#!/usr/bin/env perl

use 5.006;
use strict;
use warnings;

use File::Spec;
use File::Temp qw( tempfile tmpnam );

sub shell ($@);
sub env ($$);
sub cd ($);
sub auto_complete ($);
sub usage ($);
sub trim ($);

my (@make_cmds, @make_install_cmds);

my $root_dir = `pwd`;
chomp $root_dir;

my $OS = $^O;

my $ngx_dir;

for my $opt (@ARGV) {
    if ($opt =~ /^--platform=(.*)/) {
        $OS = $1;
        undef $opt;
    }
}

my @extra_make_env;

my ($platform, $on_solaris);

if ($OS =~ /solaris|sunos/i) {
    $platform = 'solaris';
    $on_solaris = $platform;

} elsif ($OS eq 'linux') {
    $platform = $OS;

} elsif ($OS eq 'MSWin32') {
    die "MS Windows not supported. Abort.\n",
        "(You need to use the MSYS toolchain, ",
        "including MinGW gcc, MSYS perl, MSYS bash, and etc.\n";

} elsif ($OS =~ /^(?:MacOS|darwin|rhapsody)$/) {
    $platform = 'macosx';

} elsif ($OS eq 'freebsd') {
    $platform = $OS;

} elsif ($OS =~ /^(?:openbsd|netbsd|dragonfly)$/) {
    $platform = 'bsd';

} elsif ($OS eq 'msys') {
    $platform = 'msys';

} else {
    $platform = 'posix';
}

my @modules = (
    [ndk => 'ngx_devel_kit'],
    [http_iconv => 'iconv-nginx-module', 'disabled'],
    [http_echo => 'echo-nginx-module'],
    [http_xss => 'xss-nginx-module'],
    [http_coolkit => 'ngx_coolkit'],
    [http_set_misc => 'set-misc-nginx-module'],
    [http_form_input => 'form-input-nginx-module'],
    [http_encrypted_session => 'encrypted-session-nginx-module'],
    [http_drizzle => 'drizzle-nginx-module', 'disabled'],
    [http_postgres => 'ngx_postgres', 'disabled'],
    [http_srcache => 'srcache-nginx-module'],
    [http_lua => 'ngx_lua'],
    [http_lua_upstream => 'ngx_lua_upstream'],
    [http_headers_more => 'headers-more-nginx-module'],
    [http_array_var => 'array-var-nginx-module'],
    [http_memc => 'memc-nginx-module'],
    [http_redis2 => 'redis2-nginx-module'],
    [http_redis => 'redis-nginx-module'],
    #[http_upstream_keepalive => 'upstream-keepalive-nginx-module'],
    #[http_auth_request => 'auth-request-nginx-module'],
    [http_rds_json => 'rds-json-nginx-module'],
    [http_rds_csv => 'rds-csv-nginx-module'],
    [stream_lua => 'ngx_stream_lua'],
);

my $without_resty_mods_regex;
{
    my $s = '^--without-('
        . join('|',
            map { $_->[0] }
                grep { @$_ == 2 && $_->[0] =~ /^(?:http|stream)_/ }
                @modules
          )
        . ')_module$';

    #warn "without regex: $s";

    $without_resty_mods_regex = qr/$s/;
}

my $with_resty_mods_regex;
{
    my $s = '^--with-('
        . join('|',
            map { $_->[0] }
                grep { @$_ == 3 && $_->[0] =~ /^(?:http|stream)_/ }
                @modules
          )
        . ')_module$';

    #warn "with regex: $s";

    $with_resty_mods_regex = qr/$s/;
}

my $prefix = '/usr/local/openresty';
my $ngx_sbin;
my %resty_opts;
my $dry_run;
my @ngx_rpaths;
my $cc;
my $cores;
my $luajit_xcflags = '';
my $user_luajit_xcflags;
my $no_luajit_lua52;

my (@ngx_opts, @ngx_cc_opts, @ngx_ld_opts);

# use -O2 to compile everything by default (which can be overridden
# by the user's own --with-cc-opt=OPTS option):
push @ngx_cc_opts, "-O2";

for my $opt (@ARGV) {
    next unless defined $opt;

    if ($opt =~ /^-j(\d+)/) {
        $cores = $1;
        next;
    }

    if ($opt =~ /^--with-cc=(.+)/) {
        $cc = $1;
        push @ngx_opts, "$opt";
        next;
    }

    if ($opt eq '--dry-run') {
        $dry_run = 1;
        next;
    }

    if ($opt =~ /^--with-make=(.*)/) {
        $resty_opts{make} = $1;
        next;
    }

    if ($opt =~ /^--prefix=(.*)/) {
        $prefix = $1;
        if ($prefix eq '') {
            $prefix = '.';
        }

    } elsif ($opt eq '--without-lua51') {
        die "ERROR: --without-lua51 is no longer supported.\n";

    } elsif ($opt eq '--with-lua51') {
        die "ERROR: --with-lua51 is no longer supported.\n";

    } elsif ($opt =~ /^--with-lua51=(.*)/) {
        die "ERROR: --with-lua51=PATH is no longer supported.\n";

    } elsif ($opt eq '--without-http_rewrite_module') {
        warn "WARNING: ngx_devel_kit is automatically disabled ",
            "because ngx_http_rewrite_module is disabled.\n";
        $resty_opts{no_ndk} = 1;
        push @ngx_opts, $opt;

    } elsif ($opt eq '--without-lua_cjson') {
        $resty_opts{no_lua_cjson} = 1;

    } elsif ($opt eq '--without-lua_redis_parser') {
        $resty_opts{no_lua_redis_parser} = 1;

    } elsif ($opt eq '--without-lua_resty_memcached') {
        $resty_opts{no_lua_resty_memcached} = 1;

    } elsif ($opt eq '--without-lua_resty_redis') {
        $resty_opts{no_lua_resty_redis} = 1;

    } elsif ($opt eq '--without-lua_resty_dns') {
        $resty_opts{no_lua_resty_dns} = 1;

    } elsif ($opt eq '--without-lua_resty_mysql') {
        $resty_opts{no_lua_resty_mysql} = 1;

    } elsif ($opt eq '--without-lua_resty_upload') {
        $resty_opts{no_lua_resty_upload} = 1;

    } elsif ($opt eq '--without-lua_resty_string') {
        $resty_opts{no_lua_resty_string} = 1;

    } elsif ($opt eq '--without-lua_resty_limit_traffic') {
        $resty_opts{no_lua_resty_limit_traffic} = 1;

    } elsif ($opt eq '--without-lua_resty_websocket') {
        $resty_opts{no_lua_resty_websocket} = 1;

    } elsif ($opt eq '--without-lua_resty_lock') {
        $resty_opts{no_lua_resty_lock} = 1;

