build/unix/mddepend.pl

   1 #!/usr/bin/env perl
   2
   3 # ***** BEGIN LICENSE BLOCK *****
   4 # Version: MPL 1.1/GPL 2.0/LGPL 2.1
   5 #
   6 # The contents of this file are subject to the Mozilla Public License Version
   7 # 1.1 (the "License"); you may not use this file except in compliance with
   8 # the License. You may obtain a copy of the License at
   9 # http://www.mozilla.org/MPL/
  10 #
  11 # Software distributed under the License is distributed on an "AS IS" basis,
  12 # WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  13 # for the specific language governing rights and limitations under the
  14 # License.
  15 #
  16 # The Original Code is this file as it was released upon March 8, 1999.
  17 #
  18 # The Initial Developer of the Original Code is
  19 # Netscape Communications Corporation.
  20 # Portions created by the Initial Developer are Copyright (C) 1999
  21 # the Initial Developer. All Rights Reserved.
  22 #
  23 # Contributor(s):
  24 #
  25 # Alternatively, the contents of this file may be used under the terms of
  26 # either of the GNU General Public License Version 2 or later (the "GPL"),
  27 # or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  28 # in which case the provisions of the GPL or the LGPL are applicable instead
  29 # of those above. If you wish to allow use of your version of this file only
  30 # under the terms of either the GPL or the LGPL, and not to allow others to
  31 # use your version of this file under the terms of the MPL, indicate your
  32 # decision by deleting the provisions above and replace them with the notice
  33 # and other provisions required by the GPL or the LGPL. If you do not delete
  34 # the provisions above, a recipient may use your version of this file under
  35 # the terms of any one of the MPL, the GPL or the LGPL.
  36 #
  37 # ***** END LICENSE BLOCK *****
  38
  39 # mddepend.pl - Reads in dependencies generated my -MD flag. Prints list
  40 #   of objects that need to be rebuilt. These can then be added to the
  41 #   PHONY target. Using this script copes with the problem of header
  42 #   files that have been removed from the build.
  43 #
  44 # Usage:
  45 #   mddepend.pl <output_file> <dependency_files...>
  46 #
  47 # Send comments, improvements, bugs to Steve Lamm (slamm@netscape.com).
  48
  49 use strict;
  50
  51 use constant DEBUG => 0;
  52
  53 my $outfile = shift @ARGV;
  54 my $silent = $ENV{MAKEFLAGS} =~ /^\w*s|\s-s/;
  55
  56 my $line = '';
  57 my %alldeps;
  58 # Parse dependency files
  59 while (<>) {
  60   s/\r?\n$//; # Handle both unix and DOS line endings
  61   $line .= $_;
  62   if ($line =~ /\\$/) {
  63     chop $line;
  64     next;
  65   }
  66
  67   my ($obj,$rest) = split /\s*:\s+/, $line, 2;
  68   $line = '';
  69   next if !$obj || !$rest;
  70
  71   my @deps = split /\s+/, $rest;
  72   push @{$alldeps{$obj}}, @deps;
  73   if (DEBUG >= 2) {
  74     foreach my $dep (@deps) { print "add $obj $dep\n"; }
  75   }
  76 }
  77
  78 # Test dependencies
  79 my %modtimes; # cache
  80 my @objs;     # force rebuild on these
  81 OBJ_LOOP: foreach my $obj (keys %alldeps) {
  82   my $mtime = (stat $obj)[9] or next;
  83
  84   my %not_in_cache;
  85   my $deps = $alldeps{$obj};
  86   foreach my $dep_file (@{$deps}) {
  87     my $dep_mtime = $modtimes{$dep_file};
  88     if (not defined $dep_mtime) {
  89       print "Skipping $dep_file for $obj, will stat() later\n" if DEBUG >= 2;
  90       $not_in_cache{$dep_file} = 1;
  91       next;
  92     }
  93
  94     print "Found $dep_file in cache\n" if DEBUG >= 2;
  95
  96     if ($dep_mtime > $mtime) {
  97       print "$dep_file($dep_mtime) newer than $obj($mtime)\n" if DEBUG;
  98     }
  99     elsif ($dep_mtime == -1) {
 100       print "Couldn't stat $dep_file for $obj\n" if DEBUG;
 101     }
 102     else {
 103       print "$dep_file($dep_mtime) older than $obj($mtime)\n" if DEBUG >= 2;
 104       next;
 105     }
 106
 107     push @objs, $obj; # dependency is missing or newer
 108     next OBJ_LOOP; # skip checking the rest of the dependencies
 109   }
 110
 111   foreach my $dep_file (keys %not_in_cache) {
 112     print "STAT $dep_file for $obj\n" if DEBUG >= 2;
 113     my $dep_mtime = $modtimes{$dep_file} = (stat $dep_file)[9] || -1;
 114
 115     if ($dep_mtime > $mtime) {
 116       print "$dep_file($dep_mtime) newer than $obj($mtime)\n" if DEBUG;
 117     }
 118     elsif ($dep_mtime == -1) {
 119       print "Couldn't stat $dep_file for $obj\n" if DEBUG;
 120     }
 121     else {
 122       print "$dep_file($dep_mtime) older than $obj($mtime)\n" if DEBUG >= 2;
 123       next;
 124     }
 125
 126     push @objs, $obj; # dependency is missing or newer
 127     next OBJ_LOOP; # skip checking the rest of the dependencies
 128   }
 129
 130   # If we get here it means nothing needs to be done for $obj
 131 }
 132
 133 # Output objects to rebuild (if needed).
 134 if (@objs) {
 135   my $old_output;
 136   my $new_output = "@objs: FORCE\n";
 137
 138   # Read in the current dependencies file.
 139   open(OLD, "<$outfile")
 140     and $old_output = <OLD>;
 141   close(OLD);
 142
 143   # Only write out the dependencies if they are different.
 144   if ($new_output ne $old_output) {
 145     open(OUT, ">$outfile") and print OUT "$new_output";
 146     print "Updating dependencies file, $outfile\n" unless $silent;
 147     if (DEBUG) {
 148       print "new: $new_output\n";
 149       print "was: $old_output\n" if $old_output ne '';
 150     }
 151   }
 152 } elsif (-s $outfile) {
 153   # Remove the old dependencies because all objects are up to date.
 154   print "Removing old dependencies file, $outfile\n" unless $silent;
 155
 156   if (DEBUG) {
 157     my $old_output;
 158     open(OLD, "<$outfile")
 159       and $old_output = <OLD>;
 160     close(OLD);
 161     print "was: $old_output\n";
 162   }
 163
 164   unlink $outfile;
 165 }