/***************************************************************************
 seg_manager.c Copyright (C) 2002 Xiaojun Chen, Christoph Reichenbach 


 This program may be modified and copied freely according to the terms of
 the GNU general public license (GPL), as long as the above copyright
 notice and the licensing information contained herein are preserved.

 Please refer to www.gnu.org for licensing details.

 This work is provided AS IS, without warranty of any kind, expressed or
 implied, including but not limited to the warranties of merchantibility,
 noninfringement, and fitness for a specific purpose. The author will not
 be held liable for any damage caused by this work or derivatives of it.

 By using this source code, you agree to the licensing terms as stated
 above.


 Please contact the maintainer for bug reports or inquiries.

 Current Maintainer:

    Christoph Reichenbach (CR) <jameson@linuxgames.com>

***************************************************************************/

#include "sci/include/seg_manager.h"
#include "sci/include/sciresource.h"
#include "sci/include/versions.h"
#include "sci/include/engine.h"


/*#define GC_DEBUG*/ /* Debug garbage collection */
/*#define GC_DEBUG_VERBOSE*/ /* Debug garbage verbosely */

#define SM_MEMORY_POISON	/* Poison memory upon deallocation */

mem_obj_t* mem_obj_allocate(seg_manager_t *self, seg_id_t segid, int hash_id, mem_obj_enum type);

#undef DEBUG_SEG_MANAGER /* Define to turn on debugging */
#define GET_SEGID() 	if (flag == SCRIPT_ID) \
				id = sm_seg_get (self, id); \
			VERIFY ( sm_check (self, id), "invalid seg id" );
#define VERIFY_MEM( mem_ptr, ret ) if (! (mem_ptr) )  {\
					sciprintf( "%s, *d, no enough memory", __FILE__, __LINE__ ); \
					return ret; \
				}
					
#define INVALID_SCRIPT_ID -1
	
void dbg_print( const char* msg, void *i ) {
#ifdef DEBUG_SEG_MANAGER
	char buf[1000];
	sprintf( buf, "%s = [0x%x], dec:[%d]", msg, i, i);
	perror( buf );
#endif
}

/*--------------------------*/
/*-- forward declarations --*/
/*--------------------------*/

void
sm_script_initialise_locals_zero(seg_manager_t *self, seg_id_t seg, int count);

void
sm_script_initialise_locals(seg_manager_t *self, reg_t location);

static int
_sm_deallocate (seg_manager_t* self, int seg, int recursive);

static hunk_t *
sm_alloc_hunk(seg_manager_t *self, reg_t *);

static void
sm_free_hunk(seg_manager_t *self, reg_t addr);

static int
sm_check(seg_manager_t* self, int seg);
/* Check segment validity
** Parameters: (int) seg: The segment to validate
** Returns   : (int)	0 if 'seg' is an invalid segment
**			1 if 'seg' is a valid segment
*/

/*******************************/
/** End of Memory Management  **/
/*******************************/

static inline int
find_free_id(seg_manager_t *self, int *id)
{
	char was_added = 0;
	int retval = 0;

	while (!was_added) {
		retval = int_hash_map_check_value(self->id_seg_map, self->reserved_id,
						  1, &was_added);
		*id = self->reserved_id--;
		if (self->reserved_id < -1000000)
			self->reserved_id = -10;
		/* Make sure we don't underflow */
	}

	return retval;
}

static mem_obj_t *
alloc_nonscript_segment(seg_manager_t *self, mem_obj_enum type, seg_id_t *segid)
{ /* Allocates a non-script segment */
	int id;
	*segid = find_free_id(self, &id);
	return mem_obj_allocate(self, *segid, id, type);
}


void sm_init(seg_manager_t* self, int sci1_1) {
	int i;

	self->mem_allocated = 0; /* Initialise memory count */

	self->id_seg_map = new_int_hash_map();
	self->reserved_id = INVALID_SCRIPT_ID;
	int_hash_map_check_value (self->id_seg_map, self->reserved_id, 1, NULL);	/* reserve 0 for seg_id */
	self->reserved_id--;	/* reserved_id runs in the reversed direction to make sure no one will use it. */
	
	self->heap_size = DEFAULT_SCRIPTS;
        self->heap = (mem_obj_t**) sci_calloc(self->heap_size, sizeof(mem_obj_t *));

	self->clones_seg_id = 0;
	self->lists_seg_id = 0;
	self->nodes_seg_id = 0;
	self->hunks_seg_id = 0;

	self->exports_wide = 0;
	self->sci1_1 = sci1_1;

	/*  initialize the heap pointers*/
	for (i = 0; i < self->heap_size; i++) {
		self->heap[i] = NULL;
	}

	/* gc initialisation */
	self->gc_mark_bits = 0;
}

/* destroy the object, free the memorys if allocated before */
void sm_destroy (seg_manager_t* self) {
	int i;
	/* free memory*/
	for (i = 0; i < self->heap_size; i++) {
		if (self->heap[i])
			_sm_deallocate(self, i, 0);
	}

	free_int_hash_map(self->id_seg_map);

	sci_free (self->heap);
	self->heap = NULL;
}

/* allocate a memory for script from heap
** Parameters: (state_t *) s: The state to operate on
**             (int) script_nr: The script number to load
** Returns   : 0 - allocation failure
**             1 - allocated successfully
**             seg_id - allocated segment id
*/
mem_obj_t* sm_allocate_script (seg_manager_t* self, struct _state *s, int script_nr, int* seg_id) {
	int seg;
	char was_added;
	mem_obj_t* mem;

	seg = int_hash_map_check_value (self->id_seg_map, script_nr, 1, &was_added);
	if (!was_added) {
		*seg_id = seg;
		return self->heap[*seg_id];
	}

	/* allocate the mem_obj_t */
	mem = mem_obj_allocate(self, seg, script_nr, MEM_OBJ_SCRIPT);
	if (!mem) {
		sciprintf("%s, %d, Not enough memory, ", __FILE__, __LINE__ );
		return NULL;
	}

	*seg_id = seg;
	return mem;
}

static void sm_set_script_size(mem_obj_t *mem, struct _state *s, int script_nr) 
{
	resource_t *script = scir_find_resource(s->resmgr, sci_script, script_nr, 0);
	resource_t *heap = scir_find_resource(s->resmgr, sci_heap, script_nr, 0);

	mem->data.script.script_size = script->size;
	mem->data.script.heap_size = 0; /* Set later */

	if (!script || (s->version >= SCI_VERSION(1,001,000) && !heap))
	{
		sciprintf("%s: failed to load %s\n", __FUNCTION__, 
			  !script ? "script" : "heap");
		return;
	}
	if (s->version < SCI_VERSION_FTU_NEW_SCRIPT_HEADER) {
		mem->data.script.buf_size = script->size + getUInt16(script->data)*2; 
		/* locals_size = getUInt16(script->data)*2; */
	}
	else if (s->version < SCI_VERSION(1,001,000)) {
		mem->data.script.buf_size = script->size;
	}
	else 
	{
		mem->data.script.buf_size = script->size + heap->size;
		mem->data.script.heap_size = heap->size;
	
		/* Ensure that the start of the heap resource can be word-aligned. */
		if (script->size & 2)
		{
			mem->data.script.buf_size++;
			mem->data.script.script_size++;
		}

		if (mem->data.script.buf_size > 65535)
		{
			sciprintf("Script and heap sizes combined exceed 64K.\n"
				  "This means a fundamental design bug was made in FreeSCI\n"
				  "regarding SCI1.1 games.\nPlease report this so it can be"
				  "fixed in the next major version!\n");
			return;
		}
	}
}

int sm_initialise_script(mem_obj_t *mem, struct _state *s, int script_nr) 
{
	/* allocate the script.buf */
	script_t *scr;

	sm_set_script_size(mem, s, script_nr);
	mem->data.script.buf = (byte*) sci_malloc (mem->data.script.buf_size);
	
	dbg_print( "mem->data.script.buf ", mem->data.script.buf );
	if (!mem->data.script.buf) {
		sm_free_script ( mem );
		sciprintf("seg_manager.c: Not enough memory space for script size" );
		mem->data.script.buf_size = 0;
		return 0;
	}
	
