git.delta.rocks / jrsonnet / refs/commits / d91d16dbe1e7

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crates/nix-eval/src/lib.rs21.7 KiBsourcehistory
1use std::borrow::Cow;2use std::cell::RefCell;3use std::ffi::{CStr, CString, c_char, c_int, c_uint, c_void};4use std::fmt;5use std::ptr::null_mut;6use std::sync::LazyLock;7use std::{collections::HashMap, path::PathBuf};89use anyhow::{Context, anyhow, bail};10use serde::Serialize;11use serde::de::DeserializeOwned;1213pub use anyhow::Result;1415use self::logging::nix_logging_cxx;16use self::nix_cxx::set_fetcher_setting;17use self::nix_raw::{18	alloc_value, c_context, c_context_create, err_code, err_info_msg, eval_state_build,19	eval_state_builder_new, expr_eval_from_string, fetchers_settings, fetchers_settings_free,20	fetchers_settings_new, flake_lock, flake_lock_flags, flake_lock_flags_free,21	flake_lock_flags_new, flake_reference_parse_flags, flake_reference_parse_flags_free,22	flake_reference_parse_flags_new, flake_reference_parse_flags_set_base_directory,23	flake_settings, flake_settings_free, flake_settings_new, init_bool, init_int, init_string,24	locked_flake_free, locked_flake_get_output_attrs, set_err_msg, setting_set, state_free,25	value_decref, value_incref,26};2728// Contains macros helpers29pub mod logging;30#[doc(hidden)]31pub mod macros;32pub mod util;3334#[allow(35	non_upper_case_globals,36	non_camel_case_types,37	non_snake_case,38	dead_code39)]40mod nix_raw {41	include!(concat!(env!("OUT_DIR"), "/bindings.rs"));42}43#[cxx::bridge]44pub mod nix_cxx {45	unsafe extern "C++" {46		type nix_fetchers_settings;47		include!("nix-eval/src/lib.hh");4849		unsafe fn set_fetcher_setting(50			settings: *mut nix_fetchers_settings,51			setting: *const c_char,52			value: *const c_char,53		);54	}55}5657#[derive(Debug, PartialEq, Eq)]58pub enum NixType {59	Thunk,60	Int,61	Float,62	Bool,63	String,64	Path,65	Null,66	Attrs,67	List,68	Function,69	External,70}71impl NixType {72	fn from_int(c: c_uint) -> Self {73		match c {74			0 => Self::Thunk,75			1 => Self::Int,76			2 => Self::Float,77			3 => Self::Bool,78			4 => Self::String,79			5 => Self::Path,80			6 => Self::Null,81			7 => Self::Attrs,82			8 => Self::List,83			9 => Self::Function,84			10 => Self::External,85			_ => unreachable!("unknown nix type: {c}"),86		}87	}88}8990enum FunctorKind {91	Function,92	Functor,93}9495#[derive(Debug)]96#[repr(i32)]97enum NixErrorKind {98	Unknown = 1,99	Overflow = 2,100	Key = 3,101	Generic = 4,102}103impl NixErrorKind {104	fn from_int(v: c_int) -> Option<Self> {105		Some(match v {106			0 => return None,107			-1 => Self::Unknown,108			-2 => Self::Overflow,109			-3 => Self::Key,110			-4 => Self::Generic,111			_ => {112				debug_assert!(false, "unexpected nix error kind: {v}");113				Self::Unknown114			}115		})116	}117}118119pub fn gc_register_my_thread() {120	assert_eq!(unsafe { nix_raw::GC_thread_is_registered() }, 0);121122	let mut sb = nix_raw::GC_stack_base {123		mem_base: null_mut(),124	};125	let r = unsafe { nix_raw::GC_get_stack_base(&mut sb) };126	if r as u32 != nix_raw::GC_SUCCESS {127		panic!("failed to get thread stack base");128	}129	unsafe { nix_raw::GC_register_my_thread(&sb) };130}131pub fn gc_unregister_my_thread() {132	assert_eq!