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This is the first step in sanitizing the conditional parser.

Change the conditional recognition algorithm:
scan for a sequence of alphabetic characters, hash it, and compare it against
a small table (using ohash functions).
This makes Cond_Eval entry more logical, and allows for some shortcuts in
recognizing .include, .for, .undef.

This also means that conditionals must have an intervening blank between
the keyword and the actual test, e.g.,
.ifA
will no longer work.

(but no-one actually uses this, and it's highly obfuscated)

Okay miod@.

/*	$OpenPackages$ */
/*	$OpenBSD: for.c,v 1.27 2002/06/11 21:12:11 espie Exp $	*/
/*	$NetBSD: for.c,v 1.4 1996/11/06 17:59:05 christos Exp $ */

/*
 * Copyright (c) 1999 Marc Espie.
 *
 * Extensive code modifications for the OpenBSD project.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE OPENBSD PROJECT 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 OPENBSD
 * PROJECT 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.
 */

/*
 * Copyright (c) 1992, The Regents of the University of California.
 * All rights reserved.
 *
 * 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.
 */

#include <assert.h>
#include <ctype.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "config.h"
#include "defines.h"
#include "buf.h"
#include "for.h"
#include "lst.h"
#include "error.h"
#include "var.h"
#include "lowparse.h"
#include "str.h"
#include "memory.h"

/*
 * For statements are of the form:
 *
 * .for <variable> [variable...] in <varlist>
 * ...
 * .endfor
 *
 * The trick is to look for the matching .end inside .for loops.
 * To do that, we keep track of the nesting level of .for loops
 * and matching .endfor statements, accumulating all statements between
 * the initial .for loop and the matching .endfor,
 * then we evaluate the .for loop for each variable in the varlist.
 */

/* State of a for loop.  */
struct For_ {
    char		*text;		/* Unexpanded text		*/
    LIST		vars;		/* List of variables		*/
    LstNode		var;		/* Current var			*/
    int			nvars;		/* Total number of vars		*/
    LIST		lst;		/* List of items		*/
    size_t		guess;		/* Estimated expansion size	*/
    BUFFER		buf;		/* Accumulating text		*/
    unsigned long	lineno; 	/* Line number at start of loop */
    unsigned long	level;		/* Nesting level		*/
    bool		freeold;
};

/* ForExec(value, handle);
 *	Expands next variable in loop sequence described by handle to value. */
static void ForExec(void *, void *);

/* n = build_words_list(lst, s);
 *	Cuts string into words, pushes words into list, in reverse order,
 *	because Parse_FromString works as a stack.
 *	Returns the number of words.  */
static unsigned long build_words_list(Lst, const char *);

static unsigned long
build_words_list(lst, s)
    Lst lst;
    const char *s;
{
    const char *end, *wrd;
    unsigned long n;

    n = 0;
    end = s;

    while ((wrd = iterate_words(&end)) != NULL) {
	Lst_AtFront(lst, escape_dupi(wrd, end, "\"'"));
	n++;
    }
    return n;
}

For *
For_Eval(line)
    const char	    *line;    /* Line to parse */
{
    const char	*ptr = line;
    const char	*wrd;
    char	*sub;
    const char	*endVar;
    For 	*arg;
    unsigned long n;

    while (*ptr && isspace(*ptr))
	ptr++;

    /* We found a for loop, and now we are going to parse it.  */

    arg = emalloc(sizeof(*arg));
    arg->nvars = 0;
    Lst_Init(&arg->vars);

    for (;;) {
	/* Grab the variables.  */
	for (wrd = ptr; *ptr && !isspace(*ptr); ptr++)
	    continue;
	if (ptr - wrd == 0) {
	    Parse_Error(PARSE_FATAL, "Syntax error in for");
	    return 0;
	}
	endVar = ptr++;
	while (*ptr && isspace(*ptr))
	    ptr++;
	/* End of variable list ? */
	if (endVar - wrd == 2 && wrd[0] == 'i' && wrd[1] == 'n')
	    break;
	Lst_AtEnd(&arg->vars, Str_dupi(wrd, endVar));
	arg->nvars++;
    }
    if (arg->nvars == 0) {
	Parse_Error(PARSE_FATAL, "Missing variable in for");
	return 0;
    }

