%{
/* GNU Mailutils -- a suite of utilities for electronic mail
   Copyright (C) 1999-2025 Free Software Foundation, Inc.

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

   This library 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
   Lesser General Public License for more details.

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

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <sieve-priv.h>
#include <mailutils/stdstream.h>

mu_sieve_machine_t mu_sieve_machine;
int mu_sieve_error_count;
static struct mu_sieve_node *sieve_tree;

static struct mu_sieve_node *node_alloc (enum mu_sieve_node_type,
					 struct mu_locus_range *);

static void node_list_add (struct mu_sieve_node_list *list,
			   struct mu_sieve_node *node);

%}

%define api.prefix {mu_sieve_yy}
%code requires {
#define MU_SIEVE_YYLTYPE struct mu_locus_range
#define yylloc mu_sieve_yylloc
#define yylval mu_sieve_yylval
}
%define parse.error verbose
%locations

%union {
  char *string;
  size_t number;
  size_t idx;
  struct mu_sieve_slice slice;
  struct
  {
    char *ident;
    struct mu_locus_range idloc;
    size_t first;
    size_t count;
  } command;
  struct mu_sieve_node_list node_list;
  struct mu_sieve_node *node;
}

%token <string> IDENT TAG
%token <number> NUMBER
%token <string> STRING MULTILINE
%token REQUIRE IF ELSIF ELSE ANYOF ALLOF NOT FALSE TRUE

%type <idx> arg
%type <slice> arglist maybe_arglist slist stringlist stringorlist
%type <command> command
%type <node> action test statement block cond
%type <node> else_part
%type <node_list> list testlist elsif_branch maybe_elsif

%%

input        : /* empty */
	       {
		 sieve_tree = NULL;
	       }
	     | list
	       {
		 struct mu_locus_range lr;

		 lr.beg = lr.end = @1.end;

		 node_list_add (&$1, node_alloc (mu_sieve_node_end, &lr));
		 sieve_tree = $1.head;
	       }
	     ;

list         : statement
	       {
		 $$.head = $$.tail = $1;
	       }
	     | list statement
	       {
		 node_list_add (&$1, $2);
		 $$ = $1;
	       }
	     ;

statement    : REQUIRE stringorlist ';'
	       {
		 mu_sieve_require (mu_sieve_machine, &$2);
		 /* Reclaim string slots.  The string data referred to by
		    $2 are registered in memory_pool, so we don't free them */
		 mu_sieve_machine->stringcount -= $2.count;
		 $$ = NULL;
	       }
	     | action ';'
	     /* 1  2     3       4    */
	     | IF cond block else_part
	       {
		 $$ = node_alloc (mu_sieve_node_cond, &@1);
		 $$->v.cond.expr = $2;
		 $$->v.cond.iftrue = $3;
		 $$->v.cond.iffalse = $4;
	       }
	     ;

else_part    : maybe_elsif
	       {
		 $$ = $1.head;
	       }
	     | maybe_elsif ELSE block
	       {
		 if ($1.tail)
		   {
		     $1.tail->v.cond.iffalse = $3;
		     $$ = $1.head;
		   }
		 else
		   $$ = $3;
	       }
	     ;

maybe_elsif  : /* empty */
	       {
		 $$.head = $$.tail = NULL;
	       }
	     | elsif_branch
	     ;

/* elsif branches form a singly-linked version of node_list.  Nodes in
   this list are linked by v.cond.iffalse pointer */
elsif_branch : ELSIF cond block
	       {
		 struct mu_sieve_node *node =
		   node_alloc (mu_sieve_node_cond, &@1);
		 node->v.cond.expr = $2;
		 node->v.cond.iftrue = $3;
		 node->v.cond.iffalse = NULL;
		 $$.head = $$.tail = node;
	       }
	     | elsif_branch ELSIF cond block
	       {
		 struct mu_sieve_node *node =
		   node_alloc (mu_sieve_node_cond, &@2);
		 node->v.cond.expr = $3;
		 node->v.cond.iftrue = $4;
		 node->v.cond.iffalse = NULL;

		 $1.tail->v.cond.iffalse = node;
		 $1.tail = node;

		 $$ = $1;
	       }
	     ;

block        : '{' list '}'
	       {
		 $$ = $2.head;
	       }
	     ;

testlist     : cond
	       {
		 $$.head = $$.tail = $1;
	       }
	     | testlist ',' cond
	       {
		 $3->prev = $1.tail;
		 $1.tail->next = $3;
		 $1.tail = $3;
		 $$ = $1;
	       }
	     ;

cond         : test
	     | ANYOF '(' testlist ')'
	       {
		 $$ = node_alloc (mu_sieve_node_anyof, &@1);
		 $$->v.node = $3.head;
	       }
	     | ALLOF '(' testlist ')'
	       {
		 $$ = node_alloc (mu_sieve_node_allof, &@1);
		 $$->v.node = $3.head;
	       }
	     | NOT cond
	       {
		 $$ = node_alloc (mu_sieve_node_not, &@1);
		 $$->v.node = $2;
	       }
	     ;

test         : command
	       {
		 mu_sieve_registry_t *reg;

		 mu_locus_range_copy (&mu_sieve_machine->locus, &@1);
		 reg = mu_sieve_registry_lookup (mu_sieve_machine, $1.ident,
						 mu_sieve_record_test);
		 if (!reg)
		   {
		     mu_diag_at_locus_range (MU_LOG_ERROR, &$1.idloc,
					     _("unknown test: %s"),
					     $1.ident);
		     mu_i_sv_error (mu_sieve_machine);
		   }
		 else if (!reg->required)
		   {
		     mu_diag_at_locus_range (MU_LOG_ERROR, &$1.idloc,
					     _("test '%s' has not been required"),
					     $1.ident);
		     mu_i_sv_error (mu_sieve_machine);
		   }

