https://issues.dlang.org/show_bug.cgi?id=22977

Dlang Bot <dlang-bot@dlang.rocks> changed:

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           Keywords|                            |pull

--- Comment #1 from Dlang Bot <dlang-bot@dlang.rocks> ---
@dkorpel created dlang/dmd pull request #14236 "Fix 22977 - can escape scope pointer returned by nested function" fixing this issue:

- Fix 22977 - can escape scope pointer returned by nested function

https://github.com/dlang/dmd/pull/14236

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https://issues.dlang.org/show_bug.cgi?id=22977

Walter Bright <bugzilla@digitalmars.com> changed:

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                 CC|                            |bugzilla@digitalmars.com

--- Comment #2 from Walter Bright <bugzilla@digitalmars.com> ---
Probably the most sensible way to deal with this is to allow non-static nested functions to have `return` and `scope` attributes, and then treat uplevel variable references as if they were parameters marked with those attributes.

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https://issues.dlang.org/show_bug.cgi?id=22977

--- Comment #3 from Walter Bright <bugzilla@digitalmars.com> ---
Interestingly, if `scope return` is added to `fn()`:

 int* gPtr;

 void main() @safe
 {
    scope int* sPtr;
    int* fn() scope return { return sPtr; }
    gPtr = fn();
 }

The correct error is generated:

 Error: reference to stack allocated value returned by `fn()` assigned to
non-scope `gPtr`

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https://issues.dlang.org/show_bug.cgi?id=22977

--- Comment #4 from Walter Bright <bugzilla@digitalmars.com> ---
It appears that the problem is the nested function is not inferring `return scope` when returning a scope variable from its closure.

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https://issues.dlang.org/show_bug.cgi?id=22977

--- Comment #5 from Dennis <dkorpel@live.nl> ---
(In reply to Walter Bright from comment #4)
> It appears that the problem is the nested function is not inferring `return scope` when returning a scope variable from its closure.

Indeed, the linked PR (https://github.com/dlang/dmd/pull/14236) tries to fix this, but it is currently blocked by buildkite projects.

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https://issues.dlang.org/show_bug.cgi?id=22977

--- Comment #6 from Dlang Bot <dlang-bot@dlang.rocks> ---
@WalterBright created dlang/dmd pull request #14391 "fix Issue 22977 - [dip1000] can escape scope pointer returned by nest…" fixing this issue:

- fix Issue 22977 - [dip1000] can escape scope pointer returned by nested function

https://github.com/dlang/dmd/pull/14391

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https://issues.dlang.org/show_bug.cgi?id=22977

--- Comment #7 from Walter Bright <bugzilla@digitalmars.com> ---
And now we have two fixes! Let's compare and make the best of both.

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https://issues.dlang.org/show_bug.cgi?id=22977

--- Comment #8 from Walter Bright <bugzilla@digitalmars.com> ---
Dennis, your's is better.

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https://issues.dlang.org/show_bug.cgi?id=22977

Walter Bright <bugzilla@digitalmars.com> changed:

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           See Also|                            |https://issues.dlang.org/sh
                   |                            |ow_bug.cgi?id=23438

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https://issues.dlang.org/show_bug.cgi?id=22977

Iain Buclaw <ibuclaw@gdcproject.org> changed:

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           Priority|P1                          |P3

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