: #-*- Perl -*-
# Copyright (C) 1998 Free Software Foundation, Inc.

# This file is part of XEmacs.
#
# XEmacs is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 2, or (at your option) any
# later version.
#
# XEmacs is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
# for more details.
#
# You should have received a copy of the GNU General Public License
# along with XEmacs; see the file COPYING.  If not, write to
# the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA 02111-1307, USA.

# Author: Martin Buchholz
eval 'exec perl -w -S $0 ${1+"$@"}'
  if 0;

use strict;
my ($myName, $srcdir, %exists, %uses, %generated_header);

($myName = $0) =~ s@.*/@@; my $usage ="
Usage: $myName

Generates Makefile dependencies for the XEmacs src directory.
The dependencies are written to stdout.\n";

die $usage if @ARGV;

($srcdir = $0) =~ s@[^/]+$@@;
$srcdir = "." if $srcdir eq "";
chdir $srcdir or die "$srcdir: $!";

opendir SRCDIR, "." or die "$srcdir: $!";
for (grep (/\.[ch]$/, readdir (SRCDIR))) { $exists{$_} = 1; }
closedir SRCDIR;

for (qw (config.h sheap-adjust.h paths.h Emacs.ad.h)) {
  $generated_header{$_} = 1;
}

# Although this is not technically true, it ought to be true,
# and makes the generated Makefile smaller.
$uses{'lisp.h'}{'config.h'} = 1;

for my $file (keys %exists) {
  open (FILE, $file) or die "$file: $!";
  undef $/; $_ = <FILE>;
  RemoveComments ($_);
  s/[ \t]+//g;
  # Find include dependencies
  for (/^\#include([^\n]+)/gm) {
    if (m@^\"([A-Za-z0-9._-]+\.[ch])\"@) {
      $uses{$file}{$1} = 1 if exists $exists{$1};
    } elsif (m@<([A-Za-z0-9._-]+\.h)>@) {
      $uses{$file}{$1} = 1 if exists $generated_header{$1};
    } elsif (m@\"../lwlib/([A-Za-z0-9._-]+\.h)\"@) {
      $uses{$file}{"\$(LWLIB_SRCDIR)/lwlib.h"} = 1;
    }
  }
}

# Make transitive closure of %uses
while (1) {
  my $changedP = 0;
  for my $x (keys %uses) {
    for my $y (keys %{$uses{$x}}) {
      for my $z (keys %{$uses{$y}}) {
	if (! exists $uses{$x}{$z}) {
	  $uses{$x}{$z} = 1;
	  $changedP = 1;
	}
      }
    }
  }
  last if !$changedP;
}

# Print file header
print
"## This file is automatically generated by \`$myName'.  Do not modify.

#if defined(USE_UNION_TYPE)
LISP_UNION_H=lisp-union.h
#else
LISP_UNION_H=lisp-disunion.h
#endif
";

my @LISP_H = ('lisp.h', sort keys %{$uses{'lisp.h'}});
print "LISP_H=@{[grep (!/lisp-(dis)?union\.h/, @LISP_H)]} \$(LISP_UNION_H)\n";

sub PrintDeps {
  my $file = shift;
  my $ofile = $file; $ofile =~ s/c$/o/; print "$ofile: ";
  if (exists $uses{$file}{'lisp.h'}) {
    delete @{%{$uses{$file}}}{@LISP_H};
    $uses{$file}{'$(LISP_H)'} = 1;
  }
  print "@{[sort keys %{$uses{$file}}]}\n";
}

sub PrintPatternDeps {
  my ($pattern, $CPP_SYMBOL) = @_;
  print "#if defined($CPP_SYMBOL)\n";
  for my $file (sort grep (/$pattern/ && /\.c$/, keys %uses)) {
    PrintDeps($file);
    delete $uses{$file};
  }
  print "#endif\n";
}

PrintPatternDeps ('-msw\\.',   "HAVE_MS_WINDOWS");
PrintPatternDeps ('-x\\.',     "HAVE_X_WINDOWS");
PrintPatternDeps ('-tty\\.',   "HAVE_TTY");
PrintPatternDeps ('-gtk\\.',   "HAVE_GTK");
PrintPatternDeps ('^database', "HAVE_DATABASE");
PrintPatternDeps ('^mule',     "MULE");
PrintPatternDeps ('^(?:External|extw-)', "EXTERNAL_WIDGET");

for my $file (sort grep (/\.c$/, keys %uses)) { PrintDeps($file); }

# Surprisingly robust regexp to remove comments from arbitrary C code
sub RemoveComments {
  $_[0] =~
    s{ (
	[^\"\'/]+ |
	(?:\"[^\"\\]*(?:\\.[^\"\\]*)*\" [^\"\'/]*)+ |
	(?:\'[^\'\\]*(?:\\.[^\'\\]*)*\' [^\"\'/]*)+
       )
       | / (?:
	    \*[^*]*\*+(?:[^/*][^*]*\*+)*/
	    |
	    /[^\n]*
	   )
     }{defined $1 ? $1 : ""}gsxeo;
}