unbound/android/15-android.conf

#### Android...
#
# See NOTES.ANDROID for details, and don't miss platform-specific
# comments below...

{
    use File::Spec::Functions;

    my $android_ndk = {};
    my %triplet = (
        arm     => "arm-linux-androideabi",
        armeabi => "arm-linux-androideabi",
        armv7a  => "arm-linux-androideabi",
        arm64   => "aarch64-linux-android",
        x86     => "i686-linux-android",
        x86_64  => "x86_64-linux-android"
    );

    sub android_ndk {
        unless (%$android_ndk) {
            if ($now_printing =~ m|^android|) {
                return $android_ndk = { bn_ops => "BN_AUTO" };
            }

            my $ndk_var;
            my $ndk;
            foreach (qw(ANDROID_NDK_ROOT)) {
                $ndk_var = $_;
                $ndk = $ENV{$ndk_var};
                last if defined $ndk;
            }
            die "\$ANDROID_NDK_ROOT is not defined"  if (!$ndk);
            if (!-d "$ndk/platforms" && !-f "$ndk/AndroidVersion.txt") {
                # $ndk/platforms is traditional "all-inclusive" NDK, while
                # $ndk/AndroidVersion.txt is so-called standalone toolchain
                # tailored for specific target down to API level.
                die "\$ANDROID_NDK_ROOT=$ndk is invalid";
            }
            $ndk = canonpath($ndk);

            my $ndkver = undef;

            if (open my $fh, "<$ndk/source.properties") {
                local $_;
                while(<$fh>) {
                    if (m|Pkg\.Revision\s*=\s*([0-9]+)|) {
                        $ndkver = $1;
                        last;
                    }
                }
                close $fh;
            }

            my ($sysroot, $api, $arch);

            $config{target} =~ m|[^-]+-([^-]+)$|;	# split on dash
            $arch = $1;

            if ($arch = "armeabi") {
                $arch = "arm";
            }

            if (-f "$ndk/AndroidVersion.txt") {
                $sysroot = "$ndk/sysroot";
            } else {
                $api = "*";

                # see if user passed -D__ANDROID_API__=N
                foreach (@{$useradd{CPPDEFINES}}, @{$user{CPPFLAGS}}) {
                    if (m|__ANDROID_API__=([0-9]+)|) {
                        $api = $1;
                        last;
                    }
                }

                # list available platforms (numerically)
                my @platforms = sort { $a =~ m/-([0-9]+)$/; my $aa = $1;
                                       $b =~ m/-([0-9]+)$/; $aa <=> $1;
                                     } glob("$ndk/platforms/android-$api");
                die "no $ndk/platforms/android-$api" if ($#platforms < 0);

                $sysroot = "@platforms[$#platforms]/arch-$arch";
                $sysroot =~ m|/android-([0-9]+)/arch-$arch|;
                $api = $1;
            }
            die "no sysroot=$sysroot"   if (!-d $sysroot);

            my $triarch = $triplet{$arch};
            my $cflags;
            my $cppflags;

            # see if there is NDK clang on $PATH, "universal" or "standalone"
            if (which("clang") =~ m|^$ndk/.*/prebuilt/([^/]+)/|) {
                my $host=$1;
                # harmonize with gcc default
                my $arm = $ndkver > 16 ? "armv7a" : "armv5te";
                (my $tridefault = $triarch) =~ s/^arm-/$arm-/;
                (my $tritools   = $triarch) =~ s/(?:x|i6)86(_64)?-.*/x86$1/;
                $cflags .= " -target $tridefault ";
                $user{CC} = "clang" if ($user{CC} !~ m|clang|);
                $user{CROSS_COMPILE} = undef;
                if (which("llvm-ar") =~ m|^$ndk/.*/prebuilt/([^/]+)/|) {
                    $user{AR} = "llvm-ar";
                    $user{ARFLAGS} = [ "rs" ];
                    $user{RANLIB} = ":";
                }
            } elsif (-f "$ndk/AndroidVersion.txt") {    #"standalone toolchain"
                my $cc = $user{CC} // "clang";
                # One can probably argue that both clang and gcc should be
                # probed, but support for "standalone toolchain" was added
                # *after* announcement that gcc is being phased out, so
                # favouring clang is considered adequate. Those who insist
                # have option to enforce test for gcc with CC=gcc.
                if (which("$triarch-$cc") !~ m|^$ndk|) {
                    die "no NDK $triarch-$cc on \$PATH";
                }
                $user{CC} = $cc;
                $user{CROSS_COMPILE} = "$triarch-";
            } elsif ($user{CC} eq "clang") {
                die "no NDK clang on \$PATH";
            } else {
                if (which("$triarch-gcc") !~ m|^$ndk/.*/prebuilt/([^/]+)/|) {
                    die "no NDK $triarch-gcc on \$PATH";
                }
                $cflags .= " -mandroid";
                $user{CROSS_COMPILE} = "$triarch-";
            }

            if (!-d "$sysroot/usr/include") {
                my $incroot = "$ndk/sysroot/usr/include";
                die "no $incroot"          if (!-d $incroot);
                die "no $incroot/$triarch" if (!-d "$incroot/$triarch");
                $incroot =~ s|^$ndk/||;
                $cppflags  = "-D__ANDROID_API__=$api";
            }

            $sysroot =~ s|^$ndk/||;
            $android_ndk = {
                cppflags => $cppflags,
                bn_ops   => $arch =~ m/64$/ ? "SIXTY_FOUR_BIT_LONG"
                                            : "BN_LLONG",
            };
        }

        return $android_ndk;
    }
}

my %targets = (
    "android" => {
        inherit_from     => [ "linux-generic32" ],
        template         => 1,
        ################################################################
        # Special note about -pie. The underlying reason is that
        # Lollipop refuses to run non-PIE. But what about older systems
        # and NDKs? -fPIC was never problem, so the only concern is -pie.
        cflags           => add(sub { android_ndk()->{cflags} }),
        cppflags         => add(sub { android_ndk()->{cppflags} }),
        cxxflags         => add(sub { android_ndk()->{cflags} }),
        bn_ops           => sub { android_ndk()->{bn_ops} },
        bin_cflags       => "-pie",
        enable           => [ ],
    },
    "android-arm" => {
        inherit_from     => [ "android", asm("armv4_asm") ],
        bn_ops           => add("RC4_CHAR"),
    },
    "android-arm64" => {
        inherit_from     => [ "android", asm("aarch64_asm") ],
        bn_ops           => add("RC4_CHAR"),
        perlasm_scheme   => "linux64",
    },

    "android-x86" => {
        inherit_from     => [ "android", asm("x86_asm") ],
        CFLAGS           => add(picker(release => "-fomit-frame-pointer")),
        bn_ops           => add("RC4_INT"),
        perlasm_scheme   => "android",
    },
    "android-x86_64" => {
        inherit_from     => [ "android", asm("x86_64_asm") ],
        bn_ops           => add("RC4_INT"),
        perlasm_scheme   => "elf",
    },
);