		 free ($1.ident);
		 $$ = node_alloc (mu_sieve_node_test, &@1);
		 $$->v.command.reg = reg;
		 $$->v.command.argstart = $1.first;
		 $$->v.command.argcount = $1.count;
		 $$->v.command.tagcount = 0;
		 $$->v.command.comparator = NULL;
		 mu_i_sv_lint_command (mu_sieve_machine, $$);
	       }
	     | TRUE
	       {
		 $$ = node_alloc (mu_sieve_node_true, &@1);
	       }
	     | FALSE
	       {
		 $$ = node_alloc (mu_sieve_node_false, &@1);
	       }
	     ;

command      : IDENT maybe_arglist
	       {
		 $$.ident = $1;
		 $$.idloc = @1;
		 $$.first = $2.first;
		 $$.count = $2.count;
	       }
	     ;

action       : command
	       {
		 mu_sieve_registry_t *reg;

		 mu_locus_range_copy (&mu_sieve_machine->locus, &@1);
		 reg = mu_sieve_registry_lookup (mu_sieve_machine, $1.ident,
						 mu_sieve_record_action);

		 if (!reg)
		   {
		     mu_diag_at_locus_range (MU_LOG_ERROR, &$1.idloc,
					     _("unknown action: %s"),
					     $1.ident);
		     mu_i_sv_error (mu_sieve_machine);
		   }
		 else if (!reg->required)
		   {
		     mu_diag_at_locus_range (MU_LOG_ERROR, &$1.idloc,
					     _("action '%s' has not been required"),
					     $1.ident);
		     mu_i_sv_error (mu_sieve_machine);
		   }

		 free ($1.ident);
		 $$ = node_alloc(mu_sieve_node_action, &@1);
		 $$->v.command.reg = reg;
		 $$->v.command.argstart = $1.first;
		 $$->v.command.argcount = $1.count;
		 $$->v.command.tagcount = 0;
		 mu_i_sv_lint_command (mu_sieve_machine, $$);
	       }
	     ;

maybe_arglist: /* empty */
	       {
		 $$.first = 0;
		 $$.count = 0;
	       }
	     | arglist
	     ;

arglist      : arg
	       {
		 $$.first = $1;
		 $$.count = 1;
	       }
	     | arglist arg
	       {
		 $1.count++;
		 $$ = $1;
	       }
	     ;

arg          : stringlist
	       {
		 $$ = mu_sieve_value_create (mu_sieve_machine,
					     SVT_STRING_LIST, &@1, &$1);
	       }
	     | STRING
	       {
		 $$ = mu_sieve_value_create (mu_sieve_machine, SVT_STRING,
					     &@1, $1);
	       }
	     | MULTILINE
	       {
		 $$ = mu_sieve_value_create (mu_sieve_machine, SVT_STRING,
					     &@1, $1);
	       }
	     | NUMBER
	       {
		 $$ = mu_sieve_value_create (mu_sieve_machine, SVT_NUMBER,
					     &@1, &$1);
	       }
	     | TAG
	       {
		 $$ = mu_sieve_value_create (mu_sieve_machine, SVT_TAG,
					     &@1, $1);
	       }
	     ;

stringorlist : STRING
	       {
		 $$.first = mu_i_sv_string_create (mu_sieve_machine, $1);
		 $$.count = 1;
	       }
	     | stringlist
	     ;

stringlist   : '[' slist ']'
	       {
		 $$ = $2;
	       }
	     ;

slist        : STRING
	       {
		 $$.first = mu_i_sv_string_create (mu_sieve_machine, $1);
		 $$.count = 1;
	       }
	     | slist ',' STRING
	       {
		 mu_i_sv_string_create (mu_sieve_machine, $3);
		 $1.count++;
		 $$ = $1;
	       }
	     ;

%%

int
yyerror (const char *s)
{
  mu_error ("%s", s);
  mu_i_sv_error (mu_sieve_machine);
  return 0;
}

static void
node_list_add (struct mu_sieve_node_list *list, struct mu_sieve_node *node)
{
  if (!node)
    return;

  node->prev = list->tail;
  if (list->tail)
    list->tail->next = node;
  else
    list->head = node;
  list->tail = node;
}

static struct mu_sieve_node *
node_alloc (enum mu_sieve_node_type type, struct mu_locus_range *lr)
{
  struct mu_sieve_node *node = malloc (sizeof (*node));
  if (node)
    {
      node->prev = node->next = NULL;
      node->type = type;
      mu_locus_range_init (&node->locus);
      mu_locus_range_copy (&node->locus, lr);
    }
  return node;
}

static void node_optimize (struct mu_sieve_node *node);
static void node_free (struct mu_sieve_node *node);
static void node_replace (struct mu_sieve_node *node,
			  struct mu_sieve_node *repl);
static void node_code (struct mu_sieve_machine *mach,
		       struct mu_sieve_node *node);
static void node_dump (mu_stream_t str, struct mu_sieve_node *node,
		       unsigned level, struct mu_sieve_machine *mach);

static void tree_free (struct mu_sieve_node **tree);
static void tree_optimize (struct mu_sieve_node *tree);
static void tree_code (struct mu_sieve_machine *mach,
		       struct mu_sieve_node *tree);
static void tree_dump (mu_stream_t str,
		       struct mu_sieve_node *tree, unsigned level,
		       struct mu_sieve_machine *mach);

static void
indent (mu_stream_t str, unsigned level)
{
#define tab "  "
#define tablen (sizeof (tab) - 1)
  while (level--)
    mu_stream_write (str, tab, tablen, NULL);
}

/* mu_sieve_node_noop */
static void
dump_node_noop (mu_stream_t str, struct mu_sieve_node *node, unsigned level,
		struct mu_sieve_machine *mach)
{
  indent (str, level);
  mu_stream_printf (str, "NOOP\n");
}

