gecko/build/unix/mddepend.pl

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#!/usr/bin/env perl
2012-05-21 04:12:37 -07:00
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
# 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 (slamm@netscape.com).
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;
}