[PATCH] malloc: Deprecate hook variables, __default_morecore, <mcheck.h>

[Joseph Myers]

On Wed, 26 Oct 2016, Florian Weimer wrote:

> The functionality in <mcheck.h> will eventually be replaced with
> no-op functions (and a separate, preloadable DSO).

If you declare functionality deprecated then you need to update the manual 
accordingly.  But I don't think the right approach is to declare 
deprecated on an "eventually be replaced" basis.  Rather, the deprecation 
and the new DSO should be in the same patch series, going in the same 
glibc version, so the NEWS file and the main documentation can tell users 
of the mtrace script to preload the DSO and remove calls to the mtrace 
function (if that's the intended way to update code using mtrace and the 
one to be used for all the glibc tests that make use of it).  (And that's 
general for any deprecation: make clear how people should update their 
code and ensure the replacement is actually ready first, don't just say 
something is deprecated in NEWS without the replacement being obvious.)

-- 
Joseph S. Myers
joseph@codesourcery.com