Configure

#! /usr/bin/env perl
# -*- mode: perl; -*-
# Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
#
# Licensed under the OpenSSL license (the "License").  You may not use
# this file except in compliance with the License.  You can obtain a copy
# in the file LICENSE in the source distribution or at
# https://www.openssl.org/source/license.html

##  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/;
use if $^O ne "VMS", 'File::Glob' => qw/glob/;

# 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 assembler,
# SHA1_ASM	use some extra sha1 assembler, must define L_ENDIAN for x86
# RMD160_ASM	use some extra ripemd160 assembler,
# 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.

# DEBUG_UNUSED enables __owur (warn unused result) checks.
my $gcc_devteam_warn = "-DDEBUG_UNUSED"
        # -DPEDANTIC complements -pedantic and is meant to mask code that
        # is not strictly standard-compliant and/or implementation-specifc,
        # e.g. inline assembly, disregards to alignment requirements, such
        # that -pedantic would complain about. Incidentally -DPEDANTIC has
        # to be used even in sanitized builds, because sanitizer too is
        # supposed to and does take notice of non-standard behaviour. Then
        # -pedantic with pre-C9x compiler would also complain about 'long
        # long' not being supported. As 64-bit algorithms are common now,
        # it grew impossible to resolve this without sizeable additional
        # code, so we just tell compiler to be pedantic about everything
        # but 'long long' type.
        . " -DPEDANTIC -pedantic -Wno-long-long"
        . " -Wall"
        . " -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 evaluations, 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"));

my $local_config_envname = 'OPENSSL_LOCAL_CONFIG_DIR';

$config{sourcedir} = abs2rel($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($_);
}

if (defined $ENV{$local_config_envname}) {
    if ($^O eq 'VMS') {
        # VMS environment variables are logical names,
        # which can be used as is
        $pattern = $local_config_envname . ':' . '*.conf';
    } else {
        $pattern = catfile($ENV{$local_config_envname}, '*.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);

# Explicitly 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 = (
    "afalgeng",
    "asan",
    "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",
    "fuzz-libfuzzer",
    "fuzz-afl",
    "gost",
    "heartbeats",
    "hw(-.+)?",
    "idea",
    "makedepend",
    "md2",
    "md4",
    "mdc2",
    "multiblock",
    "nextprotoneg",
    "ocb",
    "ocsp",
    "pic",
    "poly1305",
    "posix-io",
    "psk",
    "rc2",
    "rc4",
    "rc5",
    "rdrand",
    "rfc3779",
    "rmd160",
    "scrypt",
    "sctp",
    "seed",
    "shared",
    "sock",
    "srp",
    "srtp",
    "sse2",
    "ssl",
    "ssl-trace",
    "static-engine",
    "stdio",
    "threads",
    "tls",
    "ts",
    "ubsan",
    "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" => undef,
    "buf-freelists" => undef,
    "ripemd" => "rmd160"
    );

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

our %disabled = ( # "what"         => "comment"
                  "asan"		=> "default",
		  "ec_nistp_64_gcc_128" => "default",
		  "egd"                 => "default",
		  "fuzz-libfuzzer"	=> "default",
		  "fuzz-afl"		=> "default",
		  "md2"                 => "default",
		  "rc5"                 => "default",
		  "sctp"                => "default",
		  "ssl-trace"           => "default",
		  "ssl3"                => "default",
		  "ssl3-method"         => "default",
                  "ubsan"		=> "default",
		  "unit-test"           => "default",
		  "weak-ssl-ciphers"    => "default",
		  "zlib"                => "default",
		  "zlib-dynamic"        => "default",
		  "crypto-mdebug"       => "default",
		  "crypto-mdebug-backtrace" => "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" ],
    "des"		=> [ "mdc2" ],
    "ec"		=> [ "ecdsa", "ecdh" ],

    "dgram"		=> [ "dtls", "sctp" ],
    "sock"		=> [ "dgram" ],
    "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" ],

    # no-autoalginit is only useful when building non-shared
    "autoalginit"       => [ "shared", "apps" ],

    "stdio"             => [ "apps" ],
    "apps"              => [ "tests" ],
    "comp"		=> [ "zlib" ],
    sub { !$disabled{"unit-test"} } => [ "heartbeats" ],
    );

