/*
   Copyright (C) 2001-2023 Free Software Foundation, Inc.

   Authors:
   Keisuke Nishida, Roger While, Ron Norman, Simon Sobisch, Brian Tiffin,
   Edward Hart, Dave Pitts, Fabrice Le Fessant

   This file is part of GnuCOBOL.

   The GnuCOBOL compiler is free software: you can redistribute it
   and/or modify it under the terms of the GNU General Public License
   as published by the Free Software Foundation, either version 3 of the
   License, or (at your option) any later version.

   GnuCOBOL is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with GnuCOBOL.  If not, see <https://www.gnu.org/licenses/>.
*/

#include "tarstamp.h"
#include "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdarg.h>
#include <string.h>
#ifdef	HAVE_STRINGS_H
#include <strings.h>
#endif
#include <ctype.h>
#include <time.h>
#include <limits.h>

#include "cobc.h"
#include "tree.h"

/* This is an implementation of the *two* phases of COPY-REPLACING and
   REPLACE on a stream of tokens: the stream of tokens generated by the
   pplex.l/parser.y goes first through COPY-REPLACING replacements,
   and then through REPLACE replacements, as expected by the COBOL
   standard.

   However, it does not fully conform to the standard, as REPLACE are
   parsed on the input stream *before* any COPY-REPLACING could have
   been applied.

   The general entry point is `add_text_to_replace (stream, prequeue,
   token)`, it adds `token` to `stream`, `prequeue` is 1 if the
   token should not be treated immediately (because it may be merged
   with other following tokens if they are of the same kind), 0
   otherwise.

   Initially, `pp_echo()` in `pplex.l` will use
   `cb_ppecho_copy_replace()` to add tokens to the first stream
   `copy_repls` (using `add_text_to_replace`), i.e. the stream of
   copy-replacing.

   Once copy-replacing operations have been performed in this stream,
   `ppecho_replace()` is used to add tokens to the second stream
   `replace_repls` (using again `add_text_to_replace`), i.e. the
   stream of `replace`.

   Once replace operations have been performed on this second stream,
   `cb_ppecho_direct()` (in pplex.l) is used to output the final
   tokens.

   The states of both streams are stored in a struct
   `cb_replacement_state`, and `add_text_to_replace` calls the
   function `do_replace()` to perform the replacement on a given
   stream.
 */

/* Uncomment the following lines to have a trace of replacements.
   It uses macros WITH_DEPTH that adds an additional argument to every
   function to keep the depth of the recursion. */

/* #define DEBUG_REPLACE_TRACE */
/* #define DEBUG_REPLACE */

#ifdef DEBUG_REPLACE_TRACE
#define DEBUG_REPLACE
#endif

struct cb_token_list {
	struct cb_token_list	*next;			/* next pointer */
	struct cb_token_list	*last;

	 /* The text in the source to be matched. Most of the time, it
	  *  directly what appears in the source file, but it may also
	  *  be a simplified version, typically for spaces, in which
	  *  case the exact text is stored in the `token` field (to be
	  *  used if no replacement is performed) */
	const char		*text;

	/* NULL most of the time, non-NULL only if the `text` was
	 * replaced by a simplified version, i.e. space to easy
	 * testing. */
	const char		*token;
};

/* types */
enum cb_ppecho {
	CB_PPECHO_DIRECT  = 0, /* direct output */
	CB_PPECHO_REPLACE = 1, /* output to REPLACE */
};

struct cb_replacement_state {

	/* The list of tokens that are currently being checked for
	 * replacements. Empty, unless a partial match occurred. */
	struct cb_token_list *token_queue ;

	/* We don't queue WORD tokens immediately, because
	 * preprocessing could create larger words. Instead, we buffer
	 * WORD tokens (and merge them) until another kind of token
	 * (SPACE,DELIM,etc.) is received. */
	const char              *text_prequeue ;

	/* Current list of replacements specified in COPY-REPLACING or
	 * REPLACE */
	struct cb_replace_list  *replace_list ;

	/* List of replacements after a partial match that still need
	 * to be tested. */
	const struct cb_replace_list  *current_list ;

	/* The next pass to which generated tokens should be passed
	 * (either REPLACE pass or direct output */
	enum cb_ppecho           ppecho ;

#ifdef DEBUG_REPLACE
	const char* name ;
#endif
};


#ifdef DEBUG_REPLACE_TRACE

#define WITH_DEPTH int depth,
#define INIT_DEPTH 1,
#define MORE_DEPTH depth+1,

#define MAX_DEPTH 100
char depth_buffer[MAX_DEPTH+1];
#define DEPTH depth_buffer + ( MAX_DEPTH-depth )

