use strict;

use vars qw($help $debug);

sortdir() {

if (-d $::a) {

if (-d $::b) {

return ($::a cmp $::b);

} else {

return (-1);

}

} elsif (-d $::b) {

return (1);

} else {

return ($::a cmp $::b);

}

}

do_dir($$) {

my($predir, $dir) = @_;

my $newdir = $predir ne "" ? "$predir/$dir" : $dir;

print "================> $newdir\n";

unless (chdir("$dir")) {

print "cd $newdir: $1\n";

return;

}

unless (opendir(DIR, ".")) {

print "opendir $predir/$dir: $!\n";

return;

}

foreach my $entry (sort sortdir readdir(DIR)) {

next if $entry =~ /^\.\.?$/;

if (-d $entry) {

do_dir($newdir, $entry);

next;

}

next if $entry !~ /\.o$/;

do_file($entry);

}

closedir(DIR);

chdir("..") or

die "major malfunction: can't chdir to parent dir: $!\n";

print "================> $predir\n";

}

do_file($) {

my $objfile = $_[0];

my ($file, $savesource, $saveobj);

my ($config_h, $cpp_if, $prefix, $elided, $comment, $prefix_extend, $body);

unless ($objfile =~ /\.o$/) {

print "$0: skipping non-object file $objfile\n";

return;

}

($file = $objfile) =~ s%\.o$%.c%;

($savesource = $file) =~ s%$%.save%;

($saveobj = $objfile) =~ s%$%.save%;

if (-f $savesource) {

print "$savesource exists, skipping\n";

return;

}

unless (-f $file) {

print "$file does not exist, skipping\n";

return;

}

rename($file, $savesource);

rename($objfile, $saveobj);

open(SOURCE, "< $savesource");

$_ = join('', <SOURCE>);

close(SOURCE);

$prefix = '';

print "$file begin\n" if $debug;

while (1) {

eval {

# Note that only '#include <...>' is checked, not '#include "..."'.

# 1 23 4 5 6 78

if (m%(\A\Q$prefix\E((.*\n)*?))(\#include\s+(<.*?>)(.*)\n)((.*\n)*)%) {

$elided = $5;

$prefix_extend = $2 . $4;

$comment = $6;

$body = $1 . $7;

} else {

print "$file end\n" if $debug;

$elided = ""; # stop processing this file.

}

};

if ($@ ne "") {

print "$file processing failed: $@\n";

last;

}

last if $elided eq "";

print STDERR "$file checking $elided\n" if $debug;

if (! $config_h) {

$config_h = 1;

if ($elided ne "<config.h>") {

print "$file should include <config.h> before any other\n";

}

}

# Always required.

next if $elided eq "<config.h>";

# Can mark in the header file when a #include should stay even

# though it might not appear that way otherwise.

next if $comment =~ /require|provide|extend|define|contract|explicit/i;

if ($elided eq "<isc/print.h>") {

next if m%snprintf%m;

}

open(SOURCE, "> $file");

print SOURCE "$body";

close(SOURCE);

print "$file elided $elided, compiling\n" if $debug;

if (compile($objfile) == 0) {

if (! defined($cpp_if)) {

$cpp_if = /^#if/m;

print "$file has CPP #if(def), doublecheck elision recommendations.\n"

if $cpp_if;

}

print "$file does not need $elided\n";

} elsif ($elided eq "<string.h>") {

print "$file prefer <isc/string.h> to <string.h>\n";

}

} continue {

$prefix .= $prefix_extend;

}

rename($savesource, $file);

rename($saveobj, $objfile);

}

compile($) {

my $obj = $_[0];

unless ($obj =~ /\.o$/) {

warn "$obj: not a .o object file\n";

return;

}

my $output = $debug ? "/dev/tty" : "/dev/null";

open(COMPILE, "make -e $obj 2>&1 >$output |");

my $stderr_lines = join('', <COMPILE>);

print $stderr_lines if $debug;

close(COMPILE);

unlink($obj);

return ($stderr_lines ne "");

}

main() {

$| = 1;

$0 =~ s%.*/%%;

die "Usage: $0 [-debug]\n" if $help;

unless (-f 'configure' && -f 'Makefile') {

die "$0: run from top of bind9 source tree, after configure has run\n";

}

print "========================\n";

print "building initial objects\n";

print "========================\n";

# XXX bleah

unless (system("make") == 0) {

die "make all failed, couldn't be sure all objects were generated.\n";

}

unless (system("cd bin/tests && make -k all_tests") == 0) {

warn "make all_tests failed, but pressing on anyway\n";

}

print <<EOF;

================================================================

starting header elision

WARNING: Since this script only removes one header at a time,

programs might compile fine without the header because another

header provides the required information. If that header is

also recommend for removal, then removing both of them could

lead to a program that does *not* compile fine. So the only

way to be sure is to take them all out and then recompile to

see if there are any residual warnings/errors.

Similar, this program is quite ignorant when it comes to CPP

appear to be necessary because the code that depends on it

is not being compiled. To prevent this program from complaining

about such includes in later runs, put a "Required for ..."

comment on the same line as the #include.

================================================================

# XXX gcc-specific

# Disable builtin memcmp/memcpy/strcmp/strcpy/etc. When they are

# available, gcc won't warn about the lack of a prototype in a header

# file.

$ENV{'CFLAGS'} = "-fno-builtin";

do_dir("", ".");

}

main();