# 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 $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 @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 (!exists $deprecated_disablables{$word}
                        && !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)";
                                }
                        $disabled{"dtls"} = "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";
                        }
                elsif (exists $deprecated_disablables{$1})
                        {
                        $deprecated_options{$_} = 1;
                        if (defined $deprecated_disablables{$1})
                                {
                                $disabled{$deprecated_disablables{$1}} = "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;
		$nofipscanistercheck = 1;
		}
	elsif (/^[-+]/)
		{
		if (/^--prefix=(.*)$/)
			{
			$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}=$1;
			}
		elsif (/^--with-fuzzer-lib=(.*)$/)
			{
			$withargs{fuzzer_lib}=$1;
			}
		elsif (/^--with-fuzzer-include=(.*)$/)
			{
			$withargs{fuzzer_include}=$1;
			}
		elsif (/^--with-fipslibdir=(.*)$/)
			{
			$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 seriously,
		# 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{$test})) {
	    foreach(grep { !defined($disabled{$_}) } @$descendents) {
		$new_tocheckfor{$_} = 1; $disabled{$_} = "forced";
	    }
	}
    }
    @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)/);
$target{exe_extension}=".pm"  if ($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} =    $ENV{'PERL'}    || ($^O ne "VMS" ? $^X : "perl");
$target{cc} =      $ENV{'CC'}      || $target{cc}      || "cc";
$target{ranlib} =  $ENV{'RANLIB'}  || $target{ranlib}  ||
                   (which("$config{cross_compile_prefix}ranlib") ?
                          "\$(CROSS_COMPILE)ranlib" : "true");
$target{ar} =      $ENV{'AR'}      || $target{ar}      || "ar";
$target{nm} =      $ENV{'NM'}      || $target{nm}      || "nm";
$target{rc} =
    $ENV{'RC'}  || $ENV{'WINDRES'} || $target{rc}      || "windres";

# 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";

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

push @{$config{defines}}, "NDEBUG"    if $config{build_type} eq "release";

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)") {
            $disabled{threads} = "unavailable";
        }
    } else {
        # The user chose to enable threads explicitly, let's see
        # if there's a chance that's possible
        if ($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;
}

unless ($disabled{"fuzz-libfuzzer"}) {
    push @{$config{dirs}}, "fuzz";
    $config{cflags} .= "-fsanitize-coverage=edge,indirect-calls ";
}

unless ($disabled{"fuzz-afl"}) {
    push @{$config{dirs}}, "fuzz";
}

unless ($disabled{asan}) {
    $config{cflags} .= "-fsanitize=address ";
}

unless ($disabled{ubsan}) {
    # -DPEDANTIC or -fnosanitize=aligmnent may also be required on some
    # platforms.
    $config{cflags} .= "-fsanitize=undefined -fno-sanitize-recover=all ";
}

unless ($disabled{"fuzz-libfuzzer"} && $disabled{"fuzz-afl"}
        && $disabled{asan} && $disabled{ubsan}) {
    $config{cflags} .= "-fno-omit-frame-pointer -g ";
}
#
# 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 = ();

my $buildinfo_debug = defined($ENV{CONFIGURE_DEBUG_BUILDINFO});
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;

    for my $filename (( $builder_platform."-".$target{build_file}.".tmpl",
                        $target{build_file}.".tmpl" )) {
        if (defined $ENV{$local_config_envname}) {
            if ($^O eq 'VMS') {
                # VMS environment variables are logical names,
                # which can be used as is
                $build_file_template = $local_config_envname . ':' . $filename;
            } else {
                $build_file_template = catfile($ENV{$local_config_envname},
                                               $filename);
            }
        }

        last if -f $build_file_template;

