Chapter 10 Writing Assembler Control Statements

10.3.2 #undef

Syntax

#undef identifier

Functional description

This directive deletes an identifier defined by a #define directive. The effective range of an identifier is from the line following #define until the line before #undef.

To redefine the replacement string of an identifier, redefine it with #define after performing an #undef.

Coding rules

The identifier for an #undef directive must be the same string as the identifier for the corresponding #define directive. The string is case sensitive.

Usage example

A source file that uses #undef is shown below.

#define

data1

0x11

 

#define

data2

0x22

 

_CODE

section

CODE, PUBLIC, 2

 

mov

data1, D0

 

 

mov

data2, D1

 

#undef

data1

 

 

 

mov

data1, D0

 

#undef

data2

 

 

#define

 

data1

0x33

#define

 

data2

0x44

 

mov

data1, D0

 

 

mov

data2, D1

 

 

end

 

 

188 Identifier Definement

Page 200
Image 200
Panasonic MN1030 user manual 10.3.2 #undef, #undef identifier, Source file that uses #undef is shown below