[Bug middle-end/22197] New: invalid "is" used uninitialized, should be "may be"

["matz at suse dot de" <gcc-bugzilla at gcc dot gnu dot org>]

Compile this code with -O2 -Wall on 4.0.x or mainline: 
------------------------------------- 
struct testme { 
    int testval; 
    int unusedval; 
}; 
extern void forget (struct testme forgotten); 
int main () { 
    struct testme testarray[1]; 
    struct testme testvar; 
    testvar.testval = 0; 
    testarray[0] = testvar; 
    forget (testarray[0]); 
    return 0; 
} 
-------------------------------------- 
 
This will give this warning: 
unused.c:13: warning: ‘testvar.unusedval’ is used uninitialized in this 
function 
 
The problem is the copy of some uninitialized part.  Yes, it does copy 
something uninitialized, but that's okay, as long as it is not really 
accessed.  At the very least it should only be a "may be used uninit" 
warning.  This is only noticed by tree-sra.  With -fno-tree-sra there's 
no warning.  So, in effect, accesses to uninitialized parts for purpose 
of copying should not lead to such warning.

-- 
           Summary: invalid "is" used uninitialized, should be "may be"
           Product: gcc
           Version: 4.0.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: matz at suse dot de
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22197