#! /usr/bin/perl
# $OpenBSD: build-debug-info,v 1.49 2023/05/09 17:41:10 espie Exp $
# Copyright (c) 2019 Marc Espie <espie@openbsd.org>
#
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

use v5.36;

my $ports1;
BEGIN {
	$ports1 = $ENV{PORTSDIR} || '/usr/ports';
}

use lib "$ports1/infrastructure/lib";
use OpenBSD::BaseFS;
use OpenBSD::BasePlistReader;

package PlistFactory;
our @ISA = qw(OpenBSD::BasePlistFactory);

# note that contrary to update-plist, we never build the "new" plist, but
# write it on the fly (should we use nlist as well here ?)
sub stateclass($)
{
	return 'PlistReader::State';
}

sub command_name($)
{
	return 'build-debug-info';
}

sub process_next_subpackage($class, $o)
{
	my $r = $class->SUPER::process_next_subpackage($o);
	if ($r->{state}{bad} != 0) {
		$o->{state}{exitcode} = 1;
	}
}

package PlistReader::State;
our @ISA = qw(OpenBSD::BasePlistReader::State);

sub substclass($)
{
	return 'OpenBSD::Subst';
}

sub handle_options($s)
{
	$s->SUPER::handle_options;
}

# Most of the heavy lifting is done by visitor methods, as always

package OpenBSD::PackingElement;
# $self->write_debug_info($base, $fh, $o):
#	write debug info (duh) for packing element $self relative to
#	fake dir $base to filehandle $fh perusing debug object 
#	$o for storing useful info
sub write_debug_info($, $, $, $)
{
}

package OpenBSD::PackingElement::PkgPath;
sub write_debug_info($self, $, $fh, $)
{
	print $fh "\@", $self->keyword, " debug/", $self->name, "\n";
}

package OpenBSD::PackingElement::Cwd;
# so the reader stuffs a default cwd in the packing-list, which is VERY
# useful for absolute names, BUT we don't want to copy the first one.

# copy the later ones, even if there is nothing to emit afterwards (this
# is cheap)
sub write_debug_info($self, $, $fh, $o)
{
	if ($o->{first_cwd}) {
		$o->{first_cwd} = 0;
	} else {
		$self->write($fh);
	}
}

package OpenBSD::PackingElement::FileWithDebugInfo;
use File::Basename;
sub write_debug_info($self, $base, $fh, $o)
{
	return if $self->{nodebug};
	my $s = $self->name;
	my $dbg = $self->mogrify($s);
	my $dir = $dbg;
	$dir =~ s/(\/\.debug\/)[^\/]+/$1/;
	my $path = $base.$self->fullname;
	my $dbgpath = $base.$self->mogrify($self->fullname);
	if (-l $path) {
		# turns out we don't need to do anything, egdb follows symlinks
		return;
	}
	if (-f $path) {
		my $k = join('/', (stat $path)[0,1]);
		my $l = $o->{linkstash}{$k};
		if (!defined $l) {
			$self->write_debug_entry($fh, $dir, $dbg, $o);
			$o->{linkstash}{$k} = $dbg;
			$self->write_rule($o, $fh, $s, $path, $dbgpath, 
			    "OBJCOPY_RULE");
			return;
		}
		my $ldir = dirname($l)."/";
		if ($ldir eq $dir) {
			# if both mogrified dirs are the same
			# the debug-info link will do the right thing
			return;
		}
		# so we need to create a link in our dir but that link 
		# must have the right name
		my $n = $dir.basename($l);
		# that link may already exist! don't emit it again
		# TODO missing checks to be certain there's no ambiguity, just 
		# need to write an actual example and verify I can detect it.
		return if exists $o->{ostash}{$n};
		$self->write_debug_entry($fh, $dir, $n, $o);
		$self->write_rule($o, $fh, $l, $path, $dbgpath, "LINK_RULE");
	} else {
		$o->{state}->fatal("Error: #1 does not exist", $path);
	}
}

sub write_debug_entry($self, $fh, $dir, $dbg, $o)
{
	print $fh $dbg, "\n";
	if (!exists $o->{dirstash}{$dir}) {
		print $fh $dir, "\n";
		$o->{dirstash}{$dir} = 1;
	}
	$o->{ostash}{$dbg} = 1;
	delete $o->{empty};
}

sub write_rule($self, $o, $fh, $s, $p1, $p2, $what)
{
	my $mk = $o->{mk};
	print $mk "all: $p2\n";
	print $mk "$p2: $p1\n";
	print $mk "\t\@\$\{$what\}\n\n";
}

sub mogrify($self, $s)
{
	$s =~ s,([^\/]+)$,.debug/$1.dbg,;
	return $s;
}

package OpenBSD::PackingElement::StaticLib;
sub write_debug_info($, $, $, $)
{
	# don't do anything
}

package OpenBSD::PackingElement::NoDefaultConflict;
sub write_debug_info($self, $, $fh, $)
{
	$self->write($fh);
}

package OpenBSD::PackingElement::IsBranch;
sub write_debug_info($self, $, $fh, $)
{
	$self->write($fh);
}

package OpenBSD::PackingElement::Conflict;
sub write_debug_info($self, $, $fh, $)
{
	my $m = join('|', map {"debug-$_"} split(/\|/, $self->name));
	print $fh "\@", $self->keyword, " $m\n";
}

