On Tuesday, 20 January 2015 at 21:38:50 UTC, ketmar via
Digitalmars-d wrote:
On Tue, 20 Jan 2015 21:34:54 +0000
Freddy via Digitalmars-d <digitalmars-d@puremagic.com> wrote:
On Tuesday, 20 January 2015 at 18:12:27 UTC, ketmar via
Digitalmars-d wrote:
> Hello.
>
> as there is no possibility to doing GC allocations in class
> destructors, wouldn't it be nice to just force "@nogc"
> attribute on
> such dtors?
>
> i know, i know, "this will break alot of code". i'm pretty
> sure that
> this will break alot of INVALID code, which better be broken
> at
> compile-time anyway.
>
> sure, we have alot of code of pre-@nogc era, and alot of
> code where
> authord didn't bother to add attributes at all. so we can
> introduce
> "--force-dtor-nogc" CLI arg and document this change, making
> it opt-in
> for, say, six month and opt-out after that.
>
> and i know that D devs (Walter at least) are resistant to
> command-line
> flags that changing compiler behavior. i don't know how to
> overcome
> this. say, by adding "@gc" attribute, which dfix can
> automatically add?
>
> but i still believe that instead of telling people again and
> again that
> they should not allocate in class destructors, we can use
> computer
> itself to track and stop this behavior.
>
> let's see how this proposal will be rejected. will there be
> some sane
> reasons, or only the good old song about "broken code"? make
> your bets!
Not an error, Make it a warning.
alas, attribute violations are errors. turning that into
warning means
that compiler needs new flags and new code to determine if that
is
"hard restriction" or just "advise". the point of my proposal
is that
it can be done painlessly with one or two very simple changes in
compiler code.
We already have warnings such as:
Warning: toHash() must be declared as extern (D) size_t toHash()
const nothrow @safe, not const uint()
It could issue a similar warning to destructors declared without
@nogc.
