/*
** Nofrendo (c) 1998-2000 Matthew Conte (matt@conte.com)
**
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of version 2 of the GNU Library General 
** Public License as published by the Free Software Foundation.
**
** This program 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 
** Library General Public License for more details.  To obtain a 
** copy of the GNU Library General Public License, write to the Free 
** Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**
** Any permitted reproduction of these routines, in whole or in part,
** must bear this legend.
**
**
** memguard.c
**
** memory allocation wrapper routines
**
** NOTE: based on code (c) 1998 the Retrocade group
** $Id$
*/

#include "types.h"

/* undefine macro definitions, so we get real calls */
#undef malloc
#undef free

#include <string.h>
#include <stdlib.h>
#include "memguard.h"
#include "log.h"


/* Maximum number of allocated blocks at any one time */
#define  MAX_BLOCKS        16384

/* Memory block structure */
typedef struct memblock_s
{
  void *block_addr;
  int block_size;
  char *file_name;
  int line_num;
} memblock_t;

boolean mem_debug = TRUE;       /* debugging flag */


#ifdef NOFRENDO_DEBUG

static int mem_blockcount = 0;  /* allocated block count */
static memblock_t *mem_record = NULL;

#define  GUARD_STRING   "GgUuAaRrDdSsTtRrIiNnGgBbLlOoCcKk"
#define  GUARD_LENGTH   64      /* before and after allocated block */


/*
** Check the memory guard to make sure out of bounds writes have not
** occurred.
*/
static boolean
mem_checkguardblock (void *data, int guard_size)
{
  uint8 *orig, *chk, *blk;
  int i, alloc_size;

  /* get the original pointer */
  orig = (((uint8 *) data) - guard_size);

  /* get the size */
  alloc_size = *((uint32 *) orig);

  /* now skip past the size */
  blk = orig + sizeof (uint32);

  /* check leading guard string */
  chk = GUARD_STRING;
  for (i = sizeof (uint32); i < guard_size; i++) {
    if (0 == *chk)
      chk = GUARD_STRING;
    if (*blk != *chk)
      return FALSE;
    chk++;
    blk++;
  }

  /* check end of block */
  chk = GUARD_STRING;
  blk = ((uint8 *) data) + alloc_size;
  for (i = 0; i < guard_size; i++) {
    if (0 == *chk)
      chk = GUARD_STRING;
    if (*blk != *chk)
      return FALSE;
    chk++;
    blk++;
  }

  /* we're okay! */
  return TRUE;
}

/* free a guard block */
static void
mem_freeguardblock (void *data, int guard_size)
{
  uint8 *orig = (((uint8 *) data) - guard_size);

  free (orig);
}

/* fill in the memory guard, advance the pointer to the 'real' memory */
static void *
mem_guardblock (int alloc_size, int guard_size)
{
  void *orig;
  uint8 *blk, *chk;
  int i;

  /* allocate memory */
  orig = calloc (alloc_size + (guard_size * 2), 1);
  if (NULL == orig)
    return NULL;

  blk = ((uint8 *) orig);

  /* store the size of the newly allocated block */
  *((uint32 *) blk) = alloc_size;

  /* skip past the size */
  blk += sizeof (uint32);

  /* put guard string at beginning of block */
  chk = GUARD_STRING;
  for (i = sizeof (uint32); i < guard_size; i++) {
    if (0 == *chk)
      chk = GUARD_STRING;
    *blk++ = *chk++;
  }

  /* check end of block */
  chk = GUARD_STRING;
  blk = guard_size + (uint8 *) orig + alloc_size;
  for (i = 0; i < guard_size; i++) {
    if (0 == *chk)
      chk = GUARD_STRING;
    *blk++ = *chk++;
  }

  return (void *) (guard_size + (uint8 *) orig);
}


/* Allocate a bunch of memory to keep track of all memory blocks */
static void
mem_init (void)
{
  if (mem_record) {
    free (mem_record);
    mem_record = NULL;
  }

  mem_record = calloc (MAX_BLOCKS * sizeof (memblock_t), 1);
  ASSERT (mem_record);
}

/* add a block of memory to the master record */
static void
mem_addblock (void *data, int block_size, char *file, int line)
{
  int i;

  for (i = 0; i < MAX_BLOCKS; i++) {
    if (NULL == mem_record[i].block_addr) {
      mem_record[i].block_addr = data;
      mem_record[i].block_size = block_size;
      mem_record[i].file_name = file;
      mem_record[i].line_num = line;
      return;
    }
  }

  ASSERT_MSG ("out of memory blocks.");
}

/* find an entry in the block record and delete it */
static void
mem_deleteblock (void *data, char *file, int line)
{
  int i;
  char fail[256];

  for (i = 0; i < MAX_BLOCKS; i++) {
    if (data == mem_record[i].block_addr) {
      if (FALSE == mem_checkguardblock (mem_record[i].block_addr, GUARD_LENGTH)) {
        sprintf (fail,
            "mem_deleteblock 0x%08X at line %d of %s -- block corrupt",
            (uint32) data, line, file);
        ASSERT_MSG (fail);
      }

      memset (&mem_record[i], 0, sizeof (memblock_t));
      return;
    }
  }

  sprintf (fail, "mem_deleteblock 0x%08X at line %d of %s -- block not found",
      (uint32) data, line, file);
  ASSERT_MSG (fail);
}
#endif /* NOFRENDO_DEBUG */

/* allocates memory and clears it */
#ifdef NOFRENDO_DEBUG
void *
_my_malloc (int size, char *file, int line)
#else
void *
_my_malloc (int size)
#endif
{
  void *temp;
  char fail[256];

