Comment cleanups.

[pdclib] / functions / stdlib / realloc.c

diff --git a/functions/stdlib/realloc.c b/functions/stdlib/realloc.c
index 93a2aa418d2280d0853bf7cae2ee474abd8b0081..a7cc395d21a9f39d3669e4c7f4637c13f643c451 100644 (file)
--- a/functions/stdlib/realloc.c
+++ b/functions/stdlib/realloc.c
@@ -1,71 +1,56 @@
-/* ----------------------------------------------------------------------------
- * $Id$
- * ----------------------------------------------------------------------------
- * Public Domain C Library - http://pdclib.sourceforge.net
- * This code is Public Domain. Use, modify, and redistribute at will.
- * --------------------------------------------------------------------------*/
+/* void * realloc( void *, size_t )
 
-void * realloc( void * ptr, size_t size ) { /* TODO */ };
+   This file is part of the Public Domain C Library (PDCLib).
+   Permission is granted to use, modify, and / or redistribute at will.
+*/
 
-/* PDPC code - assumes size_t of memory chunk at offset -4.
-{
-    char * newptr;
-    size_t oldsize;
+#include <stdlib.h>
+#include <string.h>
+#include <stddef.h>
 
-    if ( ( newptr = malloc(size) ) != NULL )
-    {
-        if ( ptr != NULL )
-        {
-            // reading size information from hidden chunk header
-            oldsize = * (size_t *) ( (char *) ptr - 4 );
-            // correctly handle *down*sizing as well as *up*sizing
-            memcpy( newptr, ptr, ( oldsize < size ) ? oldsize : size );
-            free( ptr );
-        }
-    }
-    return ( newptr );
-}
-*/
+#ifndef REGTEST
+
+/* TODO: Primitive placeholder. Improve. */
 
-/* Thomas "Beyond Infinity" Kreitner's code - unchecked, unoptimized
+void * realloc( void * ptr, size_t size )
 {
-    uint_t found = 0;
-    uint_t length;
-    chunk_t * new;
-    chunk_t * chunk;
-    // searching the block to-be-allocated
-    chunk = used_mem.start;
-    while ( ! found && ( chunk->next != NULL )
+    void * newptr = NULL;
+    if ( ptr == NULL )
     {
-        if ( chunk->address == ptr )
-        {
-            found++;
-        }
-        else
-        {
-            chunk=chunk->next;
-        }
+        return malloc( size );
     }
-    if ( found )
+    if ( size > 0 )
     {
-        length = chunk->length;
-        // allocate new memory area
-        if ( ( new = (void *) malloc( size ) ) != NULL )
+        struct _PDCLIB_memnode_t * baseptr = (struct _PDCLIB_memnode_t *)( (char *)ptr - sizeof( struct _PDCLIB_memnode_t ) );
+        if ( baseptr->size >= size )
         {
-            // copy the data
-            memcpy( ptr, new, length );
-            // release the old memory
-            free( ptr );
+            /* Current memnode is large enough; nothing to do. */
+            return ptr;
         }
         else
         {
-            new = NULL;
+            /* Get larger memnode and copy over contents. */
+            if ( ( newptr = malloc( size ) ) == NULL )
+            {
+                return NULL;
+            }
+            memcpy( newptr, ptr, baseptr->size );
         }
     }
-    else
-    {
-        new = NULL;
-    }
-    return new;
+    free( ptr );
+    return newptr;
 }
-*/
+
+#endif
+
+#ifdef TEST
+#include <_PDCLIB_test.h>
+
+int main( void )
+{
+    /* tests covered in malloc test driver */
+    return TEST_RESULTS;
+}
+
+#endif
+