	/* Initialize objects */
	scr = &(mem->data.script);
	scr->objects = NULL;
	scr->objects_allocated = 0;
	scr->objects_nr = 0; /* No objects recorded yet */

	scr->locals_offset = 0;
	scr->locals_block = NULL;

	scr->code = NULL;
	scr->code_blocks_nr = 0;
	scr->code_blocks_allocated = 0;

	scr->nr = script_nr;
	scr->marked_as_deleted = 0;
	scr->relocated = 0;

	scr->obj_indices = new_int_hash_map();

	if (s->version >= SCI_VERSION(1,001,000))
		scr->heap_start = scr->buf + scr->script_size; 
	else
		scr->heap_start = scr->buf;

	return 1;
}

int
_sm_deallocate (seg_manager_t* self, int seg, int recursive)
{
	mem_obj_t *mobj;
	VERIFY ( sm_check (self, seg), "invalid seg id" );

	mobj = self->heap[seg];
	int_hash_map_remove_value( self->id_seg_map, mobj->segmgr_id );

	switch (mobj->type) {

	case MEM_OBJ_SCRIPT:
		sm_free_script ( mobj );

		mobj->data.script.buf = NULL;
		if (recursive && mobj->data.script.locals_segment)
			_sm_deallocate(self, mobj->data.script.locals_segment,
				       recursive);
		break;

	case MEM_OBJ_LOCALS:
		sci_free(mobj->data.locals.locals);
		mobj->data.locals.locals = NULL;
		break;

	case MEM_OBJ_DYNMEM:
		if (mobj->data.dynmem.buf)
			sci_free(mobj->data.dynmem.buf);
		mobj->data.dynmem.buf = NULL;
		break;
	case MEM_OBJ_SYS_STRINGS:
		sys_string_free_all(&(mobj->data.sys_strings));
		break;
	case MEM_OBJ_STACK:
		sci_free(mobj->data.stack.entries);
		mobj->data.stack.entries = NULL;
		break;
	case MEM_OBJ_LISTS:
		sci_free(mobj->data.lists.table);
		mobj->data.lists.table = NULL;
		mobj->data.lists.entries_nr = mobj->data.lists.max_entry = 0;
		break;
	case MEM_OBJ_NODES:
		sci_free(mobj->data.nodes.table);
		mobj->data.nodes.table = NULL;
		mobj->data.nodes.entries_nr = mobj->data.nodes.max_entry = 0;
		break;
	case MEM_OBJ_CLONES:
		sci_free(mobj->data.clones.table);
		mobj->data.clones.table = NULL;
		mobj->data.clones.entries_nr = mobj->data.clones.max_entry = 0;
		break;
	case MEM_OBJ_HUNK:
		sci_free(mobj->data.hunks.table);
		mobj->data.hunks.table = NULL;
		mobj->data.hunks.entries_nr = mobj->data.hunks.max_entry = 0;
		break;
	case MEM_OBJ_RESERVED:
		sci_free(mobj->data.reserved);
		break;
	default:
		fprintf(stderr, "Deallocating segment type %d not supported!\n",
			mobj->type);
		BREAKPOINT();
	}

	free(mobj);
	self->heap[seg] = NULL;

	return 1;
}

int sm_script_marked_deleted(seg_manager_t* self, int script_nr)
{
	script_t *scr;
	int seg = sm_seg_get( self, script_nr );
	VERIFY ( sm_check (self, seg), "invalid seg id" );
			 
	scr = &(self->heap[seg]->data.script);
	return scr->marked_as_deleted;
}

void sm_mark_script_deleted(seg_manager_t* self, int script_nr)
{
	script_t *scr;
	int seg = sm_seg_get( self, script_nr );
	VERIFY ( sm_check (self, seg), "invalid seg id" );

	scr = &(self->heap[seg]->data.script);
	scr->marked_as_deleted = 1;
}

void sm_unmark_script_deleted(seg_manager_t* self, int script_nr)
{
	script_t *scr;
	int seg = sm_seg_get( self, script_nr );
	VERIFY ( sm_check (self, seg), "invalid seg id" );

	scr = &(self->heap[seg]->data.script);
	scr->marked_as_deleted = 0;
}

int
sm_script_is_marked_as_deleted(seg_manager_t* self, seg_id_t seg)
{
	script_t *scr;

	if (!sm_check (self, seg))
		return 0;

	if (self->heap[seg]->type != MEM_OBJ_SCRIPT)
		return 0;

	scr = &(self->heap[seg]->data.script);
	return scr->marked_as_deleted;
}


int sm_deallocate_script (seg_manager_t* self, int script_nr) {
	int seg = sm_seg_get( self, script_nr );

	_sm_deallocate(self, seg, 1);
	return 1;
}

mem_obj_t*
mem_obj_allocate(seg_manager_t *self, seg_id_t segid, int hash_id, mem_obj_enum type)
{
	mem_obj_t* mem = ( mem_obj_t* ) sci_calloc( sizeof (mem_obj_t), 1 );
	if( !mem ) {
		sciprintf( "seg_manager.c: invalid mem_obj " );
		return NULL;
	}

	if (segid >= self->heap_size) {
		void *temp;
		int oldhs = self->heap_size;

		if (segid >= self->heap_size * 2) {
			sciprintf( "seg_manager.c: hash_map error or others??" );
			return NULL;
		}
		self->heap_size *= 2;
		temp = sci_realloc ((void*)self->heap, self->heap_size * sizeof( mem_obj_t* ) );
		if (!temp) {
			sciprintf("seg_manager.c: Not enough memory space for script size" );
			return NULL;
		}
		self->heap = (mem_obj_t**)  temp;

		/* Clear pointers */
		memset(self->heap + oldhs, 0, sizeof(mem_obj_t *) * (self->heap_size - oldhs));
	}

	mem->segmgr_id = hash_id;
	mem->type = type;

	/* hook it to the heap */
	self->heap[segid] = mem;
	return mem;
}

/* No longer in use? */
/* void sm_object_init (object_t* object) { */
/* 	if( !object )	return; */
/* 	object->variables_nr = 0; */
/* 	object->variables = NULL; */
/* }; */

void
sm_free_script ( mem_obj_t* mem )
{
	if( !mem ) return;
	if( mem->data.script.buf ) {
		sci_free( mem->data.script.buf );
		mem->data.script.buf = NULL;
		mem->data.script.buf_size = 0;
	}
	if( mem->data.script.objects ) {
		int i;
		for( i = 0; i < mem->data.script.objects_nr; i++ ) {
			object_t* object = &mem->data.script.objects[i];
			if( object->variables ) {
				free( object->variables );
				object->variables = NULL;
				object->variables_nr = 0;
			}
		}
		free( mem->data.script.objects );
		mem->data.script.objects = NULL;
		mem->data.script.objects_nr = 0;
	}

	free_int_hash_map(mem->data.script.obj_indices);
	if (NULL != mem->data.script.code) {
		sci_free(mem->data.script.code);
	}
}

/* memory operations */
#if 0
// Unreferenced - removed
static void
sm_mset (seg_manager_t* self, int offset, int c, size_t n, int id, int flag) {
	mem_obj_t* mem_obj;
	GET_SEGID();
	mem_obj = self->heap[id];
	switch (mem_obj->type) {
	case MEM_OBJ_SCRIPT:
		if (mem_obj->data.script.buf) {
			memset( mem_obj->data.script.buf + offset, c, n );
		}
		break;
	case MEM_OBJ_CLONES:
		sciprintf( "memset for clones haven't been implemented\n" );
		break;
	default:
		sciprintf( "unknown mem obj type\n" );
		break;
	}
}
#endif

#if 0
// Unreferenced - removed
static void
sm_mcpy_in_in (seg_manager_t* self, int dst, const int src, size_t n, int id, int flag) {
	mem_obj_t* mem_obj;
	GET_SEGID();
	mem_obj = self->heap[id];
	switch (mem_obj->type) {
	case MEM_OBJ_SCRIPT:
		if (mem_obj->data.script.buf) {
			memcpy ( mem_obj->data.script.buf + dst, mem_obj->data.script.buf + src, n );
		}
		break;
	case MEM_OBJ_CLONES:
		sciprintf( "memcpy for clones haven't been implemented\n" );
		break;
	default:
		sciprintf( "unknown mem obj type\n" );
		break;
	}
}
#endif

void
sm_mcpy_in_out (seg_manager_t* self, int dst, const void* src, size_t n, int id, int flag) {
	mem_obj_t* mem_obj;
	GET_SEGID();
	mem_obj = self->heap[id];
	switch (mem_obj->type) {
	case MEM_OBJ_SCRIPT:
		if (mem_obj->data.script.buf) {
			memcpy ( mem_obj->data.script.buf + dst, src, n );
		}
		break;
	case MEM_OBJ_CLONES:
		sciprintf( "memcpy for clones hasn't been implemented yet\n" );
		break;
	default:
		sciprintf( "unknown mem obj type\n" );
		break;
	}
}

#if 0
// Unreferenced - removed
static void
sm_mcpy_out_in (seg_manager_t* self, void* dst, const int src, size_t n, int id, int flag) {
	mem_obj_t* mem_obj;
	GET_SEGID();
	mem_obj = self->heap[id];
	switch (mem_obj->type) {
	case MEM_OBJ_SCRIPT:
		if (mem_obj->data.script.buf) {
			memcpy ( dst, mem_obj->data.script.buf + src, n );
		}
		break;
	case MEM_OBJ_CLONES:
		sciprintf( "memcpy for clones hasn't been implemented yet\n" );
		break;
	default:
		sciprintf( "unknown mem obj type\n" );
		break;
	}
}
#endif

gint16
sm_get_heap (seg_manager_t* self, reg_t reg)
{
	mem_obj_t* mem_obj;
	mem_obj_enum mem_type;

	VERIFY( sm_check (self, reg.segment), "Invalid seg id" );
	mem_obj = self->heap[reg.segment];
	mem_type = mem_obj->type;

	switch( mem_type ) {
	case MEM_OBJ_SCRIPT:
		VERIFY( reg.offset + 1 < (unsigned int)mem_obj->data.script.buf_size, "invalid offset\n" );
		return (unsigned char)mem_obj->data.script.buf[reg.offset] |
		     ( ((unsigned char)mem_obj->data.script.buf[reg.offset+1]) << 8 );
	case MEM_OBJ_CLONES:
		sciprintf( "memcpy for clones hasn't been implemented yet\n" );
		break;
	default:
		sciprintf( "unknown mem obj type\n" );
		break;
	}
	return 0;	/* never get here */
}

void sm_put_heap (seg_manager_t* self, reg_t reg, gint16 value ) {
	mem_obj_t* mem_obj;
	mem_obj_enum mem_type;

	VERIFY( sm_check (self, reg.segment), "Invalid seg id" );
	mem_obj = self->heap[reg.segment];
	mem_type = mem_obj->type;

	switch( mem_type ) {
	case MEM_OBJ_SCRIPT:
		VERIFY( reg.offset + 1 < mem_obj->data.script.buf_size, "invalid offset" );
		mem_obj->data.script.buf[reg.offset] = value & 0xff;
		mem_obj->data.script.buf[reg.offset + 1] = value >> 8;
		break;
	case MEM_OBJ_CLONES:
		sciprintf( "memcpy for clones haven't been implemented\n" );
		break;
	default:
		sciprintf( "unknown mem obj type\n" );
		break;
	}
}

/* return the seg if script_id is valid and in the map, else -1 */
int sm_seg_get (seg_manager_t* self, int script_id)
{
	return int_hash_map_check_value (self->id_seg_map, script_id, 0, NULL);
}

/* validate the seg
** return:
**	0 - invalid seg
**	1 - valid seg
*/
static int
sm_check (seg_manager_t* self, int seg) {
	if ( seg < 0 || seg >= self->heap_size ) {
		return 0;
	}
	if (!self->heap[seg]) {
		sciprintf("seg_manager.c: seg %x is removed from memory, but not removed from hash_map\n", seg );
		return 0;
	}
	return 1;
}

int sm_script_is_loaded (seg_manager_t* self, int id, id_flag flag) {
	if (flag == SCRIPT_ID)
		id = sm_seg_get (self, id);
	return sm_check (self, id);
}

void sm_increment_lockers (seg_manager_t* self, int id, id_flag flag) {
	if (flag == SCRIPT_ID)
		id = sm_seg_get (self, id);
	VERIFY ( sm_check (self, id), "invalid seg id" );
	self->heap[id]->data.script.lockers++;
}

void sm_decrement_lockers (seg_manager_t* self, int id, id_flag flag) {
	if (flag == SCRIPT_ID)
		id = sm_seg_get (self, id);
	VERIFY ( sm_check (self, id), "invalid seg id" );

	if (self->heap[id]->data.script.lockers > 0)
		self->heap[id]->data.script.lockers--;
}

int sm_get_lockers (seg_manager_t* self, int id, id_flag flag) {
	if (flag == SCRIPT_ID)
		id = sm_seg_get (self, id);
	VERIFY ( sm_check (self, id), "invalid seg id" );
	return self->heap[id]->data.script.lockers;
}

void sm_set_lockers (seg_manager_t* self, int lockers, int id, id_flag flag) {
	if (flag == SCRIPT_ID)
		id = sm_seg_get (self, id);
	VERIFY ( sm_check (self, id), "invalid seg id" );
	self->heap[id]->data.script.lockers = lockers;
}

void
sm_set_export_table_offset (struct _seg_manager_t* self, int offset, int id, id_flag flag)
{
	script_t *scr = &(self->heap[id]->data.script);

	GET_SEGID();
	if (offset) {
		scr->export_table = (guint16 *)(scr->buf + offset + 2);
		scr->exports_nr = getUInt16((byte *)(scr->export_table - 1));
	} else {
		scr->export_table = NULL;
		scr->exports_nr = 0;
	}
}

int
sm_hash_segment_data(struct _seg_manager_t* self, int id)
{
	int i, len, hash_code = 0x55555555;
	char *buf;

	if (self->heap[id]->type == MEM_OBJ_LISTS) return 0;
	if (self->heap[id]->type == MEM_OBJ_NODES) return 0;
	if (self->heap[id]->type == MEM_OBJ_CLONES) return 0;
	buf = (char*)sm_dereference(self, make_reg(id, 0), &len);

	for (i = 0; i < len; i++)
		hash_code = (hash_code * 19) + *(buf + i);

	return hash_code;
}

void
sm_set_export_width(struct _seg_manager_t* self, int flag)
{
	self->exports_wide = flag;
}

#if 0
// Unreferenced - removed
static guint16 *
sm_get_export_table_offset (struct _seg_manager_t* self, int id, int flag, int *max)
{
	GET_SEGID();
	if (max)
		*max = self->heap[id]->data.script.exports_nr;
	return self->heap[id]->data.script.export_table;
}
#endif

void
sm_set_synonyms_offset (struct _seg_manager_t* self, int offset, int id, id_flag flag) {
	GET_SEGID();
	self->heap[id]->data.script.synonyms = 
		self->heap[id]->data.script.buf + offset;
}

byte *
sm_get_synonyms(seg_manager_t *self, int id, id_flag flag)
{
	GET_SEGID();
	return self->heap[id]->data.script.synonyms;
}

void
sm_set_synonyms_nr (struct _seg_manager_t* self, int nr, int id, id_flag flag) {
	GET_SEGID();
	self->heap[id]->data.script.synonyms_nr = nr;
}

int
sm_get_synonyms_nr (struct _seg_manager_t* self, int id, id_flag flag)
{
	GET_SEGID();
	return self->heap[id]->data.script.synonyms_nr;
}

#if 0
// Unreferenced - removed
static int
sm_get_heappos (struct _seg_manager_t* self, int id, int flag)
{
	GET_SEGID();
	return 0;
}
#endif

#if 0
// Unreferenced - removed
static void
sm_set_variables (struct _seg_manager_t* self, reg_t reg, int obj_index, reg_t variable_reg, int variable_index ) {
	script_t* script;
	VERIFY ( sm_check (self, reg.segment), "invalid seg id" );
	VERIFY ( self->heap[reg.segment], "invalid mem" );
	
	script = &(self->heap[reg.segment]->data.script);

	VERIFY( obj_index < script->objects_nr, "Invalid obj_index" );

	VERIFY( variable_index >= 0
		&& variable_index < script->objects[obj_index].variables_nr,
		"Attempt to write to invalid variable number" );

	script->objects[obj_index].variables[variable_index] = variable_reg;
}
#endif

static inline int
_relocate_block(seg_manager_t *self, reg_t *block, int block_location, int block_items, seg_id_t segment, int location)
{
	int rel = location - block_location;
	int index;

	if (rel < 0)
		return 0;

	index = rel >> 1;

	if (index >= block_items)
		return 0;

	if (rel & 1) {
		sciprintf("Error: Attempt to relocate odd variable #%d.5e (relative to %04x)\n",
			  index, block_location);
		return 0;
	}
	block[index].segment = segment; /* Perform relocation */
	if (self->sci1_1)
		block[index].offset += self->heap[segment]->data.script.script_size;

	return 1;
}

static inline int
_relocate_local(seg_manager_t *self, script_t *scr, seg_id_t segment, int location)
{
	if (scr->locals_block)
		return _relocate_block(self,
				       scr->locals_block->locals, scr->locals_offset,
				       scr->locals_block->nr,
				       segment, location);
	else
		return 0; /* No hands, no cookies */
}

static inline int
_relocate_object(seg_manager_t *self, object_t *obj, seg_id_t segment, int location)
{
	return _relocate_block(self, 
			       obj->variables, obj->pos.offset, obj->variables_nr,
			       segment, location);
}

void
sm_script_add_code_block(seg_manager_t *self, reg_t location)
{
	mem_obj_t *mobj = self->heap[location.segment];
	script_t *scr;
	int index;