(unsafe { nix_raw::GC_thread_is_registered() }, 1);133134	unsafe { nix_raw::GC_unregister_my_thread() };135}136137pub struct ThreadRegisterGuard {}138impl ThreadRegisterGuard {139	pub fn new() -> Self {140		gc_register_my_thread();141		Self {}142	}143}144impl Drop for ThreadRegisterGuard {145	fn drop(&mut self) {146		gc_unregister_my_thread();147	}148}149150pub struct NixContext(*mut c_context);151impl NixContext {152	pub fn set_err(&mut self, err: NixErrorKind, msg: &CStr) {153		unsafe { set_err_msg(self.0, err as c_int, msg.as_ptr()) };154	}155	pub fn new() -> Self {156		let ctx = unsafe { c_context_create() };157		Self(ctx)158	}159	fn error_kind(&self) -> Option<NixErrorKind> {160		let code = unsafe { err_code(self.0) };161		NixErrorKind::from_int(code)162	}163	fn error<'t>(&self) -> Option<Cow<'t, str>> {164		if let NixErrorKind::Generic = self.error_kind()? {165			let mut err_out = String::new();166			unsafe {167				err_info_msg(168					null_mut(),169					self.0,170					Some(copy_nix_str),171					(&raw mut err_out).cast(),172				)173			};174			return Some(Cow::Owned(err_out));175		};176177		// TODO: Can throw error (resulting in panic) if unable to retrieve error. Should be able to resolve by passing context as a first argument,178		// but it looks ugly179		let str = unsafe { nix_raw::err_msg(null_mut(), self.0, null_mut()) };180		Some(unsafe { CStr::from_ptr(str) }.to_string_lossy())181	}182	fn clean_err(&mut self) {183		unsafe {184			nix_raw::clear_err(self.0);185		}186	}187188	fn bail_if_error(&self) -> Result<()> {189		if let Some(err) = self.error() {190			bail!("{err}");191		};192		Ok(())193	}194195	fn run_in_context<T>(&mut self, f: impl FnOnce(*mut c_context) -> T) -> Result<T> {196		self.clean_err();197		let o = f(self.0);198		self.bail_if_error()?;199		self.clean_err();200		Ok(o)201	}202}203impl Drop for NixContext {204	fn drop(&mut self) {205		unsafe {206			nix_raw::c_context_free(self.0);207		}208	}209}210struct GlobalState {211	// Store should be valid as long as EvalState is valid212	#[allow(dead_code)]213	store: Store,214	state: EvalState,215}216impl GlobalState {217	fn new() -> Result<Self> {218		let mut ctx = NixContext::new();219		let store = ctx220			.run_in_context(|c| unsafe { nix_raw::store_open(c, c"daemon".as_ptr(), null_mut()) })221			.map(Store)?;222223		let builder = ctx.run_in_context(|c| unsafe { eval_state_builder_new(c, store.0) })?;224		ctx.run_in_context(|c| {225			unsafe {226				nix_raw::eval_state_builder_set_eval_setting(227					c,228					builder,229					c"lazy-trees".as_ptr(),230					c"true".as_ptr(),231				)232			}233			// eval_s234		})?;235		let state = ctx236			.run_in_context(|c| unsafe { eval_state_build(c, builder) })237			.map(EvalState)?;238239		Ok(Self { store, state })240	}241}242243struct ThreadState {244	ctx: NixContext,245}246impl ThreadState {247	fn new() -> Result<Self> {248		let ctx = NixContext::new();249250		Ok(Self { ctx })251	}252}253254static GLOBAL_STATE: LazyLock<GlobalState> =255	LazyLock::new(|| GlobalState::new().expect("global state init shouldn't fail"));256257thread_local! {258	static THREAD_STATE: RefCell<ThreadState> = RefCell::new(ThreadState::new().expect("thread state init shouldn't fail"));259}260fn with_default_context<T>(261	f: impl FnOnce(*mut c_context, *mut nix_raw::EvalState) -> T,262) -> Result<T> {263	let global = &GLOBAL_STATE.state;264	let (ctx, state) = THREAD_STATE.with_borrow_mut(|w| (w.ctx.0, global.0));265	let mut ctx = NixContext(ctx);266	let v = ctx.run_in_context(|c| f(c, state));267	// It is reused for thread268	std::mem::forget(ctx);269	v270}271272pub fn set_setting(s: &CStr, v: &CStr) -> Result<()> {273	with_default_context(|c, _| unsafe { setting_set(c, s.as_ptr(), v.as_ptr()) }).map(|_| ())274}275276pub struct FetchSettings(*mut fetchers_settings);277impl FetchSettings {278	pub fn new() -> Self {279		Self::try_new().expect("allocation should not fail")280	}281	fn try_new() -> Result<Self> {282		with_default_context(|c, _| unsafe { fetchers_settings_new(c) }).map(Self)283	}284	pub fn set(&mut self, setting: &CStr, value: &CStr) {285		unsafe {286			set_fetcher_setting(self.0.cast(), setting.as_ptr(), value.as_ptr());287		};288	}289}290unsafe impl Send for FetchSettings {}291unsafe impl Sync for FetchSettings {}292293impl Default for FetchSettings {294	fn default() -> Self {295		Self::new()296	}297}298299impl Drop for FetchSettings {300	fn drop(&mut self) {301		unsafe { fetchers_settings_free(self.0) };302	}303}304pub struct FlakeSettings(*mut flake_settings);305impl FlakeSettings {306	pub fn new() -> Result<Self> {307		with_default_context(|c, _| unsafe { flake_settings_new(c) }).map(Self)308	}309}310unsafe impl Send for FlakeSettings {}311unsafe impl Sync for FlakeSettings {}312impl Drop for FlakeSettings {313	fn drop(&mut self) {314		unsafe {315			flake_settings_free(self.0);316		}317	}318}319320pub struct FlakeReferenceParseFlags(*mut flake_reference_parse_flags);321impl FlakeReferenceParseFlags {322	pub fn new(settings: &mut FlakeSettings) -> Result<Self> {323		with_default_context(|c, _| unsafe { flake_reference_parse_flags_new(c, settings.0) })324			.map(Self)325	}326	pub fn set_base_dir(&mut self, dir: &str) -> Result<()> {327		with_default_context(|c, _| {328			unsafe {329				flake_reference_parse_flags_set_base_directory(330					c,331					self.0,332					dir.as_ptr().cast(),333					dir.len(),334				)335			};336		})337	}338}339impl Drop for FlakeReferenceParseFlags {340	fn drop(&mut self) {341		unsafe {342			flake_reference_parse_flags_free(self.0);343		}344	}345}346struct FlakeLockFlags(*mut flake_lock_flags);347impl FlakeLockFlags {348	fn new(settings: &mut FlakeSettings) -> Result<Self> {349		with_default_context(|c, _| unsafe { flake_lock_flags_new(c, settings.0) }).map(Self)350	}351}352impl Drop for FlakeLockFlags {353	fn drop(&mut self) {354		unsafe {355			flake_lock_flags_free(self.0);356		}357	}358}359360unsafe extern "C" fn copy_nix_str(start: *const c_char, n: c_uint, user_data: *mut c_void) {361	let s = unsafe { std::slice::from_raw_parts(start.cast::<u8>(), n as usize) };362	let s = std::str::from_utf8(s).expect("c string has invalid utf-8");363	unsafe { *user_data.cast::<String>() = s.to_owned() };364}365366struct Store(*mut nix_raw::Store);367unsafe impl Send for Store {}368unsafe impl Sync for Store {}369370struct EvalState(*mut nix_raw::EvalState);371unsafe impl Send for EvalState {}372unsafe impl Sync for EvalState {}373374impl Drop for EvalState {375	fn drop(&mut self) {376		unsafe {377			state_free(self.0);378		}379	}380}381382pub struct FlakeReference(*mut nix_raw::flake_reference);383impl FlakeReference {384	pub fn new(s: &str, fetch: &FetchSettings) -> Result<(Self, String)> {385		let mut flake_settings = FlakeSettings::new()?;386		let parse_flags = FlakeReferenceParseFlags::new(&mut flake_settings)?;387388		let mut out = null_mut();389		let mut fragment = String::new();390		// let fetch_settings = fetcher_settings;391		with_default_context(|c, _| unsafe {392			nix_raw::flake_reference_and_fragment_from_string(393				c,394				fetch.0,395				flake_settings.0,396				parse_flags.0,397				s.as_ptr().cast(),398				s.len(),399				&mut out,400				Some(copy_nix_str),401				(&raw mut fragment).cast(),402			)403		})?;404		assert!