Dale Johannesen wrote:
However, as a QOI issue, I believe the compiler should treat the
reference as
volatile if either the object or the lvalue is volatile. That is
obviously the
user's intent.
I'm not disagreeing with you, but I wonder at gcc's ability to make
good on such a promise. A cast introducing a volatile qualifier
will be a NOP_EXPR, and gcc tends to strip those at every opportunity.
Also, I wonder about the following example
int const avail = <something>
int main() {
while (*(int *)&avail == Foo ())
do_something();
return 0;
}
Seeing through the const-stripping cast is a useful optimization. We'd
have to have one rule for adding volatile and a different one for removing
const.
A further pathelogical case would be,
int main() {
while (*(int *)(volatile int *)&avail)
do_something ();
return 0;
}
What should this do, treat the volatile qualifier as sticky?
nathan
--
Nathan Sidwell :: http://www.codesourcery.com :: CodeSourcery LLC
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