### /Gy Compiler Option (OS/2)

Syntax | Default
/Gy[+|-] | /Gy-

/Gy determines whether external data names are decorated with a leading underscore on OS/2.

By default, the names are not decorated.

External names are symbols exported from the module you are building so that other modules can access them. This option affects data items that you export in one of the following ways:

- Using the /EXPORT linker option
- Building with /EXPORTALL linker option
- Using #pragma export in your code
- Including the _Export keyword in the declaration of the item.

In OS/2, names are not usually decorated. Using /Gy can improve portability between OS/2 and Windows.

External names are automatically decorated in Windows.

Summary of Compiler Options