Chapter 5 Using Assembler
Command Options 77
Functional Description
The assembler directives #ifdef, #else, and #endif select which source statements are to be assembled
depending on whether an identifier has been defined by a define directive. The D option has the same
function as the define directive, but with direct specification from the command line.
Identifier specifications by define directives in source statements may be omitted. The statements to be
assembled can instead be selected by specifying identifiers with the D option as needed.
Thus, the D option allows conditions to be set freely at the assembly stage without fixing the conditions
with define directives in source statements.
There are two conditional assembly directives that can make use of the D option.
ifdef, ifndef
No error will occur if identifiers specified by the D option are not used in the source file. Assembly will
process as though conditions are unfulfilled.
Rules of Use
This option is specified with the hyphen (-) option specification character, followed by the upper-case
letter 'D', then followed by the identifier. A space can be inserted between D and the identifier. The
identifier must exactly match the string specified by #ifdef. Characters are case-sensitive.
as103 -D VERSION sample.asm
Default Specification
Unfulfilled conditions will be selected. The #else to #endif blocks will be assembled.
D identifier Specify an identifier to be used by ifdef during conditional assembly