	VERIFY( !(location.segment >= self->heap_size || mobj->type != MEM_OBJ_SCRIPT),
		"Attempt to add a code block to non-script\n" );

	scr = &(mobj->data.script);

	if (++scr->code_blocks_nr > scr->code_blocks_allocated)
	{
		scr->code_blocks_allocated += DEFAULT_OBJECTS_INCREMENT;
		scr->code = (code_block_t*)sci_realloc(scr->code, scr->code_blocks_allocated *
				sizeof(code_block_t));
	}

	index = scr->code_blocks_nr - 1;
	scr->code[index].pos = location;
	scr->code[index].size = getUInt16(scr->buf + location.offset - 2);
}

void
sm_script_relocate(seg_manager_t *self, reg_t block)
{
	mem_obj_t *mobj = self->heap[block.segment];
	script_t *scr;
	int count;
	int i;
	
	VERIFY( !(block.segment >= self->heap_size || mobj->type != MEM_OBJ_SCRIPT),
		"Attempt relocate non-script\n" );

	scr = &(mobj->data.script);

	VERIFY( block.offset < scr->buf_size
		&& getUInt16(scr->buf + block.offset)*2 + block.offset < scr->buf_size,
		"Relocation block outside of script\n" );

	count = getUInt16(scr->buf + block.offset);

	for (i = 0; i <= count; i++) {
		int pos = getUInt16(scr->buf + block.offset + 2 + (i*2));
		if (!pos) continue; /* FIXME: A hack pending investigation */

		if (!_relocate_local(self, scr, block.segment, pos)) {
			int k, done = 0;

			for (k = 0; !done && k < scr->objects_nr; k++) {
				if (_relocate_object(self, scr->objects + k, block.segment, pos))
					done = 1;
			}

			for (k = 0; !done && k < scr->code_blocks_nr; k++) {
				if (pos >= scr->code[k].pos.offset &&
				    pos < scr->code[k].pos.offset+scr->code[k].size)
					done = 1;
			}

			if (!done) {
				sciprintf("While processing relocation block "PREG":\n",
					  PRINT_REG(block));
				sciprintf("Relocation failed for index %04x (%d/%d)\n", pos, i+1, count);
				if (scr->locals_block)
					sciprintf("- locals: %d at %04x\n",
						  scr->locals_block->nr,
						  scr->locals_offset);
				else
					sciprintf("- No locals\n");
				for (k = 0; k < scr->objects_nr; k++)
					sciprintf("- obj#%d at %04x w/ %d vars\n",
						  k,
						  scr->objects[k].pos.offset,
						  scr->objects[k].variables_nr);
// SQ3 script 71 has broken relocation entries.
// Since this is mainstream, we can't break out as we used to do.
				sciprintf("Trying to continue anyway...\n");
//				BREAKPOINT(); 
			}
		}
	}
}

void
sm_heap_relocate(seg_manager_t *self, state_t *s, reg_t block)
{
	mem_obj_t *mobj = self->heap[block.segment];
	script_t *scr;
	int count;
	int i;
	
	VERIFY( !(block.segment >= self->heap_size || mobj->type != MEM_OBJ_SCRIPT),
		"Attempt relocate non-script\n" );

	scr = &(mobj->data.script);

	VERIFY( block.offset < scr->heap_size
		&& getUInt16(scr->heap_start + block.offset)*2 + block.offset < scr->buf_size,
		"Relocation block outside of script\n" );

	if (scr->relocated) return;		
	scr->relocated = 1;
	count = getUInt16(scr->heap_start + block.offset);

	for (i = 0; i < count; i++) {
		int pos = getUInt16(scr->heap_start + block.offset + 2 + (i*2)) + scr->script_size;

		if (!_relocate_local(self, scr, block.segment, pos)) {
			int k, done = 0;

			for (k = 0; !done && k < scr->objects_nr; k++) {
				if (_relocate_object(self, scr->objects + k, block.segment, pos))
					done = 1;
			}

			if (!done) {
				sciprintf("While processing relocation block "PREG":\n",
					  PRINT_REG(block));
				sciprintf("Relocation failed for index %04x (%d/%d)\n", pos, i+1, count);
				if (scr->locals_block)
					sciprintf("- locals: %d at %04x\n",
						  scr->locals_block->nr,
						  scr->locals_offset);
				else
					sciprintf("- No locals\n");
				for (k = 0; k < scr->objects_nr; k++)
					sciprintf("- obj#%d at %04x w/ %d vars\n",
						  k,
						  scr->objects[k].pos.offset,
						  scr->objects[k].variables_nr);
				sciprintf("Triggering breakpoint...\n");
				BREAKPOINT();
			}
		}
	}
}

#define INST_LOOKUP_CLASS(id) ((id == 0xffff)? NULL_REG : get_class_address(s, id, SCRIPT_GET_LOCK, NULL_REG))

reg_t
get_class_address(state_t *s, int classnr, int lock, reg_t caller);

static object_t *
sm_script_obj_init0(seg_manager_t *self, state_t *s, reg_t obj_pos)
{
	mem_obj_t *mobj = self->heap[obj_pos.segment];
	script_t *scr;
	object_t *obj;
	int id;
	unsigned int base = obj_pos.offset - SCRIPT_OBJECT_MAGIC_OFFSET;
	reg_t temp;

	VERIFY( !(obj_pos.segment >= self->heap_size || mobj->type != MEM_OBJ_SCRIPT),
		"Attempt to initialize object in non-script\n" );

	scr = &(mobj->data.script);

	VERIFY( base < scr->buf_size,
		"Attempt to initialize object beyond end of script\n" );

	if (!scr->objects) {
		scr->objects_allocated = DEFAULT_OBJECTS;
		scr->objects = (object_t*)sci_malloc(sizeof(object_t) * scr->objects_allocated);
	}
	if (scr->objects_nr == scr->objects_allocated) {
		scr->objects_allocated += DEFAULT_OBJECTS_INCREMENT;
		scr->objects = (object_t*)sci_realloc(scr->objects,
					   sizeof(object_t)
					   * scr->objects_allocated);
								
	}

	temp = make_reg(obj_pos.segment, base);
	id = int_hash_map_check_value(scr->obj_indices, base, 1, NULL);
	scr->objects_nr++;

	obj = scr->objects + id;

	VERIFY( base + SCRIPT_FUNCTAREAPTR_OFFSET  < scr->buf_size,
		"Function area pointer stored beyond end of script\n" );
		
	{
		byte *data = (byte *) (scr->buf + base);
		int funct_area = getUInt16( data + SCRIPT_FUNCTAREAPTR_OFFSET );
		int variables_nr;
		int functions_nr;
		int is_class;
		int i;

		obj->flags = 0;
		obj->pos = temp;

		VERIFY ( base + funct_area < scr->buf_size,
			 "Function area pointer references beyond end of script" );

		variables_nr = getUInt16( data + SCRIPT_SELECTORCTR_OFFSET );
		functions_nr = getUInt16( data + funct_area - 2 );
		is_class = getUInt16( data + SCRIPT_INFO_OFFSET ) & SCRIPT_INFO_CLASS;

		VERIFY ( base + funct_area + functions_nr * 2
			 /* add again for classes, since those also store selectors */
			 + (is_class? functions_nr * 2 : 0) < scr->buf_size,
			 "Function area extends beyond end of script" );

		obj->variables_nr = variables_nr;
		obj->variables = (reg_t*)sci_malloc(sizeof(reg_t) * variables_nr);

		obj->methods_nr = functions_nr;
		obj->base = scr->buf;
		obj->base_obj = data;
		obj->base_method = (guint16 *) (data + funct_area);
		obj->base_vars = NULL;

		for (i = 0; i < variables_nr; i++)
			obj->variables[i] = make_reg(0, getUInt16(data + (i*2)));
	}

	return obj;
}

static object_t *
sm_script_obj_init11(seg_manager_t *self, state_t *s, reg_t obj_pos)
{
	mem_obj_t *mobj = self->heap[obj_pos.segment];
	script_t *scr;
	object_t *obj;
	int id;
	int base = obj_pos.offset;

	VERIFY( !(obj_pos.segment >= self->heap_size || mobj->type != MEM_OBJ_SCRIPT),
		"Attempt to initialize object in non-script\n" );

	scr = &(mobj->data.script);

