/*
--
-- SYNOPSIS
--      Remove prerequisites code.
--
-- DESCRIPTION
--  This code is different for DOS and for UNIX and parallel make
--  architectures since the parallel case requires the rm's to be
--  run in parallel, whereas DOS guarantees to run them sequentially.
--
-- AUTHOR
--      Dennis Vadura, dvadura@dmake.wticorp.com
--
-- WWW
--      http://dmake.wticorp.com/
--
-- COPYRIGHT
--      Copyright (c) 1996,1997 by WTI Corp.  All rights reserved.
--
--      This program is NOT free software; you can redistribute it and/or
--      modify it under the terms of the Software License Agreement Provided
--      in the file <distribution-root>/readme/license.txt.
--
-- LOG
--      Use cvs log to obtain detailed change logs.
*/

#include "extern.h"

PUBLIC void
Remove_prq( tcp )/*
===================
   Removable targets (ie. an inferred intermediate node) are removed
   by this function by running Make() on the special target .REMOVE
   (pointed to by tcp).
   As this function can be called from within another Make() (for example
   like this:
     Make()->Exec_commands()->Do_cmnd()->runargv()->..->_finished_child()
     ->Update_time_stamp()->Remove_prq() )
   it is necessary to store and restore the dynamic macros when Make()
   is finished.

   FIXME: Another potential problem is that while building .REMOVE another
   previously started target finishes and from _finished_child() calls
   Remove_prq() again. This will delete the dynamic macros and possibly
   clear/reset the prerequisites of the previous .REMOVE target.
*/
CELLPTR tcp;
{
   static  LINKPTR rlp = NIL(LINK);
   static  int flag = 0;
   static  HASHPTR m_at, m_q, m_b, m_g, m_l, m_bb, m_up;
   char    *m_at_s, *m_g_s, *m_q_s, *m_b_s, *m_l_s, *m_bb_s, *m_up_s;
   LINKPTR tlp;

   /* Unset F_MADE and F_VISITED. */
   tcp->ce_flag         &= ~(F_MADE|F_VISITED);
   tcp->ce_time          = 0L;

   /* The idea seems to be to create a target that is used to remove
    * intermediate prerequisites. Why add something to the "CeMeToo(tlp)"
    * list? I don't understand this yet.
    * FIXME! Either comment on what is going on or fix the code. */
   for( tlp=rlp; tlp !=NIL(LINK); tlp=tlp->cl_next )
      /* Find first target that has F_VISITED not set or F_MADE set,
       * i.e. it is not currently made or already done. */
      if( (tlp->cl_prq->ce_flag & (F_VISITED|F_MADE)) != F_VISITED )
     break;

   if( tlp == NIL(LINK) ) {
      TALLOC(tlp, 1, LINK);
      TALLOC(tlp->cl_prq, 1, CELL);
      tlp->cl_next = rlp;
      rlp = tlp;
   }

   *tlp->cl_prq = *tcp;

   /* We save the dynamic macro values here, as it is possible that the
    * .REMOVE recipe is getting executed for a target while some other target
    * is in the middle of executing it's list of recipe lines, in this case
    * the values of $@ etc, must be preserved so that when we return to
    * complete the other recipe we must make certain that the values of it's
    * dynamic macros are unmodified. */

   if( !flag ) {
      /* Do the getting of the macros only once. */
      flag = 1;
      m_at = Get_name("@", Macs, TRUE);
      m_g  = Get_name(">", Macs, TRUE);
      m_q  = Get_name("?", Macs, TRUE);
      m_b  = Get_name("<", Macs, TRUE);
      m_l  = Get_name("&", Macs, TRUE);
      m_bb = Get_name("*", Macs, TRUE);
      m_up = Get_name("^", Macs, TRUE);
   }

   m_at_s = m_at->ht_value; m_at->ht_value = NIL(char);
   m_g_s  = m_g->ht_value;  m_g->ht_value  = NIL(char);
   m_q_s  = m_q->ht_value;  m_q->ht_value  = NIL(char);
   m_b_s  = m_b->ht_value;  m_b->ht_value  = NIL(char);
   m_l_s  = m_l->ht_value;  m_l->ht_value  = NIL(char);
   m_bb_s = m_bb->ht_value; m_bb->ht_value = NIL(char);
   m_up_s = m_up->ht_value; m_up->ht_value = NIL(char);

   Make( tlp->cl_prq, tcp );
   if( tlp->cl_prq->ce_dir ){
      FREE(tlp->cl_prq->ce_dir);
      tlp->cl_prq->ce_dir=NIL(char);
   }

   m_at->ht_value = m_at_s;
   m_g->ht_value  = m_g_s;
   m_q->ht_value  = m_q_s;
   m_b->ht_value  = m_b_s;
   m_l->ht_value  = m_l_s;
   m_bb->ht_value = m_bb_s;
   m_up->ht_value = m_up_s;
}