/* mu_sieve_node_false */
static void
dump_node_false (mu_stream_t str, struct mu_sieve_node *node, unsigned level,
		 struct mu_sieve_machine *mach)
{
  indent (str, level);
  mu_stream_printf (str, "FALSE\n");
}

/* mu_sieve_node_true */
static void
dump_node_true (mu_stream_t str, struct mu_sieve_node *node, unsigned level,
		struct mu_sieve_machine *mach)
{
  indent (str, level);
  mu_stream_printf (str, "TRUE\n");
}

/* mu_sieve_node_test & mu_sieve_node_action */
static void
free_node_command (struct mu_sieve_node *node)
{
  /* nothing */
}

static void
code_node_test (struct mu_sieve_machine *mach, struct mu_sieve_node *node)
{
  mu_i_sv_code_test (mach, node);
}

static void
code_node_action (struct mu_sieve_machine *mach, struct mu_sieve_node *node)
{
  mu_i_sv_code_action (mach, node);
}

void
mu_i_sv_valf (mu_sieve_machine_t mach, mu_stream_t str, mu_sieve_value_t *val)
{
  mu_stream_printf (str, " ");
  if (val->tag)
    {
      mu_stream_printf (str, ":%s", val->tag);
      if (val->type == SVT_VOID)
	return;
      mu_stream_printf (str, " ");
    }
  switch (val->type)
    {
    case SVT_VOID:
      mu_stream_printf (str, "(void)");
      break;

    case SVT_NUMBER:
      mu_stream_printf (str, "%zu", val->v.number);
      break;

    case SVT_STRING:
      mu_stream_printf (str, "\"%s\"",
			mu_sieve_string_raw (mach, &val->v.list, 0)->orig);
      break;

    case SVT_STRING_LIST:
      {
	size_t i;

	mu_stream_printf (str, "[");
	for (i = 0; i < val->v.list.count; i++)
	  {
	    if (i)
	      mu_stream_printf (str, ", ");
	    mu_stream_printf (str, "\"%s\"",
			      mu_sieve_string_raw (mach, &val->v.list, i)->orig);
	  }
	mu_stream_printf (str, "]");
      }
      break;

    case SVT_TAG:
      mu_stream_printf (str, ":%s", val->v.string);
      break;

    default:
      abort ();
    }
}

static void
dump_node_command (mu_stream_t str, struct mu_sieve_node *node, unsigned level,
		   struct mu_sieve_machine *mach)
{
  size_t i;

  indent (str, level);
  mu_stream_printf (str, "COMMAND %s", node->v.command.reg->name);
  for (i = 0; i < node->v.command.argcount + node->v.command.tagcount; i++)
    mu_i_sv_valf (mach, str, &mach->valspace[node->v.command.argstart + i]);
  mu_stream_printf (str, "\n");
}

/* mu_sieve_node_cond */
static void
free_node_cond (struct mu_sieve_node *node)
{
  tree_free (&node->v.cond.expr);
  tree_free (&node->v.cond.iftrue);
  tree_free (&node->v.cond.iffalse);
}

static void
optimize_node_cond (struct mu_sieve_node *node)
{
  tree_optimize (node->v.cond.expr);
  switch (node->v.cond.expr->type)
    {
    case mu_sieve_node_true:
      tree_optimize (node->v.cond.iftrue);
      node_replace (node, node->v.cond.iftrue);
      break;

    case mu_sieve_node_false:
      tree_optimize (node->v.cond.iffalse);
      node_replace (node, node->v.cond.iffalse);
      break;

    default:
      tree_optimize (node->v.cond.iftrue);
      tree_optimize (node->v.cond.iffalse);
    }
}

static void
code_node_cond (struct mu_sieve_machine *mach, struct mu_sieve_node *node)
{
  size_t br1;

  tree_code (mach, node->v.cond.expr);
  mu_i_sv_code (mach, (sieve_op_t) _mu_i_sv_instr_brz);
  br1 = mach->pc;
  mu_i_sv_code (mach, (sieve_op_t) 0);
  tree_code (mach, node->v.cond.iftrue);

  if (node->v.cond.iffalse)
    {
      size_t br2;

      mu_i_sv_code (mach, (sieve_op_t) _mu_i_sv_instr_branch);
      br2 = mach->pc;
      mu_i_sv_code (mach, (sieve_op_t) 0);

      mach->prog[br1].pc = mach->pc - br1 - 1;

      tree_code (mach, node->v.cond.iffalse);
      mach->prog[br2].pc = mach->pc - br2 - 1;
    }
  else
    mach->prog[br1].pc = mach->pc - br1 - 1;
}

static void
dump_node_cond (mu_stream_t str, struct mu_sieve_node *node, unsigned level,
		struct mu_sieve_machine *mach)
{
  indent (str, level);
  mu_stream_printf (str, "COND\n");

  ++level;

  indent (str, level);
  mu_stream_printf (str, "EXPR:\n");
  tree_dump (str, node->v.cond.expr, level + 1, mach);

  indent (str, level);
  mu_stream_printf (str, "IFTRUE:\n");
  tree_dump (str, node->v.cond.iftrue, level + 1, mach);

  indent (str, level);
  mu_stream_printf (str, "IFFALSE:\n");
  tree_dump (str, node->v.cond.iffalse, level + 1, mach);
}