#else /* DEBUG_REPLACE_TRACE */

#define WITH_DEPTH
#define DEPTH
#define INIT_DEPTH 
#define MORE_DEPTH

#endif /* DEBUG_REPLACE_TRACE */


#ifdef DEBUG_REPLACE

#define MAX_TEXT_LIST_STRING 10000
char text_list_string[MAX_TEXT_LIST_STRING];

/* In debugging mode only, stores a list of text/tokens into a
   preallocated string for easy display */
#define STRING_OF_LIST(kind)						\
static								        \
char * string_of_##kind##_list(const struct cb_##kind##_list *list)	\
{									\
	int pos = 1;							\
	text_list_string[0] = '[';					\
									\
	for(; list != NULL; list = list->next){				\
		size_t len = strlen (list->text);			\
		text_list_string[pos++] = '"';				\
		memcpy (text_list_string + pos, list->text, len);	\
		pos += len;						\
		text_list_string[pos++] = '"';				\
		text_list_string[pos++] = ',';				\
		text_list_string[pos++] = ' ';				\
	}								\
									\
	text_list_string[pos] = ']';					\
	text_list_string[pos+1]=0;					\
	return text_list_string;					\
}

/* string_of_token_list (...) */
STRING_OF_LIST(token)
/* string_of_text_list (...) */
STRING_OF_LIST(text)

#endif /* DEBUG_REPLACE */

/* global state */
static struct cb_replacement_state * replace_repls;
static struct cb_replacement_state * copy_repls;

/* forward definitions */
static void ppecho_replace (WITH_DEPTH const char *text, const char* token);
static void do_replace (WITH_DEPTH struct cb_replacement_state* repls);
static void check_replace_after_match (WITH_DEPTH struct cb_replacement_state *repls);
static void check_replace_all (WITH_DEPTH struct cb_replacement_state *repls,
			       const struct cb_text_list *new_text,
			       struct cb_token_list *texts,
			       const struct cb_text_list *src,
			       const struct cb_replace_list *replace_list);

static struct cb_token_list *
token_list_add (WITH_DEPTH struct cb_token_list *list,
		const char *text,
		const char *token);

/* This specific token_list_add function does a standard append on
   list, without expecting `last` field to be correctly set.  This is
   important as `pp_token_list_add` only correctly works when always
   adding on the same head, other `last` fields in the middle of the
   list not being correctly updated...
 */
static
struct cb_token_list *
token_list_add (WITH_DEPTH struct cb_token_list *list,
		const char *text, const char *token)
{
#ifdef DEBUG_REPLACE_TRACE
	fprintf (stderr, "%stoken_list_add(%s,'%s')\n",
		DEPTH, string_of_token_list(list), text);
#endif
	struct cb_token_list	*p;

	p = cobc_plex_malloc (sizeof (struct cb_token_list));
	p->text = cobc_plex_strdup (text);
	if (token == NULL) {
		p->token = NULL;
	} else {
		p->token = cobc_plex_strdup (token);
	}

	p->next = NULL;
	if (list==NULL) {
		return p;
	} else {
		struct cb_token_list *cursor = list;
		for (; cursor->next != NULL; cursor = cursor->next);
		cursor->next = p;
		return list;
	}
}

static
void pop_token (WITH_DEPTH struct cb_replacement_state *repls,
		      const char **text, const char **token)
{
	const struct cb_token_list *q = repls->token_queue;
	repls->token_queue = q->next ;
#ifdef DEBUG_REPLACE_TRACE
	fprintf (stderr, "%spop_token(%s) -> '%s'\n",
		DEPTH, repls->name, q->text);
#endif
	if (text) *text = q->text;
	if (token) *token = q->token;
}

static
void ppecho_switch (WITH_DEPTH struct cb_replacement_state *repls,
		    const char* text, const char* token)
{
#ifdef DEBUG_REPLACE_TRACE
	fprintf (stderr, "%sppecho_switch(%s, '%s')\n",
		DEPTH, repls->name, text);
#endif
	switch (repls->ppecho) {
	case CB_PPECHO_DIRECT:
#ifdef DEBUG_REPLACE
		fprintf (stderr, "%s ppecho_direct('%s')\n", DEPTH, text);
#endif
		return cb_ppecho_direct (text, token);
	case CB_PPECHO_REPLACE:
		return ppecho_replace (MORE_DEPTH text, token);
	}
}

