[Issue 23723] Attributes incorrectly inferred given the same source but compiled individually

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=23723

--- Comment #2 from RazvanN <razvan.nitu1305 at gmail.com> ---
(In reply to 212fahrenheit from comment #0)
> This will compile with dmd-2.101.2, but will produce a linking error when
> using dmd-2.102.0 or dmd-2.102.1
> 
> After upgrading DMD my project it will not build, reducing this was a head
> scratcher. this is my first time reporting on the tracker here, so hopefully
> I did a good job, if not, please tell what to do better next time.
> 
> I'm not sure what is going on, but I think this has something to do with
> attributes being inferred incorrectly, but I may be off the mark, what's
> also odd is that if you pass both files at once this bug will not be
> reproduced.
> 
> using `nm` I can see two different signatures
> 
> void std.typecons.SafeRefCounted!(test2.MyStruct, 1).SafeRefCounted.__dtor()
> pure nothrow @nogc void std.typecons.SafeRefCounted!(test2.MyStruct,
> 1).SafeRefCounted.__dtor()
> 
> 
> How to reproduce bug:
> 
> build using: dmd -c test.d && dmd -c test2.d && dmd test.o test2.o
> 
> test.d
> ```
> void main(){
> 	import test2;
> 	MyStruct.RcPtr gl_indcies = MyStruct.RcPtr(MyStruct());
> }
> ```
> 
> test2.d
> ```
> module test2;
> struct MyStruct{
> 	import std.typecons : SafeRefCounted, Unique;
> 	alias Ptr = Unique!(MyStruct);
> 	alias RcPtr = SafeRefCounted!(MyStruct);
> 	~this(){}
> }
> ```
> 
> this is the linking error produced
> ```
> /bin/ld: test.o: in function `_Dmain':
> test.d:(.text._Dmain[_Dmain]+0x2f): undefined reference to
> `_D3std8typecons__T14SafeRefCountedTS5test28MyStructVEQBzQBy24RefCountedAutoI
> nitializei1ZQCs6__dtorMFZv'
> collect2: error: ld returned 1 exit status
> ```a

Reduce to not include phobos:

//test.d

void main()
{
    import test2;
    MyStruct.Ptr a;
}

// test2.d

struct MyStruct
{
    alias Ptr = Unique!(MyStruct);
    ~this(){}
}

struct Unique(T)
{
    /// Transfer ownership from a `Unique` of a type that is convertible to our
type.
    void opAssign(U)(Unique!U u)
    if (is(u.RefT : RefT))
    {   

    }   

    ~this()
    {   
        if (_p !is null)
        {   
            destroy(*_p);                                                       
            //_p.__dtor();
        }   
    }   

    T* _p; 
}

--