inline variable is initialized more than once

Im seeing some examples of inline const variable getting initialized (and destructed) 3 times with visual studio 2017. Is this is a bug with the linker ? or is this supposed to happend in some other way ?

linker Comdat folding is set to Off.

Example Code:

#pragma once

struct A {
  A() {
    static int count = 0;
    ++count;
    ASSERT(count == 1);
  }
  ~A() {
  }
};


inline const A a = A();

In my solution, I have the assert fire twice (A constructor called 3 times). Inspecting the call stack shows all call stacks are identical and all calls come from dynamic initializer for a(). Now I know for a fact this class is not used in other parts of the solution since I just created it to investigate this issue.

Im using VS17 15.8.9

Update: Bug report here https://developercommunity.visualstudio.com/content/problem/297876/static-inline-variable-gets-destroyed-multiple-tim.html (you may upvote to help push for the bugfix)

This appears to be an MSVC bug. I'm able to reproduce it with the code below (also with VS2017 15.8.9). Interestingly, I can only reproduce with a Debug build. In Release mode, the optimizer seems to save us.

Common.h

#pragma once

#include <iostream>

class Foo
{
public:
  Foo()
  {
    std::cout << "Constructing a Foo" << std::endl;
  }

  ~Foo()
  {
    std::cout << "Destructing a Foo" << std::endl;
  }
};

inline Foo const Bar;

other.cpp

#include "common.h"

void DoOtherStuff()
{
  std::cout << &Bar << std::endl;
}

main.cpp

#include "common.h"

void DoStuff()
{
  std::cout << &Bar << std::endl;
}

extern void DoOtherStuff();

int main()
{
  DoStuff();
  DoOtherStuff();
}

Output (Debug)

Constructing a Foo
Constructing a Foo
00007FF74FD50170
00007FF74FD50170
Destructing a Foo
Destructing a Foo