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CPU-Z80-Assembler-2.04
River stage one • 1 direct dependent • 1 total dependent
/ CPU::Z80::Assembler::Macro

NAME

CPU::Z80::Assembler::Macro - Macro pre-processor for the Z80 assembler

SYNOPSIS

use CPU::Z80::Assembler::Macro;
use HOP::Stream;

my $pp_stream = z80pp($token_stream);

DESCRIPTION

This module provides a macro pre-processor to parse macro definition statements, and expand macro calls in the token stream. Both the input and output streams are HOP::Stream objects returning sequences of tokens as defined in CPU::Z80::Assembler::Lexer.

EXPORTS

By default the 'z80pp' subroutine is exported. To disable that, do:

use CPU::Z80::Assembler::Macro ();

FUNCTIONS

z80pp

Takes a HOP::Stream object as input. The stream returns lexical tokens on each HOP::Stream::drop() call, as defined in CPU::Z80::Assembler::Lexer.

The output stream contains the same input tokens, except that macro definitions are slurped and not output, and macro invocations on the input are replaced by the macro expansion on the output. During the macro expansion, the formal parameters of the definition are replaced by the actual arguments, and the defined labels are renamed to a unique name to allow multiple expansions of the same macro.

SYNTAX

Macros

Macros are created thus. This example creates an "instruction" called MAGIC that takes two parameters:

MACRO MAGIC param1, param2 {
    LD param1, 0
    BIT param2, L
    label = 0x1234
    ... more real instructions go here.
}

Within the macro, param1, param2 etc will be replaced with whatever parameters you pass to the macro. So, for example, this:

MAGIC HL, 2

Is the same as:

LD HL, 0
BIT 2, L
...

Any labels that you define inside a macro are local to that macro. Actually they're not but they get renamed to _macro_NN_... so that they effectively *are* local.

There is an alternative syntax, for compatibility with other assemblers, with exactly the same effect.

MACRO MAGIC param1 param2
    LD param1, 0
    BIT param2, L
    label = 0x1234
    ... more real instructions go here.
ENDM

A ',' can be passed as part of a macro argument, by enclosing the arguments between {braces}.

MACRO PAIR x {
    LD x
}
PAIR {A,B}

expands to:

LD A,B

BUGS and FEEDBACK

See CPU::Z80::Assembler.

SEE ALSO

HOP::Stream CPU::Z80::Assembler CPU::Z80::Assembler::Lexer

AUTHORS, COPYRIGHT and LICENCE

See CPU::Z80::Assembler.