//! Contains all the same data as `Target`, additionally introducing the concept of "the native target".
//! The purpose of this abstraction is to provide meaningful and unsurprising defaults.
//! This struct does reference any resources and it is copyable.

const CrossTarget = @This();
const std = @import("../std.zig");
const builtin = @import("builtin");
const assert = std.debug.assert;
const Target = std.Target;
const mem = std.mem;

/// `null` means native.
cpu_arch: ?Target.Cpu.Arch = null,

cpu_model: CpuModel = CpuModel.determined_by_cpu_arch,

/// Sparse set of CPU features to add to the set from `cpu_model`.
cpu_features_add: Target.Cpu.Feature.Set = Target.Cpu.Feature.Set.empty,

/// Sparse set of CPU features to remove from the set from `cpu_model`.
cpu_features_sub: Target.Cpu.Feature.Set = Target.Cpu.Feature.Set.empty,

/// `null` means native.
os_tag: ?Target.Os.Tag = null,

/// `null` means the default version range for `os_tag`. If `os_tag` is `null` (native)
/// then `null` for this field means native.
os_version_min: ?OsVersion = null,

/// When cross compiling, `null` means default (latest known OS version).
/// When `os_tag` is native, `null` means equal to the native OS version.
os_version_max: ?OsVersion = null,

/// `null` means default when cross compiling, or native when os_tag is native.
/// If `isGnuLibC()` is `false`, this must be `null` and is ignored.
glibc_version: ?SemVer = null,

/// `null` means the native C ABI, if `os_tag` is native, otherwise it means the default C ABI.
abi: ?Target.Abi = null,

/// When `os_tag` is `null`, then `null` means native. Otherwise it means the standard path
/// based on the `os_tag`.
dynamic_linker: DynamicLinker = DynamicLinker{},

/// `null` means default for the cpu/arch/os combo.
ofmt: ?Target.ObjectFormat = null,

pub const CpuModel = union(enum) {
    /// Always native
    native,

    /// Always baseline
    baseline,

    /// If CPU Architecture is native, then the CPU model will be native. Otherwise,
    /// it will be baseline.
    determined_by_cpu_arch,

    explicit: *const Target.Cpu.Model,
};

pub const OsVersion = union(enum) {
    none: void,
    semver: SemVer,
    windows: Target.Os.WindowsVersion,
};

pub const SemVer = std.builtin.Version;

pub const DynamicLinker = Target.DynamicLinker;

pub fn fromTarget(target: Target) CrossTarget {
    var result: CrossTarget = .{
        .cpu_arch = target.cpu.arch,
        .cpu_model = .{ .explicit = target.cpu.model },
        .os_tag = target.os.tag,
        .os_version_min = undefined,
        .os_version_max = undefined,
        .abi = target.abi,
        .glibc_version = if (target.isGnuLibC())
            target.os.version_range.linux.glibc
        else
            null,
    };
    result.updateOsVersionRange(target.os);

    const all_features = target.cpu.arch.allFeaturesList();
    var cpu_model_set = target.cpu.model.features;
    cpu_model_set.populateDependencies(all_features);
    {
        // The "add" set is the full set with the CPU Model set removed.

        const add_set = &result.cpu_features_add;
        add_set.* = target.cpu.features;
        add_set.removeFeatureSet(cpu_model_set);
    }
    {
        // The "sub" set is the features that are on in CPU Model set and off in the full set.

        const sub_set = &result.cpu_features_sub;
        sub_set.* = cpu_model_set;
        sub_set.removeFeatureSet(target.cpu.features);
    }
    return result;
}

fn updateOsVersionRange(self: *CrossTarget, os: Target.Os) void {
    switch (os.tag) {
        .freestanding,
        .ananas,
        .cloudabi,
        .fuchsia,
        .kfreebsd,
        .lv2,
        .solaris,
        .zos,
        .haiku,
        .minix,
        .rtems,
        .nacl,
        .aix,
        .cuda,
        .nvcl,
        .amdhsa,
        .ps4,
        .ps5,
        .elfiamcu,
        .mesa3d,
        .contiki,
        .amdpal,
        .hermit,
        .hurd,
        .wasi,
        .emscripten,
        .driverkit,
        .shadermodel,
        .uefi,
        .opencl,
        .glsl450,
        .vulkan,
        .plan9,
        .other,
        => {
            self.os_version_min = .{ .none = {} };
            self.os_version_max = .{ .none = {} };
        },

