# gcc, gcc-sys

Determines whether certain GNU macros are defined or undefined.

## Syntax

Linux: | -gcc -no-gcc -gcc-sys

macOS: | -gcc -no-gcc -gcc-sys

Windows: | None

## Arguments

None

## Default

-gcc | The compiler defines the GNU macros __GNUC__, __GNUC_MINOR__, and __GNUC_PATCHLEVEL__

## Description

This option determines whether the GNU macros __GNUC__, __GNUC_MINOR__, and __GNUC_PATCHLEVEL__ are defined or undefined.

Option | Description
--- | ---
-gcc | Defines GNU macros.
-no-gcc | Undefines GNU macros.
-gcc-sys | Defines GNU macros only during compilation of system headers.

## IDE Equivalent

Visual Studio: None

Eclipse: Preprocessor > gcc Predefined Macro Enablement

Xcode: Preprocessor > Predefine gcc Macros

## Alternate Options

None

Parent topic: Preprocessor Options