Configure

#! /usr/bin/env perl
# -*- mode: perl; -*-

##  Configure -- OpenSSL source tree configuration script

require 5.10.0;
use strict;
use File::Basename;
use File::Spec::Functions qw/:DEFAULT abs2rel rel2abs/;
use File::Path qw/mkpath/;

# see INSTALL for instructions.

my $usage="Usage: Configure [no-<cipher> ...] [enable-<cipher> ...] [-Dxxx] [-lxxx] [-Lxxx] [-fxxx] [-Kxxx] [no-hw-xxx|no-hw] [[no-]threads] [[no-]shared] [[no-]zlib|zlib-dynamic] [no-asm] [no-dso] [no-egd] [sctp] [386] [--prefix=DIR] [--openssldir=OPENSSLDIR] [--with-xxx[=vvv]] [--config=FILE] os/compiler[:flags]\n";

# Options:
#
# --config      add the given configuration file, which will be read after
#               any "Configurations*" files that are found in the same
#               directory as this script.
# --prefix      prefix for the OpenSSL installation, which includes the
#               directories bin, lib, include, share/man, share/doc/openssl
#               This becomes the value of INSTALLTOP in Makefile
#               (Default: /usr/local)
# --openssldir  OpenSSL data area, such as openssl.cnf, certificates and keys.
#               If it's a relative directory, it will be added on the directory
#               given with --prefix.
#               This becomes the value of OPENSSLDIR in Makefile and in C.
#               (Default: PREFIX/ssl)
#
# --cross-compile-prefix Add specified prefix to binutils components.
#
# --api         One of 0.9.8, 1.0.0 or 1.1.0.  Do not compile support for
#               interfaces deprecated as of the specified OpenSSL version.
#
# no-hw-xxx     do not compile support for specific crypto hardware.
#               Generic OpenSSL-style methods relating to this support
#               are always compiled but return NULL if the hardware
#               support isn't compiled.
# no-hw         do not compile support for any crypto hardware.
# [no-]threads  [don't] try to create a library that is suitable for
#               multithreaded applications (default is "threads" if we
#               know how to do it)
# [no-]shared	[don't] try to create shared libraries when supported.
# [no-]pic      [don't] try to build position independent code when supported.
#               If disabled, it also disables shared and dynamic-engine.
# no-asm        do not use assembler
# no-dso        do not compile in any native shared-library methods. This
#               will ensure that all methods just return NULL.
# no-egd        do not compile support for the entropy-gathering daemon APIs
# [no-]zlib     [don't] compile support for zlib compression.
# zlib-dynamic	Like "zlib", but the zlib library is expected to be a shared
#		library and will be loaded in run-time by the OpenSSL library.
# sctp          include SCTP support
# 386           generate 80386 code
# enable-weak-ssl-ciphers
#               Enable weak ciphers that are disabled by default. This currently
#               only includes RC4 based ciphers.
# no-sse2	disables IA-32 SSE2 code, above option implies no-sse2
# no-<cipher>   build without specified algorithm (rsa, idea, rc5, ...)
# -<xxx> +<xxx> compiler options are passed through
#
# DEBUG_SAFESTACK use type-safe stacks to enforce type-safety on stack items
#		provided to stack calls. Generates unique stack functions for
#		each possible stack type.
# BN_LLONG	use the type 'long long' in crypto/bn/bn.h
# RC4_CHAR	use 'char' instead of 'int' for RC4_INT in crypto/rc4/rc4.h
# Following are set automatically by this script
#
# MD5_ASM	use some extra md5 assember,
# SHA1_ASM	use some extra sha1 assember, must define L_ENDIAN for x86
# RMD160_ASM	use some extra ripemd160 assember,
# SHA256_ASM	sha256_block is implemented in assembler
# SHA512_ASM	sha512_block is implemented in assembler
# AES_ASM	ASE_[en|de]crypt is implemented in assembler

# Minimum warning options... any contributions to OpenSSL should at least get
# past these.

my $gcc_devteam_warn = "-DPEDANTIC -DREF_DEBUG -DDEBUG_UNUSED -DBIO_DEBUG"
        . " -pedantic"
        . " -Wall"
        . " -Wno-long-long"
        . " -Wsign-compare"
        . " -Wmissing-prototypes"
        . " -Wshadow"
        . " -Wformat"
        . " -Wtype-limits"
        . " -Werror"
        ;

# These are used in addition to $gcc_devteam_warn when the compiler is clang.
# TODO(openssl-team): fix problems and investigate if (at least) the
# following warnings can also be enabled:
#       -Wswitch-enum
#       -Wcast-align
#       -Wunreachable-code
#       -Wlanguage-extension-token -- no, we use asm()
#       -Wunused-macros -- no, too tricky for BN and _XOPEN_SOURCE etc
#       -Wextended-offsetof -- no, needed in CMS ASN1 code
my $clang_devteam_warn = ""
        . " -Qunused-arguments"
        . " -Wextra"
        . " -Wno-unused-parameter"
        . " -Wno-missing-field-initializers"
        . " -Wno-language-extension-token"
        . " -Wno-extended-offsetof"
        . " -Wconditional-uninitialized"
        . " -Wincompatible-pointer-types-discards-qualifiers"
        . " -Wmissing-variable-declarations"
        ;

# This adds backtrace information to the memory leak info.  Is only used
# when crypto-mdebug-backtrace is enabled.
my $memleak_devteam_backtrace = "-rdynamic";

my $strict_warnings = 0;

# As for $BSDthreads. Idea is to maintain "collective" set of flags,
# which would cover all BSD flavors. -pthread applies to them all,
# but is treated differently. OpenBSD expands is as -D_POSIX_THREAD
# -lc_r, which is sufficient. FreeBSD 4.x expands it as -lc_r,
# which has to be accompanied by explicit -D_THREAD_SAFE and
# sometimes -D_REENTRANT. FreeBSD 5.x expands it as -lc_r, which
# seems to be sufficient?
our $BSDthreads="-pthread -D_THREAD_SAFE -D_REENTRANT";

#
# API compability name to version number mapping.
#
my $maxapi = "1.1.0";           # API for "no-deprecated" builds
my $apitable = {
    "1.1.0" => "0x10100000L",
    "1.0.0" => "0x10000000L",
    "0.9.8" => "0x00908000L",
};

our %table = ();
our %config = ();
our %withargs = ();

# Forward declarations ###############################################

# read_config(filename)
#
# Reads a configuration file and populates %table with the contents
# (which the configuration file places in %targets).
sub read_config;

# resolve_config(target)
#
# Resolves all the late evalutations, inheritances and so on for the
# chosen target and any target it inherits from.
sub resolve_config;


# Information collection #############################################

# Unified build supports separate build dir
my $srcdir = catdir(absolutedir(dirname($0))); # catdir ensures local syntax
my $blddir = catdir(absolutedir("."));         # catdir ensures local syntax
my $dofile = abs2rel(catfile($srcdir, "util/dofile.pl"));

$config{sourcedir} = abs2rel($srcdir);
$config{builddir} = abs2rel($blddir);

# Collect version numbers
$config{version} = "unknown";
$config{version_num} = "unknown";
$config{shlib_version_number} = "unknown";
$config{shlib_version_history} = "unknown";

collect_information(
    collect_from_file(catfile($srcdir,'include/openssl/opensslv.h')),
    qr/OPENSSL.VERSION.TEXT.*OpenSSL (\S+) / => sub { $config{version} = $1; },
    qr/OPENSSL.VERSION.NUMBER.*(0x\S+)/	     => sub { $config{version_num}=$1 },
    qr/SHLIB_VERSION_NUMBER *"([^"]+)"/	     => sub { $config{shlib_version_number}=$1 },
    qr/SHLIB_VERSION_HISTORY *"([^"]*)"/     => sub { $config{shlib_version_history}=$1 }
    );
if ($config{shlib_version_history} ne "") { $config{shlib_version_history} .= ":"; }

($config{major}, $config{minor})
    = ($config{version} =~ /^([0-9]+)\.([0-9\.]+)/);
($config{shlib_major}, $config{shlib_minor})
    = ($config{shlib_version_number} =~ /^([0-9]+)\.([0-9\.]+)/);
die "erroneous version information in opensslv.h: ",
    "$config{major}, $config{minor}, $config{shlib_major}, $config{shlib_minor}\n"
    if ($config{major} eq "" || $config{minor} eq ""
	|| $config{shlib_major} eq "" ||  $config{shlib_minor} eq "");

# Collect target configurations

my $pattern = catfile(dirname($0), "Configurations", "*.conf");
foreach (sort glob($pattern) ) {
    &read_config($_);
}


print "Configuring OpenSSL version $config{version} (0x$config{version_num})\n";

$config{prefix}="";
$config{openssldir}="";
$config{processor}="";
$config{libdir}="";
$config{cross_compile_prefix}="";
$config{fipslibdir}="/usr/local/ssl/fips-2.0/lib/";
my $nofipscanistercheck=0;
$config{baseaddr}="0xFB00000";
my $auto_threads=1;    # enable threads automatically? true by default
my $default_ranlib;
$config{fips}=0;

# Top level directories to build
$config{dirs} = [ "crypto", "ssl", "engines", "apps", "test", "tools" ];
# crypto/ subdirectories to build
$config{sdirs} = [
    "objects",
    "md2", "md4", "md5", "sha", "mdc2", "hmac", "ripemd", "whrlpool", "poly1305", "blake2",
    "des", "aes", "rc2", "rc4", "rc5", "idea", "bf", "cast", "camellia", "seed", "chacha", "modes",
    "bn", "ec", "rsa", "dsa", "dh", "dso", "engine",
    "buffer", "bio", "stack", "lhash", "rand", "err",
    "evp", "asn1", "pem", "x509", "x509v3", "conf", "txt_db", "pkcs7", "pkcs12", "comp", "ocsp", "ui",
    "cms", "ts", "srp", "cmac", "ct", "async", "kdf"
    ];

