# Equivalent Compiler Options

Some compiler directives and compiler options have the same effect, as shown in the table below. However, compiler directives can be turned on and off throughout a program, while compiler options remain in effect for the whole compilation unless overridden by a compiler directive.

The following table shows compiler directives and equivalent command-line compiler options:

Compiler Directive | Equivalent Command-Line Compiler Option
--- | ---
DECLARE | -warn declarations (Linux* and macOS) /warn:declarations (Windows*)
NODECLARE | -warn nodeclarations (Linux and macOS) /warn:nodeclarations (Windows)
DEFINE name | -D name (Linux and macOS) /D name (Windows)
FIXEDFORMLINESIZE:length | -extend-source [size] (Linux and macOS) /extend-source[:size] (Windows)
FREEFORM | -free or -nofixed (Linux and macOS) /free or /nofixed (Windows)
NOFREEFORM | -nofree or -fixed (Linux and macOS) /nofree or /fixed (Windows)
INTEGER:size | -integer_size size (Linux and macOS) /integer_size:size (Windows)
OBJCOMMENT | /libdir:user (Windows)
OPTIMIZE[: n ] | -O n (Linux and macOS) /O n (Windows)
NOOPTIMIZE | -O0 (Linux and macOS) /Od (Windows)
PACK:alignment | -align recnbytes (Linux and macOS) /align:recnbytes (Windows)
REAL:size | -real-size size (Linux and macOS) /real-size:size (Windows)
STRICT | -warn stderrors with -stand f18 (Linux and macOS) /warn:stderrors with /stand:f18 (Windows)
NOSTRICT | -warn nostderrors (Linux and macOS) /warn:nostderrors (Windows)

Parent topic: Directive Enhanced Compilation