(!out.is_null());405406		Ok((Self(out), fragment))407	}408	pub fn lock(&mut self, fetch: &FetchSettings) -> Result<LockedFlake> {409		let mut settings = FlakeSettings::new()?;410		let lock_flags = FlakeLockFlags::new(&mut settings)?;411		with_default_context(|c, es| unsafe {412			flake_lock(c, fetch.0, settings.0, es, lock_flags.0, self.0)413		})414		.map(LockedFlake)415	}416}417unsafe impl Send for FlakeReference {}418unsafe impl Sync for FlakeReference {}419420pub struct LockedFlake(*mut nix_raw::locked_flake);421impl LockedFlake {422	pub fn get_attrs(&self, settings: &mut FlakeSettings) -> Result<Value> {423		with_default_context(|c, es| unsafe {424			locked_flake_get_output_attrs(c, settings.0, es, self.0)425		})426		.map(Value)427	}428}429unsafe impl Send for LockedFlake {}430unsafe impl Sync for LockedFlake {}431impl Drop for LockedFlake {432	fn drop(&mut self) {433		unsafe {434			locked_flake_free(self.0);435		};436	}437}438439type FieldName = [u8; 32];440fn init_field_name(v: &str) -> FieldName {441	let mut f = [0; 32];442	assert!(v.len() < 32, "max field name is 31 char");443	assert!(444		v.bytes().all(|v| v != 0),445		"nul bytes are unsupported in field name"446	);447	f[0..v.len()].copy_from_slice(v.as_bytes());448	f449}450451pub struct RealisedString(*mut nix_raw::realised_string);452impl fmt::Debug for RealisedString {453	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {454		self.as_str().fmt(f)455	}456}457458impl RealisedString {459	pub fn as_str(&self) -> &str {460		let len = unsafe { nix_raw::realised_string_get_buffer_size(self.0) };461		let data: *const u8 = unsafe { nix_raw::realised_string_get_buffer_start(self.0) }.cast();462		let data = unsafe { std::slice::from_raw_parts(data, len) };463		std::str::from_utf8(data).expect("non-utf8 strings not supported")464	}465	pub fn path_count(&self) -> usize {466		unsafe { nix_raw::realised_string_get_store_path_count(self.0) }467	}468	pub fn path(&self, i: usize) -> String {469		assert!(i < self.path_count());470		let path = unsafe { nix_raw::realised_string_get_store_path(self.0, i) };471		let mut err_out = String::new();472		unsafe { nix_raw::store_path_name(path, Some(copy_nix_str), (&raw mut err_out).cast()) };473		err_out474	}475}476477unsafe impl Send for RealisedString {}478impl Drop for RealisedString {479	fn drop(&mut self) {480		unsafe { nix_raw::realised_string_free(self.0) }481	}482}483484pub struct Value(*mut nix_raw::value);485486unsafe impl Send for Value {}487unsafe impl Sync for Value {}488489pub trait AsFieldName {490	fn as_field_name<T>(&self, v: impl FnOnce(FieldName) -> Result<T>) -> Result<T>;491	fn to_field_name(&self) -> Result<String>;492}493impl AsFieldName for Value {494	fn as_field_name<T>(&self, v: impl FnOnce(FieldName) -> Result<T>) -> Result<T> {495		let f = self.to_string()?;496		v(init_field_name(&f))497	}498	fn to_field_name(&self) -> Result<String> {499		self.to_string()500	}501}502impl<E> AsFieldName for E503where504	E: AsRef<str>,505{506	fn as_field_name<T>(&self, v: impl FnOnce(FieldName) -> Result<T>) -> Result<T> {507		let f = self.as_ref();508		v(init_field_name(f))509	}510	fn to_field_name(&self) -> Result<String> {511		