NAME
Asm::Preproc - Preprocessor to be called from an assembler
SYNOPSIS
use Asm::Preproc;
my $pp = Asm::Preproc->new();
my $pp = Asm::Preproc->new(@files);
$pp->add_path(@path); @path = $pp->path;
$pp->include($file); $pp->include($file, $from_line);
my $full_path = $pp->path_search($file);
$pp->include_list(@input);
my $iter = sub {return scalar <STDIN>};
$pp->include_list($iter);
my $line = $pp->getline; # isa Asm::Preproc::Line
my $strm = $pp->line_stream; # isa Iterator::Simple::LookaheadDESCRIPTION
This module implements a preprocessor that reads source files and handles recursive file includes. It is intended to be called from inside an assembler or compiler.
METHODS
new
Creates a new object. If an argument list is given, calls include for each of the file starting from the last, so that the files are read in the given order.
path
Returns the list of directories to search in sequence for source files.
add_path
Adds the given directories to the path searched for include files.
path_search
Searches for the given file in the path created by add_path, returns the first full path name where the file can be found.
Returns the input file name if the file is found in the current directory, or if it is not found in any of the path directories.
include
Open the input file and sets-up the object to read each line in sequence.
The optional second argument is a Asm::Preproc::Line object pointing at the %include line that included the file, to be used in error messages.
An exception is raised if the input file cannot be read, or if a file is included recursively, to avoid an infinite include loop.
include_list
Sets-up the object to read each element of the passed input list one line at a time.
Each element of the list is either a text string or a code reference of an iterator. The iterator may return text strings, or other iterators that will be called recursively. The iterator returns undef at the end of input.
The text strings are split by lines, so that each getline calls returns one complete line.
As the text lines are scanned for pre-processor directives, the following two lines are equivalent:
$pp->include('file.asm');
$pp->include_list('%include <file.asm>');getline
Returns the next line from the input, after doing all the pre-processing. The line is returned as a Asm::Preproc::Line object containing the actual text, and the file and line number where the text was found.
Returns undef at the end of the input.
line_stream
Returns a Iterator::Simple::Lookahead object that will return the result of getline on each next call.
PREPROCESSING
The following preprocessor-like lines are processed:
%line N+M FILEnasm-like line directive, telling that the next input line is line N from file FILE, followed by lines N+M, N+2*M, ... This information is used to generate error messages. Usefull to parse a file preprocessed by nasm.
#line N "FILE"cpp-like line directive, telling that the next input line is line N from file FILE, followed by lines N+1, N+2, ... This information is used to generate error messages. Usefull to parse a file preprocessed by cpp.
%include 'FILE'
%include "FILE"
%include <FILE>
%include FILE
#include 'FILE'
#include "FILE"
#include <FILE>
#include FILEnasm/cpp-like include directive, asking to insert the contents of the given file in the input stream.
All the other preprocessor-like lines are ignored, i.e. lines starting with '#' or '%'.
AUTHOR
Paulo Custodio, <pscust at cpan.org>
BUGS and FEEDBACK
Please report any bugs or feature requests through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Asm-Preproc.
ACKNOWLEDGEMENTS
Inspired in the Netwide Assembler, http://www.nasm.us/
LICENSE and COPYRIGHT
Copyright (c) 2010 Paulo Custodio.
This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.
See http://dev.perl.org/licenses/ for more information.