        .freebsd,
        .macos,
        .ios,
        .tvos,
        .watchos,
        .netbsd,
        .openbsd,
        .dragonfly,
        => {
            self.os_version_min = .{ .semver = os.version_range.semver.min };
            self.os_version_max = .{ .semver = os.version_range.semver.max };
        },

        .linux => {
            self.os_version_min = .{ .semver = os.version_range.linux.range.min };
            self.os_version_max = .{ .semver = os.version_range.linux.range.max };
        },

        .windows => {
            self.os_version_min = .{ .windows = os.version_range.windows.min };
            self.os_version_max = .{ .windows = os.version_range.windows.max };
        },
    }
}

/// TODO deprecated, use `std.zig.system.NativeTargetInfo.detect`.
pub fn toTarget(self: CrossTarget) Target {
    return .{
        .cpu = self.getCpu(),
        .os = self.getOs(),
        .abi = self.getAbi(),
        .ofmt = self.getObjectFormat(),
    };
}

pub const ParseOptions = struct {
    /// This is sometimes called a "triple". It looks roughly like this:
    ///     riscv64-linux-musl
    /// The fields are, respectively:
    /// * CPU Architecture
    /// * Operating System (and optional version range)
    /// * C ABI (optional, with optional glibc version)
    /// The string "native" can be used for CPU architecture as well as Operating System.
    /// If the CPU Architecture is specified as "native", then the Operating System and C ABI may be omitted.
    arch_os_abi: []const u8 = "native",

    /// Looks like "name+a+b-c-d+e", where "name" is a CPU Model name, "a", "b", and "e"
    /// are examples of CPU features to add to the set, and "c" and "d" are examples of CPU features
    /// to remove from the set.
    /// The following special strings are recognized for CPU Model name:
    /// * "baseline" - The "default" set of CPU features for cross-compiling. A conservative set
    ///                of features that is expected to be supported on most available hardware.
    /// * "native"   - The native CPU model is to be detected when compiling.
    /// If this field is not provided (`null`), then the value will depend on the
    /// parsed CPU Architecture. If native, then this will be "native". Otherwise, it will be "baseline".
    cpu_features: ?[]const u8 = null,

    /// Absolute path to dynamic linker, to override the default, which is either a natively
    /// detected path, or a standard path.
    dynamic_linker: ?[]const u8 = null,

    object_format: ?[]const u8 = null,

    /// If this is provided, the function will populate some information about parsing failures,
    /// so that user-friendly error messages can be delivered.
    diagnostics: ?*Diagnostics = null,

    pub const Diagnostics = struct {
        /// If the architecture was determined, this will be populated.
        arch: ?Target.Cpu.Arch = null,

        /// If the OS name was determined, this will be populated.
        os_name: ?[]const u8 = null,

        /// If the OS tag was determined, this will be populated.
        os_tag: ?Target.Os.Tag = null,

        /// If the ABI was determined, this will be populated.
        abi: ?Target.Abi = null,

        /// If the CPU name was determined, this will be populated.
        cpu_name: ?[]const u8 = null,

        /// If error.UnknownCpuFeature is returned, this will be populated.
        unknown_feature_name: ?[]const u8 = null,
    };
};

pub fn parse(args: ParseOptions) !CrossTarget {
    var dummy_diags: ParseOptions.Diagnostics = undefined;
    const diags = args.diagnostics orelse &dummy_diags;

    var result: CrossTarget = .{
        .dynamic_linker = DynamicLinker.init(args.dynamic_linker),
    };

    var it = mem.split(u8, args.arch_os_abi, "-");
    const arch_name = it.first();
    const arch_is_native = mem.eql(u8, arch_name, "native");
    if (!arch_is_native) {
        result.cpu_arch = std.meta.stringToEnum(Target.Cpu.Arch, arch_name) orelse
            return error.UnknownArchitecture;
    }
    const arch = result.getCpuArch();
    diags.arch = arch;

    if (it.next()) |os_text| {
        try parseOs(&result, diags, os_text);
    } else if (!arch_is_native) {
        return error.MissingOperatingSystem;
    }

    const opt_abi_text = it.next();
    if (opt_abi_text) |abi_text| {
        var abi_it = mem.split(u8, abi_text, ".");
        const abi = std.meta.stringToEnum(Target.Abi, abi_it.first()) orelse
            return error.UnknownApplicationBinaryInterface;
        result.abi = abi;
        diags.abi = abi;

