Wrong "this" pointer when using templates in C++ and targeting x64 Platform by Vladislav Malicevic

Hi Vladislav:
    A fix for this issue has been checked into the compiler sources. The fix should show up in the next release of Visual C++.

Xiang Fan
Visual C++ Team

Hi Vladislav,
    Thanks for reporting the issue.

    Here is the smaller repro:

#include <stdio.h>

template<class T>
class C {
public:
    struct S {
        int rw[10];
    };

    static S f()
    {
        return ((C *)0)->g();
    }

    S g()
    {
        printf("this ptr: \t '%p'\n", this);

        S cid = {};
        return cid;
    }
};

typedef C<int> type;

int main()
{
    type::f();
}

    The issue happens when you have two member functions (one is static, one is not static) and they have the same signature (it only reproes under x64 due to the fact that __thiscall and __cdecl are the same calling convention under x64) and both return a structure.

    So one possible workaround is,

    Add a dummy parameter with default argument to ‘f’ or ‘g’.

Any progress on this?

Thanks for reporting this issue. I am able to reproduce the error and furthermore i was able to reduce it down to a single file repro case (~50 lines). The issue seems to involve x64 calling conventions, netsed types, retrun types, and templates. I've routed the bug to the appropriate team for further investigation. This thread will be kept up to date with our progress.

thansk,
VC++ Code Generation and Optimization Team

REG: 111041556623777

Escalated to support.

Thanks for your feedback.

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