Ok(self.as_ref().to_owned())512	}513}514515struct AttrsBuilder(*mut nix_raw::BindingsBuilder);516impl AttrsBuilder {517	fn new(capacity: usize) -> Self {518		with_default_context(|c, es| unsafe { nix_raw::make_bindings_builder(c, es, capacity) })519			.map(Self)520			.expect("alloc should not fail")521	}522	fn insert(&mut self, k: &impl AsFieldName, v: Value) {523		k.as_field_name(|name| {524			with_default_context(|c, _| unsafe {525				nix_raw::bindings_builder_insert(c, self.0, name.as_ptr().cast(), v.0)526			})527		})528		.expect("builder insert shouldn't fail");529	}530}531impl Drop for AttrsBuilder {532	fn drop(&mut self) {533		unsafe { nix_raw::bindings_builder_free(self.0) };534	}535}536537impl Value {538	pub fn new_attrs(v: HashMap<&str, Value>) -> Self {539		let out = Self::new_uninit();540		let mut b = AttrsBuilder::new(v.len());541		for (k, v) in v {542			b.insert(&k, v);543		}544		with_default_context(|c, _| unsafe { nix_raw::make_attrs(c, out.0, b.0) })545			.expect("attrs initialization should not fail");546		out547	}548	fn new_list<T: Into<Self>>(v: Vec<T>) -> Self {549		todo!()550	}551	fn new_uninit() -> Self {552		let out = with_default_context(|c, es| unsafe { alloc_value(c, es) })553			.expect("value allocation should not fail");554		Self(out)555	}556	pub fn new_str(v: &str) -> Self {557		let s = CString::new(v).expect("string should not contain NULs");558		let out = Self::new_uninit();559		// String is copied, `s` is free to be dropped560		with_default_context(|c, _| unsafe { init_string(c, out.0, s.as_ptr()) })561			.expect("string initialization should not fail");562		out563	}564	pub fn new_int(i: i64) -> Self {565		let out = Self::new_uninit();566		with_default_context(|c, _| unsafe { init_int(c, out.0, i) })567			.expect("int initialization should not fail");568		out569	}570	pub fn new_bool(v: bool) -> Self {571		let out = Self::new_uninit();572		with_default_context(|c, _| unsafe { init_bool(c, out.0, v) })573			.expect("bool initialization should not fail");574		out575	}576	// TODO: As far as I can see, there is no way to get Thunks from nix public C api, so this function is useless577	// fn force(&mut self, st: &mut EvalState) -> Result<()> {578	// 	with_default_context(|c, _| unsafe { value_force(c, st.0, self.0) })?;579	// 	Ok(())580	// }581	pub fn type_of(&self) -> NixType {582		let ty = with_default_context(|c, _| unsafe { nix_raw::get_type(c, self.0) })583			.expect("get_type should not fail");584		NixType::from_int(ty)585	}586	pub fn to_string(&self) -> Result<String> {587		Ok(self.to_realised_string()?.as_str().to_owned())588	}589	pub fn to_realised_string(&self) -> Result<RealisedString> {590		with_default_context(|c, es| unsafe { nix_raw::string_realise(c, es, self.0, false) })591			.map(RealisedString)592593		// let store_paths = unsafe { nix_raw::realised_string_get_store_path_count(str) };594		// for i in 0..store_paths {595		// 	let store_path = unsafe { nix_raw::realised_string_get_store_path(str, i) };596		// 	nix_raw::store_path_name(store_path, callback, user_data);597		// }598		// dbg!(store_paths);599		// todo!();600	}601602	pub fn has_field(&self, field: &str) -> Result<bool> {603		let f = init_field_name(field);604		with_default_context(|c, es| unsafe {605			nix_raw::has_attr_byname(c, self.0, es, f.as_ptr().cast())606		})607	}608	// pub fn derivation_path(&self) {609	// 	nix_raw::real610	// }611	pub fn list_fields(&self) -> Result<Vec<String>> {612		if !matches!