On 04/07/18 23:00, Gerald Pfeifer wrote:
> On Wed, 4 Apr 2018, Bernd Edlinger wrote:
>> Is it OK for wwwdocs?
>
> Yes, except...
>
> + <li><code>-Wsizeof-pointer-div</code> warns for suspicious divisions
> + of two <code>sizeof</code> expressions that divide the pointer size by
> + the element size, which is the usual way to compute the array size but
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> + won't work out correctly with pointers.
>
> ...this is a bit misleading.
>
> Dividing the pointer size by the element size is _not_ the usual way;
Yes, it is of course the _wrong_ way. This happens usually with macros
that are meant to be used with arrays.
> using the array size is. I am sure this is what you had in mind, just
> the wording is a bit unfortunate. Perhaps "...which looks like the
> usual way..." and "the size of a pointer" and "the size of elements
> it points to"? And the sizeof expressions do not actually divide
> anything.)
>
> I seem to have a writer's block right now, or I would have proposed
> a full alternative, but hope the above gives you an indication?
>
>
> Definitely okay to commit the other parts of this patch, and let's
> just work on this item a bit more.
>
Thanks for your review!
I committed the other parts and rewrote this one along your
suggested wording. See attached patch.
Is it OK?
Bernd.
Index: htdocs/gcc-8/changes.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-8/changes.html,v
retrieving revision 1.56
diff -u -r1.56 changes.html
--- htdocs/gcc-8/changes.html 7 Apr 2018 21:15:39 -0000 1.56
+++ htdocs/gcc-8/changes.html 7 Apr 2018 21:24:14 -0000
@@ -287,6 +287,13 @@
by <code>-Wextra</code>.</li>
</ul>
<ul>
+ <li><code>-Wsizeof-pointer-div</code> warns for suspicious divisions
+ of the size of a pointer and the size of the element it points to,
+ which looks like the usual way to compute the array size but
+ won't work out correctly with pointers.
+ This warning is enabled by <code>-Wall</code>.</li>
+ </ul>
+ <ul>
<li><code>-Wcast-align=strict</code> warns whenever a pointer is cast
such that the required alignment of the target is increased. For
example, warn if a <code>char *</code> is cast to an <code>int *</code>
