nvi fixes

contrib/nvi/common/log.c

@@ -6,17 +6,6 @@
  *
  * See the LICENSE file for redistribution information.
  */
-/*
- * CHERI CHANGES START
- * {
- *   "updated": 20221129,
- *   "target_type": "prog",
- *   "changes": [
- *     "pointer_alignment"
- *   ]
- * }
- * CHERI CHANGES END
- */
 
 #include "config.h"
 
@@ -717,29 +706,18 @@ apply_with(int (*db_func)(SCR *, recno_t, CHAR_T *, size_t), SCR *sp,
     recno_t lno, u_char *p, size_t len)
 {
 #ifdef USE_WIDECHAR
-	typedef unsigned long nword;
-
 	static size_t blen;
-	static nword *bp;
-	nword *lp = (nword *)__builtin_align_down(p, sizeof(nword));
-	if (lp != (nword *)p) {
-		int offl = ((caddr_t)p - (caddr_t)lp) << 3;
-		int offr = (sizeof(nword) << 3) - offl;
-		size_t i, cnt = (len + sizeof(nword) / 2) / sizeof(nword);
+	static u_char *bp;
 
+	if (!is_aligned(p, sizeof(unsigned long))) {
 		if (len > blen) {
 			blen = p2roundup(MAX(len, 512));
-			REALLOC(sp, bp, nword *, blen);
+			REALLOC(sp, bp, u_char *, blen);
 			if (bp == NULL)
 				return (1);
 		}
-		for (i = 0; i < cnt; ++i)
-#if BYTE_ORDER == BIG_ENDIAN
-			bp[i] = (lp[i] << offl) ^ (lp[i+1] >> offr);
-#else
-			bp[i] = (lp[i] >> offl) ^ (lp[i+1] << offr);
-#endif
-		p = (u_char *)bp;
+		memmove(bp, p, len);
+		p = bp;
 	}
 #endif
 	return db_func(sp, lno, (CHAR_T *)p, len / sizeof(CHAR_T));

contrib/nvi/common/mem.h

@@ -212,6 +212,18 @@
 	return (n);
 }
 
+/*
+ * is_aligned --
+ *      Determine whether the program can safely read an object with an
+ *      alignment requirement from ptr.
+ *
+ * See also: https://clang.llvm.org/docs/LanguageExtensions.html#alignment-builtins
+ */
+static __inline int
+is_aligned(void *ptr, size_t alignment) {
+	return ((uintptr_t)ptr % alignment) == 0;
+}
+
 /* Additional TAILQ helper. */
 #define TAILQ_ENTRY_ISVALID(elm, field)					\
 	((elm)->field.tqe_prev != NULL)