	VERIFY( base < scr->buf_size,
		"Attempt to initialize object beyond end of script\n" );

	if (!scr->objects) {
		scr->objects_allocated = DEFAULT_OBJECTS;
		scr->objects = (object_t*)sci_malloc(sizeof(object_t) * scr->objects_allocated);
	}
	if (scr->objects_nr == scr->objects_allocated) {
		scr->objects_allocated += DEFAULT_OBJECTS_INCREMENT;
		scr->objects = (object_t*)sci_realloc(scr->objects,
					   sizeof(object_t)
					   * scr->objects_allocated);
								
	}

	id = int_hash_map_check_value(scr->obj_indices, obj_pos.offset, 1, NULL);
	scr->objects_nr++;

	obj = scr->objects + id;

	VERIFY( base + SCRIPT_FUNCTAREAPTR_OFFSET  < scr->buf_size,
		"Function area pointer stored beyond end of script\n" );
		
	{
		byte *data = (byte *) (scr->buf + base);
		guint16 *funct_area = (guint16 *) (scr->buf + getUInt16( data + 6 ));
		guint16 *prop_area = (guint16 *) (scr->buf + getUInt16( data + 4 ));
		int variables_nr;
		int functions_nr;
		int is_class;
		int i;
		
		obj->flags = 0;
		obj->pos = obj_pos;

		VERIFY ( (byte *) funct_area < scr->buf + scr->buf_size,
			 "Function area pointer references beyond end of script" );

		variables_nr = getUInt16(data + 2);
		functions_nr = *funct_area;
		is_class = getUInt16( data + 14 ) & SCRIPT_INFO_CLASS;

		obj->base_method = funct_area;
		obj->base_vars = prop_area;

		VERIFY ( ((byte *) funct_area + functions_nr) < scr->buf + scr->buf_size,
			 "Function area extends beyond end of script" );

		obj->variables_nr = variables_nr;
		obj->variable_names_nr = variables_nr;
		obj->variables = (reg_t*)sci_malloc(sizeof(reg_t) * variables_nr);

		obj->methods_nr = functions_nr;
		obj->base = scr->buf;
		obj->base_obj = data;

		for (i = 0; i < variables_nr; i++)
			obj->variables[i] = make_reg(0, getUInt16(data + (i*2)));
	}

	return obj;
}

object_t *
sm_script_obj_init(seg_manager_t *self, state_t *s, reg_t obj_pos)
{
	if (!self->sci1_1) 
		return sm_script_obj_init0(self, s, obj_pos);
	else
		return sm_script_obj_init11(self, s, obj_pos);
}

static local_variables_t *
_sm_alloc_locals_segment(seg_manager_t *self, script_t *scr, int count)
{
	if (!count) { /* No locals */
		scr->locals_segment = 0;
		scr->locals_block = NULL;
		return NULL;
	} else {
		mem_obj_t *mobj;
		local_variables_t *locals;

		if (scr->locals_segment) {
			mobj = self->heap[scr->locals_segment];
			VERIFY(mobj != NULL, "Re-used locals segment was NULL'd out");
			VERIFY(mobj->type == MEM_OBJ_LOCALS, "Re-used locals segment did not consist of local variables");
			VERIFY(mobj->data.locals.script_id == scr->nr, "Re-used locals segment belonged to other script");
		} else
			mobj = alloc_nonscript_segment(self, MEM_OBJ_LOCALS,
							  &scr->locals_segment);

		locals = scr->locals_block = &(mobj->data.locals);
		locals->script_id = scr->nr;
		locals->locals = (reg_t*)sci_calloc(count, sizeof(reg_t));
		locals->nr = count;

		return locals;
	}
}

void
sm_script_initialise_locals_zero(seg_manager_t *self, seg_id_t seg, int count)
{
	mem_obj_t *mobj = self->heap[seg];
	script_t *scr;

	VERIFY( !(seg >= self->heap_size || mobj->type != MEM_OBJ_SCRIPT),
		"Attempt to initialize locals in non-script\n" );

	scr = &(mobj->data.script);

	scr->locals_offset = -count * 2; /* Make sure it's invalid */

	_sm_alloc_locals_segment(self, scr, count);
}

void
sm_script_initialise_locals(seg_manager_t *self, reg_t location)
{
	mem_obj_t *mobj = self->heap[location.segment];
	unsigned int count;
	script_t *scr;
	local_variables_t *locals;

	VERIFY( !(location.segment >= self->heap_size || mobj->type != MEM_OBJ_SCRIPT),
		"Attempt to initialize locals in non-script\n" );

	scr = &(mobj->data.script);

	VERIFY( location.offset + 1 < scr->buf_size,
		"Locals beyond end of script\n" );

	if (self->sci1_1)
		count = getUInt16(scr->buf + location.offset - 2);
	else
		count = (getUInt16(scr->buf + location.offset - 2) - 4) >> 1;
	/* half block size */

	scr->locals_offset = location.offset;

	if (!(location.offset + count * 2 + 1 < scr->buf_size)) {
		sciprintf("Locals extend beyond end of script: offset %04x, count %x vs size %x\n",
			  location.offset, count, scr->buf_size);
		count = (scr->buf_size  - location.offset) >> 1;
	}

	locals = _sm_alloc_locals_segment(self, scr, count);
	if (locals) {
		int i;
		byte *base = (byte *) (scr->buf + location.offset);

		for (i = 0; i < count; i++)
			locals->locals[i].offset = getUInt16(base + i*2);
	}
}

void
sm_script_relocate_exports_sci11(seg_manager_t *self, int seg)
{
	mem_obj_t *mobj = self->heap[seg];
	script_t *scr;
	int i;
	int location;

	VERIFY( !(seg >= self->heap_size || mobj->type != MEM_OBJ_SCRIPT),
		"Attempt to relocate exports in non-script\n" );

	scr = &(mobj->data.script);
	for (i = 0; i < scr->exports_nr; i++)
	{
		/* We are forced to use an ugly heuristic here to distinguish function
		   exports from object/class exports. The former kind points into the
		   script resource, the latter into the heap resource.  */
		location = getUInt16((byte *)(scr->export_table + i));
		if (getUInt16(scr->heap_start + location) == SCRIPT_OBJECT_MAGIC_NUMBER)
		{
			putInt16((byte *)(scr->export_table + i), location+scr->heap_start-scr->buf);
		} else
		{
			/* Otherwise it's probably a function export,
			   and we don't need to do anything. */
		}
	}

}

void
sm_script_initialise_objects_sci11(seg_manager_t *self, state_t *s, int seg)
{
	mem_obj_t *mobj = self->heap[seg];
	script_t *scr;
	byte *seeker;

	VERIFY( !(seg >= self->heap_size || mobj->type != MEM_OBJ_SCRIPT),
		"Attempt to relocate exports in non-script\n" );

	scr = &(mobj->data.script);
	seeker = scr->heap_start + 4 + getUInt16(scr->heap_start + 2) * 2;

	while (getUInt16(seeker) == SCRIPT_OBJECT_MAGIC_NUMBER)
	{

		if (getUInt16(seeker + 14) & SCRIPT_INFO_CLASS)
		{
			int classpos = seeker-scr->buf;
			int species = getUInt16(seeker + 10);

			if (species < 0 || species >= s->classtable_size) {
				sciprintf("Invalid species %d(0x%x) not in interval "
					  "[0,%d) while instantiating script %d\n",
					  species, species, s->classtable_size,
					  scr->nr);
				script_debug_flag = script_error_flag = 1;
				return;
			}

			s->classtable[species].script = scr->nr;
			s->classtable[species].reg.segment = seg;
			s->classtable[species].reg.offset = classpos;
		}
		seeker += getUInt16(seeker + 2) * 2;
	}

	seeker = scr->heap_start + 4 + getUInt16(scr->heap_start + 2) * 2;
	while (getUInt16(seeker) == SCRIPT_OBJECT_MAGIC_NUMBER)
	{
		reg_t reg;
		object_t *obj;

		reg.segment = seg;
		reg.offset = seeker-scr->buf;
		obj = sm_script_obj_init(&s->seg_manager, s, reg);

#if 0
		if (obj->variables[5].offset != 0xffff)
		{
			obj->variables[5] =
				INST_LOOKUP_CLASS(obj->variables[5].offset);


			base_obj = obj_get(s, obj->variables[5]);
			obj->variable_names_nr = base_obj->variables_nr;
			obj->base_obj = base_obj->base_obj;
		}
#endif

		/* Copy base from species class, as we need its selector IDs */ 
		obj->variables[6] =
			INST_LOOKUP_CLASS(obj->variables[6].offset);
		
		seeker += getUInt16(seeker + 2) * 2;
	}

}
void
sm_script_free_unused_objects(seg_manager_t *self, seg_id_t seg)
{
	mem_obj_t *mobj = self->heap[seg];
	script_t *scr;

