WebSVN – HelenOS – Path Comparison – / – /trunk/kernel/generic/ Rev 3749 and /trunk/kernel/generic/ Rev 3750

Ignore whitespace Rev 3749 → Rev 3750

 /trunk/kernel/generic/include/memstr.h
 ,6 → 44,8
 extern void *_memcpy(void *dst, const void *src, size_t cnt);
 extern void _memsetb(void *dst, size_t cnt, uint8_t x);
 extern void _memsetw(void *dst, size_t cnt, uint16_t x);
+extern void *memmove(void *dst, const void *src, size_t cnt);
 extern char *strcpy(char *dest, const char *src);
 #endif

 /trunk/kernel/generic/src/lib/memstr.c
 ,5 → 1,6
 /*
  * Copyright (c) 2001-2004 Jakub Jermar
+ * Copyright (c) 2008 Jiri Svoboda
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
 ,6 → 77,51
     return (char *) dst;
 }
+/** Move memory block with possible overlapping.
+ *
+ * Copy cnt bytes from src address to dst address. The source and destination
+ * memory areas may overlap.
+ *
+ * @param src       Source address to copy from.
+ * @param dst       Destination address to copy to.
+ * @param cnt       Number of bytes to copy.
+ *
+ * @return      Destination address.
+ */
+void *memmove(void *dst, const void *src, size_t n)
+{
+    const uint8_t *sp;
+    uint8_t *dp;
+    /* Nothing to do? */
+    if (src == dst)
+        return dst;
+    /* Non-overlapping? */
+    if (dst >= src + n || src >= dst + n) {
+        return memcpy(dst, src, n);
+    }
+    /* Which direction? */
+    if (src > dst) {
+        /* Forwards. */
+        sp = src;
+        dp = dst;
+        while (n-- != 0)
+            *dp++ = *sp++;
+    } else {
+        /* Backwards. */
+        sp = src + (n - 1);
+        dp = dst + (n - 1);
+        while (n-- != 0)
+            *dp-- = *sp--;
+    }
+    return dst;
+}
 /** Fill block of memory
  *
  * Fill cnt bytes at dst address with the value x.  The filling is done