#ifdef NOFRENDO_DEBUG
  if (NULL == mem_record && FALSE != mem_debug)
    mem_init ();

  if (FALSE != mem_debug)
    temp = mem_guardblock (size, GUARD_LENGTH);
  else
#endif /* NOFRENDO_DEBUG */
    temp = calloc (sizeof (uint8), size);

  if (NULL == temp) {
#ifdef NOFRENDO_DEBUG
    sprintf (fail, "malloc: out of memory at line %d of %s.  block size: %d\n",
        line, file, size);
#else
    sprintf (fail, "malloc: out of memory.  block size: %d\n", size);
#endif
    ASSERT_MSG (fail);
  }
#ifdef NOFRENDO_DEBUG
  if (FALSE != mem_debug)
    mem_addblock (temp, size, file, line);

  mem_blockcount++;
#endif

  return temp;
}

/* free a pointer allocated with my_malloc */
#ifdef NOFRENDO_DEBUG
void
_my_free (void **data, char *file, int line)
#else
void
_my_free (void **data)
#endif
{
  char fail[256];

  if (NULL == data || NULL == *data
      || 0xFFFFFFFF == (uint32) * data || 0xFFFFFFFF == (uint32) data) {
#ifdef NOFRENDO_DEBUG
    sprintf (fail, "free: attempted to free NULL pointer at line %d of %s\n",
        line, file);
#else
    sprintf (fail, "free: attempted to free NULL pointer.\n");
#endif
    ASSERT_MSG (fail);
  }
#ifdef NOFRENDO_DEBUG
  /* if this is true, we are in REAL trouble */
  if (0 == mem_blockcount) {
    ASSERT_MSG ("free: attempted to free memory when no blocks available");
  }

  if (FALSE != mem_debug)
    mem_deleteblock (*data, file, line);

  mem_blockcount--;             /* dec our block count */

  if (FALSE != mem_debug)
    mem_freeguardblock (*data, GUARD_LENGTH);
  else
#endif /* NOFRENDO_DEBUG */
    free (*data);

  *data = NULL;                 /* NULL our source */
}

/* check for orphaned memory handles */
void
mem_checkleaks (void)
{
#ifdef NOFRENDO_DEBUG
  int i;

  if (FALSE == mem_debug)
    return;

  if (mem_blockcount) {
    log_printf ("memory leak - %d unfreed block%s\n\n", mem_blockcount,
        mem_blockcount == 1 ? "" : "s");

    for (i = 0; i < MAX_BLOCKS; i++) {
      if (mem_record[i].block_addr) {
        log_printf ("addr: 0x%08X, size: %d, line %d of %s%s\n",
            (uint32) mem_record[i].block_addr,
            mem_record[i].block_size,
            mem_record[i].line_num,
            mem_record[i].file_name,
            (FALSE == mem_checkguardblock (mem_record[i].block_addr,
                    GUARD_LENGTH))
            ? " -- block corrupt" : "");
      }
    }
  } else
    log_printf ("no memory leaks\n");
#endif
}

void
mem_checkblocks (void)
{
#ifdef NOFRENDO_DEBUG
  int i;

  if (FALSE == mem_debug)
    return;

  for (i = 0; i < MAX_BLOCKS; i++) {
    if (mem_record[i].block_addr) {
      if (FALSE == mem_checkguardblock (mem_record[i].block_addr, GUARD_LENGTH)) {
        log_printf ("addr: 0x%08X, size: %d, line %d of %s -- block corrupt\n",
            (uint32) mem_record[i].block_addr,
            mem_record[i].block_size,
            mem_record[i].line_num, mem_record[i].file_name);
      }
    }
  }
#endif /* NOFRENDO_DEBUG */
}

/*
** $Log$
** Revision 1.1  2006/07/13 15:07:28  wtay
** Based on patches by: Johan Dahlin <johan at gnome dot org>
** Ronald Bultje <rbultje at ronald dot bitfreak dot net>
** * configure.ac:
** * gst/nsf/Makefile.am:
** * gst/nsf/dis6502.h:
** * gst/nsf/fds_snd.c:
** * gst/nsf/fds_snd.h:
** * gst/nsf/fmopl.c:
** * gst/nsf/fmopl.h:
** * gst/nsf/gstnsf.c:
** * gst/nsf/gstnsf.h:
** * gst/nsf/log.c:
** * gst/nsf/log.h:
** * gst/nsf/memguard.c:
** * gst/nsf/memguard.h:
** * gst/nsf/mmc5_snd.c:
** * gst/nsf/mmc5_snd.h:
** * gst/nsf/nes6502.c:
** * gst/nsf/nes6502.h:
** * gst/nsf/nes_apu.c:
** * gst/nsf/nes_apu.h:
** * gst/nsf/nsf.c:
** * gst/nsf/nsf.h:
** * gst/nsf/osd.h:
** * gst/nsf/types.h:
** * gst/nsf/vrc7_snd.c:
** * gst/nsf/vrc7_snd.h:
** * gst/nsf/vrcvisnd.c:
** * gst/nsf/vrcvisnd.h:
** Added NSF decoder plugin. Fixes 151192.
**
** Revision 1.8  2000/06/26 04:54:48  matt
** simplified and made more robust
**
** Revision 1.7  2000/06/12 01:11:41  matt
** cleaned up some error output for win32
**
** Revision 1.6  2000/06/09 15:12:25  matt
** initial revision
**
*/