	VERIFY( !(seg >= self->heap_size || mobj->type != MEM_OBJ_SCRIPT),
		"Attempt to free unused objects in non-script\n" );


	scr = &(mobj->data.script);
	if (scr->objects_allocated > scr->objects_nr) {
		if (scr->objects_nr)
			scr->objects = (object_t*)sci_realloc(scr->objects, sizeof(object_t)
						   * scr->objects_nr);
		else {
			if (scr->objects_allocated)
				sci_free(scr->objects);
			scr->objects = NULL;
		}
		scr->objects_allocated = scr->objects_nr;
	}
}

static inline char *dynprintf(char *msg, ...)
{
	va_list argp;
	char *buf = (char*)sci_malloc(strlen(msg) + 100);

	va_start(argp, msg);
	vsprintf(buf, msg, argp);
	va_end(argp);

	return buf;
}


dstack_t *
sm_allocate_stack(seg_manager_t *self, int size, seg_id_t *segid)
{
	mem_obj_t *memobj = alloc_nonscript_segment(self, MEM_OBJ_STACK, segid);
	dstack_t *retval = &(memobj->data.stack);

	retval->entries = (reg_t*)sci_calloc(size, sizeof(reg_t));
	retval->nr = size;

	return retval;
}

sys_strings_t *
sm_allocate_sys_strings(seg_manager_t *self, seg_id_t *segid)
{
	mem_obj_t *memobj = alloc_nonscript_segment(self, MEM_OBJ_SYS_STRINGS, segid);
	sys_strings_t *retval = &(memobj->data.sys_strings);

	memset(retval, 0, sizeof(sys_string_t)*SYS_STRINGS_MAX);

	return retval;
}

seg_id_t
sm_allocate_reserved_segment(seg_manager_t *self, char *src_name)
{
	seg_id_t segid;
	mem_obj_t *memobj = alloc_nonscript_segment(self, MEM_OBJ_RESERVED, &segid);
	char *name = sci_strdup(src_name);

	memobj->data.reserved = name;

	return segid;
}

guint16
sm_validate_export_func(struct _seg_manager_t* self, int pubfunct, int seg ) {
	script_t* script; 
	guint16 offset;
	VERIFY ( sm_check (self, seg), "invalid seg id" );
	VERIFY (self->heap[seg]->type == MEM_OBJ_SCRIPT, "Can only validate exports on scripts");

	script = &self->heap[seg]->data.script;
	if( script->exports_nr <= pubfunct ) {
		sciprintf( "pubfunct is invalid" );
		return 0;
	}

	if (self->exports_wide) pubfunct *= 2;
	offset = getUInt16( (byte*)(script->export_table + pubfunct) ); 
	VERIFY ( offset < script->buf_size, "invalid export function pointer" );

	return offset;
}


void
sm_free_hunk_entry(seg_manager_t *self, reg_t addr)
{
	sm_free_hunk(self, addr);
}


hunk_t *
sm_alloc_hunk_entry(seg_manager_t *self, const char *hunk_type, int size, reg_t *reg)
{
	hunk_t *h = sm_alloc_hunk(self, reg);

	if (!h)
		return NULL;

	h->mem = sci_malloc(size);
	h->size = size;
	h->type = hunk_type;

	return h;
}

static void
_clone_cleanup(clone_t *clone)
{
	if (clone->variables)
		sci_free(clone->variables); /* Free the dynamically allocated memory part */
}

static void
_hunk_cleanup(hunk_t *hunk)
{
	if (hunk->mem)
		free (hunk->mem);
}

DEFINE_HEAPENTRY(list, 8, 4)
DEFINE_HEAPENTRY(node, 32, 16)
DEFINE_HEAPENTRY_WITH_CLEANUP(clone, 16, 4, _clone_cleanup)
DEFINE_HEAPENTRY_WITH_CLEANUP(hunk, 4, 4, _hunk_cleanup)

#define DEFINE_ALLOC_DEALLOC(STATIC, TYPE, SEGTYPE, PLURAL) \
STATIC TYPE##_t *										  \
sm_alloc_##TYPE(seg_manager_t *self, reg_t *addr)						  \
{												  \
	mem_obj_t *mobj;									  \
	TYPE##_table_t *table;									  \
	int offset;										  \
												  \
	if (!self->TYPE##s_seg_id) {								  \
		mobj = alloc_nonscript_segment(self, SEGTYPE, &(self->TYPE##s_seg_id));		  \
		init_##TYPE##_table(&(mobj->data.PLURAL));					  \
	} else											  \
		mobj = self->heap[self->TYPE##s_seg_id];					  \
												  \
	table = &(mobj->data.PLURAL);								  \
	offset = alloc_##TYPE##_entry(table);							  \
												  \
	*addr = make_reg(self->TYPE##s_seg_id, offset);						  \
	return &(mobj->data.PLURAL.table[offset].entry);					  \
}												  \
												  \
STATIC void											  \
sm_free_##TYPE(seg_manager_t *self, reg_t addr)							  \
{												  \
	mem_obj_t *mobj = GET_SEGMENT(*self, addr.segment, SEGTYPE);				  \
												  \
	if (!mobj) {										  \
		sciprintf("Attempt to free " #TYPE " from address "PREG				  \
			  ": Invalid segment type\n",						  \
			  PRINT_REG(addr));							  \
		return;										  \
	}											  \
												  \
	free_##TYPE##_entry(&(mobj->data.PLURAL), addr.offset);					  \
}

DEFINE_ALLOC_DEALLOC(, clone, MEM_OBJ_CLONES, clones)
DEFINE_ALLOC_DEALLOC(, list, MEM_OBJ_LISTS, lists)
DEFINE_ALLOC_DEALLOC(, node, MEM_OBJ_NODES, nodes)
DEFINE_ALLOC_DEALLOC(static, hunk, MEM_OBJ_HUNK, hunks)



byte *
sm_dereference(seg_manager_t *self, reg_t pointer, int *size)
{
	mem_obj_t *mobj;
	byte *base = NULL;
	int count;

	if (!pointer.segment
	    || (pointer.segment >= self->heap_size)
	    || !self->heap[pointer.segment]) {
		sciprintf("Error: Attempt to dereference invalid pointer "PREG"!\n",
			  PRINT_REG(pointer));
		return NULL; /* Invalid */
	}


	mobj = self->heap[pointer.segment];

	switch (mobj->type) {

	case MEM_OBJ_SCRIPT:
		if (pointer.offset > mobj->data.script.buf_size) {
			sciprintf("Error: Attempt to dereference invalid pointer "PREG
				  " into script segment (script size=%d)\n",
				  PRINT_REG(pointer), mobj->data.script.buf_size);
			return NULL;
		}
		if (size)
			*size = mobj->data.script.buf_size - pointer.offset;
		return (byte *) (mobj->data.script.buf + pointer.offset);
		break;

	case MEM_OBJ_LOCALS:
		count = mobj->data.locals.nr * sizeof(reg_t);
		base = (byte *) mobj->data.locals.locals;
		break;

	case MEM_OBJ_STACK:
		count = mobj->data.stack.nr * sizeof(reg_t);
		base = (byte *) mobj->data.stack.entries;
		break;

	case MEM_OBJ_DYNMEM:
		count = mobj->data.dynmem.size;
		base = (byte *) mobj->data.dynmem.buf;
		break;

	case MEM_OBJ_SYS_STRINGS:
		if (size)
			*size = mobj->data.sys_strings.strings[pointer.offset].max_size;
		if (pointer.offset < SYS_STRINGS_MAX
		    && mobj->data.sys_strings.strings[pointer.offset].name)
			return (byte *) (mobj->data.sys_strings.strings[pointer.offset].value);
		else {
			sciprintf("Error: Attempt to dereference invalid pointer "PREG"!\n",
				  PRINT_REG(pointer));
			return NULL;
		}

	case MEM_OBJ_RESERVED:
		sciprintf("Error: Trying to dereference pointer "PREG" to reserved segment `%s'!\n",
			  mobj->data.reserved);
		return NULL;
		break;

	default:
		sciprintf("Error: Trying to dereference pointer "PREG" to inappropriate"
			  " segment!\n",
			  PRINT_REG(pointer));
		return NULL;
	}

	if (size)
		*size = count;

	return
		base + pointer.offset;
}


unsigned char *
sm_alloc_dynmem(seg_manager_t *self, int size, const char *descr, reg_t *addr)
{
	seg_id_t seg;
	mem_obj_t *mobj = alloc_nonscript_segment(self, MEM_OBJ_DYNMEM, &seg);
	*addr = make_reg(seg, 0);

	mobj->data.dynmem.size = size;

	if (size == 0)
		mobj->data.dynmem.buf = NULL;
	else
		mobj->data.dynmem.buf = (byte*) sci_malloc(size);

	mobj->data.dynmem.description = descr;

	return (unsigned char *) (mobj->data.dynmem.buf);
}

const char *
sm_get_description(seg_manager_t *self, reg_t addr)
{ 
	mem_obj_t *mobj = self->heap[addr.segment];

	if (addr.segment >= self->heap_size)
	  return "";

	switch (mobj->type)
	{
	case MEM_OBJ_DYNMEM:
		return mobj->data.dynmem.description;
	default:
		return "";
	}
}

int
sm_free_dynmem(seg_manager_t *self, reg_t addr)
{
	
	if (addr.segment <= 0
	    || addr.segment >= self->heap_size
	    || !self->heap[addr.segment]
	    || self->heap[addr.segment]->type != MEM_OBJ_DYNMEM)
		return 1; /* error */

