/*

  $Id$

  Copyright 1989-2016 MINES ParisTech

  This file is part of PIPS.

  PIPS 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
  any later version.

  PIPS 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 PIPS.  If not, see <http://www.gnu.org/licenses/>.

*/
#ifdef HAVE_CONFIG_H
    #include "pips_config.h"
#endif

#include <stdio.h>
#include <string.h>

#include <setjmp.h>

#include "genC.h"
#include "linear.h"

#include "ri.h"
#include "effects.h"

#include "ri-util.h"
#include "effects-util.h"
#include "misc.h"

#include "effects-generic.h"
#include "effects-convex.h"

#include "semantics.h"
#include "transformer.h"

#include "pipsdbm.h"

//#include "points_to_private.h"
#include "alias-classes.h"

static list l_alias_lists, l_alias_classes;
static list l_lists, new_class, rest_list, rest_lists;


/* tests if reg1 and reg2 are the same,
 * ignoring their action_tags (IN/OUT)
 * but checking their precision (may/exact)
 */
static bool
same_reg_ignore_action(region reg1, region reg2)
    {
    Psysteme reg1_sys, reg2_sys;
    bool result = false;

    pips_debug(4,"begin\n");

    if (effect_undefined_p(reg1) || effect_undefined_p(reg2)) return result;

    if (effect_entity(reg1) == effect_entity(reg2))
    {
/*	pips_debug(1,"same entity\n"); */

	if (effect_approximation_tag(reg1) == 
		effect_approximation_tag(reg2))
	    {
/*		pips_debug(1,"same approx\n"); */

	    ifdebug(1)
		{
		    set_action_interpretation(ACTION_IN,ACTION_OUT);
		    pips_debug(1,"compare:\n\t");
		    print_region(reg1);
		    pips_debug(1,"with:\n\t");
		    print_region(reg2);
		    reset_action_interpretation();
		}

		reg1_sys = region_system(reg1);
		reg2_sys = region_system(reg2);
		if ( sc_equal_p_ofl(reg1_sys,reg2_sys) )
		{
		    result = true;

		    pips_debug(1,"same region\n");
		}
		else
		    pips_debug(1,"not same region\n");
	    }
	}
    pips_debug(4,"end\n");

    return result;
    }


/* tests if reg and any member of reg_list
 * are same_reg_ignore_action
 */
static bool
member(region reg, list reg_list)
    {
	region elem;
	list rest_list;
	bool result = false;

	pips_debug(4,"begin\n");

/*
	    ifdebug(9)
		{
		    set_action_interpretation(ACTION_IN,ACTION_OUT);
		    pips_debug(9,"test if:\n\t");
		    print_region(reg);
		    pips_debug(9,"is in:\n\t");
		    print_inout_regions(reg_list);
		    reset_action_interpretation();
		}
		*/

	rest_list = reg_list;

	if (reg_list != NIL)

			do{
			    elem = EFFECT(CAR(rest_list));
			    if (same_reg_ignore_action(elem,reg))
				{
				    result = true;

				    pips_debug(4,"is member\n");
				}

			    rest_list = CDR(rest_list);
			}while (rest_list != NIL && result == false);

	pips_debug(4,"end\n");

	return result;
    }


/* adds reg as final element on the end of reg_list
 * unless reg is already present in reg_list
 * i.e. is same_reg_ignore_action as an element of reg_list
 */
static list
append_reg_if_not_present(list reg_list, region reg)
{
    list new_reg_list;

    pips_debug(4,"begin\n");