        const abi_ver_text = abi_it.rest();
        if (abi_it.next() != null) {
            if (result.isGnuLibC()) {
                result.glibc_version = SemVer.parse(abi_ver_text) catch |err| switch (err) {
                    error.Overflow => return error.InvalidAbiVersion,
                    error.InvalidCharacter => return error.InvalidAbiVersion,
                    error.InvalidVersion => return error.InvalidAbiVersion,
                };
            } else {
                return error.InvalidAbiVersion;
            }
        }
    }

    if (it.next() != null) return error.UnexpectedExtraField;

    if (args.cpu_features) |cpu_features| {
        const all_features = arch.allFeaturesList();
        var index: usize = 0;
        while (index < cpu_features.len and
            cpu_features[index] != '+' and
            cpu_features[index] != '-')
        {
            index += 1;
        }
        const cpu_name = cpu_features[0..index];
        diags.cpu_name = cpu_name;

        const add_set = &result.cpu_features_add;
        const sub_set = &result.cpu_features_sub;
        if (mem.eql(u8, cpu_name, "native")) {
            result.cpu_model = .native;
        } else if (mem.eql(u8, cpu_name, "baseline")) {
            result.cpu_model = .baseline;
        } else {
            result.cpu_model = .{ .explicit = try arch.parseCpuModel(cpu_name) };
        }

        while (index < cpu_features.len) {
            const op = cpu_features[index];
            const set = switch (op) {
                '+' => add_set,
                '-' => sub_set,
                else => unreachable,
            };
            index += 1;
            const start = index;
            while (index < cpu_features.len and
                cpu_features[index] != '+' and
                cpu_features[index] != '-')
            {
                index += 1;
            }
            const feature_name = cpu_features[start..index];
            for (all_features) |feature, feat_index_usize| {
                const feat_index = @intCast(Target.Cpu.Feature.Set.Index, feat_index_usize);
                if (mem.eql(u8, feature_name, feature.name)) {
                    set.addFeature(feat_index);
                    break;
                }
            } else {
                diags.unknown_feature_name = feature_name;
                return error.UnknownCpuFeature;
            }
        }
    }

    if (args.object_format) |ofmt_name| {
        result.ofmt = std.meta.stringToEnum(Target.ObjectFormat, ofmt_name) orelse
            return error.UnknownObjectFormat;
    }

    return result;
}

/// Similar to `parse` except instead of fully parsing, it only determines the CPU
/// architecture and returns it if it can be determined, and returns `null` otherwise.
/// This is intended to be used if the API user of CrossTarget needs to learn the
/// target CPU architecture in order to fully populate `ParseOptions`.
pub fn parseCpuArch(args: ParseOptions) ?Target.Cpu.Arch {
    var it = mem.split(u8, args.arch_os_abi, "-");
    const arch_name = it.first();
    const arch_is_native = mem.eql(u8, arch_name, "native");
    if (arch_is_native) {
        return builtin.cpu.arch;
    } else {
        return std.meta.stringToEnum(Target.Cpu.Arch, arch_name);
    }
}

/// TODO deprecated, use `std.zig.system.NativeTargetInfo.detect`.
pub fn getCpu(self: CrossTarget) Target.Cpu {
    switch (self.cpu_model) {
        .native => {
            // This works when doing `zig build` because Zig generates a build executable using

            // native CPU model & features. However this will not be accurate otherwise, and

            // will need to be integrated with `std.zig.system.NativeTargetInfo.detect`.

            return builtin.cpu;
        },
        .baseline => {
            var adjusted_baseline = Target.Cpu.baseline(self.getCpuArch());
            self.updateCpuFeatures(&adjusted_baseline.features);
            return adjusted_baseline;
        },
        .determined_by_cpu_arch => if (self.cpu_arch == null) {
            // This works when doing `zig build` because Zig generates a build executable using

            // native CPU model & features. However this will not be accurate otherwise, and

            // will need to be integrated with `std.zig.system.NativeTargetInfo.detect`.

