-// ----------------------------------------------------------------------------
-// $Id$
-// ----------------------------------------------------------------------------
-// Public Domain C Library - http://pdclib.sourceforge.net
-// This code is Public Domain. Use, modify, and redistribute at will.
-// ----------------------------------------------------------------------------
-
-void * realloc( void * ptr, size_t size ) { /* TODO */ };
+/* $Id$ */
+
+/* void * realloc( void *, size_t )
+
+ This file is part of the Public Domain C Library (PDCLib).
+ Permission is granted to use, modify, and / or redistribute at will.
+*/
+
+#include <stdlib.h>
+#include <string.h>
+#include <stddef.h>
+
+#ifndef REGTEST
+
+/* TODO: Primitive placeholder. Improve. */
+
+void * realloc( void * ptr, size_t size )
+{
+ void * newptr = NULL;
+ if ( ptr == NULL )
+ {
+ return malloc( size );
+ }
+ if ( size > 0 )
+ {
+ struct _PDCLIB_memnode_t * baseptr = (struct _PDCLIB_memnode_t *)( (char *)ptr - sizeof( struct _PDCLIB_memnode_t ) );
+ if ( baseptr->size >= size )
+ {
+ /* Current memnode is large enough; nothing to do. */
+ return ptr;
+ }
+ else
+ {
+ /* Get larger memnode and copy over contents. */
+ newptr = malloc( size );
+ memcpy( newptr, ptr, baseptr->size );
+ }
+ }
+ free( ptr );
+ return newptr;
+}
+
+#endif
+
+#ifdef TEST
+#include <_PDCLIB_test.h>
+
+int main( void )
+{
+ /* tests covered in malloc test driver */
+ return TEST_RESULTS;
+}
+
+#endif