diff options
Diffstat (limited to 'lib/PublicInbox/HlMod.pm')
-rw-r--r-- | lib/PublicInbox/HlMod.pm | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/lib/PublicInbox/HlMod.pm b/lib/PublicInbox/HlMod.pm new file mode 100644 index 00000000..237ffaca --- /dev/null +++ b/lib/PublicInbox/HlMod.pm @@ -0,0 +1,125 @@ +# Copyright (C) 2019 all contributors <meta@public-inbox.org> +# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt> + +# I have no idea how stable or safe this is for handling untrusted +# input, but it seems to have been around for a while, and the +# highlight(1) executable is supported by gitweb and cgit. +# +# I'm also unsure about API stability, but highlight 3.x seems to +# have been around a few years and ikiwiki (apparently the only +# user of the SWIG/Perl bindings, at least in Debian) hasn't needed +# major changes to support it in recent years. +# +# Some code stolen from ikiwiki (GPL-2.0+) +# wrapper for SWIG-generated highlight.pm bindings +package PublicInbox::HlMod; +use strict; +use warnings; +use highlight; # SWIG-generated stuff + +sub _parse_filetypes ($) { + my $ft_conf = $_[0]->searchFile('filetypes.conf') or + die 'filetypes.conf not found by highlight'; + open my $fh, '<', $ft_conf or die "failed to open($ft_conf): $!"; + local $/; + my $cfg = <$fh>; + my %ext2lang; + my @shebang; # order matters + + # Hrm... why isn't this exposed by the highlight API? + # highlight >= 3.2 format (bind-style) (from ikiwiki) + while ($cfg =~ /\bLang\s*=\s*\"([^"]+)\"[,\s]+ + Extensions\s*=\s*{([^}]+)}/sgx) { + my $lang = $1; + foreach my $bit (split(/,/, $2)) { + $bit =~ s/.*"(.*)".*/$1/s; + $ext2lang{$bit} = $lang; + } + } + # AFAIK, all the regexps used by in filetypes.conf distributed + # by highlight work as Perl REs + while ($cfg =~ /\bLang\s*=\s*\"([^"]+)\"[,\s]+ + Shebang\s*=\s*\[\s*\[([^}]+)\s*\]\s*\]\s*}\s*,/sgx) { + my ($lang, $re) = ($1, $2); + eval { + my $perl_re = qr/$re/; + push @shebang, [ $lang, $perl_re ]; + }; + if ($@) { + warn "$lang shebang=[[$re]] did not work in Perl: $@"; + } + } + (\%ext2lang, \@shebang); +} + +sub new { + my ($class) = @_; + my $dir = highlight::DataDir->new; + $dir->initSearchDirectories(''); + my ($ext2lang, $shebang) = _parse_filetypes($dir); + bless { + -dir => $dir, + -ext2lang => $ext2lang, + -shebang => $shebang, + }, $class; +} + +sub _shebang2lang ($$) { + my ($self, $str) = @_; + my $shebang = $self->{-shebang}; + foreach my $s (@$shebang) { + return $s->[0] if $$str =~ $s->[1]; + } + undef; +} + +sub _path2lang ($$) { + my ($self, $path) = @_; + my ($ext) = ($path =~ m!([^\\/\.]+)\z!); + $ext = lc($ext); + $self->{-ext2lang}->{$ext} || $ext; +} + +sub do_hl { + my ($self, $str, $path) = @_; + my $lang = _path2lang($self, $path) if defined $path; + my $dir = $self->{-dir}; + my $langpath; + if (defined $lang) { + $langpath = $dir->getLangPath("$lang.lang") or return; + $langpath = undef unless -f $langpath; + } + unless (defined $langpath) { + $lang = _shebang2lang($self, $str) or return; + $langpath = $dir->getLangPath("$lang.lang") or return; + $langpath = undef unless -f $langpath; + } + return unless defined $langpath; + + my $gen = $self->{$langpath} ||= do { + my $g = highlight::CodeGenerator::getInstance($highlight::HTML); + $g->setFragmentCode(1); # generate html fragment + + # whatever theme works + my $themepath = $dir->getThemePath('print.theme'); + $g->initTheme($themepath); + $g->loadLanguage($langpath); + $g->setEncoding('utf-8'); + $g; + }; + \($gen->generateString($$str)) +} + +# SWIG instances aren't reference-counted, but $self is; +# so we need to delete all the CodeGenerator instances manually +# at our own destruction +sub DESTROY { + my ($self) = @_; + foreach my $gen (values %$self) { + if (ref($gen) eq 'highlight::CodeGenerator') { + highlight::CodeGenerator::deleteInstance($gen); + } + } +} + +1; |