            return builtin.cpu;
        } else {
            var adjusted_baseline = Target.Cpu.baseline(self.getCpuArch());
            self.updateCpuFeatures(&adjusted_baseline.features);
            return adjusted_baseline;
        },
        .explicit => |model| {
            var adjusted_model = model.toCpu(self.getCpuArch());
            self.updateCpuFeatures(&adjusted_model.features);
            return adjusted_model;
        },
    }
}

pub fn getCpuArch(self: CrossTarget) Target.Cpu.Arch {
    return self.cpu_arch orelse builtin.cpu.arch;
}

pub fn getCpuModel(self: CrossTarget) *const Target.Cpu.Model {
    return switch (self.cpu_model) {
        .explicit => |cpu_model| cpu_model,
        else => self.getCpu().model,
    };
}

pub fn getCpuFeatures(self: CrossTarget) Target.Cpu.Feature.Set {
    return self.getCpu().features;
}

/// TODO deprecated, use `std.zig.system.NativeTargetInfo.detect`.
pub fn getOs(self: CrossTarget) Target.Os {
    // `builtin.os` works when doing `zig build` because Zig generates a build executable using

    // native OS version range. However this will not be accurate otherwise, and

    // will need to be integrated with `std.zig.system.NativeTargetInfo.detect`.

    var adjusted_os = if (self.os_tag) |os_tag| os_tag.defaultVersionRange(self.getCpuArch()) else builtin.os;

    if (self.os_version_min) |min| switch (min) {
        .none => {},
        .semver => |semver| switch (self.getOsTag()) {
            .linux => adjusted_os.version_range.linux.range.min = semver,
            else => adjusted_os.version_range.semver.min = semver,
        },
        .windows => |win_ver| adjusted_os.version_range.windows.min = win_ver,
    };

    if (self.os_version_max) |max| switch (max) {
        .none => {},
        .semver => |semver| switch (self.getOsTag()) {
            .linux => adjusted_os.version_range.linux.range.max = semver,
            else => adjusted_os.version_range.semver.max = semver,
        },
        .windows => |win_ver| adjusted_os.version_range.windows.max = win_ver,
    };

    if (self.glibc_version) |glibc| {
        assert(self.isGnuLibC());
        adjusted_os.version_range.linux.glibc = glibc;
    }

    return adjusted_os;
}

pub fn getOsTag(self: CrossTarget) Target.Os.Tag {
    return self.os_tag orelse builtin.os.tag;
}

/// TODO deprecated, use `std.zig.system.NativeTargetInfo.detect`.
pub fn getOsVersionMin(self: CrossTarget) OsVersion {
    if (self.os_version_min) |version_min| return version_min;
    var tmp: CrossTarget = undefined;
    tmp.updateOsVersionRange(self.getOs());
    return tmp.os_version_min.?;
}

/// TODO deprecated, use `std.zig.system.NativeTargetInfo.detect`.
pub fn getOsVersionMax(self: CrossTarget) OsVersion {
    if (self.os_version_max) |version_max| return version_max;
    var tmp: CrossTarget = undefined;
    tmp.updateOsVersionRange(self.getOs());
    return tmp.os_version_max.?;
}

/// TODO deprecated, use `std.zig.system.NativeTargetInfo.detect`.
pub fn getAbi(self: CrossTarget) Target.Abi {
    if (self.abi) |abi| return abi;

    if (self.os_tag == null) {
        // This works when doing `zig build` because Zig generates a build executable using

        // native CPU model & features. However this will not be accurate otherwise, and

        // will need to be integrated with `std.zig.system.NativeTargetInfo.detect`.

        return builtin.abi;
    }

    return Target.Abi.default(self.getCpuArch(), self.getOs());
}

pub fn isFreeBSD(self: CrossTarget) bool {
    return self.getOsTag() == .freebsd;
}

pub fn isDarwin(self: CrossTarget) bool {
    return self.getOsTag().isDarwin();
}

pub fn isNetBSD(self: CrossTarget) bool {
    return self.getOsTag() == .netbsd;
}

pub fn isOpenBSD(self: CrossTarget) bool {
    return self.getOsTag() == .openbsd;
}

pub fn isUefi(self: CrossTarget) bool {
    return self.getOsTag() == .uefi;
}

pub fn isDragonFlyBSD(self: CrossTarget) bool {
    return self.getOsTag() == .dragonfly;
}

pub fn isLinux(self: CrossTarget) bool {
    return self.getOsTag() == .linux;
}

pub fn isWindows(self: CrossTarget) bool {
    return self.getOsTag() == .windows;
}

pub fn exeFileExt(self: CrossTarget) [:0]const u8 {
    return Target.exeFileExtSimple(self.getCpuArch(), self.getOsTag());
}