    } elsif ($opt eq '--without-lua_resty_lrucache') {
        $resty_opts{no_lua_resty_lrucache} = 1;

    } elsif ($opt eq '--without-lua_resty_core') {
        $resty_opts{no_lua_resty_core} = 1;

    } elsif ($opt eq '--without-lua_resty_upstream_healthcheck') {
        $resty_opts{no_lua_resty_upstream_healthcheck} = 1;

    } elsif ($opt eq '--without-lua_rds_parser') {
        $resty_opts{no_lua_rds_parser} = 1;

    } elsif ($opt eq '--with-debug') {
        $resty_opts{debug} = 1;

    } elsif ($opt eq '--help') {
        usage 0;

    } elsif ($opt =~ /^--with-cc-opt=(.*)/) {
        push @ngx_cc_opts, $1;

    } elsif ($opt =~ /^--with-ld-opt=(.*)/) {
        push @ngx_ld_opts, $1;

    } elsif ($opt =~ $without_resty_mods_regex) {
        #die "no_$1\n";
        $resty_opts{"no_$1"} = 1;

    } elsif ($opt eq '--without-ngx_devel_kit_module') {
        $resty_opts{no_ndk} = 1;

    } elsif ($opt =~ $with_resty_mods_regex) {
        $resty_opts{"$1"} = 1;

    } elsif ($opt eq '--with-luajit') {
        $resty_opts{luajit} = 1;

    } elsif ($opt =~ /^--with-luajit=(.*)/) {
        $resty_opts{luajit_path} = $1;

    } elsif ($opt =~ /^--with-luajit-xcflags=(.*)/) {
        $user_luajit_xcflags .= " $1";

    } elsif ($opt =~ /^--without-luajit-lua52/) {
        $no_luajit_lua52 = 1;

    } elsif ($opt =~ /^--with-libdrizzle=(.*)/) {
        $resty_opts{libdrizzle} = $1;

    } elsif ($opt =~ /^--with-libpq=(.*)/) {
        $resty_opts{libpq} = $1;
        if ($resty_opts{pg_config}) {
            die "--with-libpq is not allowed when ",
                "--with-pg_config is already specified.\n";
        }

    } elsif ($opt =~ /^--with-pg_config=(.*)/) {
        $resty_opts{pg_config} = $1;
        if ($resty_opts{libpq}) {
            die "--with-pg_config is not allowed when ",
                "--with-libpq is already specified.\n";
        }

    } elsif ($opt eq '--with-no-pool-patch') {
        $resty_opts{no_pool} = 1;

    } elsif ($opt eq '--with-http_ssl_module') {
        $resty_opts{http_ssl} = 1;
        push @ngx_opts, $opt;

    } elsif ($opt eq '--without-http_ssl_module') {
        $resty_opts{no_http_ssl} = 1;
        $resty_opts{no_http_encrypted_session} = 1;

    } elsif ($opt eq '--with-stream_ssl_module') {
        $resty_opts{stream_ssl} = 1;
        push @ngx_opts, $opt;

    } elsif ($opt eq '--with-stream_ssl_preread_module') {
        $resty_opts{stream_ssl_preread} = 1;
        push @ngx_opts, $opt;

    } elsif ($opt eq '--without-stream') {
        $resty_opts{no_stream} = 1;
        $resty_opts{no_stream_ssl} = 1;
        $resty_opts{no_stream_ssl_preread} = 1;
        $resty_opts{no_stream_lua} = 1;

    } elsif ($opt eq '--without-stream_ssl_module') {
        $resty_opts{no_stream_ssl} = 1;

    } elsif ($opt =~ /^--add-module=(.*)/) {

        my $mod_path = File::Spec->rel2abs($1);
        push @ngx_opts, "--add-module=$mod_path";

    } elsif ($opt =~ /^--add-dynamic-module=(.*)/) {

        my $mod_path = File::Spec->rel2abs($1);
        push @ngx_opts, "--add-dynamic-module=$mod_path";

    } elsif ($opt =~ /^--with-(openssl|pcre|zlib|libatomic|md5|sha1)=(.*)/) {

        my ($lib, $path) = ($1, $2);
        if ($lib eq 'openssl' && $OS eq 'darwin') {
            if (`uname -a` =~ /\bx86_64\b/) {
                $ENV{KERNEL_BITS} = 64;
                push @extra_make_env, 'KERNEL_BITS=64';
            }
        }
        $path = File::Spec->rel2abs($path);
        push @ngx_opts, "--with-$lib=$path";

    } elsif ($opt =~ /^--sbin-path=(.*)/) {
        $ngx_sbin = $1;
        push @ngx_opts, $opt;

    } elsif ($opt =~ /^--\w.*/) {
        push @ngx_opts, $opt;

    } else {
        die "Invalid option $opt\n";
    }
}

print "platform: $platform ($OS)\n";

my $ngx_prefix;
if ($platform eq 'msys') {
    $ngx_prefix = "$prefix";
} else {
    $ngx_prefix = "$prefix/nginx";
}

my $postamble = '';

if ($platform ne 'msys') {
    if (!$ngx_sbin) {
        $ngx_sbin = "$ngx_prefix/sbin/nginx";
    }
}

my $resty_opts = build_resty_opts(\%resty_opts);

if (@ngx_rpaths) {
    if ($platform eq 'macosx') {
        for (@ngx_rpaths) {
            unshift @ngx_ld_opts, "-Wl,-rpath,$_";
        }

    } else {
        unshift @ngx_ld_opts, "-Wl,-rpath," . join ":", @ngx_rpaths;
    }
}

my $ld_opts = '';
if (@ngx_ld_opts) {
    $ld_opts = " \\\n  --with-ld-opt='@ngx_ld_opts'";
}

my $cmd = "sh ./configure --prefix=$ngx_prefix"
    . $resty_opts
    . $ld_opts
    . (@ngx_opts ? " \\\n  " . quote_cli_args(\@ngx_opts) : "");
    ;

shell $cmd, $dry_run;

push @make_cmds, "cd $root_dir/build/$ngx_dir && "
    . "\$(MAKE)";

push @make_install_cmds, "cd $root_dir/build/$ngx_dir && "
    . "\$(MAKE) install DESTDIR=\$(DESTDIR)";

push @make_install_cmds,
    "mkdir -p \$(DESTDIR)$prefix/site/lualib"
    . " \$(DESTDIR)$prefix/site/pod"
    . " \$(DESTDIR)$prefix/site/manifest";

if ($platform ne 'msys') {
    push @make_install_cmds,
        "ln -sf $ngx_sbin \$(DESTDIR)$prefix/bin/openresty";
}

