[Issue 23354] [REG master] object.d(393): Error: reference to stack allocated value returned by 'new F(1)' assigned to non-scope parameter 'lhs'

Sep 21, 2022

Iain Buclaw

Sep 21, 2022

Iain Buclaw

Sep 21, 2022

Iain Buclaw

Sep 21, 2022

Iain Buclaw

Sep 23, 2022

Iain Buclaw

September 21, 2022

[Issue 23354] [REG master] object.d(393): Error: reference to stack allocated value returned by 'new F(1)' assigned to non-scope parameter 'lhs'

Posted by Iain Buclaw

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Iain Buclaw

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https://issues.dlang.org/show_bug.cgi?id=23354

--- Comment #1 from Iain Buclaw <ibuclaw@gdcproject.org> ---
Test extracted from druntime.

Fails with -preview=dip1000, succeeds with -preview=dip1000 -checkaction=context.
---
/// If same exact type => one call to method opEquals
/// This test passes `@safe` because it defines a new opEquals with `@safe`
@safe void unittest1()
{
    class F
    {
        int flag;

        this(int flag)
        {
            this.flag = flag;
        }

        bool opEquals(const F o) const @safe nothrow pure
        {
            return flag == o.flag;
        }
    }

    assert(new F(0) == new F(0));
    assert(!(new F(0) == new F(1)));
}

/// General case => symmetric calls to method opEquals
@safe void unittest2()
{
    int fEquals, gEquals;

    class Base
    {
        int flag;
        this(int flag)
        {
            this.flag = flag;
        }
    }

    class F : Base
    {
        this(int flag) { super(flag); }

        bool opEquals(const Base o) @safe
        {
            fEquals++;
            return flag == o.flag;
        }
    }

    class G : Base
    {
        this(int flag) { super(flag); }

        bool opEquals(const Base o) @safe
        {
            gEquals++;
            return flag == o.flag;
        }
    }

    assert(new F(1) == new G(1));
    assert(fEquals == 1);
    assert(gEquals == 1);
}

--

https://issues.dlang.org/show_bug.cgi?id=23354 Iain Buclaw <ibuclaw@gdcproject.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution|--- |REMIND --- Comment #2 from Iain Buclaw <ibuclaw@gdcproject.org> --- Regression PR has been reverted https://github.com/dlang/dmd/pull/14463 This needs to be checked again when re-fixing issue 19812. --

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