#!/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;

}