pub fn staticLibSuffix(self: CrossTarget) [:0]const u8 {
    return Target.staticLibSuffix_os_abi(self.getOsTag(), self.getAbi());
}

pub fn dynamicLibSuffix(self: CrossTarget) [:0]const u8 {
    return self.getOsTag().dynamicLibSuffix();
}

pub fn libPrefix(self: CrossTarget) [:0]const u8 {
    return Target.libPrefix_os_abi(self.getOsTag(), self.getAbi());
}

pub fn isNativeCpu(self: CrossTarget) bool {
    return self.cpu_arch == null and
        (self.cpu_model == .native or self.cpu_model == .determined_by_cpu_arch) and
        self.cpu_features_sub.isEmpty() and self.cpu_features_add.isEmpty();
}

pub fn isNativeOs(self: CrossTarget) bool {
    return self.os_tag == null and self.os_version_min == null and self.os_version_max == null and
        self.dynamic_linker.get() == null and self.glibc_version == null;
}

pub fn isNativeAbi(self: CrossTarget) bool {
    return self.os_tag == null and self.abi == null;
}

pub fn isNative(self: CrossTarget) bool {
    return self.isNativeCpu() and self.isNativeOs() and self.isNativeAbi();
}

pub fn zigTriple(self: CrossTarget, allocator: mem.Allocator) error{OutOfMemory}![]u8 {
    if (self.isNative()) {
        return allocator.dupe(u8, "native");
    }

    const arch_name = if (self.cpu_arch) |arch| @tagName(arch) else "native";
    const os_name = if (self.os_tag) |os_tag| @tagName(os_tag) else "native";

    var result = std.ArrayList(u8).init(allocator);
    defer result.deinit();

    try result.writer().print("{s}-{s}", .{ arch_name, os_name });

    // The zig target syntax does not allow specifying a max os version with no min, so

    // if either are present, we need the min.

    if (self.os_version_min != null or self.os_version_max != null) {
        switch (self.getOsVersionMin()) {
            .none => {},
            .semver => |v| try result.writer().print(".{}", .{v}),
            .windows => |v| try result.writer().print("{s}", .{v}),
        }
    }
    if (self.os_version_max) |max| {
        switch (max) {
            .none => {},
            .semver => |v| try result.writer().print("...{}", .{v}),
            .windows => |v| try result.writer().print("..{s}", .{v}),
        }
    }

    if (self.glibc_version) |v| {
        try result.writer().print("-{s}.{}", .{ @tagName(self.getAbi()), v });
    } else if (self.abi) |abi| {
        try result.writer().print("-{s}", .{@tagName(abi)});
    }

    return result.toOwnedSlice();
}

pub fn allocDescription(self: CrossTarget, allocator: mem.Allocator) ![]u8 {
    // TODO is there anything else worthy of the description that is not

    // already captured in the triple?

    return self.zigTriple(allocator);
}

pub fn linuxTriple(self: CrossTarget, allocator: mem.Allocator) ![]u8 {
    return Target.linuxTripleSimple(allocator, self.getCpuArch(), self.getOsTag(), self.getAbi());
}

pub fn wantSharedLibSymLinks(self: CrossTarget) bool {
    return self.getOsTag() != .windows;
}

pub const VcpkgLinkage = std.builtin.LinkMode;

/// Returned slice must be freed by the caller.
pub fn vcpkgTriplet(self: CrossTarget, allocator: mem.Allocator, linkage: VcpkgLinkage) ![]u8 {
    const arch = switch (self.getCpuArch()) {
        .i386 => "x86",
        .x86_64 => "x64",

        .arm,
        .armeb,
        .thumb,
        .thumbeb,
        .aarch64_32,
        => "arm",

        .aarch64,
        .aarch64_be,
        => "arm64",

        else => return error.UnsupportedVcpkgArchitecture,
    };

    const os = switch (self.getOsTag()) {
        .windows => "windows",
        .linux => "linux",
        .macos => "macos",
        else => return error.UnsupportedVcpkgOperatingSystem,
    };

    const static_suffix = switch (linkage) {
        .Static => "-static",
        .Dynamic => "",
    };

    return std.fmt.allocPrint(allocator, "{s}-{s}{s}", .{ arch, os, static_suffix });
}

pub fn isGnuLibC(self: CrossTarget) bool {
    return Target.isGnuLibC_os_tag_abi(self.getOsTag(), self.getAbi());
}

