This is the mail archive of the
java@gcc.gnu.org
mailing list for the Java project.
Re: Null pointer check elimination
Gabriel Dos Reis wrote:
"Michael N. Moran" <mike@mnmoran.org> writes:
| And what is the meaning of code that does this:
|
| int foo(int& a)
| {
| int* b = &a;
|
| if(b ==0)
| {
| a();
| }
| else
| {
| b();
| }
According to the standard, the compiler can assume that the test is
always false, therefore rewrite the if-else as an unconditional call to
b(). GCC already does some null-pointer check deleting.
Wow. I'm sure there is sound reasoning for this ... but I can't
understand what that might be given a client module could intentionally
(if ill-adviseadly) simply invoke the function:
void bar()
{
int* z=0;
foo(*z);
}
In short this is "surprising" to clearly under-informed me.
--
Michael N. Moran (h) 770 516 7918
5009 Old Field Ct. (c) 678 521 5460
Kennesaw, GA, USA 30144 http://mnmoran.org
"So often times it happens, that we live our lives in chains
and we never even know we have the key."
The Eagles, "Already Gone"
The Beatles were wrong: 1 & 1 & 1 is 1