	_sm_deallocate(self, addr.segment, 1);
	return 0; /* OK */
}


/************************************************************/
/* ------------------- Segment interface ------------------ */
/************************************************************/


static void
free_at_address_stub (seg_interface_t *self, reg_t sub_addr)
{
//	sciprintf("  Request to free "PREG"\n", PRINT_REG(sub_addr));
	/* STUB */
}



static reg_t
find_canonic_address_base (seg_interface_t *self, reg_t addr)
{
	addr.offset = 0;
	return addr;
}

static reg_t
find_canonic_address_id (seg_interface_t *self, reg_t addr)
{
	return addr;
}

static void
free_at_address_nop (seg_interface_t *self, reg_t sub_addr)
{
}

static void
list_all_deallocatable_nop (seg_interface_t *self, void *param, void (*note) (void*param, reg_t addr))
{
}

static void
list_all_deallocatable_base (seg_interface_t *self, void *param, void (*note) (void*param, reg_t addr))
{
	(*note) (param, make_reg (self->seg_id, 0));
}

static void
list_all_outgoing_references_nop (seg_interface_t *self, state_t *s, reg_t addr, void *param, void (*note) (void*param, reg_t addr))
{
}

static void
deallocate_self (seg_interface_t *self)
{
	sci_free (self);
}


static void
free_at_address_script (seg_interface_t *self, reg_t addr)
{
	script_t *script;
	VERIFY(self->mobj->type == MEM_OBJ_SCRIPT, "Trying to free a non-script!");
	script = &(self->mobj->data.script);
/*
	sciprintf("[GC] Freeing script "PREG"\n", PRINT_REG(addr));
	if (script->locals_segment)
		sciprintf("[GC] Freeing locals %04x:0000\n", script->locals_segment);
*/

	if (script->marked_as_deleted)
		sm_deallocate_script(self->segmgr, script->nr);
}

static void
list_all_outgoing_references_script (seg_interface_t *self, state_t *s, reg_t addr, void *param, void (*note) (void*param, reg_t addr))
{
	script_t *script = &(self->mobj->data.script);

	if (addr.offset <= script->buf_size
	    && addr.offset >= -SCRIPT_OBJECT_MAGIC_OFFSET
	    && RAW_IS_OBJECT(script->buf + addr.offset)) {
		int idx = RAW_GET_CLASS_INDEX(script, addr);
		if (idx >= 0 && idx < script->objects_nr) {
			object_t *obj = script->objects + idx;
			int i;
			
			/* Note all local variables, if we have a local variable environment */
			if (script->locals_segment)
				(*note) (param, make_reg(script->locals_segment, 0));

			for (i = 0; i < obj->variables_nr; i++)
				(*note) (param, obj->variables[i]);
		} else {
			fprintf(stderr, "Request for outgoing script-object reference at "PREG" yielded invalid index %d\n", PRINT_REG(addr), idx);
		}
	} else {
/*		fprintf(stderr, "Unexpected request for outgoing script-object references at "PREG"\n", PRINT_REG(addr));*/
			/* Happens e.g. when we're looking into strings */
	}
}

/*-------------------- script --------------------*/
static seg_interface_t seg_interface_script = {
	/* segmgr = */	NULL,
	/* mobj = */	NULL,
	/* seg_id = */	0,
	/* type_id = */	MEM_OBJ_SCRIPT,
	/* type = */	"script",
	/* find_canonic_address = */		find_canonic_address_base,
	/* free_at_address = */			free_at_address_script,
	/* list_all_deallocatable = */		list_all_deallocatable_base,
	/* list_all_outgoing_references = */	list_all_outgoing_references_script,
	/* deallocate_self = */			deallocate_self
};


#define LIST_ALL_DEALLOCATABLE(kind, kind_field) \
	mem_obj_t *mobj = self->mobj;					\
	kind##_table_t * table = &(mobj->data.kind_field);		\
	int i;								\
									\
	for (i = 0; i < table->max_entry; i++)				\
		if (ENTRY_IS_VALID(table, i))				\
			(*note) (param, make_reg(self->seg_id, i));

static void
list_all_deallocatable_clones (seg_interface_t *self, void *param, void (*note) (void*param, reg_t addr))
{
	LIST_ALL_DEALLOCATABLE(clone, clones);
}

static void
list_all_outgoing_references_clones (seg_interface_t *self, state_t *s, reg_t addr, void *param, void (*note) (void*param, reg_t addr))
{
	mem_obj_t *mobj = self->mobj;
	clone_table_t *clone_table = &(mobj->data.clones);
	clone_t *clone;
	int i;

	assert (addr.segment == self->seg_id);
	
	if (!(ENTRY_IS_VALID(clone_table, addr.offset))) {
		fprintf(stderr, "Unexpected request for outgoing references from clone at "PREG"\n", PRINT_REG(addr));
//		BREAKPOINT();
		return;
	}

	clone = &(clone_table->table[addr.offset].entry);

	/* Emit all member variables (including references to the 'super' delegate) */
	for (i = 0; i < clone->variables_nr; i++)
		(*note) (param, clone->variables[i]);

	/* Note that this also includes the 'base' object, which is part of the script and therefore also
	** emits the locals. */
	(*note) (param, clone->pos);
//	sciprintf("[GC] Reporting clone-pos "PREG"\n", PRINT_REG(clone->pos));
}


void
free_at_address_clones(seg_interface_t *self, reg_t addr)
{
	object_t *victim_obj;

	assert (addr.segment == self->seg_id);

	victim_obj = &(self->mobj->data.clones.table[addr.offset].entry);

#ifdef GC_DEBUG
	if (!(victim_obj->flags & OBJECT_FLAG_FREED))
		sciprintf("[GC] Warning: Clone "PREG" not reachable and not freed (freeing now)\n",
			  PRINT_REG(addr));
#  ifdef GC_DEBUG_VERBOSE
	else
		sciprintf("[GC-DEBUG] Clone "PREG": Freeing\n", PRINT_REG(addr));
#  endif
#endif
/*
	sciprintf("[GC] Clone "PREG": Freeing\n", PRINT_REG(addr));
	sciprintf("[GC] Clone had pos "PREG"\n", PRINT_REG(victim_obj->pos));
*/
	sci_free(victim_obj->variables);
	victim_obj->variables = NULL;
	sm_free_clone(self->segmgr, addr);
}

/*-------------------- clones --------------------*/
static seg_interface_t seg_interface_clones = {
	/* segmgr = */	NULL,
	/* mobj = */	NULL,
	/* seg_id = */	0,
	/* type_id = */	MEM_OBJ_CLONES,
	/* type = */	"clones",
	/* find_canonic_address = */		find_canonic_address_id,
	/* free_at_address = */			free_at_address_clones,
	/* list_all_deallocatable = */		list_all_deallocatable_clones,
	/* list_all_outgoing_references = */	list_all_outgoing_references_clones,
	/* deallocate_self = */			deallocate_self
};


static reg_t
find_canonic_address_locals (seg_interface_t *self, reg_t addr)
{
	local_variables_t *locals = &(self->mobj->data.locals);
	/* Reference the owning script */
	seg_id_t owner_seg = sm_seg_get(self->segmgr, locals->script_id);

	assert (owner_seg >= 0);

	return make_reg(owner_seg, 0);
}

static void
list_all_outgoing_references_locals (seg_interface_t *self, state_t *s, reg_t addr, void *param, void (*note) (void*param, reg_t addr))
{
	local_variables_t *locals = &(self->mobj->data.locals);
	int i;

	assert (addr.segment == self->seg_id);

	for (i = 0; i < locals->nr; i++)
		(*note) (param, locals->locals[i]);
}

/*-------------------- locals --------------------*/
static seg_interface_t seg_interface_locals = {
	/* segmgr = */	NULL,
	/* mobj = */	NULL,
	/* seg_id = */	0,
	/* type_id = */	MEM_OBJ_LOCALS,
	/* type = */	"locals",
	/* find_canonic_address = */		find_canonic_address_locals,
	/* free_at_address = */			free_at_address_stub,
	/* list_all_deallocatable = */		list_all_deallocatable_nop,
	/* list_all_outgoing_references = */	list_all_outgoing_references_locals,
	/* deallocate_self = */			deallocate_self
};


static void
list_all_outgoing_references_stack (seg_interface_t *self, state_t *s, reg_t addr, void *param, void (*note) (void*param, reg_t addr))
{
	int i;
fprintf(stderr, "Emitting %d stack entries\n", self->mobj->data.stack.nr);
	for (i = 0; i < self->mobj->data.stack.nr; i++) 
		(*note) (param, self->mobj->data.stack.entries[i]);
fprintf(stderr, "DONE");
}