# Known TLS and DTLS protocols
my @tls = qw(ssl3 tls1 tls1_1 tls1_2);
my @dtls = qw(dtls1 dtls1_2);

# Explicitelly known options that are possible to disable.  They can
# be regexps, and will be used like this: /^no-${option}$/
# For developers: keep it sorted alphabetically

my @disablables = (
    "aes",
    "afalgeng",
    "asm",
    "async",
    "autoalginit",
    "autoerrinit",
    "bf",
    "blake2",
    "camellia",
    "capieng",
    "cast",
    "chacha",
    "cmac",
    "cms",
    "comp",
    "crypto-mdebug",
    "crypto-mdebug-backtrace",
    "ct",
    "deprecated",
    "des",
    "dgram",
    "dh",
    "dsa",
    "dso",
    "dtls",
    "dynamic-engine",
    "ec",
    "ec2m",
    "ecdh",
    "ecdsa",
    "ec_nistp_64_gcc_128",
    "egd",
    "engine",
    "err",
    "filenames",
    "heartbeats",
    "hmac",
    "hw(-.+)?",
    "idea",
    "makedepend",
    "md2",
    "md4",
    "md5",
    "mdc2",
    "md[-_]ghost94",
    "multiblock",
    "nextprotoneg",
    "ocb",
    "ocsp",
    "pic",
    "poly1305",
    "posix-io",
    "psk",
    "rc2",
    "rc4",
    "rc5",
    "rdrand",
    "rfc3779",
    "rijndael",			# Old AES name
    "ripemd",
    "rmd160",
    "rsa",
    "scrypt",
    "sct",
    "sctp",
    "seed",
    "sha",
    "shared",
    "sock",
    "srp",
    "srtp",
    "sse2",
    "ssl",
    "ssl-trace",
    "static-engine",
    "stdio",
    "threads",
    "tls",
    "ts",
    "ui",
    "unit-test",
    "whirlpool",
    "weak-ssl-ciphers",
    "zlib",
    "zlib-dynamic",
    );
foreach my $proto ((@tls, @dtls))
	{
	push(@disablables, $proto);
	push(@disablables, "$proto-method");
	}

my @deprecated_disablables = (
    "ssl2",
    );

# All of the following is disabled by default (RC5 was enabled before 0.9.8):

our %disabled = ( # "what"         => "comment"
		  "ec_nistp_64_gcc_128" => "default",
		  "egd"                 => "default",
		  "md2"                 => "default",
		  "rc5"                 => "default",
		  "sctp"                => "default",
		  "shared"              => "default",
		  "ssl-trace"           => "default",
		  "ssl3"                => "default",
		  "ssl3-method"         => "default",
		  "unit-test"           => "default",
		  "weak-ssl-ciphers"    => "default",
		  "zlib"                => "default",
		  "zlib-dynamic"        => "default",
		  "crypto-mdebug"       => "default",
		  "heartbeats"          => "default",
		);

# Note: => pair form used for aesthetics, not to truly make a hash table
my @disable_cascades = (
    # "what"		=> [ "cascade", ... ]
    sub { $config{processor} eq "386" }
			=> [ "sse2" ],
    "ssl"		=> [ "ssl3" ],
    "ssl3-method"	=> [ "ssl3" ],
    "zlib"		=> [ "zlib-dynamic" ],
    "rijndael"		=> [ "aes" ],
    "des"		=> [ "mdc2" ],
    "ec"		=> [ "ecdsa", "ecdh" ],

    "dgram"		=> [ "dtls" ],
    "dtls"		=> [ @dtls ],

    # SSL 3.0, (D)TLS 1.0 and TLS 1.1 require MD5 and SHA
    "md5"		=> [ "ssl", "tls1", "tls1_1", "dtls1" ],
    "sha"		=> [ "ssl", "tls1", "tls1_1", "dtls1" ],

    # Additionally, SSL 3.0 requires either RSA or DSA+DH
    sub { $disabled{rsa}
	  && ($disabled{dsa} || $disabled{dh}); }
			=> [ "ssl" ],

    # (D)TLS 1.0 and TLS 1.1 also require either RSA or DSA+DH
    # or ECDSA + ECDH.  (D)TLS 1.2 has this requirement as well.
    # (XXX: We don't support PSK-only builds).
    sub { $disabled{rsa}
	  && ($disabled{dsa} || $disabled{dh})
	  && ($disabled{ecdsa} || $disabled{ecdh}); }
			=> [ "tls1", "tls1_1", "tls1_2",
			     "dtls1", "dtls1_2" ],

    "tls"		=> [ @tls ],

    # SRP and HEARTBEATS require TLSEXT
    "tlsext"		=> [ "srp", "heartbeats" ],

    "crypto-mdebug"     => [ "crypto-mdebug-backtrace" ],

    # Without DSO, we can't load dynamic engines, so don't build them dynamic
    "dso"               => [ "dynamic-engine" ],

    # Without position independent code, there can be no shared libraries or DSOs
    "pic"               => [ "shared" ],
    "shared"            => [ "dynamic-engine" ],
    "engine"            => [ "afalgeng" ],
    );

# Avoid protocol support holes.  Also disable all versions below N, if version
# N is disabled while N+1 is enabled.
#
my @list = (reverse @tls);
while ((my $first, my $second) = (shift @list, shift @list)) {
    last unless @list;
    push @disable_cascades, ( sub { !$disabled{$first} && $disabled{$second} }
			      => [ @list ] );
    unshift @list, $second;
}
my @list = (reverse @dtls);
while ((my $first, my $second) = (shift @list, shift @list)) {
    last unless @list;
    push @disable_cascades, ( sub { !$disabled{$first} && $disabled{$second} }
			      => [ @list ] );
    unshift @list, $second;
}

# Explicit "no-..." options will be collected in %disabled along with the defaults.
# To remove something from %disabled, use "enable-foo".
# For symmetry, "disable-foo" is a synonym for "no-foo".

my @generated_headers = (
    "include/openssl/opensslconf.h",
    "crypto/include/internal/bn_conf.h",
    "crypto/include/internal/dso_conf.h"
    );

my @generated_by_make_headers = (
    "crypto/buildinf.h"
    );


my $no_sse2=0;

&usage if ($#ARGV < 0);

my $user_cflags="";
my @user_defines=();
$config{openssl_api_defines}=[];
$config{openssl_algorithm_defines}=[];
$config{openssl_thread_defines}=[];
$config{openssl_sys_defines}=[];
$config{openssl_other_defines}=[];
my $libs="";
my $target="";
$config{options}="";
$config{build_type} = "release";

my $classic = 0;

my @argvcopy=@ARGV;

if (grep /^reconf(igure)?$/, @argvcopy) {
    if (-f "./configdata.pm") {
	my $file = "./configdata.pm";
	unless (my $return = do $file) {
	    die "couldn't parse $file: $@" if $@;
            die "couldn't do $file: $!"    unless defined $return;
            die "couldn't run $file"       unless $return;
	}

	@argvcopy = defined($configdata::config{perlargv}) ?
	    @{$configdata::config{perlargv}} : ();
	die "Incorrect data to reconfigure, please do a normal configuration\n"
	    if (grep(/^reconf/,@argvcopy));
	$ENV{CROSS_COMPILE} = $configdata::config{cross_compile_prefix}
	    if defined($configdata::config{cross_compile_prefix});
	$ENV{CROSS_COMPILE} = $configdata::config{cc}
	    if defined($configdata::config{cc});

	print "Reconfiguring with: ", join(" ",@argvcopy), "\n";
	print "    CROSS_COMPILE = ",$ENV{CROSS_COMPILE},"\n"
	    if $ENV{CROSS_COMPILE};
	print "    CC = ",$ENV{CC},"\n" if $ENV{CC};
    } elsif (open IN, "<Makefile") {
        #
        # THIS SECTION IS TEMPORARY, it helps transitioning from Makefile
        # centered information gathering the reading configdata.pm
        #
        while (<IN>) {
            s|\R$||;
            if (/^CONFIGURE_ARGS=\s*(.*)\s*/) {
                # Older form, we split the string and hope for the best
                @argvcopy = split /\s+/, $_;
                die "Incorrect data to reconfigure, please do a normal configuration\n"
                    if (grep(/^reconf/,@argvcopy));
            } elsif (/^CROSS_COMPILE=\s*(.*)/) {
                $ENV{CROSS_COMPILE}=$1;
            } elsif (/^CC=\s*(?:\$\(CROSS_COMPILE\))?(.*?)$/) {
                $ENV{CC}=$1;
            }
        }
        #
        # END OF TEMPORARY SECTION
        #
    } else {
	die "Insufficient data to reconfigure, please do a normal configuration\n";
    }
}

$config{perlargv} = [ @argvcopy ];

my %unsupported_options = ();
my %deprecated_options = ();
foreach (@argvcopy)
	{
	# VMS is a case insensitive environment, and depending on settings
	# out of our control, we may receive options uppercased.  Let's
	# downcase at least the part before any equal sign.
	if ($^O eq "VMS")
		{
		s/^([^=]*)/lc($1)/e;
		}
	s /^-no-/no-/; # some people just can't read the instructions

	# rewrite some options in "enable-..." form
	s /^-?-?shared$/enable-shared/;
	s /^sctp$/enable-sctp/;
	s /^threads$/enable-threads/;
	s /^zlib$/enable-zlib/;
	s /^zlib-dynamic$/enable-zlib-dynamic/;

        if (/^(no|disable|enable)-(.+)$/)
		{
		my $word = $2;
		if (grep { $word =~ /^${_}$/ } @deprecated_disablables)
			{
			$deprecated_options{$_} = 1;
			next;
			}
		elsif (!grep { $word =~ /^${_}$/ } @disablables)
			{
			$unsupported_options{$_} = 1;
			next;
			}
		}
	if (/^no-(.+)$/ || /^disable-(.+)$/)
		{
                foreach my $proto ((@tls, @dtls))
                        {
                        if ($1 eq "$proto-method")
                                {
                                $disabled{"$proto"} = "option($proto-method)";
                                last;
                                }
                        }
                if ($1 eq "dtls")
                        {
                        foreach my $proto (@dtls)
                                {
                                $disabled{$proto} = "option(dtls)";
                                }
                        }
                elsif ($1 eq "ssl")
                        {
                        # Last one of its kind
                        $disabled{"ssl3"} = "option(ssl)";
                        }
                elsif ($1 eq "tls")
                        {
                        # XXX: Tests will fail if all SSL/TLS
                        # protocols are disabled.
                        foreach my $proto (@tls)
                                {
                                $disabled{$proto} = "option(tls)";
                                }
                        }
                elsif ($1 eq "static-engine")
                        {
                        delete $disabled{"dynamic-engine"};
                        }
                elsif ($1 eq "dynamic-engine")
                        {
                        $disabled{"dynamic-engine"} = "option";
                        }
                else
                        {
                        $disabled{$1} = "option";
                        }
		# No longer an automatic choice
		$auto_threads = 0 if ($1 eq "threads");
		}
	elsif (/^enable-(.+)$/)
		{
                if ($1 eq "static-engine")
                        {
                        $disabled{"dynamic-engine"} = "option";
                        }
                elsif ($1 eq "dynamic-engine")
                        {
                        delete $disabled{"dynamic-engine"};
                        }
                elsif ($1 eq "zlib-dynamic")
                        {
                        delete $disabled{"zlib"};
                        }
		my $algo = $1;
		delete $disabled{$algo};

