X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=functions%2Fstdlib%2Frealloc.c;h=d64d756b25931fe4ae12f25ed996771027949e98;hb=d6f1494a4f38a212b29a13ee713885058dcf0fe7;hp=ac615b8a296820c62938187618ab34cb10228f5d;hpb=34893ecc2200dc7017c36a54cb6c5f4c2378b5ec;p=pdclib

diff --git a/functions/stdlib/realloc.c b/functions/stdlib/realloc.c
index ac615b8..d64d756 100644
--- a/functions/stdlib/realloc.c
+++ b/functions/stdlib/realloc.c
@@ -1,8 +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 * ptr, size_t size ) { /* TODO */ };
+/* 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. */
+            if ( ( newptr = malloc( size ) ) == NULL )
+            {
+                return NULL;
+            }
+            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
+