static
void ppecho_switch_text_list (WITH_DEPTH struct cb_replacement_state *repls,
			 const struct cb_text_list *p)
{
#ifdef DEBUG_REPLACE_TRACE
	fprintf (stderr, "%sppecho_switch_text_list(%s, %s)\n",
		DEPTH, repls->name, string_of_text_list(p));
#endif

	for (;p;p=p->next){
		ppecho_switch (MORE_DEPTH repls, p->text, NULL);
	}
}


static
void ppecho_switch_token_list (WITH_DEPTH struct cb_replacement_state *repls,
			 const struct cb_token_list *p)
{
#ifdef DEBUG_REPLACE_TRACE
	fprintf (stderr, "%sppecho_switch_token_list(%s, %s)\n",
		DEPTH, repls->name, string_of_token_list(p));
#endif

	for (;p;p=p->next){
		ppecho_switch (MORE_DEPTH repls, p->text, p->token);
	}
}

static
int is_leading_or_trailing (WITH_DEPTH int leading,
			    const char* src_text,
			    const char* text,
			    int strict)
{

	const size_t src_len = strlen (src_text);
	const size_t text_len = strlen(text);
	int result ;
	if (text_len > src_len || ( !strict && text_len == src_len )) {
		int pos = leading ? 0 : text_len - src_len ;
		if (strncasecmp (src_text, text+pos, src_len)) {
			result = 0;
		} else {
			result = 1;
		}
	} else {
		result = 0;
	}
#ifdef DEBUG_REPLACE_TRACE
	fprintf (stderr,
		"%sis_leading_or_trailing(%d, '%s', input='%s', %d) -> %d\n",
		DEPTH, leading, src_text, text, strict, result);
#endif
	return result;
}

/* after a LEADING or TRAILING match, perform the replacement within
   the text, and pass the resulting new text to the next stream */
static
void ppecho_leading_or_trailing (WITH_DEPTH struct cb_replacement_state *repls,
				 int leading,
				 const char *src_text,
				 const char *text,
				 const struct cb_text_list *   new_text)
{
#ifdef DEBUG_REPLACE_TRACE
	fprintf (stderr,
		"%sppecho_leading_or_trailing(%s, %d, '%s', input='%s', ...)\n",
		DEPTH, repls->name, leading, src_text, text);
#endif

	size_t src_len = strlen (src_text);
	size_t text_len = strlen (text);

	if (!leading && text_len > src_len) {
		/* For TRAILING, we have to keep only the non-matched
		   prefix part of the matching text */
		const char* remaining_text =
			cobc_plex_strsub (text,
					  text_len - src_len);
		ppecho_switch (MORE_DEPTH repls, remaining_text, NULL);
	}

	ppecho_switch_text_list (MORE_DEPTH repls, new_text);

	if (leading && text_len > src_len) {
		const char* remaining_text =
			cobc_plex_strsub (text+src_len,
					  text_len - src_len);
		ppecho_switch (MORE_DEPTH repls, remaining_text, NULL);
	}
}

/* `check_replace( repls, replace_list )`: check if one of the
 * replacements in the list `replace_list` applies on the stream
 * `repls`.
 * * `repls`: the current stream
 * * `replace_list`: the current list of possible replacements on check
 */

static
void check_replace (WITH_DEPTH struct cb_replacement_state* repls,
		    const struct cb_replace_list *replace_list)
{
#ifdef DEBUG_REPLACE_TRACE
	fprintf (stderr, "%scheck_replace(%s, ...)\n", DEPTH,
		repls->name);
#endif
	repls->current_list = replace_list;

	if (replace_list == NULL){

		/* NO MATCH: no possible replacement on this text */

		/* remove the text from the current stream */
		const char* text;
		const char* token;
		pop_token (MORE_DEPTH repls, &text, &token);

		/* pass it to the next stream */
		ppecho_switch (MORE_DEPTH repls, text, token);

		/* restart replacements on this stream */
		check_replace_after_match (MORE_DEPTH repls);

	} else {
		const struct cb_replace_src *src = replace_list->src;
		const struct cb_text_list *new_text = replace_list->new_text;
		replace_list = replace_list->next;

		if (src->lead_trail == CB_REPLACE_LEADING
		 || src->lead_trail == CB_REPLACE_TRAILING){
			/* LEADING and TRAILING replacements are
			 * different: they match only on one text, so
			 * we just need one test to decide if it is a
			 * match or a failure */
			int leading = (src->lead_trail == CB_REPLACE_LEADING);
			unsigned int strict = src->strict;
			const char *src_text = src->text_list->text;
			const char *text = repls->token_queue->text;

			if (is_leading_or_trailing (MORE_DEPTH leading,
						    src_text,text,strict)){