		# No longer an automatic choice
		$auto_threads = 0 if ($1 eq "threads");
		}
	elsif (/^--strict-warnings$/)
		{
		$strict_warnings = 1;
		}
	elsif (/^--debug$/)
		{
		$config{build_type} = "debug";
		}
	elsif (/^--release$/)
		{
		$config{build_type} = "release";
		}
	elsif (/^386$/)
		{ $config{processor}=386; }
	elsif (/^fips$/)
		{
		$config{fips}=1;
		}
	elsif (/^rsaref$/)
		{
		# No RSAref support any more since it's not needed.
		# The check for the option is there so scripts aren't
		# broken
		}
	elsif (/^nofipscanistercheck$/)
		{
		$config{fips} = 1;
		$nofipscanistercheck = 1;
		}
	elsif (/^[-+]/)
		{
		if (/^--classic$/)
			{
			$classic=1;
			}
		elsif (/^--prefix=(.*)$/)
			{
			$config{prefix}=$1;
			die "Directory given with --prefix MUST be absolute\n"
				unless file_name_is_absolute($config{prefix});
			}
		elsif (/^--api=(.*)$/)
			{
			$config{api}=$1;
			}
		elsif (/^--libdir=(.*)$/)
			{
			$config{libdir}=$1;
			}
		elsif (/^--openssldir=(.*)$/)
			{
			$config{openssldir}=$1;
			}
		elsif (/^--with-zlib-lib=(.*)$/)
			{
			$withargs{zlib_lib}=$1;
			}
		elsif (/^--with-zlib-include=(.*)$/)
			{
			$withargs{zlib_include}="-I$1";
			}
		elsif (/^--with-fipslibdir=(.*)$/)
			{
			$config{fipslibdir}="$1/";
			}
		elsif (/^--with-baseaddr=(.*)$/)
			{
			$config{baseaddr}="$1";
			}
		elsif (/^--cross-compile-prefix=(.*)$/)
			{
			$config{cross_compile_prefix}=$1;
			}
		elsif (/^--config=(.*)$/)
			{
			read_config $1;
			}
		elsif (/^-[lL](.*)$/ or /^-Wl,/)
			{
			$libs.=$_." ";
			}
		elsif (/^-D(.*)$/)
			{
			push @user_defines, $1;
			}
		else	# common if (/^[-+]/), just pass down...
			{
			$_ =~ s/%([0-9a-f]{1,2})/chr(hex($1))/gei;
			$user_cflags.=" ".$_;
			}
		}
	else
		{
		die "target already defined - $target (offending arg: $_)\n" if ($target ne "");
		$target=$_;
		}
	unless ($_ eq $target || /^no-/ || /^disable-/)
		{
		# "no-..." follows later after implied disactivations
		# have been derived.  (Don't take this too seroiusly,
		# we really only write OPTIONS to the Makefile out of
		# nostalgia.)

		if ($config{options} eq "")
			{ $config{options} = $_; }
		else
			{ $config{options} .= " ".$_; }
		}

        if (defined($config{api}) && !exists $apitable->{$config{api}}) {
		die "***** Unsupported api compatibility level: $config{api}\n",
        }

	if (keys %deprecated_options)
		{
		warn "***** Deprecated options: ",
			join(", ", keys %deprecated_options), "\n";
		}
	if (keys %unsupported_options)
		{
		die "***** Unsupported options: ",
			join(", ", keys %unsupported_options), "\n";
		}
	}

if ($config{fips})
	{
	delete $disabled{"shared"} if ($disabled{"shared"} =~ /^default/);
	}
else
	{
	@{$config{dirs}} = grep !/^fips$/, @{$config{dirs}};
	}

my @tocheckfor = (keys %disabled);
while (@tocheckfor) {
    my %new_tocheckfor = ();
    my @cascade_copy = (@disable_cascades);
    while (@cascade_copy) {
	my ($test, $descendents) = (shift @cascade_copy, shift @cascade_copy);
	if (ref($test) eq "CODE" ? $test->() : defined($disabled{$test})) {
	    map {
		$new_tocheckfor{$_} = 1; $disabled{$_} = "forced";
	    } grep { !defined($disabled{$_}) } @$descendents;
	}
    }
    @tocheckfor = (keys %new_tocheckfor);
}

if ($target eq "TABLE") {
    foreach (sort keys %table) {
	print_table_entry($_, "TABLE");
    }
    exit 0;
}

if ($target eq "LIST") {
    foreach (sort keys %table) {
	print $_,"\n" unless $table{$_}->{template};
    }
    exit 0;
}

if ($target eq "HASH") {
    print "%table = (\n";
    foreach (sort keys %table) {
	print_table_entry($_, "HASH");
    }
    exit 0;
}

# Backward compatibility?
if ($target =~ m/^CygWin32(-.*)$/) {
    $target = "Cygwin".$1;
}

foreach (sort (keys %disabled))
	{
	$config{options} .= " no-$_";

	printf "    no-%-12s %-10s", $_, "[$disabled{$_}]";

	if (/^dso$/)
		{ }
	elsif (/^threads$/)
		{ }
	elsif (/^shared$/)
		{ }
	elsif (/^pic$/)
		{ }
	elsif (/^zlib$/)
		{ }
	elsif (/^dynamic-engine$/)
		{ }
	elsif (/^makedepend$/)
		{ }
	elsif (/^zlib-dynamic$/)
		{ }
	elsif (/^sse2$/)
		{ $no_sse2 = 1; }
	elsif (/^engine$/)
		{
		@{$config{dirs}} = grep !/^engines$/, @{$config{dirs}};
		@{$config{sdirs}} = grep !/^engine$/, @{$config{sdirs}};
		push @{$config{openssl_other_defines}}, "OPENSSL_NO_ENGINE";
		}
	else
		{
		my ($ALGO, $algo);
		($ALGO = $algo = $_) =~ tr/[\-a-z]/[_A-Z]/;

		if (/^asm$/ || /^err$/ || /^hw$/ || /^hw-/ || /^async$/
				|| /^autoalginit/ || /^autoerrinit/)
			{
			push @{$config{openssl_other_defines}}, "OPENSSL_NO_$ALGO";
			print " OPENSSL_NO_$ALGO";

			if (/^err$/)	{ push @user_defines, "OPENSSL_NO_ERR"; }
			}
		else
			{
			($ALGO,$algo) = ("RMD160","rmd160") if ($algo eq "ripemd");

			push @{$config{openssl_algorithm_defines}}, "OPENSSL_NO_$ALGO";
			print " OPENSSL_NO_$ALGO";

			# fix-up crypto/directory name(s)
			$algo="whrlpool" if $algo eq "whirlpool";
			$algo="ripemd" if $algo eq "rmd160";
			@{$config{sdirs}} = grep { $_ ne $algo} @{$config{sdirs}};

			print " (skip dir)";
			}
		}

	print "\n";
	}

print "Configuring for $target\n";

# Support for legacy targets having a name starting with 'debug-'
my ($d, $t) = $target =~ m/^(debug-)?(.*)$/;
if ($d) {
    $config{build_type} = "debug";

    # If we do not find debug-foo in the table, the target is set to foo.
    if (!$table{$target}) {
	$target = $t;
    }
}
$config{target} = $target;
my %target = resolve_config($target);

&usage if (!%target || $target{template});

%target = ( %{$table{DEFAULTS}}, %target );

$target{exe_extension}="";
$target{exe_extension}=".exe" if ($config{target} eq "DJGPP"
                                  || $config{target} =~ /^(?:Cygwin|mingw)/);
$target{exe_extension}=".nlm" if ($config{target} =~ /netware/);
$target{exe_extension}=".pm"  if ($config{target} =~ /vos/);

($target{shared_extension_simple}=$target{shared_extension})
    =~ s|\.\$\(SHLIB_MAJOR\)\.\$\(SHLIB_MINOR\)||;
$target{dso_extension}=$target{shared_extension_simple};
($target{shared_import_extension}=$target{shared_extension_simple}.".a")
    if ($config{target} =~ /^(?:Cygwin|mingw)/);


$config{cross_compile_prefix} = $ENV{'CROSS_COMPILE'}
    if $config{cross_compile_prefix} eq "";

# Allow overriding the names of some tools.  USE WITH CARE
$config{perl} =    $ENV{'PERL'}    || which("perl5") || which("perl") || "perl";
$target{cc} =      $ENV{'CC'}      || $target{cc}      || "cc";
$target{ranlib} =  $ENV{'RANLIB'}  || $target{ranlib}  || which("ranlib") || "true";
$target{ar} =      $ENV{'AR'}      || $target{ar}      || "ar";
$target{nm} =      $ENV{'NM'}      || $target{nm}      || "nm";

# For cflags, lflags, plib_lflags, ex_libs and defines, add the debug_
# or release_ attributes.
# Do it in such a way that no spurious space is appended (hence the grep).
$config{defines} = [];
$config{cflags} = "";
$config{ex_libs} = "";
$config{shared_ldflag} = "";

# Make sure build_scheme is consistent.
$target{build_scheme} = [ $target{build_scheme} ]
    if ref($target{build_scheme}) ne "ARRAY";

###### TO BE REMOVED WHEN CLASSIC BUILD IS REMOVED
######
###### If the user has chosen --classic, we give it to them.
###### If they try that with an out-of-source config, we complain.
if ($target{build_scheme}->[0] eq "unified" && $classic) {
    die "Can't perform a classic build out of source tree\n"
        if $srcdir ne $blddir;

    $target{build_scheme} = { unix    => [ "unixmake" ],
                              windows => [ "mk1mf", $target{build_scheme}->[2] ],
                              VMS     => undef } -> {$target{build_scheme}->[1]};

    die "Classic mode unavailable on this platform\n"
        unless defined($target{build_scheme});
}

my ($builder, $builder_platform, @builder_opts) =
    @{$target{build_scheme}};

if ($target =~ /^mingw/ && `$target{cc} --target-help 2>&1` =~ m/-mno-cygwin/m)
	{
	$config{cflags} .= " -mno-cygwin";
	$config{shared_ldflag} .= " -mno-cygwin";
	}

if ($target =~ /linux.*-mips/ && !$disabled{asm} && $user_cflags !~ /-m(ips|arch=)/) {
	# minimally required architecture flags for assembly modules
	$config{cflags}="-mips2 $config{cflags}" if ($target =~ /mips32/);
	$config{cflags}="-mips3 $config{cflags}" if ($target =~ /mips64/);
}

my $no_shared_warn=0;
my $no_user_cflags=0;
my $no_user_defines=0;

# The DSO code currently always implements all functions so that no
# applications will have to worry about that from a compilation point
# of view. However, the "method"s may return zero unless that platform
# has support compiled in for them. Currently each method is enabled
# by a define "DSO_<name>" ... we translate the "dso_scheme" config
# string entry into using the following logic;
if (!$disabled{dso} && $target{dso_scheme} ne "")
	{
	$target{dso_scheme} =~ tr/[a-z]/[A-Z]/;
	if ($target{dso_scheme} eq "DLFCN")
		{
		unshift @{$config{defines}}, "DSO_DLFCN", "HAVE_DLFCN_H";
		}
	elsif ($target{dso_scheme} eq "DLFCN_NO_H")
		{
		unshift @{$config{defines}}, "DSO_DLFCN";
		}
	else
		{
		unshift @{$config{defines}}, "DSO_$target{dso_scheme}";
		}
	}

