#!/usr/bin/env perl

 # ***** BEGIN LICENSE BLOCK *****

 # Version: MPL 1.1/GPL 2.0/LGPL 2.1

 #

 # The contents of this file are subject to the Mozilla Public License Version

 # 1.1 (the "License"); you may not use this file except in compliance with

 # the License. You may obtain a copy of the License at

 # http://www.mozilla.org/MPL/

 #

 # Software distributed under the License is distributed on an "AS IS" basis,

 # WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License

 # for the specific language governing rights and limitations under the

 # License.

 #

 # The Original Code is this file as it was released upon March 8, 1999.

 #

 # The Initial Developer of the Original Code is

 # Netscape Communications Corporation.

 # Portions created by the Initial Developer are Copyright (C) 1999

 # the Initial Developer. All Rights Reserved.

 #

 # Contributor(s):

 #

 # Alternatively, the contents of this file may be used under the terms of

 # either of the GNU General Public License Version 2 or later (the "GPL"),

 # or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),

 # in which case the provisions of the GPL or the LGPL are applicable instead

 # of those above. If you wish to allow use of your version of this file only

 # under the terms of either the GPL or the LGPL, and not to allow others to

 # use your version of this file under the terms of the MPL, indicate your

 # decision by deleting the provisions above and replace them with the notice

 # and other provisions required by the GPL or the LGPL. If you do not delete

 # the provisions above, a recipient may use your version of this file under

 # the terms of any one of the MPL, the GPL or the LGPL.

 #

 # ***** END LICENSE BLOCK *****

 # mddepend.pl - Reads in dependencies generated my -MD flag. Prints list

 #   of objects that need to be rebuilt. These can then be added to the

 #   PHONY target. Using this script copes with the problem of header

 #   files that have been removed from the build.

 #    

 # Usage:

 #   mddepend.pl <output_file> <dependency_files...>

 #

 # Send comments, improvements, bugs to Steve Lamm ([email protected]).

 use strict;

 use constant DEBUG => 0;

 my $outfile = shift @ARGV;

 my $silent = $ENV{MAKEFLAGS} =~ /^\w*s|\s-s/;

 my $line = '';

 my %alldeps;

 # Parse dependency files

 while (<>) {

   s/\r?\n$//; # Handle both unix and DOS line endings

   $line .= $_;

   if ($line =~ /\\$/) {

     chop $line;

     next;

   }

   $line =~ s|\\|/|g;

   my ($obj,$rest) = split /\s*:\s+/, $line, 2;

   $line = '';

   next if !$obj || !$rest;

   my @deps = split /\s+/, $rest;

   push @{$alldeps{$obj}}, @deps;

   if (DEBUG >= 2) {

     foreach my $dep (@deps) { print STDERR "add $obj $dep\n"; }

   }

 }

 # Test dependencies

 my %modtimes; # cache

 my @objs;     # force rebuild on these

 OBJ_LOOP: foreach my $obj (keys %alldeps) {

   my $mtime = (stat $obj)[9] or next;

   my %not_in_cache;

   my $deps = $alldeps{$obj};

   foreach my $dep_file (@{$deps}) {

     my $dep_mtime = $modtimes{$dep_file};

     if (not defined $dep_mtime) {

       print STDERR "Skipping $dep_file for $obj, will stat() later\n" if DEBUG >= 2;

       $not_in_cache{$dep_file} = 1;

       next;

     }

     print STDERR "Found $dep_file in cache\n" if DEBUG >= 2;

     if ($dep_mtime > $mtime) {

       print STDERR "$dep_file($dep_mtime) newer than $obj($mtime)\n" if DEBUG;

     }

     elsif ($dep_mtime == -1) {

       print STDERR "Couldn't stat $dep_file for $obj\n" if DEBUG;

     }

     else {

       print STDERR "$dep_file($dep_mtime) older than $obj($mtime)\n" if DEBUG >= 2;

       next;

     }

     push @objs, $obj; # dependency is missing or newer

     next OBJ_LOOP; # skip checking the rest of the dependencies

   }

   foreach my $dep_file (keys %not_in_cache) {

     print STDERR "STAT $dep_file for $obj\n" if DEBUG >= 2;

     my $dep_mtime = $modtimes{$dep_file} = (stat $dep_file)[9] || -1;

     if ($dep_mtime > $mtime) {

       print STDERR "$dep_file($dep_mtime) newer than $obj($mtime)\n" if DEBUG;

     }

     elsif ($dep_mtime == -1) {

       print STDERR "Couldn't stat $dep_file for $obj\n" if DEBUG;

     }

     else {

       print STDERR "$dep_file($dep_mtime) older than $obj($mtime)\n" if DEBUG >= 2;

       next;

     }

     push @objs, $obj; # dependency is missing or newer

     next OBJ_LOOP; # skip checking the rest of the dependencies

   }

   # If we get here it means nothing needs to be done for $obj

 }

 # Output objects to rebuild (if needed).

 if ($outfile eq '-') {

     if (@objs) {

 	print "@objs: FORCE\n";

     }

 } elsif (@objs) {

   my $old_output;

   my $new_output = "@objs: FORCE\n";

   # Read in the current dependencies file.

   open(OLD, "<$outfile")

     and $old_output = <OLD>;

   close(OLD);

   # Only write out the dependencies if they are different.

   if ($new_output ne $old_output) {

     open(OUT, ">$outfile") and print OUT "$new_output";

     print "Updating dependencies file, $outfile\n" unless $silent;

     if (DEBUG) {

       print "new: $new_output\n";

       print "was: $old_output\n" if $old_output ne '';

     }

   }

 } elsif (-s $outfile) {

   # Remove the old dependencies because all objects are up to date.

   print "Removing old dependencies file, $outfile\n" unless $silent;

   if (DEBUG) {

     my $old_output;

     open(OLD, "<$outfile")

       and $old_output = <OLD>;

     close(OLD);

     print "was: $old_output\n";

   }

   unlink $outfile;

 }