Category
Pragma equivalent
#pragma options [no]ignerrno
Purpose
Allows the compiler to perform optimizations that assume errno is not modified by system calls.
Some system library functions set errno when an exception occurs. When ignerrno is in effect, the setting and subsequent side effects of errno are ignored. This allows the compiler to perform optimizations that assume errno is not modified by system calls.
Defaults
- -qnoignerrno
- -qignerrno when -O3 or higher optimization is in effect.
Usage
If you require both -O3 or higher and the ability to set errno, you should specify -qnoignerrno after the optimization option on the command line.
Predefined macros
__IGNERRNO__ is defined to
1 when ignerrno is in effect; otherwise, it is undefined.