$config{ex_libs}="$libs$config{ex_libs}" if ($libs ne "");

if ($disabled{asm})
	{
	if ($config{fips})
		{
		@{$config{defines}} = grep !/^[BL]_ENDIAN$/, @{$config{defines}};
		@{$target{defines}} = grep !/^[BL]_ENDIAN$/, @{$target{defines}};
		}
	}

# If threads aren't disabled, check how possible they are
unless ($disabled{threads}) {
    if ($auto_threads) {
        # Enabled by default, disable it forcibly if unavailable
        if ($target{thread_scheme} eq "(unknown)") {
            $disabled{threads} = "unavailable";
        }
    } else {
        # The user chose to enable threads explicitely, let's see
        # if there's a chance that's possible
        if ($target{thread_scheme} eq "(unknown)") {
            # If the user asked for "threads" and we don't have internal
            # knowledge how to do it, [s]he is expected to provide any
            # system-dependent compiler options that are necessary.  We
            # can't truly check that the given options are correct, but
            # we expect the user to know what [s]He is doing.
            if ($no_user_cflags && $no_user_defines) {
                die "You asked for multi-threading support, but didn't\n"
                    ,"provide any system-specific compiler options\n";
            }
        }
    }
}

# If threads still aren't disabled, add a C macro to ensure the source
# code knows about it.  Any other flag is taken care of by the configs.
unless($disabled{threads}) {
    foreach (("defines", "openssl_thread_defines")) {
        push @{$config{$_}}, "OPENSSL_THREADS";
    }
}

# With "deprecated" disable all deprecated features.
if (defined($disabled{"deprecated"})) {
        $config{api} = $maxapi;
}

if ($target{shared_target} eq "")
	{
	$no_shared_warn = 1
	    if ((!$disabled{shared} || !$disabled{"dynamic-engine"})
		&& !$config{fips});
	$disabled{shared} = "no-shared-target";
	$disabled{pic} = $disabled{shared} = $disabled{"dynamic-engine"} =
	    "no-shared-target";
	}

if ($disabled{"dynamic-engine"}) {
        push @{$config{defines}}, "OPENSSL_NO_DYNAMIC_ENGINE";
        $config{dynamic_engines} = 0;
} else {
        push @{$config{defines}}, "OPENSSL_NO_STATIC_ENGINE";
        $config{dynamic_engines} = 1;
}

#
# Platform fix-ups
#

# This saves the build files from having to check
if ($disabled{pic})
	{
	$target{shared_cflag} = $target{shared_ldflag} =
		$target{shared_rcflag} = "";
	}
else
	{
	push @{$config{defines}}, "OPENSSL_PIC";
	}

if ($target{sys_id} ne "")
	{
	push @{$config{openssl_sys_defines}}, "OPENSSL_SYS_$target{sys_id}";
	}

unless ($disabled{asm}) {
    $target{cpuid_asm_src}=$table{DEFAULTS}->{cpuid_asm_src} if ($config{processor} eq "386");
    $target{bn_asm_src} =~ s/\w+-gf2m.c// if (defined($disabled{ec2m}));

    # bn-586 is the only one implementing bn_*_part_words
    push @{$config{defines}}, "OPENSSL_BN_ASM_PART_WORDS" if ($target{bn_asm_src} =~ /bn-586/);
    push @{$config{defines}}, "OPENSSL_IA32_SSE2" if (!$no_sse2 && $target{bn_asm_src} =~ /86/);

    push @{$config{defines}}, "OPENSSL_BN_ASM_MONT" if ($target{bn_asm_src} =~ /-mont/);
    push @{$config{defines}}, "OPENSSL_BN_ASM_MONT5" if ($target{bn_asm_src} =~ /-mont5/);
    push @{$config{defines}}, "OPENSSL_BN_ASM_GF2m" if ($target{bn_asm_src} =~ /-gf2m/);

    if ($config{fips}) {
	push @{$config{openssl_other_defines}}, "OPENSSL_FIPS";
    }

    if ($target{sha1_asm_src}) {
	push @{$config{defines}}, "SHA1_ASM"   if ($target{sha1_asm_src} =~ /sx86/ || $target{sha1_asm_src} =~ /sha1/);
	push @{$config{defines}}, "SHA256_ASM" if ($target{sha1_asm_src} =~ /sha256/);
	push @{$config{defines}}, "SHA512_ASM" if ($target{sha1_asm_src} =~ /sha512/);
    }
    if ($target{md5_asm_src}) {
	push @{$config{defines}}, "MD5_ASM";
    }
    $target{cast_asm_src}=$table{DEFAULTS}->{cast_asm_src} unless $disabled{pic}; # CAST assembler is not PIC
    if ($target{rmd160_asm_src}) {
	push @{$config{defines}}, "RMD160_ASM";
    }
    if ($target{aes_asm_src}) {
	push @{$config{defines}}, "AES_ASM" if ($target{aes_asm_src} =~ m/\baes-/);;
	# aes-ctr.fake is not a real file, only indication that assembler
	# module implements AES_ctr32_encrypt...
	push @{$config{defines}}, "AES_CTR_ASM" if ($target{aes_asm_src} =~ s/\s*aes-ctr\.fake//);
	# aes-xts.fake indicates presence of AES_xts_[en|de]crypt...
	push @{$config{defines}}, "AES_XTS_ASM" if ($target{aes_asm_src} =~ s/\s*aes-xts\.fake//);
	$target{aes_asm_src} =~ s/\s*(vpaes|aesni)-x86\.s//g if ($no_sse2);
	push @{$config{defines}}, "VPAES_ASM" if ($target{aes_asm_src} =~ m/vpaes/);
	push @{$config{defines}}, "BSAES_ASM" if ($target{aes_asm_src} =~ m/bsaes/);
    }
    if ($target{wp_asm_src} =~ /mmx/) {
        if ($config{processor} eq "386") {
	    $target{wp_asm_src}=$table{DEFAULTS}->{wp_asm_src};
	} elsif (!$disabled{"whirlpool"}) {
	    push @{$config{defines}}, "WHIRLPOOL_ASM";
	}
    }
    if ($target{modes_asm_src} =~ /ghash-/) {
	push @{$config{defines}}, "GHASH_ASM";
    }
    if ($target{ec_asm_src} =~ /ecp_nistz256/) {
	push @{$config{defines}}, "ECP_NISTZ256_ASM";
    }
    if ($target{poly1305_asm_src} ne "") {
	push @{$config{defines}}, "POLY1305_ASM";
    }
}

my $ecc = $target{cc};
if ($^O ne "VMS" && !$disabled{makedepend}) {
    # Is the compiler gcc or clang?  $ecc is used below to see if
    # error-checking can be turned on.
    my $ccpcc = "$config{cross_compile_prefix}$target{cc}";
    open(PIPE, "$ccpcc --version 2>&1 |");
    my $lines = 2;
    while ( <PIPE> ) {
        # Find the version number and save the major.
        m|(?:.*)\b(\d+)\.\d+\.\d+\b(?:.*)|;
        my $compiler_major = $1;
        # We know that GNU C version 3 and up as well as all clang
        # versions support dependency generation
        $config{makedepprog} = $ccpcc
            if (/clang/ || (/gcc/ && $compiler_major > 3));
        $ecc = "clang" if /clang/;
        $ecc = "gcc" if /gcc/;
        last if ($config{makedepprog} || !$lines--);
    }
    close(PIPE);

    $config{makedepprog} = which('makedepend') unless $config{makedepprog};
    $disabled{makedepend} = "unavailable" unless $config{makedepprog};
}



# Deal with bn_ops ###################################################

$config{bn_ll}			=0;
$config{export_var_as_fn}	=0;
my $def_int="unsigned int";
$config{rc4_int}		=$def_int;
($config{b64l},$config{b64},$config{b32})=(0,0,1);

my $count = 0;
foreach (sort split(/\s+/,$target{bn_ops})) {
    $count++ if /SIXTY_FOUR_BIT|SIXTY_FOUR_BIT_LONG|THIRTY_TWO_BIT/;
    $config{export_var_as_fn}=1                 if $_ eq 'EXPORT_VAR_AS_FN';
    $config{bn_ll}=1				if $_ eq 'BN_LLONG';
    $config{rc4_int}="unsigned char"		if $_ eq 'RC4_CHAR';
    ($config{b64l},$config{b64},$config{b32})
	=(0,1,0)				if $_ eq 'SIXTY_FOUR_BIT';
    ($config{b64l},$config{b64},$config{b32})
	=(1,0,0)				if $_ eq 'SIXTY_FOUR_BIT_LONG';
    ($config{b64l},$config{b64},$config{b32})
	=(0,0,1)				if $_ eq 'THIRTY_TWO_BIT';
}
die "Exactly one of SIXTY_FOUR_BIT|SIXTY_FOUR_BIT_LONG|THIRTY_TWO_BIT can be set in bn_ops\n"
    if $count > 1;


# Hack cflags for better warnings (dev option) #######################

# "Stringify" the C flags string.  This permits it to be made part of a string
# and works as well on command lines.
$config{cflags} =~ s/([\\\"])/\\$1/g;

if (defined($config{api})) {
    $config{openssl_api_defines} = [ "OPENSSL_MIN_API=".$apitable->{$config{api}} ];
    my $apiflag = sprintf("OPENSSL_API_COMPAT=%s", $apitable->{$config{api}});
    push @{$config{defines}}, $apiflag;
}

if ($strict_warnings)
	{
	my $wopt;
	die "ERROR --strict-warnings requires gcc or clang"
            unless $ecc eq 'gcc' || $ecc eq 'clang';
	foreach $wopt (split /\s+/, $gcc_devteam_warn)
		{
		$config{cflags} .= " $wopt" unless ($config{cflags} =~ /(?:^|\s)$wopt(?:\s|$)/)
		}
	if ($ecc eq "clang")
		{
		foreach $wopt (split /\s+/, $clang_devteam_warn)
			{
			$config{cflags} .= " $wopt" unless ($config{cflags} =~ /(?:^|\s)$wopt(?:\s|$)/)
			}
		}
	}

unless ($disabled{"crypto-mdebug-backtrace"})
	{
	foreach my $wopt (split /\s+/, $memleak_devteam_backtrace)
		{
		$config{cflags} .= " $wopt" unless ($config{cflags} =~ /(?:^|\s)$wopt(?:\s|$)/)
		}
	if ($target =~ /^BSD-/)
		{
		$config{ex_libs} .= " -lexecinfo";
		}
	}

if ($user_cflags ne "") { $config{cflags}="$config{cflags}$user_cflags"; }
else                    { $no_user_cflags=1;  }
if (@user_defines) { $config{defines}=[ @{$config{defines}}, @user_defines ]; }
else               { $no_user_defines=1;    }