				/* MATCH */
				/* remove the text from the current stream */
				pop_token (MORE_DEPTH repls, NULL, NULL);

				/* perform a partial replacement on the text,
				   and pass it to the next stream */
				ppecho_leading_or_trailing (MORE_DEPTH repls,
							    leading,
							    src_text,text,
							    new_text) ;

				/* restart replacements on this stream */
				check_replace_after_match (MORE_DEPTH repls);
			} else {
				check_replace (MORE_DEPTH repls,replace_list);
			}
		} else {
			/* we need to compare a list of texts from
			 * this stream with a list of texts from the
			 * replacement */
			check_replace_all (MORE_DEPTH repls,new_text,
					   repls->token_queue,
					   src->text_list,
					   replace_list);
		}
	}
}

static COB_INLINE COB_A_INLINE int
is_space_or_nl (const char c)
{
	return c == ' ' || c == '\n';
}

/* `check_replace_all( repls, new_text, texts, src, replace_list )`:
 * checks whether a particular replacement is possible on the current
 * list of texts.
 * * `repls` is the current stream state
 * * `new_text` is the text by which the texts should be replace in case of match
 * * `texts` is the list of texts found in the source that remains to be matched
 * * `src` is the list of texts from the replacement to be matched
 * * `replace_list` is the next replacements to try in case of failure
 */
static
void check_replace_all (WITH_DEPTH
			struct cb_replacement_state *repls,
			const struct cb_text_list *new_text,
			struct cb_token_list *texts,
			const struct cb_text_list *src,
			const struct cb_replace_list *replace_list)
{
#ifdef DEBUG_REPLACE_TRACE
	fprintf (stderr, "%scheck_replace_all(%s,",
		DEPTH, repls->name);
	fprintf (stderr, "%s    new_text = %s,\n", DEPTH,
		string_of_text_list(new_text));
	fprintf (stderr, "%s    texts = %s,\n", DEPTH,
		string_of_token_list(texts));
	fprintf (stderr, "%s    src = %s,\n", DEPTH,
		string_of_text_list(src));
	fprintf (stderr, "%s)\n", DEPTH);
#endif

	if (src==NULL){
		/* MATCH */
		/* pass the new text to the next stream */
		ppecho_switch_text_list (MORE_DEPTH repls, new_text) ;
		/* keep only in this stream the remaining texts that have not been matched */
		repls->token_queue = texts ;
		/* restart replacements on the stream */
		check_replace_after_match (MORE_DEPTH repls);
	} else {
		const char* src_text = src->text;
		if (is_space_or_nl(src_text[0])) {
			/* skip spaces in replacement */
			check_replace_all (MORE_DEPTH repls,new_text,texts,
					   src->next, replace_list);
		} else {
			if (texts == NULL){
				/* PARTIAL MATCH, we have emptied the
				 * list of texts, but there are still
				 * texts in the replacement, so wait
				 * for more texts to be added on the
				 * stream */
#ifdef DEBUG_REPLACE_TRACE
	fprintf (stderr, "%s  check_replace_all --> PARTIAL MATCH\n", DEPTH);
#endif
			} else {
				const char* text = texts->text;
				texts = texts->next;
				if (is_space_or_nl(text[0])) {
					/* skip spaces in texts */
					check_replace_all (MORE_DEPTH repls,
							   new_text,
							   texts, src,
							   replace_list);
				} else {
					if (!strcasecmp(src_text,text)){
						/* We could match one
						 * text from the
						 * stream with a text
						 * from the
						 * replacement, so
						 * move on to the next
						 * text */
						check_replace_all(
							MORE_DEPTH repls,
							new_text,
							texts,src->next,
							replace_list);
					} else {
						/* match failed, move
						 * on to the next
						 * potential
						 * replacement */
						check_replace (
							MORE_DEPTH repls,
							replace_list);
					}
				}
			}
		}
	}
}

static
void check_replace_after_match (WITH_DEPTH struct cb_replacement_state *repls)
{
#ifdef DEBUG_REPLACE_TRACE
	fprintf (stderr, "%scheck_replace_after_match(%s)\n",
		DEPTH, repls->name);
#endif
  repls->current_list = NULL;
  if (repls->token_queue != NULL){
	  if (is_space_or_nl (repls->token_queue->text[0])) {
		  ppecho_switch (MORE_DEPTH repls,
				 repls->token_queue->text,
				 repls->token_queue->token);
		  repls->token_queue = repls->token_queue->next;
		  check_replace_after_match (MORE_DEPTH repls);
	  } else {
		  do_replace (MORE_DEPTH repls);
	  }
  }
}

