Developer Guide and Reference

Contents

U

Undefines any definition currently in effect for the specified
macro
.

Syntax

Linux:
-U
name
Windows:
/U
name
Arguments
name
Is the name of the
macro
to be undefined.
Default
OFF
Macro
definitions are in effect until they are undefined.
Description
This option undefines any definition currently in effect for the specified
macro
.
It is equivalent to an #undef preprocessing directive.
On Windows systems, use the
/u
option to undefine all previously defined preprocessor values.
IDE Equivalent
Visual Studio:
Preprocessor > Undefine Preprocessor Definitions
Eclipse:
Preprocessor > Undefine Preprocessor Definitions
Alternate Options
None
Example
To undefine a macro, enter the following command:
On Windows* systems:
icx /Uia64 prog1.cpp ! specific to C++
dpcpp-cl /Uia64 prog1.cpp ! specific to DPC++
On Linux* systems:
icpx -Uia64 prog1.cpp ! specific to C++
dpcpp -Uia64 prog1.cpp ! specific to DPC++
If you attempt to undefine an ANSI C macro, the compiler will emit an error:
invalid macro undefinition: <name of macro>

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.