#!/usr/bin/env perl
# vim:ts=4:sw=4:expandtab
#
# i3 - an improved dynamic tiling window manager
# © 2009 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 Getopt::Long;
use v5.10;
my $input = '';
my $prefix = '';
my $result = GetOptions(
'input=s' => \$input,
'prefix=s' => \$prefix
);
die qq|Input file "$input" does not exist!| unless -e $input;
# reads in a whole file
sub slurp {
open my $fh, '<', shift;
local $/;
<$fh>;
}
# Stores the different states.
my %states;
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) = ($line =~ /^state ([A-Z0-9_]+):$/)) {
#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;
# 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)) {
# Cleanup trailing/leading whitespace.
$token =~ s/^\s*//g;
$token =~ s/\s*$//g;
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} = [ $store_token ];
}
}
}
}
# Second step: Generate the enum values for all states.
# It is important to keep the order the same, so we store the keys once.
# We sort descendingly by length to be able to replace occurrences of the state
# name even when one state’s name is included in another one’s (like FOR_WINDOW
# is in FOR_WINDOW_COMMAND).
my @keys = sort { (length($b) <=> length($a)) or ($a cmp $b) } keys %states;
open(my $enumfh, '>', "GENERATED_${prefix}_enums.h");
my %statenum;
say $enumfh '#pragma once';
say $enumfh 'typedef enum {';
my $cnt = 0;
for my $state (@keys, '__CALL') {
say $enumfh ',' if $cnt > 0;
print $enumfh " $state = $cnt";
$statenum{$state} = $cnt;
$cnt++;
}
say $enumfh "\n} cmdp_state;";
close($enumfh);
# Third step: Generate the call function.
open(my $callfh, '>', "GENERATED_${prefix}_call.h");
my $resultname = uc(substr($prefix, 0, 1)) . substr($prefix, 1) . 'ResultIR';
say $callfh '#pragma once';
say $callfh "static void GENERATED_call(Match *current_match, struct stack *stack, const int call_identifier, struct $resultname *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(). Also replaces state names (like FOR_WINDOW)
# with their ID (useful for cfg_criteria_init(FOR_WINDOW) e.g.).
$cmd =~ s/$_/$statenum{$_}/g for @keys;
$cmd =~ s/\$([a-z_]+)/get_string(stack, "$1")/g;
$cmd =~ s/\&([a-z_]+)/get_long(stack, "$1")/g;
# For debugging/testing, we print the call using printf() and thus need
# to generate a format string. The format uses %d for <number>s,
# literal numbers or state IDs and %s for NULL, <string>s and literal
# strings.
# remove the function name temporarily, so that the following
# replacements only apply to the arguments.
my ($funcname) = ($fmt =~ /^(.+)\(/);
$fmt =~ s/^$funcname//;
$fmt =~ s/$_/%d/g for @keys;
$fmt =~ s/\$([a-z_]+)/%s/g;
$fmt =~ s/\&([a-z_]+)/%ld/g;
$fmt =~ s/"([a-z0-9_]+)"/%s/g;
$fmt =~ s/(?:-?|\b)[0-9]+\b/%d/g;
$fmt = $funcname . $fmt;
say $callfh " case $call_id:";
say $callfh " result->next_state = $next_state;";
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;
$cmd =~ s/, NULL//g;
say $callfh qq| fprintf(stderr, "$fmt\\n"$cmd);|;
# The cfg_criteria functions have side-effects which are important for
# testing. They are implemented as stubs in the test parser code.
if ($real_cmd =~ /^cfg_criteria/) {
say $callfh qq| $real_cmd;|;
}
say $callfh '#endif';
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 ' assert(false);';
say $callfh ' }';
say $callfh '}';
close($callfh);
# Fourth step: Generate the token datastructures.
open(my $tokfh, '>', "GENERATED_${prefix}_tokens.h");
say $tokfh '#pragma once';
for my $state (@keys) {
my $tokens = $states{$state};
say $tokfh 'static 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 :).
$token_name =~ s/'$//;
}
# Escape double quotes:
$token_name =~ s,",\\",g;
my $next_state = $token->{next_state};
if ($next_state =~ /^call /) {
($call_identifier) = ($next_state =~ /^call ([0-9]+)$/);
$next_state = '__CALL';
}
my $identifier;
# Set $identifier to NULL if there is no identifier
if ($token->{identifier} eq ""){
$identifier = "NULL"
}
else{
$identifier = qq|"$token->{identifier}"|;
}
say $tokfh qq| { "$token_name", $identifier, $next_state, { $call_identifier } },|;
}
say $tokfh '};';
}
say $tokfh 'static cmdp_token_ptr tokens[' . scalar @keys . '] = {';
for my $state (@keys) {
my $tokens = $states{$state};
say $tokfh ' { tokens_' . $state . ', ' . scalar @$tokens . ' },';
}
say $tokfh '};';
close($tokfh);