# ALL MODIFICATIONS TO %config and %target MUST BE DONE FROM HERE ON

unless ($disabled{afalgeng}) {
    $config{afalgeng}="";
    if ($target =~ m/^linux/) {
        my $minver = 4*10000 + 1*100 + 0;
        if ($config{cross_compile_prefix} eq "") {
            my $verstr = `uname -r`;
            my ($ma, $mi1, $mi2) = split("\\.", $verstr);
            ($mi2) = $mi2 =~ /(\d+)/;
            my $ver = $ma*10000 + $mi1*100 + $mi2;
            if ($ver < $minver) {
                $disabled{afalgeng} = "too-old-kernel";
            } else {
                push @{$config{engdirs}}, "afalg";
            }
        } else {
            $disabled{afalgeng} = "cross-compiling";
        }
    } else {
        $disabled{afalgeng}  = "not-linux";
    }
}

push @{$config{openssl_other_defines}}, "OPENSSL_NO_AFALGENG" if ($disabled{afalgeng});

# If we use the unified build, collect information from build.info files
my %unified_info = ();

if ($builder eq "unified") {
    # Store the name of the template file we will build the build file from
    # in %config.  This may be useful for the build file itself.
    my $build_file_template =
        catfile($srcdir, "Configurations",
                $builder_platform."-".$target{build_file}.".tmpl");
    $build_file_template =
        catfile($srcdir, "Configurations", $target{build_file}.".tmpl")
        if (! -f $build_file_template);
    $config{build_file_template} = $build_file_template;

    use lib catdir(dirname(__FILE__),"util");
    use with_fallback qw(Text::Template);

    sub cleandir {
        my $base = shift;
        my $dir = shift;
        my $relativeto = shift || ".";

        $dir = catdir($base,$dir) unless isabsolute($dir);

        # Make sure the directories we're building in exists
        mkpath($dir);

        my $res = abs2rel(absolutedir($dir), rel2abs($relativeto));
        #print STDERR "DEBUG[cleandir]: $dir , $base => $res\n";
        return $res;
    }

    sub cleanfile {
        my $base = shift;
        my $file = shift;
        my $relativeto = shift || ".";

        $file = catfile($base,$file) unless isabsolute($file);

        my $d = dirname($file);
        my $f = basename($file);

        # Make sure the directories we're building in exists
        mkpath($d);

        my $res = abs2rel(catfile(absolutedir($d), $f), rel2abs($relativeto));
        #print STDERR "DEBUG[cleanfile]: $d , $f => $res\n";
        return $res;
    }

    my @build_infos = ( [ ".", "build.info" ] );
    foreach (@{$config{dirs}}) {
        push @build_infos, [ $_, "build.info" ]
            if (-f catfile($srcdir, $_, "build.info"));
    }
    foreach (@{$config{sdirs}}) {
        push @build_infos, [ catdir("crypto", $_), "build.info" ]
            if (-f catfile($srcdir, "crypto", $_, "build.info"));
    }
    foreach (@{$config{engdirs}}) {
        push @build_infos, [ catdir("engines", $_), "build.info" ]
            if (-f catfile($srcdir, "engines", $_, "build.info"));
    }

    $config{build_infos} = [ ];

    foreach (@build_infos) {
        my $sourced = catdir($srcdir, $_->[0]);
        my $buildd = catdir($blddir, $_->[0]);

        mkpath($buildd);

        my $f = $_->[1];
        # The basic things we're trying to build
        my @programs = ();
        my @libraries = ();
        my @engines = ();
        my @scripts = ();
        my @extra = ();
        my @overrides = ();
        my @intermediates = ();
        my @rawlines = ();

        my %ordinals = ();
        my %sources = ();
        my %includes = ();
        my %depends = ();
        my %renames = ();
        my %sharednames = ();
        my %generate = ();

        push @{$config{build_infos}}, catfile(abs2rel($sourced, $blddir), $f);
        my $template = Text::Template->new(TYPE => 'FILE',
                                           SOURCE => catfile($sourced, $f));
        die "Something went wrong with $sourced/$f: $!\n" unless $template;
        my @text =
            split /^/m,
            $template->fill_in(HASH => { config => \%config,
                                         target => \%target,
                                         disabled => \%disabled,
                                         builddir => abs2rel($buildd, $blddir),
                                         sourcedir => abs2rel($sourced, $blddir),
                                         buildtop => abs2rel($blddir, $blddir),
                                         sourcetop => abs2rel($srcdir, $blddir) },
                               DELIMITERS => [ "{-", "-}" ]);

        # The top item of this stack has the following values
        # -2 positive already run and we found ELSE (following ELSIF should fail)
        # -1 positive already run (skip until ENDIF)
        # 0 negatives so far (if we're at a condition, check it)
        # 1 last was positive (don't skip lines until next ELSE, ELSIF or ENDIF)
        # 2 positive ELSE (following ELSIF should fail)
        my @skip = ();
        collect_information(
            collect_from_array([ @text ],
                               qr/\\$/ => sub { my $l1 = shift; my $l2 = shift;
                                                $l1 =~ s/\\$//; $l1.$l2 }),
            # Info we're looking for
            qr/^\s*IF\[((?:\\.|[^\\\]])*)\]\s*$/
            => sub {
                if (! @skip || $skip[$#skip] > 0) {
                    push @skip, !! $1;
                } else {
                    push @skip, -1;
                }
            },
            qr/^\s*ELSIF\[((?:\\.|[^\\\]])*)\]\s*$/
            => sub { die "ELSIF out of scope" if ! @skip;
                     die "ELSIF following ELSE" if abs($skip[$#skip]) == 2;
                     $skip[$#skip] = -1 if $skip[$#skip] != 0;
                     $skip[$#skip] = !! $1
                         if $skip[$#skip] == 0; },
            qr/^\s*ELSE\s*$/
            => sub { die "ELSE out of scope" if ! @skip;
                     $skip[$#skip] = -2 if $skip[$#skip] != 0;
                     $skip[$#skip] = 2 if $skip[$#skip] == 0; },
            qr/^\s*ENDIF\s*$/
            => sub { die "ENDIF out of scope" if ! @skip;
                     pop @skip; },
            qr/^\s*PROGRAMS\s*=\s*(.*)\s*$/
            => sub { push @programs, split(/\s+/, $1)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*LIBS\s*=\s*(.*)\s*$/
            => sub { push @libraries, split(/\s+/, $1)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*ENGINES\s*=\s*(.*)\s*$/
            => sub { push @engines, split(/\s+/, $1)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*SCRIPTS\s*=\s*(.*)\s*$/
            => sub { push @scripts, split(/\s+/, $1)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*EXTRA\s*=\s*(.*)\s*$/
            => sub { push @extra, split(/\s+/, $1)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*OVERRIDES\s*=\s*(.*)\s*$/
            => sub { push @overrides, split(/\s+/, $1)
                         if !@skip || $skip[$#skip] > 0 },

            qr/^\s*ORDINALS\[((?:\\.|[^\\\]])+)\]\s*=\s*(.*)\s*$/,
            => sub { push @{$ordinals{$1}}, split(/\s+/, $2)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*SOURCE\[((?:\\.|[^\\\]])+)\]\s*=\s*(.*)\s*$/
            => sub { push @{$sources{$1}}, split(/\s+/, $2)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*INCLUDE\[((?:\\.|[^\\\]])+)\]\s*=\s*(.*)\s*$/
            => sub { push @{$includes{$1}}, split(/\s+/, $2)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*DEPEND\[((?:\\.|[^\\\]])+)\]\s*=\s*(.*)\s*$/
            => sub { push @{$depends{$1}}, split(/\s+/, $2)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*GENERATE\[((?:\\.|[^\\\]])+)\]\s*=\s*(.*)\s*$/
            => sub { push @{$generate{$1}}, $2
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*RENAME\[((?:\\.|[^\\\]])+)\]\s*=\s*(.*)\s*$/
            => sub { push @{$renames{$1}}, split(/\s+/, $2)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*SHARED_NAME\[((?:\\.|[^\\\]])+)\]\s*=\s*(.*)\s*$/
            => sub { push @{$sharednames{$1}}, split(/\s+/, $2)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*BEGINRAW\[((?:\\.|[^\\\]])+)\]\s*$/
            => sub {
                my $lineiterator = shift;
                my $target_kind = $1;
                while (defined $lineiterator->()) {
                    s|\R$||;
                    if (/^\s*ENDRAW\[((?:\\.|[^\\\]])+)\]\s*$/) {
                        die "ENDRAW doesn't match BEGINRAW"
                            if $1 ne $target_kind;
                        last;
                    }
                    next if @skip && $skip[$#skip] <= 0;
                    push @rawlines,  $_
                        if ($target_kind eq $target{build_file}
                            || $target_kind eq $target{build_file}."(".$builder_platform.")");
                }
            },
            qr/^(?:#.*|\s*)$/ => sub { },
            "OTHERWISE" => sub { die "Something wrong with this line:\n$_\nat $sourced/$f" }
            );
        die "runaway IF?" if (@skip);

        foreach (keys %renames) {
            die "$_ renamed to more than one thing: "
                ,join(" ", @{$renames{$_}}),"\n"
                if scalar @{$renames{$_}} > 1;
            my $dest = cleanfile($buildd, $_, $blddir);
            my $to = cleanfile($buildd, $renames{$_}->[0], $blddir);
            die "$dest renamed to more than one thing: "
                ,$unified_info{rename}->{$dest}, $to
                unless !defined($unified_info{rename}->{$dest})
                or $unified_info{rename}->{$dest} eq $to;
            $unified_info{rename}->{$dest} = $to;
        }

        foreach (@programs) {
            my $program = cleanfile($buildd, $_, $blddir);
            if ($unified_info{rename}->{$program}) {
                $program = $unified_info{rename}->{$program};
            }
            $unified_info{programs}->{$program} = 1;
        }

        foreach (@libraries) {
            my $library = cleanfile($buildd, $_, $blddir);
            if ($unified_info{rename}->{$library}) {
                $library = $unified_info{rename}->{$library};
            }
            $unified_info{libraries}->{$library} = 1;
        }

        die <<"EOF" if scalar @engines and !$config{dynamic_engines};
ENGINES can only be used if configured with 'dynamic-engine'.
This is usually a fault in a build.info file.
EOF
        foreach (@engines) {
            my $library = cleanfile($buildd, $_, $blddir);
            if ($unified_info{rename}->{$library}) {
                $library = $unified_info{rename}->{$library};
            }
            $unified_info{engines}->{$library} = 1;
        }

        foreach (@scripts) {
            my $script = cleanfile($buildd, $_, $blddir);
            if ($unified_info{rename}->{$script}) {
                $script = $unified_info{rename}->{$script};
            }
            $unified_info{scripts}->{$script} = 1;
        }

        foreach (@extra) {
            my $extra = cleanfile($buildd, $_, $blddir);
            $unified_info{extra}->{$extra} = 1;
        }

        foreach (@overrides) {
            my $override = cleanfile($buildd, $_, $blddir);
            $unified_info{overrides}->{$override} = 1;
        }

        push @{$unified_info{rawlines}}, @rawlines;

        unless ($disabled{shared}) {
            # Check sharednames.
            foreach (keys %sharednames) {
                my $dest = cleanfile($buildd, $_, $blddir);
                if ($unified_info{rename}->{$dest}) {
                    $dest = $unified_info{rename}->{$dest};
                }
                die "shared_name for $dest with multiple values: "
                    ,join(" ", @{$sharednames{$_}}),"\n"
                    if scalar @{$sharednames{$_}} > 1;
                my $to = cleanfile($buildd, $sharednames{$_}->[0], $blddir);
                die "shared_name found for a library $dest that isn't defined\n"
                    unless $unified_info{libraries}->{$dest};
                die "shared_name for $dest with multiple values: "
                    ,$unified_info{sharednames}->{$dest}, ", ", $to
                    unless !defined($unified_info{sharednames}->{$dest})
                    or $unified_info{sharednames}->{$dest} eq $to;
                $unified_info{sharednames}->{$dest} = $to;
            }