        $build_file_template = catfile($srcdir, "Configurations", $filename);

        last 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 %shared_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,
            $template->fill_in(HASH => { config => \%config,
                                         target => \%target,
                                         disabled => \%disabled,
                                         withargs => \%withargs,
                                         builddir => abs2rel($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, tokenize($1)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*LIBS\s*=\s*(.*)\s*$/
            => sub { push @libraries, tokenize($1)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*ENGINES\s*=\s*(.*)\s*$/
            => sub { push @engines, tokenize($1)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*SCRIPTS\s*=\s*(.*)\s*$/
            => sub { push @scripts, tokenize($1)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*EXTRA\s*=\s*(.*)\s*$/
            => sub { push @extra, tokenize($1)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*OVERRIDES\s*=\s*(.*)\s*$/
            => sub { push @overrides, tokenize($1)
                         if !@skip || $skip[$#skip] > 0 },

            qr/^\s*ORDINALS\[((?:\\.|[^\\\]])+)\]\s*=\s*(.*)\s*$/,
            => sub { push @{$ordinals{$1}}, tokenize($2)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*SOURCE\[((?:\\.|[^\\\]])+)\]\s*=\s*(.*)\s*$/
            => sub { push @{$sources{$1}}, tokenize($2)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*SHARED_SOURCE\[((?:\\.|[^\\\]])+)\]\s*=\s*(.*)\s*$/
            => sub { push @{$shared_sources{$1}}, tokenize($2)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*INCLUDE\[((?:\\.|[^\\\]])+)\]\s*=\s*(.*)\s*$/
            => sub { push @{$includes{$1}}, tokenize($2)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*DEPEND\[((?:\\.|[^\\\]])*)\]\s*=\s*(.*)\s*$/
            => sub { push @{$depends{$1}}, tokenize($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}}, tokenize($2)
                         if !@skip || $skip[$#skip] > 0 },
            qr/^\s*SHARED_NAME\[((?:\\.|[^\\\]])+)\]\s*=\s*(.*)\s*$/
            => sub { push @{$sharednames{$1}}, tokenize($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" },
            "BEFORE" => sub {
                if ($buildinfo_debug) {
                    print STDERR "DEBUG: Parsing ",join(" ", @_),"\n";
                    print STDERR "DEBUG: ... before parsing, skip stack is ",join(" ", map { int($_) } @skip),"\n";
                }
            },
            "AFTER" => sub {
                if ($buildinfo_debug) {
                    print STDERR "DEBUG: .... after parsing, skip stack is ",join(" ", map { int($_) } @skip),"\n";
                }
            },
            );
        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 %shared_sources) {
            my $dest = $_;
            my $ddest = cleanfile($buildd, $_, $blddir);
            if ($unified_info{rename}->{$ddest}) {
                $ddest = $unified_info{rename}->{$ddest};
            }
            foreach (@{$shared_sources{$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);
                    $unified_info{shared_sources}->{$ddest}->{$o} = 1;
                    $unified_info{sources}->{$o}->{$s} = 1;
                } else {
                    die "unrecognised source file type for shared library: $s\n";
                }
            }
        }

        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 = $dest eq "" ? "" : cleanfile($sourced, $_, $blddir);

            # If the destination doesn't exist in source, it can only be
            # a generated file in the build tree.
            if ($ddest ne "" && ! -f $ddest) {
                $ddest = cleanfile($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, $_, $blddir) }
                        grep { /\.h$/ } keys %{$unified_info{generate}})) {
                    $d = cleanfile($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}->{$d} = 1;
                # If we depend on a header file or a perl module, let's make
                # sure it can get included
                if ($dest ne "" && $d =~ /\.(h|pm)$/) {
                    my $i = dirname($d);
                    push @{$unified_info{includes}->{$ddest}}, $i
                        unless grep { $_ eq $i } @{$unified_info{includes}->{$ddest}};
                }
            }
        }

        foreach (keys %includes) {
            my $dest = $_;
            my $ddest = cleanfile($sourced, $_, $blddir);

            # If the destination doesn't exist in source, it can only be
            # a generated file in the build tree.
            if (! -f $ddest) {
                $ddest = cleanfile($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", "shared_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 \@disablables);

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 \@disablables = (\n";
foreach (@disablables) {
    print OUT "  ", quotify("perl", $_), ",\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 "CC            =$config{cross_compile_prefix}$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        =", $target{ranlib} eq '$(CROSS_COMPILE)ranlib' ?
                             "$config{cross_compile_prefix}ranlib" :
                             "$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;

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

$builders{$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

print <<"EOF" if (-f catfile($srcdir, "configdata.pm") && $srcdir ne $blddir);

WARNING: there are indications that another build was made in the source
directory.  This build may have picked up artifacts from that build, the
safest course of action is to clean the source directory and redo this
configuration.
EOF

exit(0);

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

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

# Note: All of the helper functions are for lazy evaluation.  They all
# return a CODE ref, which will return the intended value when evaluated.
# Thus, whenever there's mention of a returned value, it's about that
# intended value.

