[Issue 14894] mangling of mixins and lambdas is not unique and depends on compilation flags

[via Digitalmars-d-bugs]

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

Martin Nowak <code at 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 at 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

--