            # Additionally, we set up sharednames for libraries that don't
            # have any, as themselves.
            foreach (keys %{$unified_info{libraries}}) {
                if (!defined $unified_info{sharednames}->{$_}) {
                    $unified_info{sharednames}->{$_} = $_
                }
            }
        }

        foreach (keys %ordinals) {
            my $dest = $_;
            my $ddest = cleanfile($buildd, $_, $blddir);
            if ($unified_info{rename}->{$ddest}) {
                $ddest = $unified_info{rename}->{$ddest};
            }
            foreach (@{$ordinals{$dest}}) {
                my %known_ordinals =
                    (
                     crypto =>
                     cleanfile($sourced, catfile("util", "libcrypto.num"), $blddir),
                     ssl =>
                     cleanfile($sourced, catfile("util", "libssl.num"), $blddir)
                    );
                my $o = $known_ordinals{$_};
                die "Ordinals for $ddest defined more than once\n"
                    if $unified_info{ordinals}->{$ddest};
                $unified_info{ordinals}->{$ddest} = [ $_, $o ];
            }
        }

        foreach (keys %sources) {
            my $dest = $_;
            my $ddest = cleanfile($buildd, $_, $blddir);
            if ($unified_info{rename}->{$ddest}) {
                $ddest = $unified_info{rename}->{$ddest};
            }
            foreach (@{$sources{$dest}}) {
                my $s = cleanfile($sourced, $_, $blddir);

                # If it isn't in the source tree, we assume it's generated
                # in the build tree
                if (! -f $s) {
                    $s = cleanfile($buildd, $_, $blddir);
                }
                # We recognise C and asm files
                if ($s =~ /\.[csS]\b$/) {
                    (my $o = $_) =~ s/\.[csS]\b$/.o/;
                    $o = cleanfile($buildd, $o, $blddir);
                    $unified_info{sources}->{$ddest}->{$o} = 1;
                    $unified_info{sources}->{$o}->{$s} = 1;
                } else {
                    $unified_info{sources}->{$ddest}->{$s} = 1;
                }
            }
        }

        foreach (keys %generate) {
            my $dest = $_;
            my $ddest = cleanfile($buildd, $_, $blddir);
            if ($unified_info{rename}->{$ddest}) {
                $ddest = $unified_info{rename}->{$ddest};
            }
            die "more than one generator for $dest: "
                    ,join(" ", @{$generate{$_}}),"\n"
                    if scalar @{$generate{$_}} > 1;
            my @generator = split /\s+/, $generate{$dest}->[0];
            $generator[0] = cleanfile($sourced, $generator[0], $blddir),
            $unified_info{generate}->{$ddest} = [ @generator ];
        }

        foreach (keys %depends) {
            my $dest = $_;
            my $ddest = cleanfile($buildd, $_, $blddir);
            if ($unified_info{rename}->{$ddest}) {
                $ddest = $unified_info{rename}->{$ddest};
            }
            foreach (@{$depends{$dest}}) {
                my $d = cleanfile($sourced, $_, $blddir);

                # If we know it's generated, or assume it is because we can't
                # find it in the source tree, we set file we depend on to be
                # in the build tree rather than the source tree, and assume
                # and that there are lines to build it in a BEGINRAW..ENDRAW
                # section or in the Makefile template.
                if (! -f $d
                    || !(grep { $d eq $_ }
                         map { cleanfile($srcdir, $_, $blddir) }
                         (@generated_headers, @generated_by_make_headers))) {
                    $d = cleanfile($buildd, $_, $blddir);
                }
                # Take note if the file to depend on is being renamed
                if ($unified_info{rename}->{$d}) {
                    $d = $unified_info{rename}->{$d};
                }
                $unified_info{depends}->{$ddest}->{$d} = 1;
                # If we depend on a header file, let's make sure it
                # can get included
                if ($d =~ /\.h$/) {
                    my $i = dirname($d);
                    push @{$unified_info{includes}->{$ddest}}, $i
                        unless grep { $_ eq $i } @{$unified_info{includes}->{$ddest}};
                }
            }
        }

        foreach (keys %includes) {
            my $dest = $_;
            my $ddest = cleanfile($buildd, $_, $blddir);
            if ($unified_info{rename}->{$ddest}) {
                $ddest = $unified_info{rename}->{$ddest};
            }
            foreach (@{$includes{$dest}}) {
                my $i = cleandir($sourced, $_, $blddir);
                push @{$unified_info{includes}->{$ddest}}, $i
                    unless grep { $_ eq $i } @{$unified_info{includes}->{$ddest}};
            }
        }
    }

    ### Make unified_info a bit more efficient
    # One level structures
    foreach (("programs", "libraries", "engines", "scripts", "extra", "overrides")) {
        $unified_info{$_} = [ sort keys %{$unified_info{$_}} ];
    }
    # Two level structures
    foreach my $l1 (("sources", "ldadd", "depends")) {
        foreach my $l2 (sort keys %{$unified_info{$l1}}) {
            $unified_info{$l1}->{$l2} =
                [ sort keys %{$unified_info{$l1}->{$l2}} ];
        }
    }
}

# For the schemes that need it, we provide the old *_obj configs
# from the *_asm_obj ones
foreach (grep /_(asm|aux)_src$/, keys %target) {
    my $src = $_;
    (my $obj = $_) =~ s/_(asm|aux)_src$/_obj/;
    ($target{$obj} = $target{$src}) =~ s/\.[csS]\b/.o/g;
}

# Write down our configuration where it fits #########################

open(OUT,">configdata.pm") || die "unable to create configdata.pm: $!\n";
print OUT <<"EOF";
package configdata;

use strict;
use warnings;

use Exporter;
#use vars qw(\@ISA \@EXPORT);
our \@ISA = qw(Exporter);
our \@EXPORT = qw(\%config \%target %disabled %withargs %unified_info);

EOF
print OUT "our %config = (\n";
foreach (sort keys %config) {
    if (ref($config{$_}) eq "ARRAY") {
	print OUT "  ", $_, " => [ ", join(", ",
					   map { quotify("perl", $_) }
					   @{$config{$_}}), " ],\n";
    } else {
	print OUT "  ", $_, " => ", quotify("perl", $config{$_}), ",\n"
    }
}
print OUT <<"EOF";
);

EOF
print OUT "our %target = (\n";
foreach (sort keys %target) {
    if (ref($target{$_}) eq "ARRAY") {
	print OUT "  ", $_, " => [ ", join(", ",
					   map { quotify("perl", $_) }
					   @{$target{$_}}), " ],\n";
    } else {
	print OUT "  ", $_, " => ", quotify("perl", $target{$_}), ",\n"
    }
}
print OUT <<"EOF";
);

EOF
print OUT "our \%available_protocols = (\n";
print OUT "  tls => [ ", join(", ", map { quotify("perl", $_) } @tls), " ],\n";
print OUT "  dtls => [ ", join(", ", map { quotify("perl", $_) } @dtls), " ],\n";
print OUT <<"EOF";
);

EOF
print OUT "our \%disabled = (\n";
foreach (sort keys %disabled) {
    print OUT "  ", quotify("perl", $_), " => ", quotify("perl", $disabled{$_}), ",\n";
}
print OUT <<"EOF";
);

EOF
print OUT "our %withargs = (\n";
foreach (sort keys %withargs) {
    if (ref($withargs{$_}) eq "ARRAY") {
	print OUT "  ", $_, " => [ ", join(", ",
					   map { quotify("perl", $_) }
					   @{$withargs{$_}}), " ],\n";
    } else {
	print OUT "  ", $_, " => ", quotify("perl", $withargs{$_}), ",\n"
    }
}
print OUT <<"EOF";
);

EOF
if ($builder eq "unified") {
    my $recurse;
    $recurse = sub {
        my $indent = shift;
        foreach (@_) {
            if (ref $_ eq "ARRAY") {
                print OUT " "x$indent, "[\n";
                foreach (@$_) {
                    $recurse->($indent + 4, $_);
                }
                print OUT " "x$indent, "],\n";
            } elsif (ref $_ eq "HASH") {
                my %h = %$_;
                print OUT " "x$indent, "{\n";
                foreach (sort keys %h) {
                    if (ref $h{$_} eq "") {
                        print OUT " "x($indent + 4), quotify("perl", $_), " => ", quotify("perl", $h{$_}), ",\n";
                    } else {
                        print OUT " "x($indent + 4), quotify("perl", $_), " =>\n";
                        $recurse->($indent + 8, $h{$_});
                    }
                }
                print OUT " "x$indent, "},\n";
            } else {
                print OUT " "x$indent, quotify("perl", $_), ",\n";
            }
        }
    };
    print OUT "our %unified_info = (\n";
    foreach (sort keys %unified_info) {
        if (ref $unified_info{$_} eq "") {
            print OUT " "x4, quotify("perl", $_), " => ", quotify("perl", $unified_info{$_}), ",\n";
        } else {
            print OUT " "x4, quotify("perl", $_), " =>\n";
            $recurse->(8, $unified_info{$_});
        }
    }
    print OUT <<"EOF";
);