/*
  ifdebug(9)
  {
		    set_action_interpretation(ACTION_IN,ACTION_OUT);
  pips_debug(9,"add:\n\t");
  print_region(reg);
  pips_debug(9,"to:\n\t");
  print_inout_regions(reg_list);
		    reset_action_interpretation();
  }
*/

    if (!member(reg,reg_list))
	new_reg_list = gen_nconc(reg_list,CONS(EFFECT,reg,NIL));
    else
	new_reg_list = reg_list;

    pips_debug(4,"end\n");

    return new_reg_list;
}


/* add a copy of each element in additional_list
 * not already present in initial_reg_list
 * to the end of initial_reg_list
 * (ignoring the action)
 */
static list
union_lists(list initial_reg_list, list additional_list)
{
    list new_reg_list = initial_reg_list;

    pips_debug(4,"begin\n");

    MAP(EFFECT,additional_reg,
	{
	    new_reg_list =
		append_reg_if_not_present(new_reg_list,additional_reg);
	},additional_list);

    pips_debug(4,"end\n");

    return new_reg_list;
}


/* global variables IN: rest_list, l_lists
 * global variables modified: rest_list, l_lists
 */
static void
compare_other_list(region elem, list other_list)
{
    bool result = false;
    region other_elem;
    list rest_other_list;

    ifdebug(4)
	{
	    pips_debug(4,"begin for elem:\n");
	    set_action_interpretation(ACTION_IN,ACTION_OUT);	    
	    print_region(elem);
	    reset_action_interpretation();	    
	    pips_debug(4,"and list:\n");
	    print_inout_regions(other_list);
	}

    if (other_list != NIL)
    {
	rest_other_list = other_list;
	do {
	    other_elem = EFFECT(CAR(rest_other_list));
	    rest_other_list = CDR(rest_other_list);

	    ifdebug(9)
		{
		    pips_debug(9,"compare elem:\n");
		    set_action_interpretation(ACTION_IN,ACTION_OUT);	    
		    print_region(other_elem);
		    reset_action_interpretation();	    
		}

	    if ( effect_exact_p(other_elem) )
	    {
		pips_debug(9,"exact\n");

/* here, it doesn't matter whether the regions have the same action */
		if ( same_reg_ignore_action(elem,other_elem) )
		{
		    pips_debug(9,"same\n");

		    rest_list = union_lists(rest_list,other_list);
		    result = true;
		}
	    }
	} while (result == false && rest_other_list != NIL);
	if (result == false)
	    l_lists = CONS(LIST,other_list,l_lists);
    }
    pips_debug(4,"end\n");
}


/* global variables IN: rest_list, rest_lists, l_lists
 * global variables modified: rest_list, l_lists, rest_lists
 * compares "elem" (the current element from
 * the list currently being made into a class)
 * to each element of each list of "rest_lists"
 * (the other lists not yet made into classes)
 * if a match is found, "other_list"
 * (the other list containing the matching element "other_elem")
 * is appended to "rest_list" (the not yet treated elements from the list
 * currently being made into a class)
 * and "other_list" will no longer be a member of "l_lists"
 * if not, "other_list" is appended to "l_lists"
 */
static void
compare_rest_lists(region elem)
{
    list other_list;

    while (rest_lists != NIL)
    {
    ifdebug(4)
	{
	    pips_debug(4,"begin for:\n");
	    set_action_interpretation(ACTION_IN,ACTION_OUT);	    
	    print_region(elem);
	    reset_action_interpretation();	    
	}

    other_list = LIST(CAR(rest_lists));
    rest_lists = CDR(rest_lists);
    compare_other_list(elem, other_list);
    }
    pips_debug(4,"end\n");
}


/* global variables IN: new_class, rest_lists, l_lists
 * global variables modified: new_class, l_lists, rest_lists, rest_list
 */
static void
make_class_from_list(list reg_list)
{
    region elem;

    ifdebug(4)
	{
	    pips_debug(4,"begin for:\n");
	    print_inout_regions(reg_list);
	}

    rest_list = reg_list;

    while (rest_list != NIL)
    {
	elem = EFFECT(CAR(rest_list));
	rest_list = CDR(rest_list);