# This is the BuildDebugInfo main code proper
package BuildDebugInfo::State;
our @ISA = qw(OpenBSD::AddCreateDelete::State);
sub handle_options($state)
{
	$state->SUPER::handle_options('vqFP:', 
	    '[-Fmnqvx]',
	    '-P pkgdir',
	    '-- pkg_create_args ...');
    	$state->{pkgdir} = $state->opt('P');
	if (!defined $state->{pkgdir}) {
		$state->fatal("-P pkgdir is mandatory");
	}
	$state->{verbose} = $state->opt('v');
	$state->{quiet} = $state->opt('q');
}

sub openfile($self, $name)
{
	open my $fh, ">", $name or 
	    $self->fatal("Can't write to #1: #2", $name, $!);
	$self->say("Writing #1", $name) unless $self->{quiet};
	return $fh;
}

package BuildDebugInfo;
our @ISA = qw(OpenBSD::BaseFS);
use File::Basename;
use File::Compare;

sub new($class)
{
	return $class->SUPER::new(undef, BuildDebugInfo::State->new);
}

my $self = BuildDebugInfo->new;
my $state = $self->{state};
$state->{exitcode} = 0;
my $base = PlistFactory->parse_args($self);
use File::Basename;
$self->{mk} = $state->openfile($state->{pkgdir}."/Makefile.new");
print {$self->{mk}} << 'EOPREAMBLE';
# Makefile generated by build-debug-info $OpenBSD: build-debug-info,v 1.49 2023/05/09 17:41:10 espie Exp $
# No serviceable parts
# Intended to run under the stage area after cd ${WRKINST}

OBJCOPY_RULE = ${INSTALL_DATA_DIR} ${@D} && \
    perm=`stat -f "%p" $?` && chmod u+rw $? && \
    echo "> Extracting debug info from $?" && \
    if readelf 2>/dev/null -wi $?|cmp -s /dev/null -; then \
    	echo "Warning: no debug-info in $?"; \
    fi && \
    llvm-objcopy --only-keep-debug $? $@ && \
    ${DWZ} $@ && \
    strip -d -o $?.stripped $? && cp $?.stripped $? && rm $?.stripped && \
    llvm-objcopy --add-gnu-debuglink=$@ $? $?.debuglink && cp $?.debuglink $? && rm $?.debuglink && \
    chmod $$perm $? && \
    touch $@

LINK_RULE = ${INSTALL_DATA_DIR} ${@D} && \
    echo "> Link debug info from $? to $@" && ln $? $@

all:
.PHONY: all

EOPREAMBLE

# XXX even though links may end up in different subpackages, the
# logic has to be global, as this is used by the generated makefile
# to extract debug info. pkg_create/pkg_add may then create copies,
# but they will contain the right information
$self->{linkstash} = {};
$self->{ostash} = {};
for my $l (@{$self->{lists}}) {
	$self->{empty} = 1;
	$self->{dirstash} = {};
	$self->{prefix} = $base."/".$l->{state}{prefix};
	my $name = pop @{$l->{base_plists}};
	$name = $state->{pkgdir}."/".(basename $name);
	my $fh = $state->openfile($name);
	$self->{first_cwd} = 1;
	$l->olist->write_debug_info($base, $fh, $self);
	close($fh) or $state->fatal("Can't write plist: #1", $!);
	$self->warn_if_empty($state, $l);
}

close($self->{mk}) or $state->fatal("Can't close Makefile.new: #1", $!);

sub warn_if_empty
{
	my ($self, $state, $l) = @_;
	return unless $self->{empty};
	$state->errsay("Warning: no debug-info in #1", $l->olist->pkgname);
	return if @{$self->{lists}} == 1;
	$state->errsay("Set DEBUG_PACKAGES manually ?");
}

if (!$state->{exitcode}) {
	my $f = $state->{pkgdir}."/Makefile";
	$state->say("Renaming #1 to #2", "$f.new", "Makefile") unless $state->{quiet};
	rename("$f.new", $f) or $state->fatal("Can't create Makefile: #1", $!);
}
exit($state->{exitcode});