EOF
}
print OUT "1;\n";
close(OUT);


print "IsMK1MF       =", ($builder eq "mk1mf" ? "yes" : "no"), "\n";
print "CC            =$target{cc}\n";
print "CFLAG         =$target{cflags} $config{cflags}\n";
print "SHARED_CFLAG  =$target{shared_cflag}\n";
print "DEFINES       =",join(" ", @{$target{defines}}, @{$config{defines}}),"\n";
print "LFLAG         =$target{lflags}\n";
print "PLIB_LFLAG    =$target{plib_lflags}\n";
print "EX_LIBS       =$target{ex_libs} $config{ex_libs}\n";
print "APPS_OBJ      =$target{apps_obj}\n";
print "CPUID_OBJ     =$target{cpuid_obj}\n";
print "UPLINK_OBJ    =$target{uplink_obj}\n";
print "BN_ASM        =$target{bn_obj}\n";
print "EC_ASM        =$target{ec_obj}\n";
print "DES_ENC       =$target{des_obj}\n";
print "AES_ENC       =$target{aes_obj}\n";
print "BF_ENC        =$target{bf_obj}\n";
print "CAST_ENC      =$target{cast_obj}\n";
print "RC4_ENC       =$target{rc4_obj}\n";
print "RC5_ENC       =$target{rc5_obj}\n";
print "MD5_OBJ_ASM   =$target{md5_obj}\n";
print "SHA1_OBJ_ASM  =$target{sha1_obj}\n";
print "RMD160_OBJ_ASM=$target{rmd160_obj}\n";
print "CMLL_ENC      =$target{cmll_obj}\n";
print "MODES_OBJ     =$target{modes_obj}\n";
print "PADLOCK_OBJ   =$target{padlock_obj}\n";
print "CHACHA_ENC    =$target{chacha_obj}\n";
print "POLY1305_OBJ  =$target{poly1305_obj}\n";
print "BLAKE2_OBJ    =$target{blake2_obj}\n";
print "PROCESSOR     =$config{processor}\n";
print "RANLIB        =$target{ranlib}\n";
print "ARFLAGS       =$target{arflags}\n";
print "PERL          =$config{perl}\n";
print "\n";
print "SIXTY_FOUR_BIT_LONG mode\n" if $config{b64l};
print "SIXTY_FOUR_BIT mode\n" if $config{b64};
print "THIRTY_TWO_BIT mode\n" if $config{b32};
print "BN_LLONG mode\n" if $config{bn_ll};
print "RC4 uses $config{rc4_int}\n" if $config{rc4_int} ne $def_int;

for (@generated_headers) {
    mkpath(catdir($blddir, dirname($_)));
    run_dofile(catfile($blddir, $_),
               catfile($srcdir, $_.".in"));
}

###
### When the old "unixmake" scheme goes away, so does this function
###
sub build_Makefile {
    run_dofile("Makefile","Makefile.in");

    # Copy all Makefile.in to Makefile (except top-level)
    use File::Find;
    use IO::File;
    find(
        {
            preprocess => sub {
                grep(!/^\./, @_);
            },
            wanted => sub {
                return if ($_ ne "Makefile.in" || $File::Find::dir eq ".");
                my $in = IO::File->new($_, "r") or
                    die sprintf "Error reading Makefile.in in %s: !$\n",
                    $File::Find::dir;
                my $out = IO::File->new("Makefile", "w") or
                    die sprintf "Error writing Makefile in %s: !$\n",
                    $File::Find::dir;
                print $out "# Generated from $_, do not edit\n";
                while (my $line = <$in>) { print $out $line }
                $in->close() or
                    die sprintf "Error reading Makefile.in in %s: !$\n",
                    $File::Find::dir;
                $out->close() or
                    die sprintf "Error writing Makefile in %s: !$\n",
                    $File::Find::dir;
            },
        },
        ".");
}

my %builders = (
    unified => sub {
        run_dofile(catfile($blddir, $target{build_file}),
                   $config{build_file_template},
                   catfile($srcdir, "Configurations", "common.tmpl"));
    },
    unixmake => sub {
        build_Makefile();

        run_dofile("util/domd", "util/domd.in");
        chmod 0755, "util/domd";
    },
    mk1mf => sub {
        my $platform = shift;
        # The only reason we do this is to have something to build MINFO from
        build_Makefile();

	# create the ms/version32.rc file if needed
	if ($platform ne "netware") {
	    my ($v1, $v2, $v3, $v4);
	    if ($config{version_num} =~ /^0x([0-9a-f]{1})([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{1})L$/i) {
		$v1=hex $1;
		$v2=hex $2;
		$v3=hex $3;
		$v4=hex $4;
	    }
	    open (OUT,">ms/version32.rc") || die "Can't open ms/version32.rc";
	    print OUT <<"EOF";
#include <winver.h>

LANGUAGE 0x09,0x01

1 VERSIONINFO
  FILEVERSION $v1,$v2,$v3,$v4
  PRODUCTVERSION $v1,$v2,$v3,$v4
  FILEFLAGSMASK 0x3fL
#ifdef _DEBUG
  FILEFLAGS 0x01L
#else
  FILEFLAGS 0x00L
#endif
  FILEOS VOS__WINDOWS32
  FILETYPE VFT_DLL
  FILESUBTYPE 0x0L
BEGIN
    BLOCK "StringFileInfo"
    BEGIN
	BLOCK "040904b0"
	BEGIN
	    // Required:
	    VALUE "CompanyName", "The OpenSSL Project, http://www.openssl.org/\\0"
	    VALUE "FileDescription", "OpenSSL Shared Library\\0"
	    VALUE "FileVersion", "$config{version}\\0"
#if defined(CRYPTO)
	    VALUE "InternalName", "libcrypto32\\0"
	    VALUE "OriginalFilename", "libcrypto32.dll\\0"
#elif defined(SSL)
	    VALUE "InternalName", "libssl32\\0"
	    VALUE "OriginalFilename", "libssl32.dll\\0"
#endif
	    VALUE "ProductName", "The OpenSSL Toolkit\\0"
	    VALUE "ProductVersion", "$config{version}\\0"
	    // Optional:
	    //VALUE "Comments", "\\0"
	    VALUE "LegalCopyright", "Copyright © 1998-2015 The OpenSSL Project. Copyright © 1995-1998 Eric A. Young, Tim J. Hudson. All rights reserved.\\0"
	    //VALUE "LegalTrademarks", "\\0"
	    //VALUE "PrivateBuild", "\\0"
	    //VALUE "SpecialBuild", "\\0"
	END
    END
    BLOCK "VarFileInfo"
    BEGIN
        VALUE "Translation", 0x409, 0x4b0
    END
END
EOF
	    close(OUT);
	}
    },
    );

$builders{$builder}->($builder_platform, @builder_opts);

print <<"EOF";

Configured for $target.
EOF

print <<"EOF" if ($disabled{threads} eq "unavailable");

The library could not be configured for supporting multi-threaded
applications as the compiler options required on this system are not known.
See file INSTALL for details if you need multi-threading.
EOF

print <<"EOF" if ($no_shared_warn);

The options 'shared', 'pic' and 'dynamic-engine' aren't supported on this
platform, so we will pretend you gave the option 'no-pic', which also disables
'shared' and 'dynamic-engine'.  If you know how to implement shared libraries
or position independent code, please let us know (but please first make sure
you have tried with a current version of OpenSSL).
EOF

exit(0);

######################################################################
#
# Helpers and utility functions
#

# Configuration file reading #########################################

# Helper function to implement conditional inheritance depending on the
# value of $disabled{asm}.  Used in inherit_from values as follows:
#
#      inherit_from => [ "template", asm("asm_tmpl") ]
#
sub asm {
    my @x = @_;
    sub {
	$disabled{asm} ? () : @x;
    }
}

our $add_called = 0;
# Helper function to implement adding values to already existing configuration
# values.  It handles elements that are ARRAYs, CODEs and scalars
sub _add {
    my $separator = shift;

    # If there's any ARRAY in the collection of values OR the separator
    # is undef, we will return an ARRAY of combined values, otherwise a
    # string of joined values with $separator as the separator.
    my $found_array = !defined($separator);

    my @values =
	map {
	    my $res = $_;
	    while (ref($res) eq "CODE") {
		$res = $res->();
	    }
	    if (defined($res)) {
		if (ref($res) eq "ARRAY") {
		    $found_array = 1;
		    @$res;
		} else {
		    $res;
		}
	    } else {
		();
	    }
    } (@_);

    $add_called = 1;

    if ($found_array) {
	[ @values ];
    } else {
	join($separator, grep { defined($_) && $_ ne "" } @values);
    }
}
sub add_before {
    my $separator = " ";
    if (ref($_[$#_]) eq "HASH") {
        my $opts = pop;
        $separator = $opts->{separator};
    }
    my @x = @_;
    sub { _add($separator, @x, @_) };
}
sub add {
    my $separator = " ";
    if (ref($_[$#_]) eq "HASH") {
        my $opts = pop;
        $separator = $opts->{separator};
    }
    my @x = @_;
    sub { _add($separator, @_, @x) };
}

# configuration reader, evaluates the input file as a perl script and expects
# it to fill %targets with target configurations.  Those are then added to
# %table.
sub read_config {
    my $fname = shift;
    open(CONFFILE, "< $fname")
	or die "Can't open configuration file '$fname'!\n";
    my $x = $/;
    undef $/;
    my $content = <CONFFILE>;
    $/ = $x;
    close(CONFFILE);
    my %targets = ();
    {
	local %table = %::table;    # Protect %table from tampering

	eval $content;
	warn $@ if $@;
    }

    # For each target, check that it's configured with a hash table.
    foreach (keys %targets) {
	if (ref($targets{$_}) ne "HASH") {
	    if (ref($targets{$_}) eq "") {
		warn "Deprecated target configuration for $_, ignoring...\n";
	    } else {
		warn "Misconfigured target configuration for $_ (should be a hash table), ignoring...\n";
	    }
	    delete $targets{$_};
	}
    }

    %table = (%table, %targets);

}

# configuration resolver.  Will only resolve all the lazy evalutation
# codeblocks for the chozen target and all those it inherits from,
# recursively
sub resolve_config {
    my $target = shift;
    my @breadcrumbs = @_;

#    my $extra_checks = defined($ENV{CONFIGURE_EXTRA_CHECKS});

    if (grep { $_ eq $target } @breadcrumbs) {
	die "inherit_from loop!  target backtrace:\n  "
	    ,$target,"\n  ",join("\n  ", @breadcrumbs),"\n";
    }

    if (!defined($table{$target})) {
	warn "Warning! target $target doesn't exist!\n";
	return ();
    }
    # Recurse through all inheritances.  They will be resolved on the
    # fly, so when this operation is done, they will all just be a
    # bunch of attributes with string values.
    # What we get here, though, are keys with references to lists of
    # the combined values of them all.  We will deal with lists after
    # this stage is done.
    my %combined_inheritance = ();
    if ($table{$target}->{inherit_from}) {
	my @inherit_from =
	    map { ref($_) eq "CODE" ? $_->() : $_ } @{$table{$target}->{inherit_from}};
	foreach (@inherit_from) {
	    my %inherited_config = resolve_config($_, $target, @breadcrumbs);