cd '../..'; # to the root
#die "pwd: " .. `pwd`;

gen_makefile();

if ($postamble) {
    print $postamble;
}

sub env ($$) {
    my ($name, $val) = @_;
    if (!defined $name) {
        die "env not defined";
    }
    if (!defined $val) {
        die "env $name takes undef value";
    }
    print "export $name='$val'\n";
    $ENV{$name} = $val;
}

sub shell ($@) {
    my ($cmd, $dry_run) = @_;

    print "$cmd\n";

    unless ($dry_run) {
        system($cmd) == 0 or
            die "ERROR: failed to run command: ", trim($cmd), "\n";
    }
}

sub trim ($) {
    my $cmd = shift;
    $cmd =~ s/\n.*/.../s;
    $cmd;
}

sub auto_complete ($) {
    my $name = shift;
    my @dirs = glob "$name-[0-9]*" or
        die "No source directory found for $name\n";

    if (@dirs > 1) {
        die "More than one hits for $name: @dirs\n";
    }

    return $dirs[0];
}

sub cd ($) {
    my $dir = shift;
    print("cd $dir\n");
    chdir $dir or die "failed to cd $dir: $!\n";
}

sub build_resty_opts {
    my $opts = shift;

    my $make;

    if ($opts->{make}) {
        $make = $opts->{make};
        if (! can_run($make)) {
            die "make utility $make cannot be run.\n";
        }

    } else {
        if (can_run("gmake")) {  # msys has no gmake
            $make = 'gmake';

        } else {
            # no gmake found

            if ($platform =~ /bsd/i) {
                die "error: I cannot find \"gmake\" (Gnu make) in your PATH ".
                    "envirnonment. You can also specify your make by the ".
                    "--with-make=PATH option\n";
            }

            if (can_run("make")) {
                $make = "make";

            } else {
                die "No gmake nor make found in PATH.\n";
            }
        }
    }

    $postamble .= <<"_END_";
Type the following commands to build and install:
    $make
    $make install
_END_

    if ($opts->{no_ndk}) {
        for my $name (qw(set_misc iconv lz_session form_input array_var
                         encrypted_session))
        {
            if (! $opts->{"no_http_$name"}) {
                warn "WARNING: ngx_http_${name}_module is automatically ",
                     "disabled because ngx_devel_kit_module is disabled.\n";
                $opts->{"no_http_$name"} = 1;
            }
        }
    }

    if (!$opts->{no_stream_lua}) {
        push @ngx_opts, '--with-stream';
    }

    if ($opts->{no_stream_ssl} && $opts->{stream_ssl}) {
        die "--with-stream_ssl_module conflicts with --without-stream_ssl_module.",
            "\n";
    }

    if (!$opts->{no_stream}
        && ! $opts->{no_stream_ssl}
        && ! $opts->{stream_ssl})
    {
        $opts->{stream_ssl} = 1;
        push @ngx_opts, '--with-stream_ssl_module';
    }

    if (!$opts->{no_stream}
        && ! $opts->{no_stream_ssl_preread}
        && ! $opts->{stream_ssl_preead})
    {
        $opts->{stream_ssl_preread} = 1;
        push @ngx_opts, '--with-stream_ssl_preread_module';
    }

    if (!$opts->{lua}
        && !$opts->{lua_path}
        && (!$opts->{no_http_lua} || !$opts->{no_stream_lua})
        && !$opts->{luajit_path})
    {
        #warn "HIT!";
        $opts->{luajit} = 1;
    }

    #die "luajit: ", $opts->{luajit};

    if ($opts->{luajit} && $opts->{luajit_path}) {
        die "--with-luajit and --with-luajit=DIR are mutually exclusive.\n";
    }

    if ($opts->{no_http_ssl} && $opts->{http_ssl}) {
        die "--with-http_ssl_module conflicts with --without-http_ssl_module.",
            "\n";
    }

    if (! $opts->{no_http_ssl} && ! $opts->{http_ssl}) {
        $opts->{http_ssl} = 1;
        push @ngx_opts, '--with-http_ssl_module';
    }

    if (! $opts->{http_drizzle} && $opts->{libdrizzle}) {
        die "The http_drizzle_module is not enabled while --with-libdrizzle ",
            "is specified.\n";
    }

    if (! $opts->{http_postgres} && $opts->{libpq}) {
        die "The http_postgres_module is not enabled while --with-libpq is ",
            "specified.\n";
    }

    if (! $opts->{http_postgres} && $opts->{pg_config}) {
        die "The http_postgres_module is not enabled while --with-pg_config ",
            "is specified.\n";
    }

    if ($platform eq 'linux' && $opts->{luajit} && ! can_run("ldconfig")) {
        die "you need to have ldconfig in your PATH env when enabling luajit.",
            "\n";
    }

    my $opts_line = '';

    if ($opts->{debug}) {
        unshift @ngx_cc_opts, '-DNGX_LUA_USE_ASSERT',
            '-DNGX_LUA_ABORT_AT_PANIC';
        $opts_line .= " \\\n  --with-debug";

    } else {
        #unshift @ngx_cc_opts, '-O2';
    }

    if (-d 'build') {
        system("rm -rf build") == 0 or
            die "failed to remove directory build/.\n";
    }

    if (-e 'build') {
        die "file or directory \"build\" already exists. please remove it ",
            "first.\n";
    }
    shell "cp -rp bundle/ build";

    cd 'build';

    push @make_install_cmds, "mkdir -p \$(DESTDIR)$prefix/",
        "-cp $root_dir/COPYRIGHT \$(DESTDIR)$prefix/";

    # build 3rd-party C libraries if required

    if ($opts->{no_pool}) {
        if (! can_run("patch")) {
            die "no \"patch\" utility found in your PATH environment.\n";
        }

        shell "patch -p0 < nginx-no_pool.patch";
    }

    if (my $drizzle_prefix = $opts->{libdrizzle}) {
        my $drizzle_lib = "$drizzle_prefix/lib";
        env LIBDRIZZLE_LIB => $drizzle_lib;
        env LIBDRIZZLE_INC => "$drizzle_prefix/include/libdrizzle-1.0";
        push @ngx_rpaths, $drizzle_lib;
    }

    if (my $pg_prefix = $opts->{libpq}) {
        my $pg_lib = "$pg_prefix/lib";
        env LIBPQ_LIB => $pg_lib;
        env LIBPQ_INC => "$pg_prefix/include";
        push @ngx_rpaths, $pg_lib;
    }

    if (my $pg_config = $opts->{pg_config}) {
        if (!can_run($pg_config)) {
            die "pg_config is not runnable.\n";
        }

        my $cmd = "$pg_config --libdir";
        my $pg_lib = `$cmd`;
        chomp $pg_lib;
        if (!defined $pg_lib) {
            die "Failed to run command $cmd\n";
        }

        $cmd = "$pg_config --includedir";
        my $pg_inc = `$cmd`;
        chomp $pg_inc;
        if (!defined $pg_inc) {
            die "Failed to run command $cmd\n";
        }

        env LIBPQ_LIB => $pg_lib;
        env LIBPQ_INC => $pg_inc;
        push @ngx_rpaths, $pg_lib;
    }

    if ($opts->{luajit_path}) {
        my $luajit_prefix = $opts->{luajit_path};

        my $lib = File::Spec->catfile($luajit_prefix, "lib");
        my $inc = File::Spec->catfile($luajit_prefix, "include", "luajit-2.1");

        env LUAJIT_LIB => $lib;
        env LUAJIT_INC => $inc;

        #unshift @ngx_ld_opts, "-L$lib";
        #unshift @ngx_cc_opts, "-I$inc";

        push @ngx_rpaths, "$luajit_prefix/lib";

    } elsif ($opts->{luajit}) {
        my $luajit_src = auto_complete 'LuaJIT';
        my $luajit_prefix = File::Spec->catfile($prefix, "luajit");
        my $luajit_root = File::Spec->rel2abs("luajit-root");

        if (-d $luajit_root) {
            shell "rm -rf $luajit_root";
        }

        mkdir $luajit_root or
            die "create create directory luajit-root: $!\n";

        cd $luajit_src;

        my $extra_opts = ' TARGET_STRIP=@: CCDEBUG=-g';

       {
            my $comp = ($cc || 'cc');
            my $ver = `$comp --version`;
            if (defined $ver && $ver =~ /\(GCC\) (\d+\.\d+)/) {
                my $v = $1;
                if ($v < 4.5) {
                    $luajit_xcflags .= " -std=gnu99";
                }
            }
        }

        if (!$no_luajit_lua52
            && (!$user_luajit_xcflags
                || $user_luajit_xcflags !~ /-DLUAJIT_ENABLE_LUA52COMPAT\b/))
        {
            $luajit_xcflags .= " -DLUAJIT_ENABLE_LUA52COMPAT";
        }

        if (!$user_luajit_xcflags
            || $user_luajit_xcflags !~ /-msse4\.2\b/)
        {
            # check -msse4.2
            my ($out, $cfile) = tempfile("resty-config-XXXXXX",
                                         SUFFIX => '.c', TMPDIR => 1,
                                         UNLINK => 1);

            print $out "
int main(void) {
#ifndef __SSE4_2__
#   error SSE 4.2 not found
#endif
    return 0;
}
";
            close $out;

            my $ofile = tmpnam();
            my $comp = ($cc || 'cc');
            my $found;

            if (system("$comp -o $ofile -msse4.2 -c $cfile") == 0
                && -s $ofile)
            {
                unlink $ofile;

                if (system("$comp -o $ofile -march=native -c $cfile") == 0
                    && -s $ofile)
                {
                    print "INFO: found -msse4.2 in $comp.\n";
                    $found = 1;
                    $luajit_xcflags .= " -msse4.2";
                }
            }

            if (-f $ofile) {
                unlink $ofile;
            }

            if (!$found) {
                print "WARNING: -msse4.2 not supported in $comp.\n";
            }
        }

        if ($opts->{debug}) {
            $luajit_xcflags .= " -DLUA_USE_APICHECK -DLUA_USE_ASSERT";

            if ($user_luajit_xcflags) {
                $luajit_xcflags .= $user_luajit_xcflags;
            }
            $luajit_xcflags =~ s/^ +//;

            $extra_opts .= qq{ Q= XCFLAGS='$luajit_xcflags'};

        } else {
            if ($user_luajit_xcflags) {
                $luajit_xcflags .= $user_luajit_xcflags;
            }

            if ($luajit_xcflags) {
                $luajit_xcflags =~ s/^ +//;
                $extra_opts .= qq{ XCFLAGS='$luajit_xcflags'};
            }
        }

        #if ($platform =~ /bsd/i) {
        #$extra_opts .= ' CFLAGS=-I..';
        #}

        if ($on_solaris) {
            $extra_opts .= " INSTALL_X='$root_dir/build/install -m 0755' " .
                    "INSTALL_F='$root_dir/build/install -m 0644'";
        }

        if (defined $cc) {
            $extra_opts .= " CC='$cc'";

        } else {
            $extra_opts .= " CC=cc";
        }

        if ($platform eq 'macosx') {
            my $v = $ENV{MACOSX_DEPLOYMENT_TARGET};
            if (!defined $v || $v !~ /^\d+\.\d+$/) {
                $v = `sw_vers -productVersion`;
                if (defined $v && $v =~ /^\s*(\d+\.\d+)/) {
                    $ENV{MACOSX_DEPLOYMENT_TARGET} = $1;
                    #warn "MACOSX_DEPLOYMENT_TARGET = $1";
                }
            }
        }

        if (defined $cores) {
            shell "${make} -j$cores$extra_opts PREFIX=$luajit_prefix", $dry_run;
        } else {
            shell "${make}$extra_opts PREFIX=$luajit_prefix", $dry_run;
        }

        my ($lib, $inc);

        if ($platform eq 'msys') {
            $lib = $luajit_root;
            shell "install -m 0755 src/luajit.exe src/lua51.dll $lib/",
                  $dry_run;

            my $lua_jit_dir = File::Spec->catfile($luajit_root, "lua", "jit");
            shell "mkdir -p $lua_jit_dir", $dry_run;

            shell "install -m 0644 src/jit/*.lua $lua_jit_dir/", $dry_run;

            $inc = File::Spec->catfile($luajit_root, "include", "luajit-2.1");
            shell "mkdir -p $inc", $dry_run;

            shell "cd src && install -m 0644 lua.h lualib.h lauxlib.h "
                  . "luaconf.h lua.hpp luajit.h $inc/",
                  $dry_run;

        } else {
            shell "${make} install$extra_opts PREFIX=$luajit_prefix "
                  . "DESTDIR=$luajit_root/", $dry_run;

            $lib = File::Spec->catfile($luajit_root, $luajit_prefix, "lib");
            $inc = File::Spec->catfile($luajit_root, $luajit_prefix,
                                       "include", "luajit-2.1");
        }

        push @make_cmds, "cd $root_dir/build/$luajit_src && "
            . "\$(MAKE)$extra_opts PREFIX=$luajit_prefix";

        my $abs_luajit_src =
            File::Spec->rel2abs(File::Spec->catfile($root_dir, "build",
                                                    $luajit_src),
                                $root_dir);

        if ($platform eq 'msys') {
            push @make_install_cmds, "cd $abs_luajit_src && "
                . "cp -rv $luajit_root/* \$(DESTDIR)$prefix/";

        } else {
            push @make_install_cmds, "cd $abs_luajit_src && "
                . "\$(MAKE) install$extra_opts PREFIX=$luajit_prefix "
                . "DESTDIR=\$(DESTDIR)";
        }

        env LUAJIT_LIB => $lib;
        env LUAJIT_INC => $inc;

        #unshift @ngx_ld_opts, "-L$lib";
        #unshift @ngx_cc_opts, "-I$inc";

        if ($platform ne 'msys') {
            push @ngx_rpaths, File::Spec->catfile($luajit_prefix, "lib");
        }

        cd '..';

    } elsif ($opts->{lua_path}) {
        my $lua_prefix = $opts->{lua_path};
        env LUA_LIB => File::Spec->catfile($lua_prefix, "lib");
        env LUA_INC => File::Spec->catfile($lua_prefix, "include");

        push @ngx_rpaths, File::Spec->catfile($lua_prefix, "lib");

    } elsif ($opts->{lua}) {
        # build stdandard lua

        my $lua_src = auto_complete 'lua';

        if (!defined $lua_src) {
            die "No lua5 found";
        }

        my $lua_prefix = File::Spec->catfile($prefix, "lua");
        my $lua_root = File::Spec->rel2abs("lua-root");

        if (-d $lua_root) {
            shell "rm -rf $lua_root";
        }

        mkdir $lua_root or
            die "create create directory lua-root: $!\n";

        cd $lua_src;

        my $extra_opts = '';
        if (defined $cc) {
            $extra_opts .= " CC='$cc'";
        }

        if (defined $cores) {
            shell "${make} -j$cores$extra_opts $platform", $dry_run;
        } else {
            shell "${make}$extra_opts $platform", $dry_run;
        }

        my $install_top = File::Spec->catfile($lua_root, $lua_prefix);
        shell "${make} install$extra_opts INSTALL_TOP=$install_top/", $dry_run;

        env LUA_LIB => File::Spec->catfile($lua_root, $lua_prefix, "lib");
        env LUA_INC => File::Spec->catfile($lua_root, $lua_prefix, "include");

        push @make_cmds,
            "cd $root_dir/build/$lua_src && \$(MAKE)$extra_opts $platform";

        push @make_install_cmds, "cd $root_dir/build/$lua_src && "
            . "\$(MAKE) install$extra_opts INSTALL_TOP=\$(DESTDIR)$lua_prefix";

        cd '..';
    }

    if ($opts->{lua} || $opts->{lua_path}
        || $opts->{luajit} || $opts->{luajit_path})
    {
        # build lua modules

        my $lualib_prefix = File::Spec->catfile($prefix, "lualib");
        my $site_lualib_prefix = File::Spec->catfile($prefix, "site/lualib");

        my $ngx_lua_dir = auto_complete 'ngx_lua';

        open my $in, ">>$ngx_lua_dir/config" or
            die "Cannot open $ngx_lua_dir/config for appending: $!\n";

        {
            print $in <<"_EOC_";

ngx_lua_dquote='"'
CFLAGS="\$CFLAGS -DLUA_DEFAULT_PATH='\${ngx_lua_dquote}$site_lualib_prefix/?.ljbc;$site_lualib_prefix/?/init.ljbc;$lualib_prefix/?.ljbc;$lualib_prefix/?/init.ljbc;$site_lualib_prefix/?.lua;$site_lualib_prefix/?/init.lua;$lualib_prefix/?.lua;$lualib_prefix/?/init.lua\$ngx_lua_dquote'"
CFLAGS="\$CFLAGS -DLUA_DEFAULT_CPATH='\${ngx_lua_dquote}$site_lualib_prefix/?.so;$lualib_prefix/?.so\$ngx_lua_dquote'"
_EOC_
        }

        close $in;

        unless ($opts->{no_lua_cjson}) {
            my $dir = auto_complete 'lua-cjson';
            if (!defined $dir) {
                die "No lua-cjson found";
            }

            my $lua_inc;
            if ($opts->{luajit} || $opts->{luajit_path}) {
                $lua_inc = $ENV{LUAJIT_INC};

            } else {
                $lua_inc = $ENV{LUA_INC};
            }

            my $extra_opts = " DESTDIR=\$(DESTDIR) LUA_INCLUDE_DIR=$lua_inc " .
                "LUA_CMODULE_DIR=$lualib_prefix LUA_MODULE_DIR=$lualib_prefix";

            if ($platform eq 'msys') {
                my $luajit_root = File::Spec->rel2abs("luajit-root");
                $extra_opts .=
                    " CJSON_LDFLAGS=\"-shared -L$luajit_root -llua51\"";
            }

            if ($on_solaris) {
                #$extra_opts .= " INSTALL=$root_dir/build/install";
                if ($opts->{debug}) {
                    $extra_opts .=
                        " CJSON_CFLAGS=\"-g -O -fpic -DUSE_INTERNAL_ISINF\"";

                } else {
                    $extra_opts .=
                        " CJSON_CFLAGS=\"-g -fpic -DUSE_INTERNAL_ISINF\"";
                }

            } else {
                if ($opts->{debug}) {
                    $extra_opts .= " CJSON_CFLAGS=\"-g -O -fpic\"";
                } else {
                    $extra_opts .= " CJSON_CFLAGS=\"-g -fpic\"";
                }
            }

            if ($platform eq 'macosx') {
                $extra_opts .=
                    " CJSON_LDFLAGS='-bundle -undefined dynamic_lookup'";
            }

            if (defined $cc) {
                $extra_opts .= " CC='$cc'";
            } else {
                $extra_opts .= " CC=cc";
            }

            push @make_cmds, "cd $root_dir/build/$dir && ".
                "\$(MAKE)$extra_opts";

            push @make_install_cmds, "cd $root_dir/build/$dir && " .
                "\$(MAKE) install$extra_opts";
        }

        unless ($opts->{no_lua_redis_parser}) {
            my $dir = auto_complete 'lua-redis-parser';
            if (!defined $dir) {
                die "No lua-redis-parser found";
            }

            my $lua_inc;
            if ($opts->{luajit} || $opts->{luajit_path}) {
                $lua_inc = $ENV{LUAJIT_INC};

            } else {
                $lua_inc = $ENV{LUA_INC};
            }

            my $extra_opts = " DESTDIR=\$(DESTDIR) LUA_INCLUDE_DIR=$lua_inc " .
                "LUA_LIB_DIR=$lualib_prefix";

            if ($platform eq 'msys') {
                my $luajit_root = File::Spec->rel2abs("luajit-root");
                $extra_opts .= " LDFLAGS=\"-shared -L$luajit_root -llua51\"";
            }

            if ($on_solaris) {
                $extra_opts .= " INSTALL=$root_dir/build/install";
                if ($opts->{debug}) {
                    $extra_opts .= " CFLAGS=\"-g -O -Wall\"";
                }

            } else {
                if ($opts->{debug}) {
                    $extra_opts .= " CFLAGS=\"-g -O -Wall\"";
                }
            }

            if ($platform eq 'macosx') {
                $extra_opts .= " LDFLAGS='-bundle -undefined dynamic_lookup'";
            }

            if (defined $cc) {
                $extra_opts .= " CC='$cc'";
            } else {
                $extra_opts .= " CC=cc";
            }

            push @make_cmds, "cd $root_dir/build/$dir && ".
                "\$(MAKE)$extra_opts";

            push @make_install_cmds, "cd $root_dir/build/$dir && " .
                "\$(MAKE) install$extra_opts";
        }

        unless ($opts->{no_lua_rds_parser}) {
            my $dir = auto_complete 'lua-rds-parser';
            if (!defined $dir) {
                die "No lua-rds-parser found";
            }

            my $lua_inc;
            if ($opts->{luajit} || $opts->{luajit_path}) {
                $lua_inc = $ENV{LUAJIT_INC};

            } else {
                $lua_inc = $ENV{LUA_INC};
            }

            my $extra_opts = " DESTDIR=\$(DESTDIR) LUA_INCLUDE_DIR=$lua_inc " .
                "LUA_LIB_DIR=$lualib_prefix";

            if ($platform eq 'msys') {
                my $luajit_root = File::Spec->rel2abs("luajit-root");
                $extra_opts .= " LDFLAGS=\"-shared -L$luajit_root -llua51\"";
            }

            if ($on_solaris) {
                $extra_opts .= " INSTALL=$root_dir/build/install";
                if ($opts->{debug}) {
                    $extra_opts .= " CFLAGS=\"-g -O -Wall\"";

                }

            } else {
                if ($opts->{debug}) {
                    $extra_opts .= " CFLAGS=\"-g -O -Wall\"";
                }
            }

            if ($platform eq 'macosx') {
                $extra_opts .= " LDFLAGS='-bundle -undefined dynamic_lookup'";
            }

            if (defined $cc) {
                $extra_opts .= " CC='$cc'";
            } else {
                $extra_opts .= " CC=cc";
            }

            push @make_cmds, "cd $root_dir/build/$dir && ".
                "\$(MAKE)$extra_opts";

            push @make_install_cmds, "cd $root_dir/build/$dir && " .
                "\$(MAKE) install$extra_opts";
        }

        for my $key (qw(dns memcached redis mysql string upload websocket
                        lock lrucache core upstream_healthcheck limit_traffic))
        {
            unless ($opts->{"no_lua_resty_$key"}) {
                (my $key2 = $key) =~ s/_/-/g;
                my $name = "lua-resty-$key2";
                my $dir = auto_complete $name;
                if (!defined $dir) {
                    die "No $name found";
                }

                my $extra_opts =
                    " DESTDIR=\$(DESTDIR) LUA_LIB_DIR=$lualib_prefix"
                    ." INSTALL=$root_dir/build/install";

                push @make_install_cmds, "cd $root_dir/build/$dir && " .
                    "\$(MAKE) install$extra_opts";
            }
        }
    }

    # configure opm:
    {
        my $opm_dir = auto_complete 'opm';
        my $target_dir;
        if ($platform eq 'msys') {
            $target_dir = "\$(DESTDIR)$prefix/";
        } else {
            $target_dir = "\$(DESTDIR)$prefix/bin/";
        }
        push @make_install_cmds, "cd $root_dir/build/$opm_dir && "
             . "$root_dir/build/install bin/* $target_dir";
    }

    # configure resty-cli:

    {
        my $resty_cli_dir = auto_complete 'resty-cli';
        my $target_dir;
        if ($platform eq 'msys') {
            $target_dir = "\$(DESTDIR)$prefix/";
        } else {
            $target_dir = "\$(DESTDIR)$prefix/bin/";
        }
        push @make_install_cmds, "cd $root_dir/build/$resty_cli_dir && "
             . "$root_dir/build/install bin/* $target_dir";

        if ($platform ne 'msys') {
            # patch the resty script:

            print "patching the resty script with hard-coded nginx binary ",
                  "path...\n";

            my $resty_bin = "$root_dir/build/$resty_cli_dir/bin/resty";
            open my $in, $resty_bin
                or die "Cannot open $resty_bin for reading: $!\n";
            my ($new, $found);
            while (<$in>) {
                if (/^my \$nginx_path;$/) {
                    $found = 1;
                    $new .= qq/my \$nginx_path = '$ngx_sbin';\n/;

                } else {
                    $new .= $_;
                }
            }
            close $in;

            if (!$found) {
                die "failed to patch $resty_bin: the line 'my \$nginx_path' ",
                    "was not found.\n";
            }

            open my $out, ">$resty_bin"
                or die "Cannot open $resty_bin for writing: $!\n";
            print $out $new;
            close $out;
        }
    }

    # configure restydoc indexes

    push @make_install_cmds,
        "cp $root_dir/build/resty.index \$(DESTDIR)$prefix/",
        "cp -r $root_dir/build/pod \$(DESTDIR)$prefix/";

    # prepare nginx configure line

    $ngx_dir = auto_complete "nginx";

    if (@ngx_cc_opts) {
        $opts_line .= " \\\n  --with-cc-opt='@ngx_cc_opts'";
    }

    cd $ngx_dir;

    for my $mod (@modules) {
        my ($name, $prefix, $attr) = @$mod;

        if ($attr && $attr eq 'disabled') {
            next if not $opts->{"$name"};

        } else {
            next if $opts->{"no_$name"};
        }

        my $dir = auto_complete "../$prefix";

        $opts_line .= " \\\n  --add-module=$dir";
    }

    return $opts_line;
}

sub usage ($) {
    my $retval = shift;
    my $msg = <<'_EOC_';
  --help                             this message

  --prefix=PATH                      set the installation prefix (default to /usr/local/openresty)

  --with-debug                       enable debug logging
  --with-dtrace-probes               enable dtrace USDT probes
  --with-dtrace=PATH                 set dtrace utility pathname

  --with-no-pool-patch               enable the no-pool patch for debugging memory issues

  -jN                                pass -jN option to make while building the bundled
                                     Lua 5.1 interpreter or LuaJIT 2.1

_EOC_

    my $opt_max_len = length "  --without-ngx_devel_kit_module     ";

    #warn "opt max len: $opt_max_len";

    my $with_resty_opts = '';

    for my $mod (@modules) {
        my $name = $mod->[0];
        if ($name =~ /^(?:http|stream)_/) {
            if (@$mod == 2) {
                my $opt = "  --without-${name}_module";
                $msg .= $opt;

                my $n = $opt_max_len - length $opt;

                if ($n > 0) {
                    $msg .= " " x $n;

                } else {
                    $msg .= "\n" . (" " x $opt_max_len);
                }

                $msg .= "disable ngx_${name}_module\n";

            } else {
                my $opt = "  --with-${name}_module";
                $with_resty_opts .= $opt;

                my $n = $opt_max_len - length $opt;

                if ($n > 0) {
                    $with_resty_opts .= " " x $n;

                } else {
                    $with_resty_opts .= "\n" . (" " x $opt_max_len);
                }

                $with_resty_opts .= "enable ngx_${name}_module\n";
            }
        }
    }

    $msg .= <<'_EOC_';
  --without-ngx_devel_kit_module     disable ngx_devel_kit_module
  --without-http_ssl_module          disable ngx_http_ssl_module
  --without-stream_ssl_module        disable ngx_stream_ssl_module

_EOC_

    $msg .= $with_resty_opts;

    $msg .= <<'_EOC_';

  --without-lua_cjson                disable the lua-cjson library
  --without-lua_redis_parser         disable the lua-redis-parser library
  --without-lua_rds_parser           disable the lua-rds-parser library
  --without-lua_resty_dns            disable the lua-resty-dns library
  --without-lua_resty_memcached      disable the lua-resty-memcached library
  --without-lua_resty_redis          disable the lua-resty-redis library
  --without-lua_resty_mysql          disable the lua-resty-mysql library
  --without-lua_resty_upload         disable the lua-resty-upload library
  --without-lua_resty_upstream_healthcheck
                                     disable the lua-resty-upstream-healthcheck library
  --without-lua_resty_string         disable the lua-resty-string library
  --without-lua_resty_websocket      disable the lua-resty-websocket library
  --without-lua_resty_limit_traffic  disable the lua-resty-limit-traffic library
  --without-lua_resty_lock           disable the lua-resty-lock library
  --without-lua_resty_lrucache       disable the lua-resty-lrucache library
  --without-lua_resty_core           disable the lua-resty-core library

  --with-luajit                      enable and build the bundled LuaJIT 2.1 (the default)
  --with-luajit=DIR                  use the external LuaJIT 2.1 installation specified by DIR
  --with-luajit-xcflags=FLAGS        Specify extra C compiler flags for LuaJIT 2.1
  --without-luajit-lua52             Turns off the LuaJIT extensions from Lua 5.2 that may break
                                     backward compatibility.

  --with-libdrizzle=DIR              specify the libdrizzle 1.0 (or drizzle) installation prefix
  --with-libpq=DIR                   specify the libpq (or postgresql) installation prefix
  --with-pg_config=PATH              specify the path of the pg_config utility

Options directly inherited from nginx

  --sbin-path=PATH                   set nginx binary pathname
  --modules-path=PATH                set modules path
  --conf-path=PATH                   set nginx.conf pathname
  --error-log-path=PATH              set error log pathname
  --pid-path=PATH                    set nginx.pid pathname
  --lock-path=PATH                   set nginx.lock pathname
  --tapset-prefix=PATH               set systemtap tapset directory prefix
  --stap-nginx-path=PATH             set stap-nginx pathname

  --user=USER                        set non-privileged user for
                                     worker processes
  --group=GROUP                      set non-privileged group for
                                     worker processes

  --build=NAME                       set build name
  --builddir=DIR                     set the build directory

  --with-select_module               enable select module
  --without-select_module            disable select module
  --with-poll_module                 enable poll module
  --without-poll_module              disable poll module

  --with-threads                     enable thread pool support

  --with-file-aio                    enable file AIO support
  --with-ipv6                        enable IPv6 support

  --with-http_v2_module              enable ngx_http_v2_module
  --with-http_realip_module          enable ngx_http_realip_module
  --with-http_addition_module        enable ngx_http_addition_module
  --with-http_xslt_module            enable ngx_http_xslt_module
  --with-http_xslt_module=dynamic    enable dynamic ngx_http_xslt_module
  --with-http_image_filter_module    enable ngx_http_image_filter_module
  --with-http_image_filter_module=dynamic
                                     enable dynamic ngx_http_image_filter_module
  --with-http_geoip_module           enable ngx_http_geoip_module
  --with-http_geoip_module=dynamic   enable dynamic ngx_http_geoip_module
  --with-http_sub_module             enable ngx_http_sub_module
  --with-http_dav_module             enable ngx_http_dav_module
  --with-http_flv_module             enable ngx_http_flv_module
  --with-http_mp4_module             enable ngx_http_mp4_module
  --with-http_gunzip_module          enable ngx_http_gunzip_module
  --with-http_gzip_static_module     enable ngx_http_gzip_static_module
  --with-http_auth_request_module    enable ngx_http_auth_request_module
  --with-http_random_index_module    enable ngx_http_random_index_module
  --with-http_secure_link_module     enable ngx_http_secure_link_module
  --with-http_degradation_module     enable ngx_http_degradation_module
  --with-http_slice_module           enable ngx_http_slice_module
  --with-http_stub_status_module     enable ngx_http_stub_status_module

  --without-http_charset_module      disable ngx_http_charset_module
  --without-http_gzip_module         disable ngx_http_gzip_module
  --without-http_ssi_module          disable ngx_http_ssi_module
  --without-http_userid_module       disable ngx_http_userid_module
  --without-http_access_module       disable ngx_http_access_module
  --without-http_auth_basic_module   disable ngx_http_auth_basic_module
  --without-http_autoindex_module    disable ngx_http_autoindex_module
  --without-http_geo_module          disable ngx_http_geo_module
  --without-http_map_module          disable ngx_http_map_module
  --without-http_split_clients_module disable ngx_http_split_clients_module
  --without-http_referer_module      disable ngx_http_referer_module
  --without-http_rewrite_module      disable ngx_http_rewrite_module
  --without-http_proxy_module        disable ngx_http_proxy_module
  --without-http_fastcgi_module      disable ngx_http_fastcgi_module
  --without-http_uwsgi_module        disable ngx_http_uwsgi_module
  --without-http_scgi_module         disable ngx_http_scgi_module
  --without-http_memcached_module    disable ngx_http_memcached_module
  --without-http_limit_conn_module   disable ngx_http_limit_conn_module
  --without-http_limit_req_module    disable ngx_http_limit_req_module
  --without-http_empty_gif_module    disable ngx_http_empty_gif_module
  --without-http_browser_module      disable ngx_http_browser_module
  --without-http_upstream_hash_module
                                     disable ngx_http_upstream_hash_module
  --without-http_upstream_ip_hash_module
                                     disable ngx_http_upstream_ip_hash_module
  --without-http_upstream_least_conn_module
                                     disable ngx_http_upstream_least_conn_module
  --without-http_upstream_keepalive_module
                                     disable ngx_http_upstream_keepalive_module

  --without-http_upstream_zone_module
                                     disable ngx_http_upstream_zone_module
  --with-http_perl_module            enable ngx_http_perl_module
  --with-http_perl_module=dynamic    enable dynamic ngx_http_perl_module
  --with-perl_modules_path=PATH      set Perl modules path
  --with-perl=PATH                   set perl binary pathname

  --http-log-path=PATH               set http access log pathname
  --http-client-body-temp-path=PATH  set path to store
                                     http client request body temporary files
  --http-proxy-temp-path=PATH        set path to store
                                     http proxy temporary files
  --http-fastcgi-temp-path=PATH      set path to store
                                     http fastcgi temporary files
  --http-uwsgi-temp-path=PATH        set path to store
                                     http uwsgi temporary files
  --http-scgi-temp-path=PATH         set path to store
                                     http scgi temporary files

  --without-http                     disable HTTP server
  --without-http-cache               disable HTTP cache

  --with-mail                        enable POP3/IMAP4/SMTP proxy module
  --with-mail=dynamic                enable dynamic POP3/IMAP4/SMTP proxy module
  --with-mail_ssl_module             enable ngx_mail_ssl_module
  --without-mail_pop3_module         disable ngx_mail_pop3_module
  --without-mail_imap_module         disable ngx_mail_imap_module
  --without-mail_smtp_module         disable ngx_mail_smtp_module

  --without-stream                   disable TCP/UDP proxy module
  --without-stream_ssl_module        disable ngx_stream_ssl_module

  --with-stream                      enable TCP/UDP proxy module (default on)
  --with-stream=dynamic              enable dynamic TCP/UDP proxy module
  --with-stream_ssl_module           enable ngx_stream_ssl_module (default on)
  --with-stream_realip_module        enable ngx_stream_realip_module
  --with-stream_geoip_module         enable ngx_stream_geoip_module
  --with-stream_geoip_module=dynamic enable dynamic ngx_stream_geoip_module
  --with-stream_ssl_preread_module   enable ngx_stream_ssl_preread_module
  --without-stream_limit_conn_module disable ngx_stream_limit_conn_module
  --without-stream_access_module     disable ngx_stream_access_module
  --without-stream_geo_module        disable ngx_stream_geo_module
  --without-stream_map_module        disable ngx_stream_map_module
  --without-stream_split_clients_module
                                     disable ngx_stream_split_clients_module
  --without-stream_return_module     disable ngx_stream_return_module
  --without-stream_upstream_hash_module
                                     disable ngx_stream_upstream_hash_module
  --without-stream_upstream_least_conn_module
                                     disable ngx_stream_upstream_least_conn_module
  --without-stream_upstream_zone_module
                                     disable ngx_stream_upstream_zone_module

  --with-google_perftools_module     enable ngx_google_perftools_module
  --with-cpp_test_module             enable ngx_cpp_test_module

  --add-module=PATH                  enable external module
  --add-dynamic-module=PATH          enable dynamic external module

  --with-cc=PATH                     set C compiler pathname
  --with-cpp=PATH                    set C preprocessor pathname
  --with-cc-opt=OPTIONS              set additional C compiler options
  --with-ld-opt=OPTIONS              set additional linker options
  --with-cpu-opt=CPU                 build for the specified CPU, valid values:
                                     pentium, pentiumpro, pentium3, pentium4,
                                     athlon, opteron, sparc32, sparc64, ppc64

  --without-pcre                     disable PCRE library usage
  --with-pcre                        force PCRE library usage
  --with-pcre=DIR                    set path to PCRE library sources
  --with-pcre-opt=OPTIONS            set additional make options for PCRE
  --with-pcre-conf-opt=OPTIONS       set additional configure options for PCRE
  --with-pcre-jit                    build PCRE with JIT compilation support

  --with-zlib=DIR                    set path to zlib library sources
  --with-zlib-opt=OPTIONS            set additional build options for zlib
  --with-zlib-asm=CPU                use zlib assembler sources optimized
                                     for the specified CPU, valid values:
                                     pentium, pentiumpro

  --with-libatomic                   force libatomic_ops library usage
  --with-libatomic=DIR               set path to libatomic_ops library sources

  --with-openssl=DIR                 set path to OpenSSL library sources
  --with-openssl-opt=OPTIONS         set additional build options for OpenSSL

  --dry-run                          dry running the configure, for testing only
  --platform=PLATFORM                forcibly specify a platform name, for testing only
_EOC_

    if ($retval == 0) {
        print $msg;
        exit 0;
    }

    warn $msg;
    exit $retval;
}

sub gen_makefile {
    if (-f 'Makefile') {
        unlink 'Makefile' or
            die "ERROR: failed to remove existing Makefile: $!\n";
    }

    open my $out, ">Makefile" or
        die "Cannot open Makefile for writing: $!\n";

    for my $line (@extra_make_env) {
        print $out "export $line\n";
    }

    if (File::Spec->rel2abs($prefix) ne File::Spec->canonpath($prefix)) {
        # prefix is a relative path.
        print $out "DESTDIR ?= $root_dir/\n\n";
    }

    print $out ".PHONY: all install clean\n\n";

    print $out "all:\n\t" . join("\n\t", @make_cmds) . "\n\n";

    print $out "install: all\n\t" . join("\n\t", @make_install_cmds) . "\n\n";

    print $out "clean:\n\trm -rf build\n";

    close $out;
}

# check if we can run some command
sub can_run {
    my ($cmd) = @_;

    #warn "can run: @_\n";
    my $_cmd = $cmd;
    return $_cmd if -x $_cmd;

    return undef if $_cmd =~ m{[\\/]};

    # FIXME: this is a hack; MSWin32 is not supported anyway
    my $path_sep = ':';

    for my $dir ((split /$path_sep/, $ENV{PATH}), '.') {
        next if $dir eq '';
        my $abs = File::Spec->catfile($dir, $_[0]);
        return $abs if -x $abs;
    }

    return undef;
}

sub quote_cli_args {
    my $args = shift;
    my @quoted;
    for my $arg (@$args) {
        if ($arg =~ /[\\\s'"\$]/) {
            if ($arg =~ /'/) {
                $arg =~ s/([\\'])/\\$1/g;
                push @quoted, "\$'$arg'";
            } else {
                push @quoted, "'$arg'";
            }
        } else {
            push @quoted, $arg;
        }
    }
    join " ", @quoted;
}