# 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;
    }
}

# Helper function to implement conditional value variants, with a default
# plus additional values based on the value of $config{build_type}.
# Arguments are given in hash table form:
#
#       picker(default => "Basic string: ",
#              debug   => "debug",
#              release => "release")
#
# When configuring with --debug, the resulting string will be
# "Basic string: debug", and when not, it will be "Basic string: release"
#
# This can be used to create variants of sets of flags according to the
# build type:
#
#       cflags => picker(default => "-Wall",
#                        debug   => "-g -O0",
#                        release => "-O3")
#
sub picker {
    my %opts = @_;
    return sub { add($opts{default} || (),
                     $opts{$config{build_type}} || ())->(); }
}

# Helper function to combine several values of different types into one.
# This is useful if you want to combine a string with the result of a
# lazy function, such as:
#
#       cflags => combine("-Wall", sub { $disabled{zlib} ? () : "-DZLIB" })
#
sub combine {
    my @stuff = @_;
    return sub { add(@stuff)->(); }
}

# Helper function to implement conditional values depending on the value
# of $disabled{threads}.  Can be used as follows:
#
#       cflags => combine("-Wall", threads("-pthread"))
#
sub threads {
    my @flags = @_;
    return sub { add($disabled{threads} ? () : @flags)->(); }
}



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 evaluation
# codeblocks for the chosen 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};

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

    # 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
    #   empty 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, $!";
}

sub which
{
    my ($name)=@_;

    if (eval { require IPC::Cmd; 1; }) {
        IPC::Cmd->import();
        return scalar IPC::Cmd::can_run($name);
    } else {
        # if there is $directories component in splitpath,
        # then it's not something to test with $PATH...
        return $name if (File::Spec->splitpath($name))[1];

        foreach (File::Spec->path()) {
            my $fullpath = catfile($_, "$name$target{exe_extension}");
            if (-f $fullpath and -x $fullpath) {
                return $fullpath;
            }
        }
    }
}

# 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 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; };

    return 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 $found = 0;
        if ($collectors{"BEFORE"}) {
            $collectors{"BEFORE"}->($_);
        }
        foreach my $re (keys %collectors) {
            if ($re !~ /^OTHERWISE|BEFORE|AFTER$/ && /$re/) {
                $collectors{$re}->($lineiterator);
                $found = 1;
            };
        }
        if ($collectors{"OTHERWISE"}) {
            $collectors{"OTHERWISE"}->($lineiterator, $_)
                unless $found || !defined $collectors{"OTHERWISE"};
        }
        if ($collectors{"AFTER"}) {
            $collectors{"AFTER"}->($_);
        }
    }
}

# tokenize($line)
# $line is a line of text to split up into tokens
# returns a list of tokens
#
# Tokens are divided by spaces.  If the tokens include spaces, they
# have to be quoted with single or double quotes.  Double quotes
# inside a double quoted token must be escaped.  Escaping is done
# with backslash.
# Basically, the same quoting rules apply for " and ' as in any
# Unix shell.
sub tokenize {
    my $line = my $debug_line = shift;
    my @result = ();

    while ($line =~ s|^\s+||, $line ne "") {
        my $token = "";
        while ($line ne "" && $line !~ m|^\s|) {
            if ($line =~ m/^"((?:[^"\\]+|\\.)*)"/) {
                $token .= $1;
                $line = $';
            } elsif ($line =~ m/^'([^']*)'/) {
                $token .= $1;
                $line = $';
            } elsif ($line =~ m/^(\S+)/) {
                $token .= $1;
                $line = $';
            }
        }
        push @result, $token;
    }

    if ($ENV{CONFIGURE_DEBUG_TOKENIZE}) {
	print STDERR "DEBUG[tokenize]: Parsed '$debug_line' into:\n";
	print STDERR "DEBUG[tokenize]: ('", join("', '", @result), "')\n";
    }
    return @result;
}