#!/usr/bin/perl -w

my $abinew = shift;
my $abiold = shift;
my $skipabi = shift;

$abinew =~ /abi-(.*)/;
my $abinum = $1;

my $fail_exit = 1;
my $EE = "EE:";
my $errors = 0;
my $abiskip = 0;

my $count;

print "II: Checking ABI...\n";

if ($skipabi) {
	print "WW: Explicitly asked to ignore ABI, running in no-fail mode\n";
	$fail_exit = 0;
	$abiskip = 1;
	$EE = "WW:";
}

#if ($prev_abinum != $abinum) {
#	print "II: Different ABI's, running in no-fail mode\n";
#	$fail_exit = 0;
#	$EE = "WW:";
#}
#
if (not -f "$abinew" or not -f "$abiold") {
	print "EE: Previous or current ABI file missing!\n";
	print "    $abinew\n" if not -f "$abinew";
	print "    $abiold\n" if not -f "$abiold";

	# Exit if the ABI files are missing, but return status based on whether
	# skip ABI was indicated.
	if ("$abiskip" eq "1") {
		exit(0);
	} else {
		exit(1);
	}
}

my %symbols;
my %symbols_ignore;
my %modules_ignore;
my %module_syms;

# See if we have any ignores
my $ignore = 0;
print "    Reading symbols/modules to ignore...";

for $file ("abi-blacklist") {
	if (-f $file) {
		open(IGNORE, "< $file") or
			die "Could not open $file";
		while (<IGNORE>) {
			chomp;
			if ($_ =~ m/M: (.*)/) {
				$modules_ignore{$1} = 1;
			} else {
				$symbols_ignore{$_} = 1;
			}
			$ignore++;
		}
		close(IGNORE);
	}
}
print "read $ignore symbols/modules.\n";

sub is_ignored($$) {
	my ($mod, $sym) = @_;

	die "Missing module name in is_ignored()" if not defined($mod);
	die "Missing symbol name in is_ignored()" if not defined($sym);

	if (defined($symbols_ignore{$sym}) or defined($modules_ignore{$mod})) {
		return 1;
	}
	return 0;
}

# Read new syms first
print "    Reading new symbols ($abinum)...";
$count = 0;
open(NEW, "< $abinew") or
	die "Could not open $abinew";
while (<NEW>) {
	chomp;
	m/^(\S+)\s(.+)\s(0x[0-9a-f]+)\s(.+)$/;
	$symbols{$4}{'type'} = $1;
	$symbols{$4}{'loc'} = $2;
	$symbols{$4}{'hash'} = $3;
	$module_syms{$2} = 0;
	$count++;
}
close(NEW);
print "read $count symbols.\n";

# Now the old symbols, checking for missing ones
print "    Reading old symbols...";
$count = 0;
open(OLD, "< $abiold") or
	die "Could not open $abiold";
while (<OLD>) {
	chomp;
	m/^(\S+)\s(.+)\s(0x[0-9a-f]+)\s(.+)$/;
	$symbols{$4}{'old_type'} = $1;
	$symbols{$4}{'old_loc'} = $2;
	$symbols{$4}{'old_hash'} = $3;
	$count++;
}
close(OLD);

print "read $count symbols.\n";

print "II: Checking for missing symbols in new ABI...";
$count = 0;
foreach $sym (keys(%symbols)) {
	if (!defined($symbols{$sym}{'type'})) {
		print "\n" if not $count;
		printf("    MISS : %s%s\n", $sym,
			is_ignored($symbols{$sym}{'old_loc'}, $sym) ? " (ignored)" : "");
		$count++ if !is_ignored($symbols{$sym}{'old_loc'}, $sym);
	}
}
print "    " if $count;
print "found $count missing symbols\n";
if ($count) {
	print "$EE Symbols gone missing (what did you do!?!)\n";
	$errors++;
}


print "II: Checking for new symbols in new ABI...";
$count = 0;
foreach $sym (keys(%symbols)) {
	if (!defined($symbols{$sym}{'old_type'})) {
		print "\n" if not $count;
		print "    NEW : $sym\n";
		$count++;
	}
}
print "    " if $count;
print "found $count new symbols\n";
if ($count) {
	print "WW: Found new symbols. Not recommended unless ABI was bumped\n";
}

print "II: Checking for changes to ABI...\n";
$count = 0;
my $moved = 0;
my $changed_type = 0;
my $changed_hash = 0;
foreach $sym (keys(%symbols)) {
	if (!defined($symbols{$sym}{'old_type'}) or
	    !defined($symbols{$sym}{'type'})) {
		next;
	}

	# Changes in location don't hurt us, but log it anyway
	if ($symbols{$sym}{'loc'} ne $symbols{$sym}{'old_loc'}) {
		printf("    MOVE : %-40s : %s => %s\n", $sym, $symbols{$sym}{'old_loc'},
			$symbols{$sym}{'loc'});
		$moved++;
	}

	# Changes to export type are only bad if new type isn't
	# EXPORT_SYMBOL. Changing things to GPL are bad.
	if ($symbols{$sym}{'type'} ne $symbols{$sym}{'old_type'}) {
		printf("    TYPE : %-40s : %s => %s%s\n", $sym, $symbols{$sym}{'old_type'}.
			$symbols{$sym}{'type'}, is_ignored($symbols{$sym}{'loc'}, $sym)
			? " (ignored)" : "");
		$changed_type++ if $symbols{$sym}{'type'} ne "EXPORT_SYMBOL"
			and !is_ignored($symbols{$sym}{'loc'}, $sym);
	}

	# Changes to the hash are always bad
	if ($symbols{$sym}{'hash'} ne $symbols{$sym}{'old_hash'}) {
		printf("    HASH : %-40s : %s => %s%s\n", $sym, $symbols{$sym}{'old_hash'},
			$symbols{$sym}{'hash'}, is_ignored($symbols{$sym}{'loc'}, $sym)
			? " (ignored)" : "");
		$changed_hash++ if !is_ignored($symbols{$sym}{'loc'}, $sym);
		$module_syms{$symbols{$sym}{'loc'}}++;
	}
}

print "WW: $moved symbols changed location\n" if $moved;
print "$EE $changed_type symbols changed export type and weren't ignored\n" if $changed_type;
print "$EE $changed_hash symbols changed hash and weren't ignored\n" if $changed_hash;

$errors++ if $changed_hash or $changed_type;
if ($changed_hash) {
	print "II: Module hash change summary...\n";
	foreach $mod (sort { $module_syms{$b} <=> $module_syms{$a} } keys %module_syms) {
		next if ! $module_syms{$mod};
		printf("    %-40s: %d\n", $mod, $module_syms{$mod});
	}
}

print "II: Done\n";

if ($errors) {
	exit($fail_exit);
} else {
	exit(0);
}