#! /usr/bin/env perl
 
 # This script will print the dependency of a Texinfo file to stdout.
 # texidep.pl <src-path> <input.texi> <output.ext>
 
 use warnings;
 use strict;
 
 die unless @ARGV == 3;
 
 my ($src_path, $root, $target) = @ARGV;
 
 sub print_deps {
     my ($file, $deps) = @_;
     $deps->{$file} = 1;
 
     open(my $fh, "<", "$file") or die "Cannot open file '$file': $!";
     while (<$fh>) {
         if (my ($i) = /^\@(?:verbatim)?include\s+(\S+)/) {
             die "Circular dependency found in file $root\n" if exists $deps->{"doc/$1"};
             print "$target: doc/$1\n";
 
             # skip looking for config.texi dependencies, since it has
             # none, and is not located in the source tree
             if ("$1" ne "config.texi") {
                 print_deps("$src_path/doc/$1", {%$deps});
             }
         }
     }
 }
 
 print_deps($root, {});