/* mu_sieve_node_anyof & mu_sieve_node_allof */
static void
free_node_x_of (struct mu_sieve_node *node)
{
  tree_free (&node->v.node);
}

static void
optimize_x_of (struct mu_sieve_node *node, enum mu_sieve_node_type solve)
{
  struct mu_sieve_node *cur;
  tree_optimize (node->v.node);
  cur = node->v.node;
  if (cur->next == NULL)
    node_replace (node, cur);
  else
    {
      while (cur)
	{
	  struct mu_sieve_node *next = cur->next;
	  switch (cur->type)
	    {
	    case mu_sieve_node_false:
	    case mu_sieve_node_true:
	      if (cur->type == solve)
		{
		  tree_free (&node->v.node);
		  node->type = solve;
		  return;
		}
	      else
		{
		  if (cur->prev)
		    cur->prev->next = next;
		  else
		    node->v.node = next;
		  if (next)
		    next->prev = cur->prev;
		  node_free (cur);
		}
	      break;

	    default:
	      break;
	    }

	  cur = next;
	}

      if (!node->v.node)
	node->type = solve == mu_sieve_node_false
			  ? mu_sieve_node_true : mu_sieve_node_false;
    }
}

static void
code_node_x_of (struct mu_sieve_machine *mach, struct mu_sieve_node *node,
		sieve_op_t op)
{
  struct mu_sieve_node *cur = node->v.node;
  size_t pc = 0;
  size_t end;

  while (cur)
    {
      node_code (mach, cur);
      if (cur->next)
	{
	  mu_i_sv_code (mach, op);
	  mu_i_sv_code (mach, (sieve_op_t) pc);
	  pc = mach->pc - 1;
	}
      cur = cur->next;
    }

  /* Fix-up locations */
  end = mach->pc;
  while (pc != 0)
    {
      size_t prev = mach->prog[pc].pc;
      mach->prog[pc].pc = end - pc - 1;
      pc = prev;
    }
}

static void
dump_node_x_of (mu_stream_t str, struct mu_sieve_node *node, unsigned level,
		mu_sieve_machine_t mach)
{
  enum mu_sieve_node_type t = node->type;

  indent (str, level);
  mu_stream_printf (str, "%s:\n",
		    t == mu_sieve_node_allof ? "ALLOF" : "ANYOF");

  ++level;
  node = node->v.node;
  while (node)
    {
      node_dump (str, node, level + 1, mach);
      node = node->next;
      if (node)
	{
	  indent (str, level);
	  mu_stream_printf (str, "%s:\n",
			    t == mu_sieve_node_allof ? "AND" : "OR");
	}
    }
}

/* mu_sieve_node_anyof */
static void
optimize_node_anyof (struct mu_sieve_node *node)
{
  optimize_x_of (node, mu_sieve_node_true);
}

static void
code_node_anyof (struct mu_sieve_machine *mach, struct mu_sieve_node *node)
{
  code_node_x_of (mach, node, (sieve_op_t) _mu_i_sv_instr_brnz);
}

/* mu_sieve_node_allof */
static void
optimize_node_allof (struct mu_sieve_node *node)
{
  return optimize_x_of (node, mu_sieve_node_false);
}

static void
code_node_allof (struct mu_sieve_machine *mach, struct mu_sieve_node *node)
{
  code_node_x_of (mach, node, (sieve_op_t) _mu_i_sv_instr_brz);
}

/* mu_sieve_node_not */
static void
free_node_not (struct mu_sieve_node *node)
{
  tree_free (&node->v.node);
}

static void
optimize_node_not (struct mu_sieve_node *node)
{
  tree_optimize (node->v.node);
  switch (node->v.node->type)
    {
    case mu_sieve_node_false:
      tree_free (&node->v.node);
      node->type = mu_sieve_node_true;
      break;

    case mu_sieve_node_true:
      tree_free (&node->v.node);
      node->type = mu_sieve_node_false;
      break;

    default:
      break;
    }
}

static void
code_node_not (struct mu_sieve_machine *mach, struct mu_sieve_node *node)
{
  node_code (mach, node->v.node);
  mu_i_sv_code (mach, (sieve_op_t) _mu_i_sv_instr_not);
}

static void
dump_node_not (mu_stream_t str, struct mu_sieve_node *node, unsigned level,
	       struct mu_sieve_machine *mach)
{
  indent (str, level);
  mu_stream_printf (str, "NOT\n");
  node_dump (str, node->v.node, level + 1, mach);
}

/* mu_sieve_node_end */
static void
code_node_end (struct mu_sieve_machine *mach, struct mu_sieve_node *node)
{
  mu_i_sv_code (mach, (sieve_op_t) (sieve_instr_t) 0);
}

static void
dump_node_end (mu_stream_t str, struct mu_sieve_node *node, unsigned level,
	       struct mu_sieve_machine *mach)
{
  indent (str, level);
  mu_stream_printf (str, "END\n");
}

struct node_descr
{
  void (*code_fn) (struct mu_sieve_machine *mach, struct mu_sieve_node *node);
  void (*optimize_fn) (struct mu_sieve_node *node);
  void (*free_fn) (struct mu_sieve_node *node);
  void (*dump_fn) (mu_stream_t str, struct mu_sieve_node *node, unsigned level,
		   mu_sieve_machine_t);

