
				return symind;
		}
	}
	return -1;
}
/*
 *   getlin - expands tabs if asked for
 *            and (if compiled in) treats form-feed as an end-of-line
 */
int
getlin(line, maxline, inp, expandtabs)
	char *line;
	int     maxline;
	FILE   *inp;
	int     expandtabs;
{
	int     tmp;
	int num;
	int chr;
#ifdef  FFSPECIAL
	static char havechar = NO;	/* have leftover char from last time */
	static char svchar;
#endif				/* FFSPECIAL */

	num = 0;
#ifdef  FFSPECIAL
	if (havechar) {
		havechar = NO;
		chr = svchar;
		goto ent;
	}
#endif				/* FFSPECIAL */
	while (num + 8 < maxline) {	/* leave room for tab */
		chr = getc(inp);
		if (chr == EOF)
			return EOF;
		if (isprint(chr)) {
#ifdef  FFSPECIAL
	ent:
#endif				/* FFSPECIAL */
			*line++ = chr;
			num++;
		} else
			switch (chr) {
			case '\t':
				if (expandtabs) {
					num += tmp = 8 - (num & 7);
					do
						*line++ = ' ';
					while (--tmp);
					break;
				}
			default:
				*line++ = chr;
				num++;
				break;

			case '\n':
				*line = '\n';
				num++;
				goto end;

#ifdef  FFSPECIAL
			case '\f':
				if (++num == 1)
					*line = '\f';
				else {
					*line = '\n';
					havechar = YES;
					svchar = chr;
				}
				goto end;
#endif				/* FFSPECIAL */
			}
	}
end:
	*++line = '\0';
	return num;
}

void
flushline(keep)
	Bool    keep;
{
	if ((keep && reject != REJ_YES) ^ complement) {
		char *line = tline;
		FILE *out = stdout;
		char chr;

		while ((chr = *line++))
			putc(chr, out);
	} else
		if (lnblank)
			putc('\n', stdout);
	return;
}

void
prname()
{
	fprintf(stderr, "%s: ", progname);
	return;
}

int
error(err, line, depth)
	int     err;		/* type of error & index into error string
				 * array */
	int     line;		/* line number */
	int     depth;		/* how many ifdefs we are inside */
{
	if (err == END_ERR)
		return err;

	prname();

#ifndef TESTING
	fprintf(stderr, "Error in %s line %d: %s.\n", filename, line, errs[err]);
#else				/* TESTING */
	fprintf(stderr, "Error in %s line %d: %s. ", filename, line, errs[err]);
	fprintf(stderr, "ifdef depth: %d\n", depth);
#endif				/* TESTING */

	exitstat = 2;
	return depth > 1 ? IEOF_ERR : END_ERR;
}