#!/usr/bin/env perl
  # SPDX-License-Identifier: GPL-2.0
  #
  # checkincludes: find/remove files included more than once
  #
  # Copyright abandoned, 2000, Niels Kristian Bech Jensen <nkbj@image.dk>.
  # Copyright 2009 Luis R. Rodriguez <mcgrof@gmail.com>
  #
  # This script checks for duplicate includes. It also has support
  # to remove them in place. Note that this will not take into
  # consideration macros so you should run this only if you know
  # you do have real dups and do not have them under #ifdef's. You
  # could also just review the results.
  
  use strict;
  
  sub usage {
  	print "Usage: checkincludes.pl [-r]
  ";
  	print "By default we just warn of duplicates
  ";
  	print "To remove duplicated includes in place use -r
  ";
  	exit 1;
  }
  
  my $remove = 0;
  
  if ($#ARGV < 0) {
  	usage();
  }
  
  if ($#ARGV >= 1) {
  	if ($ARGV[0] =~ /^-/) {
  		if ($ARGV[0] eq "-r") {
  			$remove = 1;
  			shift;
  		} else {
  			usage();
  		}
  	}
  }
  
  my $dup_counter = 0;
  
  foreach my $file (@ARGV) {
  	open(my $f, '<', $file)
  	    or die "Cannot open $file: $!.
  ";
  
  	my %includedfiles = ();
  	my @file_lines = ();
  
  	while (<$f>) {
  		if (m/^\s*#\s*include\s*[<"](\S*)[>"]/o) {
  			++$includedfiles{$1};
  		}
  		push(@file_lines, $_);
  	}
  
  	close($f);
  
  	if (!$remove) {
  		foreach my $filename (keys %includedfiles) {
  			if ($includedfiles{$filename} > 1) {
  				print "$file: $filename is included more than once.
  ";
  				++$dup_counter;
  			}
  		}
  		next;
  	}
  
  	open($f, '>', $file)
  	    or die("Cannot write to $file: $!");
  
  	my $dups = 0;
  	foreach (@file_lines) {
  		if (m/^\s*#\s*include\s*[<"](\S*)[>"]/o) {
  			foreach my $filename (keys %includedfiles) {
  				if ($1 eq $filename) {
  					if ($includedfiles{$filename} > 1) {
  						$includedfiles{$filename}--;
  						$dups++;
  						++$dup_counter;
  					} else {
  						print {$f} $_;
  					}
  				}
  			}
  		} else {
  			print {$f} $_;
  		}
  	}
  	if ($dups > 0) {
  		print "$file: removed $dups duplicate includes
  ";
  	}
  	close($f);
  }
  
  if ($dup_counter == 0) {
  	print "No duplicate includes found.
  ";
  }