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-Uname

This option removes any initial definition of the macro name.

The macro name can be either:

  • a predefined macro

  • a macro specified using the -D option.

Note

Not all compiler predefined macros can be undefined.

Syntax

-Uname

Where:

name

is the name of the macro to be undefined.

Usage

Specifying -Uname has the same effect as placing the text #undef name at the head of each source file.

Restrictions

The compiler defines and undefines macros in the following order:

  1. compiler predefined macros

  2. macros defined explicitly, using -Dname

  3. macros explicitly undefined, using -Uname.