	    # 'template' is a marker that's considered private to
	    # the config that had it.
	    delete $inherited_config{template};

	    map {
		if (!$combined_inheritance{$_}) {
		    $combined_inheritance{$_} = [];
		}
		push @{$combined_inheritance{$_}}, $inherited_config{$_};
	    } keys %inherited_config;
	}
    }

    # We won't need inherit_from in this target any more, since we've
    # resolved all the inheritances that lead to this
    delete $table{$target}->{inherit_from};

    # Now is the time to deal with those lists.  Here's the place to
    # decide what shall be done with those lists, all based on the
    # values of the target we're currently dealing with.
    # - If a value is a coderef, it will be executed with the list of
    #   inherited values as arguments.
    # - If the corresponding key doesn't have a value at all or is the
    #   emoty string, the inherited value list will be run through the
    #   default combiner (below), and the result becomes this target's
    #   value.
    # - Otherwise, this target's value is assumed to be a string that
    #   will simply override the inherited list of values.
    my $default_combiner = add();

    my %all_keys =
	map { $_ => 1 } (keys %combined_inheritance,
			 keys %{$table{$target}});

    sub process_values {
	my $object    = shift;
	my $inherited = shift;  # Always a [ list ]
	my $target    = shift;
	my $entry     = shift;

        $add_called = 0;

        while(ref($object) eq "CODE") {
            $object = $object->(@$inherited);
        }
        if (!defined($object)) {
            return ();
        }
        elsif (ref($object) eq "ARRAY") {
            local $add_called;  # To make sure recursive calls don't affect it
            return [ map { process_values($_, $inherited, $target, $entry) }
                     @$object ];
        } elsif (ref($object) eq "") {
            return $object;
        } else {
            die "cannot handle reference type ",ref($object)
                ," found in target ",$target," -> ",$entry,"\n";
        }
    }

    foreach (sort keys %all_keys) {
        my $previous = $combined_inheritance{$_};

	# Current target doesn't have a value for the current key?
	# Assign it the default combiner, the rest of this loop body
	# will handle it just like any other coderef.
	if (!exists $table{$target}->{$_}) {
	    $table{$target}->{$_} = $default_combiner;
	}

	$table{$target}->{$_} = process_values($table{$target}->{$_},
					       $combined_inheritance{$_},
					       $target, $_);
        unless(defined($table{$target}->{$_})) {
            delete $table{$target}->{$_};
        }
#        if ($extra_checks &&
#            $previous && !($add_called ||  $previous ~~ $table{$target}->{$_})) {
#            warn "$_ got replaced in $target\n";
#        }
    }

    # Finally done, return the result.
    return %{$table{$target}};
}

sub usage
	{
	print STDERR $usage;
	print STDERR "\npick os/compiler from:\n";
	my $j=0;
	my $i;
        my $k=0;
	foreach $i (sort keys %table)
		{
		next if $table{$i}->{template};
		next if $i =~ /^debug/;
		$k += length($i) + 1;
		if ($k > 78)
			{
			print STDERR "\n";
			$k=length($i);
			}
		print STDERR $i . " ";
		}
	foreach $i (sort keys %table)
		{
		next if $table{$i}->{template};
		next if $i !~ /^debug/;
		$k += length($i) + 1;
		if ($k > 78)
			{
			print STDERR "\n";
			$k=length($i);
			}
		print STDERR $i . " ";
		}
	print STDERR "\n\nNOTE: If in doubt, on Unix-ish systems use './config'.\n";
	exit(1);
	}

sub run_dofile
{
    my $out = shift;
    my @templates = @_;

    unlink $out || warn "Can't remove $out, $!"
        if -f $out;
    foreach (@templates) {
        die "Can't open $_, $!" unless -f $_;
    }
    my $cmd = "$config{perl} \"-I.\" \"-Mconfigdata\" $dofile -o\"Configure\" \"".join("\" \"",@templates)."\" > \"$out.new\"";
    #print STDERR "DEBUG[run_dofile]: \$cmd = $cmd\n";
    system($cmd);
    exit 1 if $? != 0;
    rename("$out.new", $out) || die "Can't rename $out.new, $!";
}

# Configuration printer ##############################################

sub print_table_entry
{
    my $target = shift;
    my %target = resolve_config($target);
    my $type = shift;

    # Don't print the templates
    return if $target{template};

    my @sequence = (
	"sys_id",
	"cc",
	"cflags",
	"defines",
	"unistd",
	"ld",
	"lflags",
	"plib_lflags",
	"ex_libs",
	"bn_ops",
	"cpuid_obj",
	"bn_obj",
	"ec_obj",
	"des_obj",
	"aes_obj",
	"bf_obj",
	"md5_obj",
	"sha1_obj",
	"cast_obj",
	"rc4_obj",
	"rmd160_obj",
	"rc5_obj",
	"wp_obj",
	"cmll_obj",
	"modes_obj",
	"padlock_obj",
	"thread_scheme",
	"perlasm_scheme",
	"dso_scheme",
	"shared_target",
	"shared_cflag",
	"shared_ldflag",
	"shared_rcflag",
	"shared_extension",
	"shared_extension_simple",
	"shared_import_extension",
	"dso_extension",
	"obj_extension",
	"exe_extension",
	"ranlib",
	"ar",
	"arflags",
	"multilib",
	"build_scheme",
	);

    if ($type eq "TABLE") {
	print "\n";
	print "*** $target\n";
        foreach (@sequence) {
            if (ref($target{$_}) eq "ARRAY") {
                printf "\$%-12s = %s\n", $_, join(" ", @{$target{$_}});
            } else {
                printf "\$%-12s = %s\n", $_, $target{$_};
            }
        }
    } elsif ($type eq "HASH") {
	my $largest =
	    length((sort { length($a) <=> length($b) } @sequence)[-1]);
	print "    '$target' => {\n";
	foreach (@sequence) {
	    if ($target{$_}) {
                if (ref($target{$_}) eq "ARRAY") {
                    print "      '",$_,"'"," " x ($largest - length($_))," => [ ",join(", ", map { "'$_'" } @{$target{$_}})," ],\n";
                } else {
                    print "      '",$_,"'"," " x ($largest - length($_))," => '",$target{$_},"',\n";
                }
	    }
	}
	print "    },\n";
    }
}

# Utility routines ###################################################

# On VMS, if the given file is a logical name, File::Spec::Functions
# will consider it an absolute path.  There are cases when we want a
# purely syntactic check without checking the environment.
sub isabsolute {
    my $file = shift;

    # On non-platforms, we just use file_name_is_absolute().
    return file_name_is_absolute($file) unless $^O eq "VMS";

    # If the file spec includes a device or a directpry spec,
    # file_name_is_absolute() is perfectly safe.
    return file_name_is_absolute($file) if $file =~ m|[:\[]|;

    # Here, we know the given file spec isn't absolute
    return 0;
}

# Makes a directory absolute and cleans out /../ in paths like foo/../bar
# On some platforms, this uses rel2abs(), while on others, realpath() is used.
# realpath() requires that at least all path components except the last is an
# existing directory.  On VMS, the last component of the directory spec must
# exist.
sub absolutedir {
    my $dir = shift;

    # realpath() is quite buggy on VMS.  It uses LIB$FID_TO_NAME, which
    # will return the volume name for the device, no matter what.  Also,
    # it will return an incorrect directory spec if the argument is a
    # directory that doesn't exist.
    if ($^O eq "VMS") {
        return rel2abs($dir);
    }

    # We use realpath() on Unix, since no other will properly clean out
    # a directory spec.
    use Cwd qw/realpath/;

    return realpath($dir);
}

sub which
	{
	my($name)=@_;
	my $path;
	foreach $path (split /:/, $ENV{PATH})
		{
		my $fullpath = "$path/$name$target{exe_extension}";
		if (-f $fullpath and -x $fullpath)
			{
			return $fullpath
			    unless ($name eq "perl" and
				    system("$fullpath -e " . '\'exit($]<5.0);\''));
			}
		}
	}

sub quotify {
    my %processors = (
	perl    => sub { my $x = shift;
			 $x =~ s/([\\\$\@"])/\\$1/g;
			 return '"'.$x.'"'; },
	);
    my $for = shift;
    my $processor =
	defined($processors{$for}) ? $processors{$for} : sub { shift; };

    map { $processor->($_); } @_;
}

# collect_from_file($filename, $line_concat_cond_re, $line_concat)
# $filename is a file name to read from
# $line_concat_cond_re is a regexp detecting a line continuation ending
# $line_concat is a CODEref that takes care of concatenating two lines
sub collect_from_file {
    my $filename = shift;
    my $line_concat_cond_re = shift;
    my $line_concat = shift;

    open my $fh, $filename || die "unable to read $filename: $!\n";
    return sub {
        my $saved_line = "";
        $_ = "";
        while (<$fh>) {
            s|\R$||;
            if (defined $line_concat) {
                $_ = $line_concat->($saved_line, $_);
                $saved_line = "";
            }
            if (defined $line_concat_cond_re && /$line_concat_cond_re/) {
                $saved_line = $_;
                next;
            }
            return $_;
        }
        die "$filename ending with continuation line\n" if $_;
        close $fh;
        return undef;
    }
}

# collect_from_array($array, $line_concat_cond_re, $line_concat)
# $array is an ARRAYref of lines
# $line_concat_cond_re is a regexp detecting a line continuation ending
# $line_concat is a CODEref that takes care of concatenating two lines
sub collect_from_array {
    my $array = shift;
    my $line_concat_cond_re = shift;
    my $line_concat = shift;
    my @array = (@$array);

    return sub {
        my $saved_line = "";
        $_ = "";
        while (defined($_ = shift @array)) {
            s|\R$||;
            if (defined $line_concat) {
                $_ = $line_concat->($saved_line, $_);
                $saved_line = "";
            }
            if (defined $line_concat_cond_re && /$line_concat_cond_re/) {
                $saved_line = $_;
                next;
            }
            return $_;
        }
        die "input text ending with continuation line\n" if $_;
        return undef;
    }
}

# collect_information($lineiterator, $line_continue, $regexp => $CODEref, ...)
# $lineiterator is a CODEref that delivers one line at a time.
# All following arguments are regex/CODEref pairs, where the regexp detects a
# line and the CODEref does something with the result of the regexp.
sub collect_information {
    my $lineiterator = shift;
    my %collectors = @_;

    while(defined($_ = $lineiterator->())) {
        s|\R$||;
        my $found = 0;
        foreach my $re (keys %collectors) {
            if ($re ne "OTHERWISE" && /$re/) {
                $collectors{$re}->($lineiterator);
                $found = 1;
            };
        }
        if ($collectors{"OTHERWISE"}) {
            $collectors{"OTHERWISE"}->($lineiterator, $_)
                unless $found || !defined $collectors{"OTHERWISE"};
        }
    }
}