https://issues.dlang.org/show_bug.cgi?id=23969

Walter Bright <bugzilla@digitalmars.com> changed:

           What    |Removed                     |Added
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           Keywords|                            |dll

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https://issues.dlang.org/show_bug.cgi?id=23969

Walter Bright <bugzilla@digitalmars.com> changed:

           What    |Removed                     |Added
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            Summary|TLS in Windows cannot       |Windows cannot
                   |export/import TLS from DLLs |export/import TLS from DLLs

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https://issues.dlang.org/show_bug.cgi?id=23969

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

           What    |Removed                     |Added
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           Keywords|                            |pull

--- Comment #1 from Dlang Bot <dlang-bot@dlang.rocks> ---
@WalterBright created dlang/dmd pull request #15296 "fix Issue 23969 - Windows cannot export/import TLS from DLLs" fixing this issue:

- fix Issue 23969 - Windows cannot export/import TLS from DLLs

https://github.com/dlang/dmd/pull/15296

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https://issues.dlang.org/show_bug.cgi?id=23969

Walter Bright <bugzilla@digitalmars.com> changed:

           What    |Removed                     |Added
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           See Also|                            |https://issues.dlang.org/sh
                   |                            |ow_bug.cgi?id=9816

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https://issues.dlang.org/show_bug.cgi?id=23969

--- Comment #2 from Walter Bright <bugzilla@digitalmars.com> ---
What Microsoft has to say about it:

https://learn.microsoft.com/en-us/cpp/parallel/thread-local-storage-tls?view=msvc-170

TL/DR: exporting TLS from DLLs causes a system crash.

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https://issues.dlang.org/show_bug.cgi?id=23969

Richard Cattermole <alphaglosined@gmail.com> changed:

           What    |Removed                     |Added
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                 CC|                            |alphaglosined@gmail.com

--- Comment #3 from Richard Cattermole <alphaglosined@gmail.com> ---
(In reply to Walter Bright from comment #2)
> TL/DR: exporting TLS from DLLs causes a system crash.

But only on operating systems below Vista, which we don't support.

However in saying that, we should probably disallow exporting of TLS variables anyway as it'll be platform/libc dependent and that could get old very fast trying to figure out why your application doesn't work when ported. Only then to have to rewrite everything.

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https://issues.dlang.org/show_bug.cgi?id=23969

--- Comment #4 from Walter Bright <bugzilla@digitalmars.com> ---
Microsoft VC will not compile:

    __declspec(dllexport) __declspec(thread) int x = 3;

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