	ifdebug(9)
	    {
		pips_debug(9,"elem:\n");
		   set_action_interpretation(ACTION_IN,ACTION_OUT);	    
		   print_region(elem);
		   reset_action_interpretation();	    
	    }
	
	if ( effect_exact_p(elem) )
	{
	    pips_debug(9,"exact\n");

	    rest_lists = l_lists;
	    l_lists = NIL;
	    compare_rest_lists(elem);
	}
	new_class = gen_nconc(new_class,CONS(EFFECT,elem,NIL));
    }

    pips_debug(4,"end\n");
}


/* global variables IN: l_lists, l_alias_classes
 * global variables modified:class, l_lists, rest_lists, rest_list,
 *                           l_alias_classes
 */
static void
unite_lists_containing_same_exact_region()
{
    list next_list;

    while (l_lists != NIL)
    {
    pips_debug(4,"begin\n");

    next_list = LIST(CAR(l_lists));
    l_lists = CDR(l_lists);
    new_class = NIL;

    make_class_from_list(next_list);
    l_alias_classes = CONS(EFFECTS,
			   make_effects(regions_dup(new_class)),
			   l_alias_classes);

/*    ifdebug(9)
	{
	    pips_debug(9,"new_class:\n");
	    print_inout_regions(new_class);		    
	    pips_debug(9,"l_lists:\n");
	    MAP(LIST,alias_list,
		{
		    print_inout_regions(alias_list);		    
		    pips_debug(9,"---\n");
		},
		    l_lists);
	}*/

/*    if (l_lists != NIL) unite_lists_containing_same_exact_region(); */
    }
    pips_debug(4,"end\n");
}


/* global variables IN: l_alias_lists
 * global variables modified: l_alias_lists
 * compares "head" (the head of the current list)
 * to the head of each list of "rest_lists"
 * (the other lists not yet treated)
 * if a match is found, "other_list"
 * (the other list containing the matching head "other_head")
 * is appended to "new_list"
 * and "other_list" will no longer be a member of "l_alias_lists"
 * if not, "other_list" is appended to "l_alias_lists"
 */
static list
compare_heads_rest_lists(region head, list new_list)
{
    list rest_lists;
    region other_head;

    rest_lists = l_alias_lists;
    l_alias_lists = NIL;

    MAP(LIST, other_list,
    {
    ifdebug(4)
	{
	    pips_debug(4,"begin for:\n");
	    set_action_interpretation(ACTION_IN,ACTION_OUT);	    
	    print_region(head);
	    reset_action_interpretation();	    
	}

    if (other_list != NIL)
    {
	    other_head = EFFECT(CAR(other_list));

	    ifdebug(9)
		{
		    pips_debug(9,"compare elem:\n");
		    set_action_interpretation(ACTION_IN,ACTION_OUT);	    
		    print_region(other_head);
		    reset_action_interpretation();	    
		}

/* here, we don't need to account of the actions of the
 * two regions: if a sub-program has the same IN and
 * OUT regions for one array, then we will have
 * created two alias lists which are identical except for
 * the actions of the regions: now we get rid of one
 */
	    if ( same_reg_ignore_action(head,other_head) )
	    {
		pips_debug(9,"same\n");

		new_list = union_lists(new_list,CDR(other_list));
	    }
	    else
	    {
	    l_alias_lists = CONS(LIST,other_list,l_alias_lists);
	    }
    }

    },rest_lists);

    pips_debug(4,"end\n");

    return new_list;
}


/* global variables IN: l_alias_lists, l_lists
 * global variables modified: l_alias_lists, l_lists
 */
static void
unite_lists_with_same_head()
{
    list next_list, new_list;
    region head;

    pips_debug(4,"begin\n");

    while (l_alias_lists != NIL)
    {

    next_list = LIST(CAR(l_alias_lists));
    l_alias_lists = CDR(l_alias_lists);
    new_list = next_list;

    if (next_list != NIL)
    {
	   head = EFFECT(CAR(next_list));

	   ifdebug(9)
	       {
		   pips_debug(9,"head:\n");
		   set_action_interpretation(ACTION_IN,ACTION_OUT);	    
		   print_region(head);
		   reset_action_interpretation();	    
	       }

	   new_list = compare_heads_rest_lists(head, new_list);
    }

    l_lists = CONS(LIST,new_list,l_lists);

