Am 28.01.2013 17:30, schrieb deadalnix:
> On Monday, 28 January 2013 at 16:26:29 UTC, Paulo Pinto wrote:
>> This is not true for current native compilers and JVMs.
>>
>> If escape analysis can prove the object does not leave scope, new
>> actually allocates on the stack.
>>
>
> Modern can even speculate that an object will not leave scope, allocate
> it on stack, and move it on heap if it escape !

That is how Go works if you return a pointer to something declared on the stack.

On Mon, Jan 28, 2013 at 06:21:17PM +0100, Paulo Pinto wrote:
> Am 28.01.2013 17:30, schrieb deadalnix:
> >On Monday, 28 January 2013 at 16:26:29 UTC, Paulo Pinto wrote:
> >>This is not true for current native compilers and JVMs.
> >>
> >>If escape analysis can prove the object does not leave scope, new actually allocates on the stack.
> >>
> >
> >Modern can even speculate that an object will not leave scope, allocate it on stack, and move it on heap if it escape !
> 
> That is how Go works if you return a pointer to something declared on the stack.

I think DMD needs something like this, to fix all of those ref-to-stack bugs, like:

- Unsafe slicing of static arrays
- Slicing of variadic arguments
- Delegates that reference a returned struct (becomes invalid because
  caller moves the struct but doesn't update the delegate's context ptr)
- ref functions returning ref to local variables

And many others. All of these become non-problems if the compiler (or code at runtime) detects the escaping reference and move the stuff onto the heap.


T

-- 
Some ideas are so stupid that only intellectuals could believe them. -- George Orwell

On Sunday, 27 January 2013 at 08:49:39 UTC, Freddie Chopin wrote:
> On Saturday, 26 January 2013 at 22:16:09 UTC, Rob T wrote:
>> For comparison, I wonder what the situation is for the various major implementations of C++11. Anyone know?
>
> You're looking for something like this?
>
> http://gcc.gnu.org/projects/cxx0x.html
>
> 4\/3!!

More like this.

http://gcc.gnu.org/bugzilla/buglist.cgi?product=gcc&component=c%2B%2B&resolution=---

Those are bugs listed for C++ front end only.

--rt