The “start_map_region” Pragma

Syntax

#pragma start_map_region ( [ filename ] )

where filename is a string literal.

This pragma expects that any earlier use will have been cancelled by a #pragma stop_map_region. If an earlier instance remains in effect, warning C4194 is raised at level 1.

That filename, if given, is a string is simply assumed. Omission induces the compiler to dereference a null pointer. The consequent access violation is typically reported as an internal compiler error (C1001).