};

static struct node_descr node_descr[] = {
  [mu_sieve_node_noop]  = { NULL, NULL, NULL, dump_node_noop },
  [mu_sieve_node_false]  = { NULL, NULL, NULL, dump_node_false },
  [mu_sieve_node_true]   = { NULL, NULL, NULL, dump_node_true },
  [mu_sieve_node_test]   = { code_node_test, NULL,
			     free_node_command, dump_node_command },
  [mu_sieve_node_action] = { code_node_action, NULL,
			     free_node_command, dump_node_command },
  [mu_sieve_node_cond]   = { code_node_cond, optimize_node_cond,
			     free_node_cond, dump_node_cond },
  [mu_sieve_node_anyof]  = { code_node_anyof, optimize_node_anyof,
			     free_node_x_of, dump_node_x_of },
  [mu_sieve_node_allof]  = { code_node_allof, optimize_node_allof,
			     free_node_x_of, dump_node_x_of },
  [mu_sieve_node_not]    = { code_node_not, optimize_node_not,
			     free_node_not, dump_node_not },
  [mu_sieve_node_end]    = { code_node_end, NULL, NULL, dump_node_end }
};

static void
node_optimize (struct mu_sieve_node *node)
{
  if ((int)node->type >= MU_ARRAY_SIZE (node_descr))
    abort ();
  if (node_descr[node->type].optimize_fn)
    node_descr[node->type].optimize_fn (node);
}

static void
node_free (struct mu_sieve_node *node)
{
  if ((int)node->type >= MU_ARRAY_SIZE (node_descr))
    abort ();
  if (node_descr[node->type].free_fn)
    node_descr[node->type].free_fn (node);
  free (node);
}

static void
node_replace (struct mu_sieve_node *node, struct mu_sieve_node *repl)
{
  struct mu_sieve_node copy;

  if ((int)node->type >= MU_ARRAY_SIZE (node_descr))
    abort ();

  copy = *node;
  if (repl)
    {
      node->type = repl->type;
      node->v = repl->v;

      switch (copy.type)
	{
	case mu_sieve_node_cond:
	  if (repl == copy.v.cond.expr)
	    copy.v.cond.expr = NULL;
	  else if (repl == copy.v.cond.iftrue)
	    copy.v.cond.iftrue = NULL;
	  else if (repl == copy.v.cond.iffalse)
	    copy.v.cond.iffalse = NULL;
	  break;

	case mu_sieve_node_not:
	case mu_sieve_node_allof:
	case mu_sieve_node_anyof:
	  if (repl == copy.v.node)
	    copy.v.node = NULL;
	  break;

	default:
	  break;
	}
      if (node->next)
	{
	  if (repl->next)
	    {
	      struct mu_sieve_node *tail;
	      for (tail = repl->next; tail->next; tail = tail->next)
		;
	      if (tail)
		{
		  node->next->prev = tail;
		  tail->next = node->next;

		  node->next = repl->next;
		  node->next->prev = node;
		}
	    }
	}
      else
	{
	  node->next = repl->next;
	  if (node->next)
	    node->next->prev = node;
	}
    }
  else
    node->type = mu_sieve_node_noop;

  if (node_descr[copy.type].free_fn)
    node_descr[copy.type].free_fn (&copy);
  free (repl);
}

static void
node_code (struct mu_sieve_machine *mach, struct mu_sieve_node *node)
{
  if ((int)node->type >= MU_ARRAY_SIZE (node_descr))
    abort ();

  if (node_descr[node->type].code_fn)
    {
      mu_i_sv_locus (mach, &node->locus);
      node_descr[node->type].code_fn (mach, node);
    }
}

static void
node_dump (mu_stream_t str, struct mu_sieve_node *node, unsigned level,
	   struct mu_sieve_machine *mach)
{
  if ((int)node->type >= MU_ARRAY_SIZE (node_descr)
      || !node_descr[node->type].dump_fn)
    abort ();
  node_descr[node->type].dump_fn (str, node, level, mach);
}


static void
tree_free (struct mu_sieve_node **tree)
{
  struct mu_sieve_node *cur = *tree;
  while (cur)
    {
      struct mu_sieve_node *next = cur->next;
      node_free (cur);
      cur = next;
    }
}

static void
tree_optimize (struct mu_sieve_node *tree)
{
  while (tree)
    {
      node_optimize (tree);
      tree = tree->next;
    }
}

static void
tree_code (struct mu_sieve_machine *mach, struct mu_sieve_node *tree)
{
  while (tree)
    {
      node_code (mach, tree);
      tree = tree->next;
    }
}

static void
tree_dump (mu_stream_t str, struct mu_sieve_node *tree, unsigned level,
	   struct mu_sieve_machine *mach)
{
  while (tree)
    {
      node_dump (str, tree, level, mach);
      tree = tree->next;
    }
}

void
mu_i_sv_error (mu_sieve_machine_t mach)
{
  mach->state = mu_sieve_state_error;
}

int
mu_sieve_machine_create (mu_sieve_machine_t *pmach)
{
  int rc;
  mu_sieve_machine_t mach;

  mu_sieve_debug_init ();
  mach = malloc (sizeof (*mach));
  if (!mach)
    return ENOMEM;
  memset (mach, 0, sizeof (*mach));
  mach->memory_pool = NULL;
  rc = mu_opool_create (&mach->string_pool, MU_OPOOL_DEFAULT);
  if (rc)
    {
      mu_list_destroy (&mach->memory_pool);
      free (mach);
      return rc;
    }

  mach->data = NULL;

  mu_sieve_set_diag_stream (mach, mu_strerr);
  mu_sieve_set_dbg_stream (mach, mu_strerr);

  *pmach = mach;
  return 0;
}

void
mu_i_sv_free_stringspace (mu_sieve_machine_t mach)
{
  size_t i;

  for (i = 0; i < mach->stringcount; i++)
    {
      if (mach->stringspace[i].rx)
	{
	  regex_t *rx = mach->stringspace[i].rx;
	  regfree (rx);
	}
      /* There's no need to free mach->stringspace[i].exp, because
	 it is allocated in mach's memory pool */
    }
}

int
mu_sieve_machine_reset (mu_sieve_machine_t mach)
{
  switch (mach->state)
    {
    case mu_sieve_state_init:
      /* Nothing to do */
      return 0;

    case mu_sieve_state_error:
    case mu_sieve_state_compiled:
      /* Do the right thing */
      break;

    case mu_sieve_state_running:
    case mu_sieve_state_disass:
      /* Can't reset a running machine */
      return MU_ERR_FAILURE;
    }

