gri3-wm/generate-command-parser.pl

203 lines
6.4 KiB
Perl
Executable File
Raw Blame History

This file contains ambiguous Unicode characters!

This file contains ambiguous Unicode characters that may be confused with others in your current locale. If your use case is intentional and legitimate, you can safely ignore this warning. Use the Escape button to highlight these characters.

#!/usr/bin/env perl
# vim:ts=4:sw=4:expandtab
#
# i3 - an improved dynamic tiling window manager
# © 2009-2012 Michael Stapelberg and contributors (see also: LICENSE)
#
# generate-command-parser.pl: script to generate parts of the command parser
# from its specification file parser-specs/commands.spec.
#
# Requires only perl >= 5.10, no modules.
use strict;
use warnings;
use Data::Dumper;
use v5.10;
# reads in a whole file
sub slurp {
open my $fh, '<', shift;
local $/;
<$fh>;
}
# Stores the different states.
my %states;
# XXX: dont hardcode input and output
my $input = '../parser-specs/commands.spec';
my @raw_lines = split("\n", slurp($input));
my @lines;
# XXX: In the future, we might switch to a different way of parsing this. The
# parser is in many ways not good — one obvious one is that it is hand-crafted
# without a good reason, also it preprocesses lines and forgets about line
# numbers. Luckily, this is just an implementation detail and the specification
# for the i3 command parser is in-tree (not user input).
# -- michael, 2012-01-12
# First step of preprocessing:
# Join token definitions which are spread over multiple lines.
for my $line (@raw_lines) {
next if $line =~ /^\s*#/ || $line =~ /^\s*$/;
if ($line =~ /^\s+->/) {
# This is a continued token definition, append this line to the
# previous one.
$lines[$#lines] = $lines[$#lines] . $line;
} else {
push @lines, $line;
next;
}
}
# First step: We build up the data structure containing all states and their
# token rules.
my $current_state;
for my $line (@lines) {
if (my ($state) = ($line =~ /^state ([A-Z_]+):$/)) {
#say "got a new state: $state";
$current_state = $state;
} else {
# Must be a token definition:
# [identifier = ] <tokens> -> <action>
#say "token definition: $line";
my ($identifier, $tokens, $action) =
($line =~ /
^\s* # skip leading whitespace
([a-z_]+ \s* = \s*|) # optional identifier
(.*?) -> \s* # token
(.*) # optional action
/x);
# Cleanup the identifier (if any).
$identifier =~ s/^\s*(\S+)\s*=\s*$/$1/g;
# Cleanup the tokens (remove whitespace).
$tokens =~ s/\s*//g;
# The default action is to stay in the current state.
$action = $current_state if length($action) == 0;
#say "identifier = *$identifier*, token = *$tokens*, action = *$action*";
for my $token (split(',', $tokens)) {
my $store_token = {
token => $token,
identifier => $identifier,
next_state => $action,
};
if (exists $states{$current_state}) {
push @{$states{$current_state}}, $store_token;
} else {
$states{$current_state} = [ $store_token ];
}
}
}
}
# Second step: Generate the enum values for all states.
# It is important to keep the order the same, so we store the keys once.
my @keys = keys %states;
open(my $enumfh, '>', 'GENERATED_enums.h');
# XXX: we might want to have a way to do this without a trailing comma, but gcc
# seems to eat it.
say $enumfh 'typedef enum {';
my $cnt = 0;
for my $state (@keys, '__CALL') {
say $enumfh " $state = $cnt,";
$cnt++;
}
say $enumfh '} cmdp_state;';
close($enumfh);
# Third step: Generate the call function.
open(my $callfh, '>', 'GENERATED_call.h');
say $callfh 'static void GENERATED_call(const int call_identifier, struct CommandResult *result) {';
say $callfh ' switch (call_identifier) {';
my $call_id = 0;
for my $state (@keys) {
my $tokens = $states{$state};
for my $token (@$tokens) {
next unless $token->{next_state} =~ /^call /;
my ($cmd) = ($token->{next_state} =~ /^call (.*)/);
my ($next_state) = ($cmd =~ /; ([A-Z_]+)$/);
$cmd =~ s/; ([A-Z_]+)$//;
# Go back to the INITIAL state unless told otherwise.
$next_state ||= 'INITIAL';
my $fmt = $cmd;
# Replace the references to identified literals (like $workspace) with
# calls to get_string().
$cmd =~ s/\$([a-z_]+)/get_string("$1")/g;
# Used only for debugging/testing.
$fmt =~ s/\$([a-z_]+)/%s/g;
$fmt =~ s/"([a-z0-9_]+)"/%s/g;
say $callfh " case $call_id:";
say $callfh '#ifndef TEST_PARSER';
my $real_cmd = $cmd;
if ($real_cmd =~ /\(\)/) {
$real_cmd =~ s/\(/(&current_match, result/;
} else {
$real_cmd =~ s/\(/(&current_match, result, /;
}
say $callfh " $real_cmd;";
say $callfh '#else';
# debug
$cmd =~ s/[^(]+\(//;
$cmd =~ s/\)$//;
$cmd = ", $cmd" if length($cmd) > 0;
say $callfh qq| printf("$fmt\\n"$cmd);|;
say $callfh '#endif';
say $callfh " state = $next_state;";
say $callfh " break;";
$token->{next_state} = "call $call_id";
$call_id++;
}
}
say $callfh ' default:';
say $callfh ' printf("BUG in the parser. state = %d\n", call_identifier);';
say $callfh ' }';
say $callfh '}';
close($callfh);
# Fourth step: Generate the token datastructures.
open(my $tokfh, '>', 'GENERATED_tokens.h');
for my $state (@keys) {
my $tokens = $states{$state};
say $tokfh 'cmdp_token tokens_' . $state . '[' . scalar @$tokens . '] = {';
for my $token (@$tokens) {
my $call_identifier = 0;
my $token_name = $token->{token};
if ($token_name =~ /^'/) {
# To make the C code simpler, we leave out the trailing single
# quote of the literal. We can do strdup(literal + 1); then :).
$token_name =~ s/'$//;
}
my $next_state = $token->{next_state};
if ($next_state =~ /^call /) {
($call_identifier) = ($next_state =~ /^call ([0-9]+)$/);
$next_state = '__CALL';
}
my $identifier = $token->{identifier};
say $tokfh qq| { "$token_name", "$identifier", $next_state, { $call_identifier } }, |;
}
say $tokfh '};';
}
say $tokfh 'cmdp_token_ptr tokens[' . scalar @keys . '] = {';
for my $state (@keys) {
my $tokens = $states{$state};
say $tokfh ' { tokens_' . $state . ', ' . scalar @$tokens . ' },';
}
say $tokfh '};';
close($tokfh);