Use the C_ARRAY_LENGTH.

Use the C_ARRAY_LENGTH instead of sizeof(c_array)/sizeof(c_array[0])
or sizeof(c_array)/sizeof(type_of_element_in_c_array), and C_ARRAY_END
for c_array + C_ARRAY_LENGTH(c_array).

While doing this found potential off-by-one error in sv.c:Perl_sv_magic:
how > C_ARRAY_LENGTH(PL_magic_data)
should probably have been
how >= C_ARRAY_LENGTH(PL_magic_data)
No tests fail, but this seems to be more of an internal sanity check.

1 files changed, 6 insertions, 1 deletions

diff --git a/handy.h b/handy.h
index 3f84eff9af..9332f8de97 100644
--- a/handy.h
+++ b/handy.h
@@ -1936,8 +1936,13 @@ void Perl_mem_log_del_sv(const SV *sv, const char *filename, const int linenumbe
 #define StructCopy(s,d,t) Copy(s,d,1,t)
 #endif
 
+/* C_ARRAY_LENGTH is the number of elements in the C array (so you
+ * want your zero-based indices to be less than but not equal to).
+ *
+ * C_ARRAY_END is one past the last: half-open/half-closed range,
+ * not last-inclusive range. */
 #define C_ARRAY_LENGTH(a)	(sizeof(a)/sizeof((a)[0]))
-#define C_ARRAY_END(a)		(a) + (sizeof(a)/sizeof((a)[0]))
+#define C_ARRAY_END(a)		((a) + C_ARRAY_LENGTH(a))
 
 #ifdef NEED_VA_COPY
 # ifdef va_copy