  mu_i_sv_free_stringspace (mach);
  mu_list_clear (mach->destr_list);
  mu_opool_free (mach->string_pool, NULL);
  mu_i_sv_free_idspace (mach);
  mu_list_clear (mach->registry);
  mu_list_clear (mach->memory_pool);

  mach->stringspace = NULL;
  mach->stringcount = 0;
  mach->stringmax = 0;

  mach->valspace = NULL;
  mach->valcount = 0;
  mach->valmax = 0;

  mach->idspace = NULL;
  mach->idcount = 0;
  mach->idmax = 0;

  mach->progsize = 0;
  mach->prog = NULL;

  mu_assoc_destroy (&mach->vartab);
  mach->match_string = NULL;
  mach->match_buf = NULL;
  mach->match_count = 0;
  mach->match_max = 0;

  mach->state = mu_sieve_state_init;

  return 0;
}

static int
regdup (void *item, void *data)
{
  mu_sieve_registry_t *reg = item;
  mu_sieve_machine_t mach = data;
  return mu_sieve_registry_clone (mach, reg);
}

static void
copy_stream_state (mu_sieve_machine_t child, mu_sieve_machine_t parent)
{
  child->state_flags = parent->state_flags;
  child->err_mode    = parent->err_mode;
  mu_locus_range_copy (&child->err_locus, &parent->err_locus);
  child->dbg_mode    = parent->dbg_mode;
  mu_locus_range_copy (&child->dbg_locus, &parent->dbg_locus);
  child->errstream = parent->errstream;
  mu_stream_ref (child->errstream);
  child->dbgstream = parent->dbgstream;
  mu_stream_ref (child->dbgstream);
}

int
mu_sieve_machine_clone (mu_sieve_machine_t const parent,
			mu_sieve_machine_t *pmach)
{
  size_t i;
  mu_sieve_machine_t child;
  int rc;

  if (!parent || parent->state == mu_sieve_state_error)
    return EINVAL;

  rc = mu_sieve_machine_create (&child);
  if (rc)
    return rc;

  rc = setjmp (child->errbuf);

  if (rc == 0)
    {
      switch (parent->state)
	{
	case mu_sieve_state_running:
	case mu_sieve_state_disass:
	  child->state = mu_sieve_state_compiled;
	  break;

	default:
	  child->state = parent->state;
	}

      mu_i_sv_register_standard_actions (child);
      mu_i_sv_register_standard_tests (child);
      mu_i_sv_register_standard_comparators (child);

      /* Load necessary modules */
      mu_list_foreach (parent->registry, regdup, child);

      /* Copy identifiers */
      child->idspace = mu_sieve_calloc (child, parent->idcount,
					sizeof (child->idspace[0]));
      child->idcount = child->idmax = parent->idcount;
      for (i = 0; i < child->idcount; i++)
	child->idspace[i] = mu_sieve_strdup (child, parent->idspace[i]);

      /* Copy string constants */
      child->stringspace = mu_sieve_calloc (child, parent->stringcount,
					    sizeof (child->stringspace[0]));
      child->stringcount = child->stringmax = parent->stringcount;
      for (i = 0; i < parent->stringcount; i++)
	{
	  memset (&child->stringspace[i], 0, sizeof (child->stringspace[0]));
	  child->stringspace[i].orig =
	    mu_sieve_strdup (child, parent->stringspace[i].orig);
	}

      /* Copy value space */
      child->valspace = mu_sieve_calloc (child, parent->valcount,
					 sizeof child->valspace[0]);
      child->valcount = child->valmax = parent->valcount;
      for (i = 0; i < child->valcount; i++)
	{
	  child->valspace[i].type = parent->valspace[i].type;
	  child->valspace[i].tag =
	    mu_sieve_strdup (child, parent->valspace[i].tag);
	  switch (child->valspace[i].type)
	    {
	    case SVT_TAG:
	      child->valspace[i].v.string =
		mu_sieve_strdup (child, parent->valspace[i].v.string);
	      break;

	    default:
	      child->valspace[i].v = parent->valspace[i].v;
	    }
	}

      /* Copy progspace */
      child->progsize = parent->progsize;
      child->prog = mu_sieve_calloc (child, parent->progsize,
				     sizeof child->prog[0]);
      memcpy (child->prog, parent->prog,
	      parent->progsize * sizeof (child->prog[0]));

      /* Copy variables */
      if (mu_sieve_has_variables (parent))
	{
	  mu_i_sv_copy_variables (child, parent);
	  child->match_string = NULL;
	  child->match_buf = NULL;
	  child->match_count = 0;
	  child->match_max = 0;
	}

      /* Copy user-defined settings */

      child->dry_run     = parent->dry_run;

      copy_stream_state (child, parent);

      child->data = parent->data;
      child->logger = parent->logger;
      child->daemon_email = parent->daemon_email;

      *pmach = child;
    }
  else
    mu_sieve_machine_destroy (&child);

  return rc;
}

int
mu_sieve_machine_dup (mu_sieve_machine_t const in, mu_sieve_machine_t *out)
{
  int rc;
  mu_sieve_machine_t mach;

  if (!in || in->state == mu_sieve_state_error)
    return EINVAL;
  mach = malloc (sizeof (*mach));
  if (!mach)
    return ENOMEM;
  memset (mach, 0, sizeof (*mach));
  rc = mu_list_create (&mach->memory_pool);
  if (rc)
    {
      free (mach);
      return rc;
    }
  mach->destr_list = NULL;
  mach->registry = NULL;

  mach->progsize = in->progsize;
  mach->prog = in->prog;

  switch (in->state)
    {
    case mu_sieve_state_running:
    case mu_sieve_state_disass:
      mach->state = mu_sieve_state_compiled;
      break;

    default:
      mach->state = in->state;
    }

  rc = setjmp (mach->errbuf);

  if (rc == 0)
    {
      mach->pc = 0;
      mach->reg = 0;

      mach->dry_run = in->dry_run;

      mach->state_flags = in->state_flags;
      mach->err_mode    = in->err_mode;
      mu_locus_range_copy (&mach->err_locus, &in->err_locus);
      mach->dbg_mode    = in->dbg_mode;
      mu_locus_range_copy (&mach->dbg_locus, &in->dbg_locus);

      copy_stream_state (mach, in);

      mu_i_sv_copy_variables (mach, in);

      mach->data = in->data;
      mach->logger = in->logger;
      mach->daemon_email = in->daemon_email;