(self.type_of(), NixType::Attrs) {613			bail!("invalid type: expected attrs");614		}615616		let len = with_default_context(|c, _| unsafe { nix_raw::get_attrs_size(c, self.0) })?;617		let mut out = Vec::with_capacity(len as usize);618619		for i in 0..len {620			let name = with_default_context(|c, es| unsafe {621				nix_raw::get_attr_name_byidx(c, self.0, es, i)622			})?;623			let c = unsafe { CStr::from_ptr(name) };624			out.push(c.to_str().expect("nix field names are utf-8").to_owned());625		}626		Ok(out)627	}628	pub fn get_elem(&self, v: usize) -> Result<Self> {629		if !matches!(self.type_of(), NixType::List) {630			bail!("invalid type: expected list");631		}632		let len =633			with_default_context(|c, _| unsafe { nix_raw::get_list_size(c, self.0) })? as usize;634		if v >= len {635			bail!("oob list get: {v} >= {len}");636		}637638		with_default_context(|c, es| unsafe { nix_raw::get_list_byidx(c, self.0, es, v as u32) })639			.map(Self)640	}641	pub fn attrs_update(self, other: Value) -> Result<Self> {642		let a_fields = self.list_fields()?;643		let b_fields = other.list_fields()?;644		match (a_fields.len(), b_fields.len()) {645			(_, 0) => return Ok(self),646			(0, _) => return Ok(other),647			_ => {}648		}649		let mut out = HashMap::new();650		for f in a_fields.iter() {651			if b_fields.contains(f) {652				break;653			}654			out.insert(f.as_str(), self.get_field(f)?);655		}656		if out.is_empty() {657			// All fields from lhs are overriden by rhs658			return Ok(other);659		}660		for f in b_fields.iter() {661			out.insert(f.as_str(), other.get_field(f)?);662		}663		Ok(Self::new_attrs(out))664	}665	pub fn get_field(&self, name: impl AsFieldName) -> Result<Self> {666		if !matches!(self.type_of(), NixType::Attrs) {667			bail!("invalid type: expected attrs");668		}669670		name.as_field_name(|name| {671			with_default_context(|c, es| unsafe {672				nix_raw::get_attr_byname(c, self.0, es, name.as_ptr().cast())673			})674			.map(Self)675		})676		.with_context(|| format!("getting field {:?}", name.to_field_name()))677	}678	pub fn call(&self, v: Value) -> Result<Self> {679		let kind = self680			.functor_kind()681			.ok_or_else(|| anyhow!("can only call function or functor"))?;682683		let function = match kind {684			FunctorKind::Function => self.clone(),685			FunctorKind::Functor => {686				let f = self.get_field("__functor")?;687				assert_eq!(688					f.type_of(),689					NixType::Function,690					"invalid functor encountered"691				);692				f693			}694		};695696		let out = Value::new_uninit();697		with_default_context(|c, es| unsafe {698			nix_raw::value_call(c, es, function.0, v.0, out.0)699		})?;700701		Ok(out)702	}703	pub fn eval(v: &str) -> Result<Self> {704		let s = CString::new(v).expect("expression shouldn't have internal NULs");705		let out = Self::new_uninit();706		with_default_context(|c, es| unsafe {707			expr_eval_from_string(c, es, s.as_ptr(), c"/homeless-shelter".as_ptr(), out.0)708		})?;709		Ok(out)710	}711	pub async fn build(&self, output: &str) -> Result<PathBuf> {712		if !self.is_derivation() {713			bail!("expected derivation to build")714		}715		let output_name = self.get_field("outputName")?.to_string()?;716		let v = if output_name != output {717			let out = self.get_field(output)?;718			if !out.is_derivation() {719				bail!