On 06/07/2015 06:19 AM, Andreas Schwab wrote:
> Another fallout:
>
> FAIL: obj-c++.dg/try-catch-5.mm -fgnu-runtime (test for excess errors)
> Excess errors:
> <built-in>: warning: '_OBJC_Module' defined but not used [-Wunused-variable]

check_global_declarations is called for more symbols now.  All the 
defined but not used errors I've seen in development have been 
legitimate.  For tests, the tests should be fixed.  For built-ins such 
as these, does the attached fix the problem?

It is up to the objc maintainers, we can either fix this with the 
attached patch, or setting DECL_IN_SYSTEM_HEADER.

/* Nonzero for a given ..._DECL node means that no warnings should be
    generated just because this node is unused.  */
#define DECL_IN_SYSTEM_HEADER(NODE) \
   (in_system_header_at (DECL_SOURCE_LOCATION (NODE)))

Let me know what you prefer.
Aldy