      *out = mach;
    }
  else
    mu_sieve_machine_destroy (&mach);

  return rc;
}

void
mu_sieve_get_diag_stream (mu_sieve_machine_t mach, mu_stream_t *pstr)
{
  *pstr = mach->errstream;
  mu_stream_ref (*pstr);
}

void
mu_sieve_set_diag_stream (mu_sieve_machine_t mach, mu_stream_t str)
{
  mu_stream_unref (mach->errstream);
  mach->errstream = str;
  mu_stream_ref (mach->errstream);
}

void
mu_sieve_set_dbg_stream (mu_sieve_machine_t mach, mu_stream_t str)
{
  mu_stream_unref (mach->dbgstream);
  mach->dbgstream = str;
  mu_stream_ref (mach->dbgstream);
}

void
mu_sieve_get_dbg_stream (mu_sieve_machine_t mach, mu_stream_t *pstr)
{
  *pstr = mach->dbgstream;
  mu_stream_ref (*pstr);
}

void
mu_sieve_set_logger (mu_sieve_machine_t mach, mu_sieve_action_log_t logger)
{
  mach->logger = logger;
}

mu_mailer_t
mu_sieve_get_mailer (mu_sieve_machine_t mach)
{
  if (!mach->mailer)
    {
      int rc;

      rc = mu_mailer_create (&mach->mailer, NULL);
      if (rc)
	{
	  mu_sieve_error (mach,
			  _("%lu: cannot create mailer: %s"),
			  (unsigned long) mu_sieve_get_message_num (mach),
			  mu_strerror (rc));
	  return NULL;
	}
      rc = mu_mailer_open (mach->mailer, 0);
      if (rc)
	{
	  mu_url_t url = NULL;
	  mu_mailer_get_url (mach->mailer, &url);
	  mu_sieve_error (mach,
			  _("%lu: cannot open mailer %s: %s"),
			  (unsigned long) mu_sieve_get_message_num (mach),
			  mu_url_to_string (url), mu_strerror (rc));
	  mu_mailer_destroy (&mach->mailer);
	  return NULL;
	}
    }
  return mach->mailer;
}

void
mu_sieve_set_mailer (mu_sieve_machine_t mach, mu_mailer_t mailer)
{
  mu_mailer_destroy (&mach->mailer);
  mach->mailer = mailer;
}

#define MAILER_DAEMON_PFX "MAILER-DAEMON@"

char *
mu_sieve_get_daemon_email (mu_sieve_machine_t mach)
{
  if (!mach->daemon_email)
    {
      const char *domain = NULL;

      mu_get_user_email_domain (&domain);
      mach->daemon_email = mu_sieve_malloc (mach,
					    sizeof(MAILER_DAEMON_PFX) +
					    strlen (domain));
      sprintf (mach->daemon_email, "%s%s", MAILER_DAEMON_PFX, domain);
    }
  return mach->daemon_email;
}

void
mu_sieve_set_daemon_email (mu_sieve_machine_t mach, const char *email)
{
  mu_sieve_free (mach, (void *)mach->daemon_email);
  mach->daemon_email = mu_sieve_strdup (mach, email);
}

struct sieve_destr_record
{
  mu_sieve_destructor_t destr;
  void *ptr;
};

static void
run_destructor (void *data)
{
  struct sieve_destr_record *p = data;
  p->destr (p->ptr);
  free (data);
}

void
mu_sieve_machine_add_destructor (mu_sieve_machine_t mach,
				 mu_sieve_destructor_t destr,
				 void *ptr)
{
  int rc;
  struct sieve_destr_record *p;

  if (!mach->destr_list)
    {
      rc = mu_list_create (&mach->destr_list);
      if (rc)
	{
	  mu_sieve_error (mach, "mu_list_create: %s", mu_strerror (rc));
	  destr (ptr);
	  mu_sieve_abort (mach);
	}
      mu_list_set_destroy_item (mach->destr_list, run_destructor);
    }
  p = malloc (sizeof (*p));
  if (!p)
    {
      mu_sieve_error (mach, "%s", mu_strerror (errno));
      destr (ptr);
      mu_sieve_abort (mach);
    }
  p->destr = destr;
  p->ptr = ptr;
  rc = mu_list_prepend (mach->destr_list, p);
  if (rc)
    {
      mu_sieve_error (mach, "mu_list_prepend: %s", mu_strerror (rc));
      destr (ptr);
      free (p);
      mu_sieve_abort (mach);
    }
}

void
mu_sieve_machine_destroy (mu_sieve_machine_t *pmach)
{
  mu_sieve_machine_t mach = *pmach;

  mu_assoc_destroy (&mach->exenv);
  mu_i_sv_free_stringspace (mach);
  mu_sieve_free (mach, mach->stringspace);
  mu_stream_destroy (&mach->errstream);
  mu_stream_destroy (&mach->dbgstream);
  mu_mailer_destroy (&mach->mailer);
  mu_list_destroy (&mach->destr_list);
  mu_sieve_free (mach, mach->idspace);
  mu_opool_destroy (&mach->string_pool);
  mu_list_destroy (&mach->memory_pool);
  mu_assoc_destroy (&mach->vartab);
  mu_list_destroy (&mach->init_var);
  mu_assoc_destroy (&mach->mailboxes);
  /*
   * NOTE: Registry must be freed after memory_pool, because it will unload
   * any external modules its entries are referring to, and these modules
   * may have registered reclaim functions in memory_pool.  Thus, it is
   * important that these functions be executed (this is triggered
   * by destroying memory_pool) prior to unloading them.
   */
  mu_list_destroy (&mach->registry);