static
void do_replace (WITH_DEPTH struct cb_replacement_state* repls)
{
#ifdef DEBUG_REPLACE_TRACE
	fprintf (stderr, "%sdo_replace(%s)\n",DEPTH, repls->name);
#endif
	if (repls->current_list == NULL){
		if (repls->replace_list == NULL){

			/* Beware: this is incorrect if a REPLACE is
			 * withing the queue, as it has already been
			 * parsed before any COPY-REPLACING
			 * substitution. */
			ppecho_switch_token_list (MORE_DEPTH repls,
					    repls->token_queue);
			repls->token_queue = NULL;
		} else {
			check_replace (MORE_DEPTH repls, repls->replace_list);
		}
	} else {
		check_replace (MORE_DEPTH repls, repls->current_list);
	}
}

/* Whether a word matches the definition of WORD in pplex.l */
static
int is_word (WITH_DEPTH const char* s) {
	int i;
	size_t len = strlen (s);

	for (i = 0; i<len ; i++) {
		char c = s[i];
		if (c == '_'
		 || c == '-'
		 || ( c >= '0' && c <= '9' )
		 || ( c >= 'A' && c <= 'Z' )
		 || ( c >= 'a' && c <= 'z' )
		 || ( c >= 128 && c <= 255 ) ) {
			/* word character, just go on */
		} else {
#ifdef DEBUG_REPLACE_TRACE
			fprintf (stderr, "%sis_word('%s') -> 0\n", DEPTH, s);
#endif
			return 0;
		}
	}
#ifdef DEBUG_REPLACE_TRACE
	fprintf (stderr, "%sis_word('%s') -> 1\n", DEPTH, s);
#endif
	return 1;
}

static void add_text_to_replace (WITH_DEPTH struct cb_replacement_state *repls,
			int prequeue, const char* text, const char* token
	)
{
	/* CHECKME: this function takes >35% of the parsing cpu instructions,
	   with > 18% for memory allocation - can we reduce especially the
	   later in cases where REPLACE / REPLACING is not active? */
#ifdef DEBUG_REPLACE_TRACE
	fprintf (stderr, "%sadd_text_to_replace (%s%s, '%s')\n", DEPTH,
		repls->name, prequeue ? ", PREQUEUE" : "", text);
#endif
	if (prequeue) {

		if (is_word (MORE_DEPTH text) ) {

			if (repls->text_prequeue == NULL) {
				/* a word should be kept in the prequeue */
				repls->text_prequeue =
					cobc_plex_strdup (text);
			} else {
				/* two following words should be merged,
				   and keep waiting in the prequeue */
				repls->text_prequeue =
					cobc_plex_stradd (repls->text_prequeue,
							  text);
			}
		} else if (repls->text_prequeue == NULL) {
			/* not a word, and empty prequeue,
			   just perform replacements */
			add_text_to_replace (MORE_DEPTH repls, 0, text, token);
		} else {
			/* not a word, one word in the prequeue,
			   flush the word from the prequeue and pass the
			   current text to the replacements */
			const char *pretext = repls->text_prequeue;
			repls->text_prequeue = NULL;
			add_text_to_replace (MORE_DEPTH repls, 0, pretext, NULL);
			add_text_to_replace (MORE_DEPTH repls, 0, text, token);
		}

	} else {

		if (repls->token_queue == NULL
		 && is_space_or_nl (text[0]) ) {
			ppecho_switch (MORE_DEPTH repls, text, token);
		} else {
#ifdef DEBUG_REPLACE_TRACE
			fprintf (stderr,
				"%s add_text_to_replace () -> push_text()\n",
				DEPTH);
#endif
			repls->token_queue =
				token_list_add(MORE_DEPTH repls->token_queue,
					       text, token);

			do_replace (MORE_DEPTH repls);
		}
	}
}

/* pass a text to the replace stream (called from the copy-replacing
  stream). Use prequeue = 1 so that texts of the same kind are
  merged into a single text.
 */
static void ppecho_replace (WITH_DEPTH const char *text, const char *token)
{
#ifdef DEBUG_REPLACE
	fprintf (stderr, "%sppecho_replace('%s')\n", DEPTH, text);
#endif
	add_text_to_replace (MORE_DEPTH replace_repls, 1, text, token);
}

