If (null) is executed on a specific computer compiler using clang ++

Question

I have a great code that we have been using for a long time in our team. But its a few weeks that there is a problem with it when it is compiled on my machine. The code is cross-compiled for the Intel Atom processor and runs on a specific machine.

When it is compiled on my computer, unlike others, it calls segmentation fault. Segmentation errors occur inside a block ifthat should not be executed:

Settings *s = &Global::getSettings();
std::cout << "Pointer value before if : " << s << std::endl;
if(s != 0)
{
  std::cout << "Pointer value after if : " << &Global::getSettings() << std::endl;
  .
  .
  .
}

Global::getSettings() as follows:

.
.
.

private:
  static __thread Settings* theSettings;

public:
  static Settings& getSettings() {return *theSettings;}

.
.
.

__thread Settings* Global::theSettings = 0;

In my test, the value of Global :: theSettings does not change and is equal to zero. The output of the top code snippet is as follows:

Pointer value before if : 0
Pointer value after if : 0

Question: How to fulfill ifwith a condition equal to zero ?!

PS: I use clang ++ to compile code on a Debian machine.

Answer 1

undefined .

, , , null .

"" undefined.

-.