https://issues.dlang.org/show_bug.cgi?id=14894

Martin Nowak <code@dawg.eu> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|nobody@puremagic.com        |code@dawg.eu

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https://issues.dlang.org/show_bug.cgi?id=14894

--- Comment #1 from Martin Nowak <code@dawg.eu> ---
Happens b/c the mangling is determined by the number of member in the parent scope. This number can vary between compilations w/ and w/o -unittest.

cat > main.d << CODE
import bug;

void main()
{
    Foo foo;
    foo.onReceive();
}
CODE

cat > bug.d << CODE
mixin template Protocol()
{
    void onReceive() {}
}

struct Foo
{
    mixin Protocol!();

    unittest
    {
    }
}
CODE
----
dmd -c bug
dmd -unittest main bug.o
----

The manifestation of this bug is caused by skipping unittest parsing [¹], but
the underlying problem can also be triggered by any other version/debug block
member.
The code to derive a unique mixin mangling was already added with 2.065.0 [²]
and is also used for lambdas.

[¹]: https://github.com/D-Programming-Language/dmd/pull/4704 [²]: https://github.com/D-Programming-Language/dmd/pull/3019

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https://issues.dlang.org/show_bug.cgi?id=14894

Martin Nowak <code@dawg.eu> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |pull

--- Comment #2 from Martin Nowak <code@dawg.eu> ---
https://github.com/D-Programming-Language/dmd/pull/4871

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https://issues.dlang.org/show_bug.cgi?id=14894

Walter Bright <bugzilla@digitalmars.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bugzilla@digitalmars.com
           Hardware|x86_64                      |All
                 OS|Linux                       |All

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https://issues.dlang.org/show_bug.cgi?id=14894

--- Comment #3 from github-bugzilla@puremagic.com ---
Commits pushed to stable at https://github.com/D-Programming-Language/dmd

https://github.com/D-Programming-Language/dmd/commit/d10bd6c88426b3566c25f42d7194bf5c98a90a38 workaround Issue 14894 - linkage error with mixin template in std.net.curl

https://github.com/D-Programming-Language/dmd/commit/24214150e3463c94709f55c4ade912b974bbf911 Merge pull request #4871 from MartinNowak/workaround14894

workaround Issue 14894 - linkage error with mixin template in std.net.curl

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https://issues.dlang.org/show_bug.cgi?id=14894

Martin Nowak <code@dawg.eu> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|pull                        |
            Summary|[Reg 2.068.0-rc1] linkage   |mangling of mixins and
                   |error with mixin template   |lambdas can change w/
                   |in std.net.curl             |-unittest or other versions
           Severity|regression                  |normal

--- Comment #4 from Martin Nowak <code@dawg.eu> ---
We still need a long-term solution to make the mangling not dependent on flags
like -unittest or -release.
Using source position (line and col) doesn't work b/c the position might
differ, e.g. in a .di file or when editing a comment.

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https://issues.dlang.org/show_bug.cgi?id=14894

--- Comment #5 from github-bugzilla@puremagic.com ---
Commits pushed to master at https://github.com/D-Programming-Language/dmd

https://github.com/D-Programming-Language/dmd/commit/d10bd6c88426b3566c25f42d7194bf5c98a90a38 workaround Issue 14894 - linkage error with mixin template in std.net.curl

https://github.com/D-Programming-Language/dmd/commit/24214150e3463c94709f55c4ade912b974bbf911 Merge pull request #4871 from MartinNowak/workaround14894

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https://issues.dlang.org/show_bug.cgi?id=14894

--- Comment #6 from Martin Nowak <code@dawg.eu> ---
(In reply to Martin Nowak from comment #4)
> We still need a long-term solution to make the mangling not dependent on
> flags like -unittest or -release.
> Using source position (line and col) doesn't work b/c the position might
> differ, e.g. in a .di file or when editing a comment.

This is very similar to the -debug issues we have with template instantiation. The bottom line would be that only libs with the same flags are linkable.

BTW, g++ counts the number of lambdas per function and assigns them an increasing id. Using separate counters per scope per entity at least mitigates the issue.

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https://issues.dlang.org/show_bug.cgi?id=14894

Martin Nowak <code@dawg.eu> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |meapineapple@gmail.com

--- Comment #7 from Martin Nowak <code@dawg.eu> ---
*** Issue 16994 has been marked as a duplicate of this issue. ***

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https://issues.dlang.org/show_bug.cgi?id=14894

Martin Nowak <code@dawg.eu> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|mangling of mixins and      |mangling of mixins and
                   |lambdas can change w/       |lambdas is not unique and
                   |-unittest or other versions |depends on compilation
                   |                            |flags
           Severity|normal                      |critical

--- Comment #8 from Martin Nowak <code@dawg.eu> ---
Apparently can also cause calls of the wrong function instead of linker errors,
see issue 16994.
Different compilations end up with instances of the same mangling.

cat > lib.d << CODE
alias min = (a, b) => a < b ? a : b;
alias max = (a, b) => a > b ? a : b;

auto reduce(alias func, T...)(T args)
{
    return func(args);
}
CODE
cat > a.d << CODE
import lib;

unittest
{
    assert(reduce!min(1, 2) == 1);
}
CODE
cat > b.d << CODE
import lib;

unittest
{
    assert(reduce!max(1, 2) == 2);
}
CODE

# works
dmd -main -unittest -ofmain a.d b.d
./main

# fails
dmd -unittest -c a.d
dmd -unittest -c b.d
dmd -main -ofmain a.o b.o // one of the tests calls the wrong reduce
./main

----

$ dmd -unittest -c a.d
$ nm a.o | grep lambda
0000000000000000 W _D3lib18__T9__lambda5TiTiZ9__lambda5FNaNbNiNfiiZi
0000000000000000 W _D3lib32__T6reduceS143lib9__lambda5TiTiZ6reduceFNaNbNiNfiiZi
$ dmd -unittest -c b.d
$ nm b.o | grep lambda
0000000000000000 W _D3lib18__T9__lambda5TiTiZ9__lambda5FNaNbNiNfiiZi
0000000000000000 W _D3lib32__T6reduceS143lib9__lambda5TiTiZ6reduceFNaNbNiNfiiZi

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