# falias, Oa

Specifies whether or not a procedure call may have hidden aliases of local variables not supplied as actual arguments.

## Syntax

Linux: | -falias -fno-alias

macOS: | -falias -fno-alias

Windows: | /Oa /Oa-

## Arguments

None

## Default

-fno-alias or /Oa | Procedure calls do not alias local variables.

## Description

This option specifies whether or not the compiler can assume that during a procedure call, local variables in the caller that are not present in the actual argument list and not visible by host association, are not referenced or redefined due to hidden aliasing. The Fortran standard generally prohibits such aliasing.

If you specify -falias (Linux* and macOS) or /Oa- (Windows*), aliasing during a procedure call is assumed; this can possibly affect performance.

If you specify -fno-alias or /Oa (the default), aliasing during a procedure call is not assumed.

## IDE Equivalent

None

## Alternate Options

None

Parent topic: Optimization Options

## See Also

ffnalias compiler option