  free (mach);
  *pmach = NULL;
}

int
with_machine (mu_sieve_machine_t mach, int (*thunk) (void *), void *data)
{
  int rc = 0;
  mu_stream_t save_errstr;

  rc = mu_sieve_machine_reset (mach);
  if (rc)
    return rc;

  save_errstr = mu_strerr;
  mu_stream_ref (save_errstr);
  mu_strerr = mach->errstream;
  mu_stream_ref (mu_strerr);

  mu_sieve_machine = mach;
  rc = setjmp (mach->errbuf);

  if (rc == 0)
    {
      mach->state = mu_sieve_state_init;
      mu_i_sv_register_standard_actions (mach);
      mu_i_sv_register_standard_tests (mach);
      mu_i_sv_register_standard_comparators (mach);

      mu_sieve_stream_save (mach);
      rc = thunk (data);
      mu_sieve_stream_restore (mach);

      mu_stream_unref (save_errstr);
      mu_strerr = save_errstr;
      mu_stream_unref (mu_strerr);
    }
  else
    mach->state = mu_sieve_state_error;

  return rc;
}

/* Rescan all registered strings to determine their properties */
static void
string_rescan (mu_sieve_machine_t mach)
{
  size_t i;
  int hasvar = mu_sieve_has_variables (mach);

  for (i = 0; i < mach->stringcount; i++)
    {
      mach->stringspace[i].changed = 0;
      if (hasvar)
	{
	  mach->stringspace[i].constant = 0;
	  mu_sieve_string_get (mach, &mach->stringspace[i]);
	  mu_sieve_free (mach, mach->stringspace[i].exp);
	  mach->stringspace[i].exp = NULL;
	  mach->stringspace[i].constant = !mach->stringspace[i].changed;
	  mach->stringspace[i].changed = 0;
	}
      else
	mach->stringspace[i].constant = 1;
    }
}

static int
sieve_parse (void)
{
  int rc;
  int old_mode, mode;

  sieve_tree = NULL;
  yydebug = mu_debug_level_p (mu_sieve_debug_handle, MU_DEBUG_TRACE3);

  mu_stream_ioctl (mu_strerr, MU_IOCTL_LOGSTREAM,
		   MU_IOCTL_LOGSTREAM_GET_MODE, &old_mode);
  mode = old_mode | MU_LOGMODE_LOCUS;
  mu_stream_ioctl (mu_strerr, MU_IOCTL_LOGSTREAM,
		   MU_IOCTL_LOGSTREAM_SET_MODE, &mode);

  rc = yyparse ();
  mu_stream_ioctl (mu_strerr, MU_IOCTL_LOGSTREAM,
		   MU_IOCTL_LOGSTREAM_SET_MODE, &old_mode);

  mu_i_sv_lex_finish ();
  if (rc)
    mu_i_sv_error (mu_sieve_machine);
  if (mu_sieve_machine->state == mu_sieve_state_init)
    {
      if (mu_debug_level_p (mu_sieve_debug_handle, MU_DEBUG_TRACE1))
	{
	  mu_error (_("Unoptimized parse tree"));
	  tree_dump (mu_strerr, sieve_tree, 0, mu_sieve_machine);
	}
      tree_optimize (sieve_tree);
      if (mu_debug_level_p (mu_sieve_debug_handle, MU_DEBUG_TRACE2))
	{
	  mu_error (_("Optimized parse tree"));
	  tree_dump (mu_strerr, sieve_tree, 0, mu_sieve_machine);
	}
      mu_i_sv_code (mu_sieve_machine, (sieve_op_t) (sieve_instr_t) 0);

      /* Clear location, so that mu_i_sv_locus will do its job. */
      /* FIXME: is it still needed? */
      mu_locus_range_deinit (&mu_sieve_machine->locus);

      tree_code (mu_sieve_machine, sieve_tree);
      mu_i_sv_code (mu_sieve_machine, (sieve_op_t) (sieve_instr_t) 0);
    }

  if (rc == 0)
    {
      if (mu_sieve_machine->state == mu_sieve_state_error)
	rc = MU_ERR_PARSE;
      else
	{
	  string_rescan (mu_sieve_machine);
	  mu_sieve_machine->state = mu_sieve_state_compiled;
	}
    }

  tree_free (&sieve_tree);
  return rc;
}

static int
sieve_compile_file (void *name)
{
  if (mu_i_sv_lex_begin (name) == 0)
    return sieve_parse ();
  return MU_ERR_FAILURE;
}

int
mu_sieve_compile (mu_sieve_machine_t mach, const char *name)
{
  return with_machine (mach, sieve_compile_file, (void *) name);
}

struct strbuf
{
  const char *ptr;
  size_t size;
  struct mu_locus_point const *pt;
};

static int
sieve_compile_strbuf (void *name)
{
  struct strbuf *buf = name;
  if (mu_i_sv_lex_begin_string (buf->ptr, buf->size, buf->pt) == 0)
    return sieve_parse ();
  return MU_ERR_FAILURE;
}

int
mu_sieve_compile_text (mu_sieve_machine_t mach,
		       const char *str, size_t strsize,
		       struct mu_locus_point const *loc)
{
  struct strbuf buf;
  buf.ptr = str;
  buf.size = strsize;
  buf.pt = loc;
  return with_machine (mach, sieve_compile_strbuf, &buf);
}