pub fn setGnuLibCVersion(self: *CrossTarget, major: u32, minor: u32, patch: u32) void {
    assert(self.isGnuLibC());
    self.glibc_version = SemVer{ .major = major, .minor = minor, .patch = patch };
}

pub fn getObjectFormat(self: CrossTarget) Target.ObjectFormat {
    return self.ofmt orelse Target.ObjectFormat.default(self.getOsTag(), self.getCpuArch());
}

pub fn updateCpuFeatures(self: CrossTarget, set: *Target.Cpu.Feature.Set) void {
    set.removeFeatureSet(self.cpu_features_sub);
    set.addFeatureSet(self.cpu_features_add);
    set.populateDependencies(self.getCpuArch().allFeaturesList());
    set.removeFeatureSet(self.cpu_features_sub);
}

fn parseOs(result: *CrossTarget, diags: *ParseOptions.Diagnostics, text: []const u8) !void {
    var it = mem.split(u8, text, ".");
    const os_name = it.first();
    diags.os_name = os_name;
    const os_is_native = mem.eql(u8, os_name, "native");
    if (!os_is_native) {
        result.os_tag = std.meta.stringToEnum(Target.Os.Tag, os_name) orelse
            return error.UnknownOperatingSystem;
    }
    const tag = result.getOsTag();
    diags.os_tag = tag;

    const version_text = it.rest();
    if (it.next() == null) return;

    switch (tag) {
        .freestanding,
        .ananas,
        .cloudabi,
        .fuchsia,
        .kfreebsd,
        .lv2,
        .solaris,
        .zos,
        .haiku,
        .minix,
        .rtems,
        .nacl,
        .aix,
        .cuda,
        .nvcl,
        .amdhsa,
        .ps4,
        .ps5,
        .elfiamcu,
        .mesa3d,
        .contiki,
        .amdpal,
        .hermit,
        .hurd,
        .wasi,
        .emscripten,
        .uefi,
        .opencl,
        .glsl450,
        .vulkan,
        .plan9,
        .driverkit,
        .shadermodel,
        .other,
        => return error.InvalidOperatingSystemVersion,

        .freebsd,
        .macos,
        .ios,
        .tvos,
        .watchos,
        .netbsd,
        .openbsd,
        .linux,
        .dragonfly,
        => {
            var range_it = mem.split(u8, version_text, "...");

            const min_text = range_it.next().?;
            const min_ver = SemVer.parse(min_text) catch |err| switch (err) {
                error.Overflow => return error.InvalidOperatingSystemVersion,
                error.InvalidCharacter => return error.InvalidOperatingSystemVersion,
                error.InvalidVersion => return error.InvalidOperatingSystemVersion,
            };
            result.os_version_min = .{ .semver = min_ver };

            const max_text = range_it.next() orelse return;
            const max_ver = SemVer.parse(max_text) catch |err| switch (err) {
                error.Overflow => return error.InvalidOperatingSystemVersion,
                error.InvalidCharacter => return error.InvalidOperatingSystemVersion,
                error.InvalidVersion => return error.InvalidOperatingSystemVersion,
            };
            result.os_version_max = .{ .semver = max_ver };
        },

        .windows => {
            var range_it = mem.split(u8, version_text, "...");

            const min_text = range_it.first();
            const min_ver = std.meta.stringToEnum(Target.Os.WindowsVersion, min_text) orelse
                return error.InvalidOperatingSystemVersion;
            result.os_version_min = .{ .windows = min_ver };

            const max_text = range_it.next() orelse return;
            const max_ver = std.meta.stringToEnum(Target.Os.WindowsVersion, max_text) orelse
                return error.InvalidOperatingSystemVersion;
            result.os_version_max = .{ .windows = max_ver };
        },
    }
}

test "CrossTarget.parse" {
    if (builtin.target.isGnuLibC()) {
        var cross_target = try CrossTarget.parse(.{});
        cross_target.setGnuLibCVersion(2, 1, 1);

        const text = try cross_target.zigTriple(std.testing.allocator);
        defer std.testing.allocator.free(text);

        var buf: [256]u8 = undefined;
        const triple = std.fmt.bufPrint(
            buf[0..],
            "native-native-{s}.2.1.1",
            .{@tagName(builtin.abi)},
        ) catch unreachable;