/*    ifdebug(9)
	{
	    pips_debug(9,"new_list:\n");
	    print_inout_regions(new_list);		    
	    pips_debug(9,"l_alias_lists:\n");
	    MAP(LIST,alias_list,
		{
		    print_inout_regions(alias_list);		    
		    pips_debug(9,"---\n");
		},
		    l_alias_lists);
	}
	*/
    }

    pips_debug(4,"end\n");
}


bool
alias_classes( const char* module_name )
{
    entity module;
    list module_alias_lists;

    debug_on("ALIAS_CLASSES_DEBUG_LEVEL");
    pips_debug(4,"begin for module %s\n",module_name);
    ifdebug(4)
	{
	    /* ATTENTION: we have to do ALL this
	     * just to call print_inout_regions for debug !!
	     */
	    set_current_module_entity(
		local_name_to_top_level_entity(module_name) );
	    module = get_current_module_entity();
	    set_current_module_statement( (statement)
					  db_get_memory_resource(DBR_CODE,
								 module_name,
								 true) );
	    set_cumulated_rw_effects((statement_effects)
				     db_get_memory_resource(
					 DBR_CUMULATED_EFFECTS,
					 module_name,
					 true));
	    set_proper_rw_effects((statement_effects)
				     db_get_memory_resource(
					 DBR_PROPER_EFFECTS,
					 module_name,
					 true));
	    module_to_value_mappings(module);
	    /* and this to call print_region
	    set_action_interpretation(ACTION_IN,ACTION_OUT);	 */    
	    /* that's it, but we musn't forget to reset everything below */
	}

    l_alias_lists = NIL;
    l_alias_classes = NIL;
    l_lists = NIL;

    module_alias_lists =
	effects_classes_classes((effects_classes)
				db_get_memory_resource(DBR_ALIAS_LISTS,
						       module_name,
						       true));
    MAP(EFFECTS,module_alias_list_effects,
	    {
		list module_alias_list =
		    effects_effects(module_alias_list_effects);

/*		ifdebug(9)
		    {
			pips_debug(9,"add list:\n");
			print_inout_regions(module_alias_list);
		    }
		    */
		l_alias_lists = CONS(LIST,module_alias_list,l_alias_lists);
	    },module_alias_lists);

    ifdebug(9)
	{
	    pips_debug(9,"alias lists:\n");
	    MAP(LIST,alias_list,
		{
		    print_inout_regions(alias_list);
		    pips_debug(9,"---\n");
		},
		    l_alias_lists);
	}

    unite_lists_with_same_head();

    ifdebug(9)
	{
	    pips_debug(9,"new lists:\n");
	    MAP(LIST,alias_list,
		{
		    print_inout_regions(alias_list);		    
		    pips_debug(9,"---\n");
		},
		    l_lists);
	}

    unite_lists_containing_same_exact_region();

    ifdebug(9)
	{
	    pips_debug(9,"classes:\n");
	    MAP(EFFECTS,alias_class,
		{
		    print_inout_regions(effects_effects(alias_class));
		},
		    l_alias_classes);
	}

    DB_PUT_MEMORY_RESOURCE(DBR_ALIAS_CLASSES, 
			   strdup(module_name),
			   (char*) make_effects_classes(l_alias_classes));    

    ifdebug(4)
	{
	    free_value_mappings();
	    reset_current_module_statement();
	    reset_cumulated_rw_effects();
	    reset_proper_rw_effects();
	    reset_current_module_entity();
	}
    pips_debug(4,"end\n");
    debug_off();

    return true;
}