mergedep.pl

   1 #!/usr/bin/perl
   2 # Copyright 2003 Bryan Ford
   3 # Distributed under the GNU General Public License.
   4 #
   5 # Usage: mergedep <main-depfile> [<new-depfiles> ...]
   6 #
   7 # This script merges the contents of all <new-depfiles> specified
   8 # on the command line into the single file <main-depfile>,
   9 # which may or may not previously exist.
  10 # Dependencies in the <new-depfiles> will override
  11 # any existing dependencies for the same targets in <main-depfile>.
  12 # The <new-depfiles> are deleted after <main-depfile> is updated.
  13 #
  14 # The <new-depfiles> are typically generated by GCC with the -MD option,
  15 # and the <main-depfile> is typically included from a Makefile,
  16 # as shown here for GNU 'make':
  17 #
  18 #       .deps: $(wildcard *.d)
  19 #               perl mergedep $@ $^
  20 #       -include .deps
  21 #
  22 # This script properly handles multiple dependencies per <new-depfile>,
  23 # including dependencies having no target,
  24 # so it is compatible with GCC3's -MP option.
  25 #
  26
  27 sub readdeps {
  28         my $filename = shift;
  29
  30         open(DEPFILE, $filename) or return 0;
  31         while (<DEPFILE>) {
  32                 if (/([^:]*):([^\\:]*)([\\]?)$/) {
  33                         my $target = $1;
  34                         my $deplines = $2;
  35                         my $slash = $3;
  36                         while ($slash ne '') {
  37                                 $_ = <DEPFILE>;
  38                                 defined($_) or die
  39                                         "Unterminated dependency in $filename";
  40                                 /(^[ \t][^\\]*)([\\]?)$/ or die
  41                                         "Bad continuation line in $filename";
  42                                 $deplines = "$deplines\\\n$1";
  43                                 $slash = $2;
  44                         }
  45                         #print "DEPENDENCY [[$target]]: [[$deplines]]\n";
  46                         $dephash{$target} = $deplines;
  47                 } elsif (/^[#]?[ \t]*$/) {
  48                         # ignore blank lines and comments
  49                 } else {
  50                         die "Bad dependency line in $filename: $_";
  51                 }
  52         }
  53         close DEPFILE;
  54         return 1;
  55 }
  56
  57
  58 if ($#ARGV < 0) {
  59         print "Usage: mergedep <main-depfile> [<new-depfiles> ..]\n";
  60         exit(1);
  61 }
  62
  63 %dephash = ();
  64
  65 # Read the main dependency file
  66 $maindeps = $ARGV[0];
  67 readdeps($maindeps);
  68
  69 # Read and merge in the new dependency files
  70 foreach $i (1 .. $#ARGV) {
  71         readdeps($ARGV[$i]) or die "Can't open $ARGV[$i]";
  72 }
  73
  74 # Update the main dependency file
  75 open(DEPFILE, ">$maindeps.tmp") or die "Can't open output file $maindeps.tmp";
  76 foreach $target (keys %dephash) {
  77         print DEPFILE "$target:$dephash{$target}";
  78 }
  79 close DEPFILE;
  80 rename("$maindeps.tmp", "$maindeps") or die "Can't overwrite $maindeps";
  81
  82 # Finally, delete the new dependency files
  83 foreach $i (1 .. $#ARGV) {
  84         unlink($ARGV[$i]) or print "Error removing $ARGV[$i]\n";
  85 }
  86