/* pass a text to the copy-replacing stream (called from ppecho() in
   pplex.l).  Use prequeue = 0 as texts of the same kind from the
   source file should not be merged.
 */
void cb_ppecho_copy_replace (const char *text, const char *token)
{
#ifdef DEBUG_REPLACE
	fprintf (stderr, "cb_ppecho_copy_replace('%s')\n", text);
#endif
	add_text_to_replace (INIT_DEPTH copy_repls, 0, text, token);
}


static
struct cb_replacement_state * create_replacements (enum cb_ppecho ppecho)
{
	struct cb_replacement_state * s;

	s = cobc_malloc (sizeof(struct cb_replacement_state));

	s->text_prequeue = NULL;
	s->token_queue = NULL;
	s->replace_list = NULL ;
	s->current_list = NULL ;
	s->ppecho = ppecho;

#ifdef DEBUG_REPLACE
	if (ppecho == CB_PPECHO_REPLACE) {
		s->name = "COPY-REPLACING";
	} else {
		s->name = "REPLACE";
	}
#endif

	return s;
}

static void reset_replacements (struct cb_replacement_state * s)
{
	s->text_prequeue = NULL;
	s->token_queue = NULL;
	s->replace_list = NULL ;
        s->current_list = NULL ;
}

static
void init_replace( void )
{
#ifdef DEBUG_REPLACE_TRACE
	for(int i=0; i<MAX_DEPTH; i++) depth_buffer[i] = ' ';
	depth_buffer[MAX_DEPTH]=0;
#endif
	copy_repls = create_replacements (CB_PPECHO_REPLACE);
	replace_repls = create_replacements (CB_PPECHO_DIRECT);
}

static
void reset_replace (void)
{
	reset_replacements (copy_repls);
	reset_replacements (replace_repls);
}

/* Called by pplex.l at EOF of top file */
void cb_free_replace( void )
{
	reset_replace ();
	cobc_free (copy_repls);
	copy_repls = NULL;
	cobc_free (replace_repls);
	replace_repls = NULL;
}

/* Called by pplex.l when a new file is opened to save the previous
   stack of active copy-replacing */
struct cb_replace_list *cb_get_copy_replacing_list (void)
{
	if (copy_repls == NULL) {
		init_replace();
	}
	return copy_repls->replace_list ;
}

/* Called by pplex.l, either at the end of a file to restore the
previous stack of active copy-replacing, or when a new file is open to
set additional copy replacing */
void cb_set_copy_replacing_list (struct cb_replace_list *list)
{
	copy_repls->current_list = NULL;
	copy_repls->replace_list = list ;
#ifdef DEBUG_REPLACE
	fprintf (stderr, "set_copy_replacing_list(\n");
	for(;list != NULL; list=list->next){
		fprintf (stderr, "    repl = {\n");
		fprintf (stderr, "       src = %s\n",
			string_of_text_list(list->src->text_list));
		fprintf (stderr, "       leading = %d\n",
			list->src->lead_trail);
		fprintf (stderr, "       new_text = %s\n",
			string_of_text_list(list->new_text));
		fprintf (stderr, "           };\n");
	}
	fprintf (stderr, "   )\n");
#endif
}

/* Called by pplex.l from pp_set_replace_list() after a REPLACE statement:

                          list          is_pushpop
 REPLACE <repls>.         <> NULL       false
 REPLACE ALSO <repls>.    <> NULL       true
 REPLACE LAST OFF.        NULL          true
 REPLACE OFF.             NULL          false
 */
void
cb_set_replace_list (struct cb_replace_list *list, const int is_pushpop)
{
#ifdef DEBUG_REPLACE_TRACE
	fprintf (stderr, "set_replace_list(...)\n");
#endif
	if (!list) {
		/* REPLACE [LAST] OFF */
		if (!is_pushpop) {
			replace_repls->replace_list = NULL;
			return;
		}
		if (!replace_repls->replace_list) {
			return;
		}
		replace_repls->replace_list = replace_repls->replace_list->prev;
		return;
	}
	/* REPLACE [ALSO] ... */
	if (replace_repls->replace_list && is_pushpop) {
		list->last->next = replace_repls->replace_list;
		list->prev = replace_repls->replace_list;
	} else {
		list->prev = NULL;
	}
	replace_repls->replace_list = list;
	if (cb_src_list_file) {
		cb_set_print_replace_list (list);
	}
}