#!/usr/bin/perl -w
#
# Find all the UAPI files in the nominated directory
#

die "Need directory argument\n"
    if ($#ARGV == -1);

my $dir = $ARGV[0];
my $kbuild = $dir . "/Kbuild";

die "$kbuild not present"
    unless (-r "$dir/Kbuild");

#
# We assume that only Kbuild files in include directories are pertinent to
# determining which headers are UAPI headers.
#
my %headers = ();

opendir my $dh, $dir or die;
foreach $_ (readdir($dh)) {
    $headers{$_} = 1
	if ($_ =~ /[.]h$/ || $_ =~ /[.]agh$/ || $_ =~ /[.]inc$/);
}
closedir($dh) or die;

# Read the common arch list
open FD, '<include/uapi/asm-generic/Kbuild.asm' or die "open Kbuild.asm: $!\n";
my @kbuild_asm = <FD>;
close FD or die;

my %uapihdrs = ();

open FD, '<', $kbuild or die "open $kbuild: $!\n";
my @lines = <FD>;
close FD or die;

for (my $l = 0; $l <= $#lines; $l++) {
    my $line = $lines[$l];

    # parse out the blocks
    # - this may be split over multiple lines using backslashes
    my $block = $line;
  restart:
    $block =~ s@#.*$@@;
    $block =~ s@\s+$@@g;
    $block =~ s@\s+@ @g;

    if ($block =~ /^(.*)[\\]$/) {
	$l++;
	$block = $1 . $lines[$l];
	goto restart;
    }

    $block =~ s@\s+$@@g;
    $block =~ s@\s\s+@ @g;

    if ($block =~ m@^include include/asm-generic/Kbuild.asm@) {
	push @lines, @kbuild_asm;
    }

    if ($block =~ m@^header-y\s*[+:]?=\s*(.*)@ ||
	$block =~ m@^opt-header\s*[+:]?=\s*(.*)@ ||
	$block =~ m@^asm-headers\s*[+:]?=\s*(.*)@
	) {
	my $files = $1;
	next if ($block =~ m@[$][(]foreach@);
	foreach $h (grep m@[^/]$@, split /\s+/, $files) {
	    if (exists $headers{"$h"}) {
		$uapihdrs{"$h"} = 1;
	    }
	}
    }
}

print map { $_ . "\n"; } sort keys %uapihdrs;