Compiler Warning (level 1) C4042

  • Article

'identifier' : has bad storage class

The specified storage class cannot be used with this identifier in this context. The compiler uses the default storage class instead:

  • extern, if identifier is a function.

  • auto, if identifier is a formal parameter or local variable.

  • No storage class, if identifier is a global variable.

This warning can be caused by specifying a storage class other than register in a parameter declaration.

The following sample generates C4042

// C4042.cpp
// compile with: /W1 /LD
int func2( __declspec( thread ) int tls_i )    // C4042
// try the following line instead
// int func2( int tls_i )
{
   return tls_i;
}