Tells the optimizer how to find the errno identifier.
#pragma errno_name id | ...
When this pragma is used, the optimizer can use the identifier errno (either a macro or a function call) to optimize standard C library functions better. If not used, the optimizer makes worst-case assumptions about the effects of calls to the standard C library.
If errno resolves to a variable name, specify it like this:
#pragma errno_name _Errno
If errno is a function call accessing ordinarily inaccessible global variables, use this form:
#pragma errno_name ...
Otherwise, do not use this pragma to prevent incorrect optimizations.
This pragma does not correspond to any panel setting. By default, this pragma is unspecified (worst case assumption).