    /* Make a list with the remaining words.  */
    sub = Var_Subst(ptr, NULL, false);
    if (DEBUG(FOR)) {
    	LstNode ln;
	(void)fprintf(stderr, "For: Iterator ");
	for (ln = Lst_First(&arg->vars); ln != NULL; ln = Lst_Adv(ln))
		(void)fprintf(stderr, "%s ", (char *)Lst_Datum(ln));
	(void)fprintf(stderr, "List %s\n", sub);
    }

    Lst_Init(&arg->lst);
    n = build_words_list(&arg->lst, sub);
    free(sub);
    if (arg->nvars != 1 && n % arg->nvars != 0) {
	Parse_Error(PARSE_FATAL, "Wrong number of items in for loop");
    	return 0;
    }
    arg->lineno = Parse_Getlineno();
    arg->level = 1;
    Buf_Init(&arg->buf, 0);

    return arg;
}


bool
For_Accumulate(arg, line)
    For 	    *arg;
    const char	    *line;    /* Line to parse */
{
    const char	    *ptr = line;

    assert(arg->level > 0);

    if (*ptr == '.') {

	for (ptr++; *ptr && isspace(*ptr); ptr++)
	    continue;

	if (strncmp(ptr, "endfor", 6) == 0 &&
	    (isspace(ptr[6]) || !ptr[6])) {
	    if (DEBUG(FOR))
		(void)fprintf(stderr, "For: end for %lu\n", arg->level);
	    /* If matching endfor, don't add line to buffer.  */
	    if (--arg->level == 0)
		return false;
	}
	else if (strncmp(ptr, "for", 3) == 0 &&
		 isspace(ptr[3])) {
	    arg->level++;
	    if (DEBUG(FOR))
		(void)fprintf(stderr, "For: new loop %lu\n", arg->level);
	}
    }
    Buf_AddString(&arg->buf, line);
    Buf_AddChar(&arg->buf, '\n');
    return true;
}


#define GUESS_EXPANSION 32
static void
ForExec(valuep, argp)
    void *valuep;
    void *argp;
{
    char *value = (char *)valuep;
    For *arg = (For *)argp;
    BUFFER buf;

    /* Parse_FromString pushes stuff back, so we need to go over vars in
       reverse.  */
    if (arg->var == NULL) {
    	arg->var = Lst_Last(&arg->vars);
	arg->text = Buf_Retrieve(&arg->buf);
	arg->freeold = false;
    }

    if (DEBUG(FOR))
	(void)fprintf(stderr, "--- %s = %s\n", (char *)Lst_Datum(arg->var),
	    value);
    Buf_Init(&buf, arg->guess);
    Var_SubstVar(&buf, arg->text, Lst_Datum(arg->var), value);
    if (arg->freeold)
    	free(arg->text);
    arg->text = Buf_Retrieve(&buf);
    arg->freeold = true;
    arg->var = Lst_Rev(arg->var);
    if (arg->var == NULL)
	Parse_FromString(arg->text, arg->lineno);
}


void
For_Run(arg)
    For *arg;
{
    arg->text = Buf_Retrieve(&arg->buf);
    arg->guess = Buf_Size(&arg->buf) + GUESS_EXPANSION;

    arg->var = NULL;
    Lst_ForEach(&arg->lst, ForExec, arg);
    Buf_Destroy(&arg->buf);
    Lst_Destroy(&arg->vars, (SimpleProc)free);
    Lst_Destroy(&arg->lst, (SimpleProc)free);
    free(arg);
}