Re: c/6801: void * dereference warning given when no evaluation occurs

Re: c/6801: void * dereference warning given when no evaluation occurs

[jsm28]

Synopsis: void * dereference warning given when no evaluation occurs

State-Changed-From-To: open->closed
State-Changed-By: jsm28
State-Changed-When: Fri Aug 23 13:16:11 2002
State-Changed-Why:
    Fixed on mainline, probably by:
    
    2002-08-15  Alexandre Oliva  <aoliva@redhat.com>
    
            * c-tree.h (skip_evaluation): Move declaration...
            * c-common.h: ... here.
            * c-typeck.c (build_external_ref): Don't assemble_external nor
            mark a tree as used if skip_evaluation is set.
            * c-parse.in (typeof): New non-terminal to set skip_evaluation
            around TYPEOF.
            (typespec_nonreserved_nonattr): Use it.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6801

c/6801: void * dereference warning given when no evaluation occurs

[davem]

>Number:         6801
>Category:       c
>Synopsis:       void * dereference warning given when no evaluation occurs
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri May 24 10:56:00 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     davem@redhat.com
>Release:        3.1
>Organization:
>Environment:
sparc-unknown-linux
>Description:
__typeof__(*ptr) *foo;

causes a warning if 'ptr' is 'void *' It warns about a
void pointer dereference, but this expression does not
evaluate, it only determines the type, so the warning appears
at best silly.

This makes some macros very hard to implement.
>How-To-Repeat:
Try to use __typeof__(*ptr) when 'ptr' is 'void *'
>Fix:
No idea.
>Release-Note:
>Audit-Trail:
>Unformatted: