Fix a few Configure errors
[openssl.git] / Configure
index c1a3f8a26ef536fe5d04d22a5e0de30ea799725d..efbe0f8587132c3c0eebfb4bb5c5db1a958881cd 100755 (executable)
--- a/Configure
+++ b/Configure
@@ -1,11 +1,7 @@
 #! /usr/bin/env perl
 # -*- mode: perl; -*-
 
-##
 ##  Configure -- OpenSSL source tree configuration script
-##  If editing this file, run this command before committing
-##     make -f Makefile.in TABLE
-##
 
 require 5.000;
 use strict;
@@ -57,6 +53,9 @@ my $usage="Usage: Configure [no-<cipher> ...] [enable-<cipher> ...] [-Dxxx] [-lx
 #              library and will be loaded in run-time by the OpenSSL library.
 # sctp          include SCTP support
 # 386           generate 80386 code
+# enable-weak-ssl-ciphers
+#               Enable weak ciphers that are disabled by default. This currently
+#               only includes RC4 based ciphers.
 # no-sse2      disables IA-32 SSE2 code, above option implies no-sse2
 # no-<cipher>   build without specified algorithm (rsa, idea, rc5, ...)
 # -<xxx> +<xxx> compiler options are passed through
@@ -199,7 +198,6 @@ foreach (sort glob($pattern) ) {
 
 print "Configuring OpenSSL version $config{version} (0x$config{version_num})\n";
 
-$config{perl};
 $config{prefix}="";
 $config{openssldir}="";
 $config{processor}="";
@@ -217,7 +215,7 @@ $config{dirs} = [ "crypto", "ssl", "engines", "apps", "test", "tools" ];
 # crypto/ subdirectories to build
 $config{sdirs} = [
     "objects",
-    "md2", "md4", "md5", "sha", "mdc2", "hmac", "ripemd", "whrlpool", "poly1305",
+    "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",
@@ -240,6 +238,7 @@ my @disablables = (
     "autoalginit",
     "autoerrinit",
     "bf",
+    "blake2",
     "camellia",
     "capieng",
     "cast",
@@ -271,12 +270,13 @@ my @disablables = (
     "hmac",
     "hw(-.+)?",
     "idea",
-    "locking",
+    "makedepend",
     "md2",
     "md4",
     "md5",
     "mdc2",
     "md[-_]ghost94",
+    "multiblock",
     "nextprotoneg",
     "ocb",
     "ocsp",
@@ -313,6 +313,7 @@ my @disablables = (
     "ui",
     "unit-test",
     "whirlpool",
+    "weak-ssl-ciphers",
     "zlib",
     "zlib-dynamic",
     );
@@ -330,17 +331,21 @@ my @deprecated_disablables = (
 
 our %disabled = ( # "what"         => "comment"
                  "ec_nistp_64_gcc_128" => "default",
-                 "egd"            => "default",
-                 "md2"            => "default",
-                 "rc5"            => "default",
-                 "sctp"           => "default",
-                 "shared"         => "default",
-                 "ssl-trace"      => "default",
-                 "static-engine"  => "default",
-                 "unit-test"      => "default",
-                 "zlib"           => "default",
-                 "crypto-mdebug"  => "default",
-                 "heartbeats"     => "default",
+                 "egd"                 => "default",
+                 "md2"                 => "default",
+                 "rc5"                 => "default",
+                 "sctp"                => "default",
+                 "shared"              => "default",
+                 "ssl-trace"           => "default",
+                 "ssl3"                => "default",
+                 "ssl3-method"         => "default",
+                 "static-engine"       => "default",
+                 "unit-test"           => "default",
+                 "weak-ssl-ciphers"    => "default",
+                 "zlib"                => "default",
+                 "zlib-dynamic"        => "default",
+                 "crypto-mdebug"       => "default",
+                 "heartbeats"          => "default",
                );
 
 # Note: => pair form used for aesthetics, not to truly make a hash table
@@ -387,7 +392,8 @@ my @disable_cascades = (
     "dso"               => [ "dynamic-engine" ],
 
     # Without position independent code, there can be no shared libraries or DSOs
-    "pic"               => [ "shared", "dynamic-engine" ],
+    "pic"               => [ "shared" ],
+    "shared"            => [ "dynamic-engine" ],
     );
 
 # Avoid protocol support holes.  Also disable all versions below N, if version
@@ -429,7 +435,6 @@ my $no_sse2=0;
 
 my $user_cflags="";
 my @user_defines=();
-my $unified = 0;
 $config{openssl_api_defines}=[];
 $config{openssl_algorithm_defines}=[];
 $config{openssl_thread_defines}=[];
@@ -440,6 +445,8 @@ my $target="";
 $config{options}="";
 $config{build_type} = "release";
 
+my $classic = 0;
+
 my @argvcopy=@ARGV;
 
 if (grep /^reconf(igure)?$/, @argvcopy) {
@@ -582,6 +589,10 @@ foreach (@argvcopy)
                         {
                         delete $disabled{"dynamic-engine"};
                         }
+                elsif ($1 eq "zlib-dynamic")
+                        {
+                        delete $disabled{"zlib"};
+                        }
                my $algo = $1;
                delete $disabled{$algo};
 
@@ -619,9 +630,9 @@ foreach (@argvcopy)
                }
        elsif (/^[-+]/)
                {
-               if (/^--unified$/)
+               if (/^--classic$/)
                        {
-                       $unified=1;
+                       $classic=1;
                        }
                elsif (/^--prefix=(.*)$/)
                        {
@@ -730,7 +741,7 @@ while (@tocheckfor) {
        my ($test, $descendents) = (shift @cascade_copy, shift @cascade_copy);
        if (ref($test) eq "CODE" ? $test->() : defined($disabled{$test})) {
            map {
-               $new_tocheckfor{$_} => 1; $disabled{$_} = "forced";
+               $new_tocheckfor{$_} = 1; $disabled{$_} = "forced";
            } grep { !defined($disabled{$_}) } @$descendents;
        }
     }
@@ -782,6 +793,8 @@ foreach (sort (keys %disabled))
                { }
        elsif (/^dynamic-engine$/)
                { }
+       elsif (/^makedepend$/)
+               { }
        elsif (/^zlib-dynamic$/)
                { }
        elsif (/^sse2$/)
@@ -869,22 +882,29 @@ $target{nm} =      $ENV{'NM'}      || $target{nm}      || "nm";
 # For cflags, lflags, plib_lflags, ex_libs and defines, add the debug_
 # or release_ attributes.
 # Do it in such a way that no spurious space is appended (hence the grep).
-$config{defines} = $target{defines} || [];
-$config{cflags} = $target{cflags} || "";
-$config{ex_libs} = $target{ex_libs} || "";
+$config{defines} = [];
+$config{cflags} = "";
+$config{ex_libs} = "";
+$config{shared_ldflag} = "";
 
 # Make sure build_scheme is consistent.
 $target{build_scheme} = [ $target{build_scheme} ]
     if ref($target{build_scheme}) ne "ARRAY";
 
-###### TO BE REMOVED BEFORE FINAL RELEASE
+###### TO BE REMOVED WHEN CLASSIC BUILD IS REMOVED
 ######
-###### If the user has chosen --unified, we give it to them.
-###### The same happens if we detect that they try to build out-of-source.
-if ($target{build_file} eq "Makefile"
-    && $target{build_scheme}->[0] eq "unixmake"
-    && ($unified || $srcdir ne $blddir)) {
-    $target{build_scheme} = [ "unified", "unix" ];
+###### If the user has chosen --classic, we give it to them.
+###### If they try that with an out-of-source config, we complain.
+if ($target{build_scheme}->[0] eq "unified" && $classic) {
+    die "Can't perform a classic build out of source tree\n"
+        if $srcdir ne $blddir;
+
+    $target{build_scheme} = { unix    => [ "unixmake" ],
+                              windows => [ "mk1mf", $target{build_scheme}->[2] ],
+                              VMS     => undef } -> {$target{build_scheme}->[1]};
+
+    die "Classic mode unavailable on this platform\n"
+        unless defined($target{build_scheme});
 }
 
 my ($builder, $builder_platform, @builder_opts) =
@@ -893,7 +913,7 @@ my ($builder, $builder_platform, @builder_opts) =
 if ($target =~ /^mingw/ && `$target{cc} --target-help 2>&1` =~ m/-mno-cygwin/m)
        {
        $config{cflags} .= " -mno-cygwin";
-       $target{shared_ldflag} .= " -mno-cygwin";
+       $config{shared_ldflag} .= " -mno-cygwin";
        }
 
 if ($target =~ /linux.*-mips/ && !$disabled{asm} && $user_cflags !~ /-m(ips|arch=)/) {
@@ -917,17 +937,15 @@ if (!$disabled{dso} && $target{dso_scheme} ne "")
        $target{dso_scheme} =~ tr/[a-z]/[A-Z]/;
        if ($target{dso_scheme} eq "DLFCN")
                {
-               $config{defines} = [ "DSO_DLFCN", "HAVE_DLFCN_H",
-                                    @{$config{defines}} ]
+               unshift @{$config{defines}}, "DSO_DLFCN", "HAVE_DLFCN_H";
                }
        elsif ($target{dso_scheme} eq "DLFCN_NO_H")
                {
-               $config{defines} = [ "DSO_DLFCN", @{$config{defines}} ]
+               unshift @{$config{defines}}, "DSO_DLFCN";
                }
        else
                {
-               $config{defines} = [ "DSO_$target{dso_scheme}",
-                                    @{$config{defines}} ]
+               unshift @{$config{defines}}, "DSO_$target{dso_scheme}";
                }
        }
 
@@ -935,8 +953,11 @@ $config{ex_libs}="$libs$config{ex_libs}" if ($libs ne "");
 
 if ($disabled{asm})
        {
-       @{$config{defines}} = grep !/^[BL]_ENDIAN$/, @{$config{defines}}
-           if ($config{fips});
+       if ($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
@@ -1057,7 +1078,7 @@ unless ($disabled{asm}) {
         if ($config{processor} eq "386") {
            $target{wp_asm_src}=$table{DEFAULTS}->{wp_asm_src};
        } elsif (!$disabled{"whirlpool"}) {
-           $config{cflags}.=" -DWHIRLPOOL_ASM";
+           push @{$config{defines}}, "WHIRLPOOL_ASM";
        }
     }
     if ($target{modes_asm_src} =~ /ghash-/) {
@@ -1072,21 +1093,32 @@ unless ($disabled{asm}) {
 }
 
 my $ecc = $target{cc};
-if ($^O ne "VMS") {
+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}";
-    $config{makedepprog} = 'makedepend';
-    open(PIPE, "$ccpcc --version 2>&1 | head -2 |");
+    open(PIPE, "$ccpcc --version 2>&1 |");
+    my $lines = 2;
     while ( <PIPE> ) {
-        $config{makedepprog} = $ccpcc if /clang|gcc/;
+        # 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;
@@ -1116,7 +1148,7 @@ die "Exactly one of SIXTY_FOUR_BIT|SIXTY_FOUR_BIT_LONG|THIRTY_TWO_BIT can be set
 
 # "Stringify" the C flags string.  This permits it to be made part of a string
 # and works as well on command lines.
-$config{cflags} =~ s/([\\\"])/\\\1/g;
+$config{cflags} =~ s/([\\\"])/\\$1/g;
 
 if (defined($config{api})) {
     $config{openssl_api_defines} = [ "OPENSSL_MIN_API=".$apitable->{$config{api}} ];
@@ -1161,6 +1193,28 @@ else               { $no_user_defines=1;    }
 
 # ALL MODIFICATIONS TO %config and %target MUST BE DONE FROM HERE ON
 
+unless ($disabled{engine}) {
+    $config{afalg}="";
+    if ($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) {
+                $disabled{afalg} = "too-old-kernel";
+            } else {
+                push @{$config{engdirs}}, "afalg";
+            }
+        }
+    } else {
+        $disabled{afalg}  = "not-linux";
+    }
+}
+
+push @{$config{openssl_other_defines}}, "OPENSSL_NO_AFALGENG" if ($disabled{afalg});
+
 # If we use the unified build, collect information from build.info files
 my %unified_info = ();
 
@@ -1240,6 +1294,7 @@ if ($builder eq "unified") {
         my @engines = ();
         my @scripts = ();
         my @extra = ();
+        my @overrides = ();
         my @intermediates = ();
         my @rawlines = ();
 
@@ -1249,6 +1304,7 @@ if ($builder eq "unified") {
         my %depends = ();
         my %renames = ();
         my %sharednames = ();
+        my %generate = ();
 
         push @{$config{build_infos}}, catfile(abs2rel($sourced, $blddir), $f);
         my $template = Text::Template->new(TYPE => 'FILE',
@@ -1278,7 +1334,13 @@ if ($builder eq "unified") {
                                                 $l1 =~ s/\\$//; $l1.$l2 }),
             # Info we're looking for
             qr/^\s*IF\[((?:\\.|[^\\\]])*)\]\s*$/
-            => sub { push @skip, !! $1; },
+            => 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[$#skip]) == 2;
@@ -1307,6 +1369,9 @@ if ($builder eq "unified") {
             qr/^\s*EXTRA\s*=\s*(.*)\s*$/
             => sub { push @extra, split(/\s+/, $1)
                          if !@skip || $skip[$#skip] > 0 },
+            qr/^\s*OVERRIDES\s*=\s*(.*)\s*$/
+            => sub { push @overrides, split(/\s+/, $1)
+                         if !@skip || $skip[$#skip] > 0 },
 
             qr/^\s*ORDINALS\[((?:\\.|[^\\\]])+)\]\s*=\s*(.*)\s*$/,
             => sub { push @{$ordinals{$1}}, split(/\s+/, $2)
@@ -1320,6 +1385,9 @@ if ($builder eq "unified") {
             qr/^\s*DEPEND\[((?:\\.|[^\\\]])+)\]\s*=\s*(.*)\s*$/
             => sub { push @{$depends{$1}}, split(/\s+/, $2)
                          if !@skip || $skip[$#skip] > 0 },
+            qr/^\s*GENERATE\[((?:\\.|[^\\\]])+)\]\s*=\s*(.*)\s*$/
+            => sub { push @{$generate{$1}}, $2
+                         if !@skip || $skip[$#skip] > 0 },
             qr/^\s*RENAME\[((?:\\.|[^\\\]])+)\]\s*=\s*(.*)\s*$/
             => sub { push @{$renames{$1}}, split(/\s+/, $2)
                          if !@skip || $skip[$#skip] > 0 },
@@ -1402,6 +1470,11 @@ EOF
             $unified_info{extra}->{$extra} = 1;
         }
 
+        foreach (@overrides) {
+            my $override = cleanfile($buildd, $_, $blddir);
+            $unified_info{overrides}->{$override} = 1;
+        }
+
         push @{$unified_info{rawlines}}, @rawlines;
 
         unless ($disabled{shared}) {
@@ -1443,9 +1516,9 @@ EOF
                 my %known_ordinals =
                     (
                      crypto =>
-                     cleanfile($sourced, catfile("util", "libeay.num"), $blddir),
+                     cleanfile($sourced, catfile("util", "libcrypto.num"), $blddir),
                      ssl =>
-                     cleanfile($sourced, catfile("util", "ssleay.num"), $blddir)
+                     cleanfile($sourced, catfile("util", "libssl.num"), $blddir)
                     );
                 my $o = $known_ordinals{$_};
                 die "Ordinals for $ddest defined more than once\n"
@@ -1480,6 +1553,20 @@ EOF
             }
         }
 
+        foreach (keys %generate) {
+            my $dest = $_;
+            my $ddest = cleanfile($buildd, $_, $blddir);
+            if ($unified_info{rename}->{$ddest}) {
+                $ddest = $unified_info{rename}->{$ddest};
+            }
+            die "more than one generator for $dest: "
+                    ,join(" ", @{$generate{$_}}),"\n"
+                    if scalar @{$generate{$_}} > 1;
+            my @generator = split /\s+/, $generate{$dest}->[0];
+            $generator[0] = cleanfile($sourced, $generator[0], $blddir),
+            $unified_info{generate}->{$ddest} = [ @generator ];
+        }
+
         foreach (keys %depends) {
             my $dest = $_;
             my $ddest = cleanfile($buildd, $_, $blddir);
@@ -1531,7 +1618,7 @@ EOF
 
     ### Make unified_info a bit more efficient
     # One level structures
-    foreach (("programs", "libraries", "engines", "scripts", "extra")) {
+    foreach (("programs", "libraries", "engines", "scripts", "extra", "overrides")) {
         $unified_info{$_} = [ sort keys %{$unified_info{$_}} ];
     }
     # Two level structures
@@ -1671,11 +1758,12 @@ close(OUT);
 
 print "IsMK1MF       =", ($builder eq "mk1mf" ? "yes" : "no"), "\n";
 print "CC            =$target{cc}\n";
-print "CFLAG         =$config{cflags}\n";
-print "DEFINES       =",join(" ", @{$config{defines}}),"\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       =$config{ex_libs}\n";
+print "EX_LIBS       =$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";
@@ -1695,6 +1783,7 @@ print "MODES_OBJ     =$target{modes_obj}\n";
 print "PADLOCK_OBJ   =$target{padlock_obj}\n";
 print "CHACHA_ENC    =$target{chacha_obj}\n";
 print "POLY1305_OBJ  =$target{poly1305_obj}\n";
+print "BLAKE2_OBJ    =$target{blake2_obj}\n";
 print "PROCESSOR     =$config{processor}\n";
 print "RANLIB        =$target{ranlib}\n";
 print "ARFLAGS       =$target{arflags}\n";
@@ -1704,7 +1793,7 @@ 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} != $def_int;
+print "RC4 uses $config{rc4_int}\n" if $config{rc4_int} ne $def_int;
 
 for (@generated_headers) {
     mkpath(catdir($blddir, dirname($_)));
@@ -1801,11 +1890,11 @@ BEGIN
            VALUE "FileDescription", "OpenSSL Shared Library\\0"
            VALUE "FileVersion", "$config{version}\\0"
 #if defined(CRYPTO)
-           VALUE "InternalName", "libeay32\\0"
-           VALUE "OriginalFilename", "libeay32.dll\\0"
+           VALUE "InternalName", "libcrypto32\\0"
+           VALUE "OriginalFilename", "libcrypto32.dll\\0"
 #elif defined(SSL)
-           VALUE "InternalName", "ssleay32\\0"
-           VALUE "OriginalFilename", "ssleay32.dll\\0"
+           VALUE "InternalName", "libssl32\\0"
+           VALUE "OriginalFilename", "libssl32.dll\\0"
 #endif
            VALUE "ProductName", "The OpenSSL Toolkit\\0"
            VALUE "ProductVersion", "$config{version}\\0"
@@ -1851,39 +1940,6 @@ or position independent code, please let us know (but please first make sure
 you have tried with a current version of OpenSSL).
 EOF
 
-###### TO BE REMOVED BEFORE FINAL RELEASE
-######
-###### If the user hasn't chosen --unified, try to nudge them.
-if ($target{build_file} eq "Makefile"
-    && $target{build_scheme}->[0] eq "unixmake"
-    && !$unified) {
-
-    my $plausible_builddir =
-        abs2rel(rel2abs("../_openssl-build_$target"),rel2abs("."));
-    my $plausible_to_sourcedir =
-        abs2rel(rel2abs("."),rel2abs("../_openssl-build_$target"));
-    print <<"EOF";
-
-----------------------------------------------------------------------
-Please consider configuring with the flag --unified .
-It's to test out a new "unified" building system.
-
-One cool feature is that you can have your build directory elsewhere,
-for example:
-
-    make clean          # Clean the current configuration away
-    mkdir $plausible_builddir
-    cd $plausible_builddir
-    $plausible_to_sourcedir/config --unified
-    make
-    make test
-
-Please report any problem you have.
-----------------------------------------------------------------------
-
-EOF
-}
-
 exit(0);
 
 ######################################################################
@@ -2004,7 +2060,7 @@ sub resolve_config {
     my $target = shift;
     my @breadcrumbs = @_;
 
-    my $extra_checks = defined($ENV{CONFIGURE_EXTRA_CHECKS});
+#    my $extra_checks = defined($ENV{CONFIGURE_EXTRA_CHECKS});
 
     if (grep { $_ eq $target } @breadcrumbs) {
        die "inherit_from loop!  target backtrace:\n  "
@@ -2104,10 +2160,10 @@ sub resolve_config {
         unless(defined($table{$target}->{$_})) {
             delete $table{$target}->{$_};
         }
-        if ($extra_checks &&
-            $previous && !($add_called ||  $previous ~~ $table{$target}->{$_})) {
-            warn "$_ got replaced in $target\n";
-        }
+#        if ($extra_checks &&
+#            $previous && !($add_called ||  $previous ~~ $table{$target}->{$_})) {
+#            warn "$_ got replaced in $target\n";
+#        }
     }
 
     # Finally done, return the result.
@@ -2149,7 +2205,7 @@ sub usage
        exit(1);
        }
 
-sub run_dofile()
+sub run_dofile
 {
     my $out = shift;
     my @templates = @_;
@@ -2299,10 +2355,12 @@ sub which
        my $path;
        foreach $path (split /:/, $ENV{PATH})
                {
-               if (-f "$path/$name$target{exe_extension}" and -x _)
+               my $fullpath = "$path/$name$target{exe_extension}";
+               if (-f $fullpath and -x $fullpath)
                        {
-                       return "$path/$name$target{exe_extension}" unless ($name eq "perl" and
-                        system("$path/$name$target{exe_extension} -e " . '\'exit($]<5.0);\''));
+                       return $fullpath
+                           unless ($name eq "perl" and
+                                   system("$fullpath -e " . '\'exit($]<5.0);\''));
                        }
                }
        }