("unknown output: {output}");720			}721			out722		} else {723			self.clone()724		};725		// to_string here blocks until the path is built726		let drv_path = tokio::task::spawn_blocking(move || v.get_field("outPath")?.to_string())727			.await728			.expect("should not fail")?;729		Ok(PathBuf::from(drv_path))730	}731	pub fn as_json<T: DeserializeOwned>(&self) -> Result<T> {732		let to_json = Self::eval("builtins.toJSON")?;733		let s = to_json.call(self.clone())?.to_string()?;734		Ok(serde_json::from_str(&s)?)735	}736	pub fn serialized<T: Serialize>(v: &T) -> Result<Self> {737		Self::eval(&nixlike::serialize(v)?)738	}739740	// Convert to string/evaluate derivations/etc741	// fn to_string_weak(&self) -> Result<String> {742	// 	// TODO: For now, it works exactly like to_string, see the comment for fn force()743	// 	self.to_string()744	// }745746	fn is_derivation(&self) -> bool {747		if !matches!(self.type_of(), NixType::Attrs) {748			return false;749		}750		let Some(ty) = self.get_field("type").ok() else {751			return false;752		};753		matches!(ty.to_string().as_deref(), Ok("derivation"))754	}755	fn functor_kind(&self) -> Option<FunctorKind> {756		match self.type_of() {757			NixType::Attrs => self758				.has_field("__functor")759				.expect("has_field shouldn't fail for attrs")760				.then_some(FunctorKind::Functor),761			NixType::Function => Some(FunctorKind::Function),762			_ => None,763		}764	}765	pub fn is_function(&self) -> bool {766		self.functor_kind().is_some()767	}768}769770impl From<String> for Value {771	fn from(value: String) -> Self {772		Value::new_str(&value)773	}774}775impl From<bool> for Value {776	fn from(value: bool) -> Self {777		Value::new_bool(value)778	}779}780impl From<&str> for Value {781	fn from(value: &str) -> Self {782		Value::new_str(value)783	}784}785impl<T> From<Vec<T>> for Value786where787	T: Into<Value>,788{789	fn from(value: Vec<T>) -> Self {790		Value::new_list(value)791	}792}793794impl Clone for Value {795	fn clone(&self) -> Self {796		with_default_context(|c, _| unsafe { value_incref(c, self.0) })797			.expect("value incref should not fail");798		Self(self.0)799	}800}801impl Drop for Value {802	fn drop(&mut self) {803		with_default_context(|c, _| unsafe { value_decref(c, self.0) })804			.expect("value drop should not fail");805	}806}807808pub fn init_libraries() {809	unsafe { nix_raw::GC_allow_register_threads() };810811	let mut ctx = NixContext::new();812	ctx.run_in_context(|c| unsafe { nix_raw::libutil_init(c) })813		.expect("util init should not fail");814	ctx.run_in_context(|c| unsafe { nix_raw::libstore_init(c) })815		.expect("store init should not fail");816	ctx.run_in_context(|c| unsafe { nix_raw::libexpr_init(c) })817		.expect("expr init should not fail");818819	nix_logging_cxx::apply_tracing_logger();820}821822#[test_log::test]823fn test_native() -> Result<()> {824	init_libraries();825826	let mut fetch_settings = FetchSettings::new();827	fetch_settings.set(c"warn-dirty", c"false");828829	let manifest = format!("{}/../../", env!("CARGO_MANIFEST_DIR"));830	let (mut r, _) = FlakeReference::new(&manifest, &fetch_settings)?;831	let locked = r.lock(&fetch_settings)?;832	let attrs = locked.get_attrs(&mut FlakeSettings::new()?)?;833834	let builtins = Value::eval("builtins")?;835	assert_eq!(builtins.type_of(), NixType::Attrs);836837	assert_eq!(attrs.type_of(), NixType::Attrs);838	let test_data = nix_go!(attrs.testData);839840	let test_string: String = nix_go_json!(test_data.testString);841	assert_eq!(test_string, "hello");842843	Ok(())844}