        try std.testing.expectEqualSlices(u8, triple, text);
    }
    {
        const cross_target = try CrossTarget.parse(.{
            .arch_os_abi = "aarch64-linux",
            .cpu_features = "native",
        });

        try std.testing.expect(cross_target.cpu_arch.? == .aarch64);
        try std.testing.expect(cross_target.cpu_model == .native);
    }
    {
        const cross_target = try CrossTarget.parse(.{ .arch_os_abi = "native" });

        try std.testing.expect(cross_target.cpu_arch == null);
        try std.testing.expect(cross_target.isNative());

        const text = try cross_target.zigTriple(std.testing.allocator);
        defer std.testing.allocator.free(text);
        try std.testing.expectEqualSlices(u8, "native", text);
    }
    {
        const cross_target = try CrossTarget.parse(.{
            .arch_os_abi = "x86_64-linux-gnu",
            .cpu_features = "x86_64-sse-sse2-avx-cx8",
        });
        const target = cross_target.toTarget();

        try std.testing.expect(target.os.tag == .linux);
        try std.testing.expect(target.abi == .gnu);
        try std.testing.expect(target.cpu.arch == .x86_64);
        try std.testing.expect(!Target.x86.featureSetHas(target.cpu.features, .sse));
        try std.testing.expect(!Target.x86.featureSetHas(target.cpu.features, .avx));
        try std.testing.expect(!Target.x86.featureSetHas(target.cpu.features, .cx8));
        try std.testing.expect(Target.x86.featureSetHas(target.cpu.features, .cmov));
        try std.testing.expect(Target.x86.featureSetHas(target.cpu.features, .fxsr));

        try std.testing.expect(Target.x86.featureSetHasAny(target.cpu.features, .{ .sse, .avx, .cmov }));
        try std.testing.expect(!Target.x86.featureSetHasAny(target.cpu.features, .{ .sse, .avx }));
        try std.testing.expect(Target.x86.featureSetHasAll(target.cpu.features, .{ .mmx, .x87 }));
        try std.testing.expect(!Target.x86.featureSetHasAll(target.cpu.features, .{ .mmx, .x87, .sse }));

        const text = try cross_target.zigTriple(std.testing.allocator);
        defer std.testing.allocator.free(text);
        try std.testing.expectEqualSlices(u8, "x86_64-linux-gnu", text);
    }
    {
        const cross_target = try CrossTarget.parse(.{
            .arch_os_abi = "arm-linux-musleabihf",
            .cpu_features = "generic+v8a",
        });
        const target = cross_target.toTarget();

        try std.testing.expect(target.os.tag == .linux);
        try std.testing.expect(target.abi == .musleabihf);
        try std.testing.expect(target.cpu.arch == .arm);
        try std.testing.expect(target.cpu.model == &Target.arm.cpu.generic);
        try std.testing.expect(Target.arm.featureSetHas(target.cpu.features, .v8a));

        const text = try cross_target.zigTriple(std.testing.allocator);
        defer std.testing.allocator.free(text);
        try std.testing.expectEqualSlices(u8, "arm-linux-musleabihf", text);
    }
    {
        const cross_target = try CrossTarget.parse(.{
            .arch_os_abi = "aarch64-linux.3.10...4.4.1-gnu.2.27",
            .cpu_features = "generic+v8a",
        });
        const target = cross_target.toTarget();

        try std.testing.expect(target.cpu.arch == .aarch64);
        try std.testing.expect(target.os.tag == .linux);
        try std.testing.expect(target.os.version_range.linux.range.min.major == 3);
        try std.testing.expect(target.os.version_range.linux.range.min.minor == 10);
        try std.testing.expect(target.os.version_range.linux.range.min.patch == 0);
        try std.testing.expect(target.os.version_range.linux.range.max.major == 4);
        try std.testing.expect(target.os.version_range.linux.range.max.minor == 4);
        try std.testing.expect(target.os.version_range.linux.range.max.patch == 1);
        try std.testing.expect(target.os.version_range.linux.glibc.major == 2);
        try std.testing.expect(target.os.version_range.linux.glibc.minor == 27);
        try std.testing.expect(target.os.version_range.linux.glibc.patch == 0);
        try std.testing.expect(target.abi == .gnu);

        const text = try cross_target.zigTriple(std.testing.allocator);
        defer std.testing.allocator.free(text);
        try std.testing.expectEqualSlices(u8, "aarch64-linux.3.10...4.4.1-gnu.2.27", text);
    }
}