/*-------------------- stack --------------------*/
static seg_interface_t seg_interface_stack = {
	/* segmgr = */	NULL,
	/* mobj = */	NULL,
	/* seg_id = */	0,
	/* type_id = */	MEM_OBJ_STACK,
	/* type = */	"stack",
	/* find_canonic_address = */		find_canonic_address_base,
	/* free_at_address = */			free_at_address_nop,
	/* list_all_deallocatable = */		list_all_deallocatable_nop,
	/* list_all_outgoing_references = */	list_all_outgoing_references_stack,
	/* deallocate_self = */			deallocate_self
};

/*-------------------- system strings --------------------*/
static seg_interface_t seg_interface_sys_strings = {
	/* segmgr = */	NULL,
	/* mobj = */	NULL,
	/* seg_id = */	0,
	/* type_id = */	MEM_OBJ_SYS_STRINGS,
	/* type = */	"system strings",
	/* find_canonic_address = */		find_canonic_address_id,
	/* free_at_address = */			free_at_address_nop,
	/* list_all_deallocatable = */		list_all_deallocatable_nop,
	/* list_all_outgoing_references = */	list_all_outgoing_references_nop,
	/* deallocate_self = */			deallocate_self
};

static void
list_all_deallocatable_list (seg_interface_t *self, void *param, void (*note) (void*param, reg_t addr))
{
	LIST_ALL_DEALLOCATABLE(list, lists);
}

static void
list_all_outgoing_references_list (seg_interface_t *self, state_t *s, reg_t addr, void *param, void (*note) (void*param, reg_t addr))
{
	list_table_t *table = &(self->mobj->data.lists);
	list_t *list = &(table->table[addr.offset].entry);

	if (!ENTRY_IS_VALID(table, addr.offset)) {
		fprintf(stderr, "Invalid list referenced for outgoing references: "PREG"\n", PRINT_REG(addr));
		return;
	}

	note (param, list->first);
	note (param, list->last);
	/* We could probably get away with just one of them, but
	** let's be conservative here. */
}

static void
free_at_address_lists (seg_interface_t *self, reg_t sub_addr)
{
	sm_free_list (self->segmgr, sub_addr);
}

/*-------------------- lists --------------------*/
static seg_interface_t seg_interface_lists = {
	/* segmgr = */	NULL,
	/* mobj = */	NULL,
	/* seg_id = */	0,
	/* type_id = */	MEM_OBJ_LISTS,
	/* type = */	"lists",
	/* find_canonic_address = */		find_canonic_address_id,
	/* free_at_address = */			free_at_address_lists,
	/* list_all_deallocatable = */		list_all_deallocatable_list,
	/* list_all_outgoing_references = */	list_all_outgoing_references_list,
	/* deallocate_self = */			deallocate_self
};

static void
list_all_deallocatable_nodes (seg_interface_t *self, void *param, void (*note) (void*param, reg_t addr))
{
	LIST_ALL_DEALLOCATABLE(node, nodes);
}

static void
list_all_outgoing_references_nodes (seg_interface_t *self, state_t *s, reg_t addr, void *param, void (*note) (void*param, reg_t addr))
{
	node_table_t *table = &(self->mobj->data.nodes);
	node_t *node = &(table->table[addr.offset].entry);

	if (!ENTRY_IS_VALID(table, addr.offset)) {
		fprintf(stderr, "Invalid node referenced for outgoing references: "PREG"\n", PRINT_REG(addr));
		return;
	}

	/* We need all four here. Can't just stick with 'pred' OR 'succ' because node operations allow us
	** to walk around from any given node */
	note (param, node->pred);
	note (param, node->succ);
	note (param, node->key);
	note (param, node->value);
}

static void
free_at_address_nodes (seg_interface_t *self, reg_t sub_addr)
{
	sm_free_node (self->segmgr, sub_addr);
}

/*-------------------- nodes --------------------*/
static seg_interface_t seg_interface_nodes = {
	/* segmgr = */	NULL,
	/* mobj = */	NULL,
	/* seg_id = */	0,
	/* type_id = */	MEM_OBJ_NODES,
	/* type = */	"nodes",
	/* find_canonic_address = */		find_canonic_address_id,
	/* free_at_address = */			free_at_address_nodes,
	/* list_all_deallocatable = */		list_all_deallocatable_nodes,
	/* list_all_outgoing_references = */	list_all_outgoing_references_nodes,
	/* deallocate_self = */			deallocate_self
};

static void
list_all_deallocatable_hunk (seg_interface_t *self, void *param, void (*note) (void*param, reg_t addr))
{
	LIST_ALL_DEALLOCATABLE(hunk, hunks);
}

/*-------------------- hunk --------------------*/
static seg_interface_t seg_interface_hunk = {
	/* segmgr = */	NULL,
	/* mobj = */	NULL,
	/* seg_id = */	0,
	/* type_id = */	MEM_OBJ_HUNK,
	/* type = */	"hunk",
	/* find_canonic_address = */		find_canonic_address_id,
	/* free_at_address = */			free_at_address_stub,
	/* list_all_deallocatable = */		list_all_deallocatable_hunk,
	/* list_all_outgoing_references = */	list_all_outgoing_references_nop,
	/* deallocate_self = */			deallocate_self
};



/*-------------------- dynamic memory --------------------*/
static seg_interface_t seg_interface_dynmem = {
	/* segmgr = */	NULL,
	/* mobj = */	NULL,
	/* seg_id = */	0,
	/* type_id = */	MEM_OBJ_DYNMEM,
	/* type = */	"dynamic memory",
	/* find_canonic_address = */		find_canonic_address_base,
	/* free_at_address = */			free_at_address_stub,
	/* list_all_deallocatable = */		list_all_deallocatable_base,
	/* list_all_outgoing_references = */	list_all_outgoing_references_nop,
	/* deallocate_self = */			deallocate_self
};

/*-------------------- reserved --------------------*/
static seg_interface_t seg_interface_reserved = {
	/* segmgr = */	NULL,
	/* mobj = */	NULL,
	/* seg_id = */	0,
	/* type_id = */	MEM_OBJ_RESERVED,
	/* type = */	"reserved",
	/* find_canonic_address = */		find_canonic_address_id,
	/* free_at_address = */			free_at_address_nop,
	/* list_all_deallocatable = */		list_all_deallocatable_nop,
	/* list_all_outgoing_references = */	list_all_outgoing_references_nop,
	/* deallocate_self = */			deallocate_self
};


static seg_interface_t* seg_interfaces[MEM_OBJ_MAX] = {
	&seg_interface_script,
	&seg_interface_clones,
	&seg_interface_locals,
	&seg_interface_stack,
	&seg_interface_sys_strings,
	&seg_interface_lists,
	&seg_interface_nodes,
	&seg_interface_hunk,
	&seg_interface_dynmem,
	&seg_interface_reserved
};


seg_interface_t *
get_seg_interface(seg_manager_t *self, seg_id_t segid)
{
	mem_obj_t *mobj;
	seg_interface_t *retval;

	if (!sm_check(self, segid))
		return NULL; /* Invalid segment */

	mobj = self->heap[segid];
	retval = (seg_interface_t*)sci_malloc(sizeof(seg_interface_t));
	memcpy(retval, seg_interfaces[mobj->type - 1], sizeof (seg_interface_t));

	if (mobj->type != retval->type_id) {
		fprintf(stderr, "Improper segment interface for %d", mobj->type );
		exit(1);
	}

	retval->segmgr = self;
	retval->mobj = mobj;
	retval->seg_id = segid;

	return retval;
}