5 macro_rules! define_handles {
7 'owned: $($oty:ident,)*
8 'interned: $($ity:ident,)*
11 #[allow(non_snake_case)]
12 pub struct HandleCounters {
13 $($oty: AtomicUsize,)*
14 $($ity: AtomicUsize,)*
18 // FIXME(eddyb) use a reference to the `static COUNTERS`, instead of
19 // a wrapper `fn` pointer, once `const fn` can reference `static`s.
20 extern "C" fn get() -> &'static Self {
21 static COUNTERS: HandleCounters = HandleCounters {
22 $($oty: AtomicUsize::new(1),)*
23 $($ity: AtomicUsize::new(1),)*
29 // FIXME(eddyb) generate the definition of `HandleStore` in `server.rs`.
31 #[allow(non_snake_case)]
32 pub(super) struct HandleStore<S: server::Types> {
33 $($oty: handle::OwnedStore<S::$oty>,)*
34 $($ity: handle::InternedStore<S::$ity>,)*
37 impl<S: server::Types> HandleStore<S> {
38 pub(super) fn new(handle_counters: &'static HandleCounters) -> Self {
40 $($oty: handle::OwnedStore::new(&handle_counters.$oty),)*
41 $($ity: handle::InternedStore::new(&handle_counters.$ity),)*
48 pub(crate) struct $oty(handle::Handle);
49 impl !Send for $oty {}
50 impl !Sync for $oty {}
52 // Forward `Drop::drop` to the inherent `drop` method.
59 impl<S> Encode<S> for $oty {
60 fn encode(self, w: &mut Writer, s: &mut S) {
67 impl<S: server::Types> DecodeMut<'_, '_, HandleStore<server::MarkedTypes<S>>>
68 for Marked<S::$oty, $oty>
70 fn decode(r: &mut Reader<'_>, s: &mut HandleStore<server::MarkedTypes<S>>) -> Self {
71 s.$oty.take(handle::Handle::decode(r, &mut ()))
75 impl<S> Encode<S> for &$oty {
76 fn encode(self, w: &mut Writer, s: &mut S) {
81 impl<S: server::Types> Decode<'_, 's, HandleStore<server::MarkedTypes<S>>>
82 for &'s Marked<S::$oty, $oty>
84 fn decode(r: &mut Reader<'_>, s: &'s HandleStore<server::MarkedTypes<S>>) -> Self {
85 &s.$oty[handle::Handle::decode(r, &mut ())]
89 impl<S> Encode<S> for &mut $oty {
90 fn encode(self, w: &mut Writer, s: &mut S) {
95 impl<S: server::Types> DecodeMut<'_, 's, HandleStore<server::MarkedTypes<S>>>
96 for &'s mut Marked<S::$oty, $oty>
100 s: &'s mut HandleStore<server::MarkedTypes<S>>
102 &mut s.$oty[handle::Handle::decode(r, &mut ())]
106 impl<S: server::Types> Encode<HandleStore<server::MarkedTypes<S>>>
107 for Marked<S::$oty, $oty>
109 fn encode(self, w: &mut Writer, s: &mut HandleStore<server::MarkedTypes<S>>) {
110 s.$oty.alloc(self).encode(w, s);
114 impl<S> DecodeMut<'_, '_, S> for $oty {
115 fn decode(r: &mut Reader<'_>, s: &mut S) -> Self {
116 $oty(handle::Handle::decode(r, s))
123 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
124 pub(crate) struct $ity(handle::Handle);
125 impl !Send for $ity {}
126 impl !Sync for $ity {}
128 impl<S> Encode<S> for $ity {
129 fn encode(self, w: &mut Writer, s: &mut S) {
134 impl<S: server::Types> DecodeMut<'_, '_, HandleStore<server::MarkedTypes<S>>>
135 for Marked<S::$ity, $ity>
137 fn decode(r: &mut Reader<'_>, s: &mut HandleStore<server::MarkedTypes<S>>) -> Self {
138 s.$ity.copy(handle::Handle::decode(r, &mut ()))
142 impl<S: server::Types> Encode<HandleStore<server::MarkedTypes<S>>>
143 for Marked<S::$ity, $ity>
145 fn encode(self, w: &mut Writer, s: &mut HandleStore<server::MarkedTypes<S>>) {
146 s.$ity.alloc(self).encode(w, s);
150 impl<S> DecodeMut<'_, '_, S> for $ity {
151 fn decode(r: &mut Reader<'_>, s: &mut S) -> Self {
152 $ity(handle::Handle::decode(r, s))
176 // FIXME(eddyb) generate these impls by pattern-matching on the
177 // names of methods - also could use the presence of `fn drop`
178 // to distinguish between 'owned and 'interned, above.
179 // Alternatively, special 'modes" could be listed of types in with_api
180 // instead of pattern matching on methods, here and in server decl.
182 impl Clone for TokenStream {
183 fn clone(&self) -> Self {
188 impl Clone for TokenStreamIter {
189 fn clone(&self) -> Self {
194 impl Clone for Group {
195 fn clone(&self) -> Self {
200 impl Clone for Literal {
201 fn clone(&self) -> Self {
206 impl fmt::Debug for Literal {
207 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
208 f.debug_struct("Literal")
209 // format the kind without quotes, as in `kind: Float`
210 .field("kind", &format_args!("{}", &self.debug_kind()))
211 .field("symbol", &self.symbol())
212 // format `Some("...")` on one line even in {:#?} mode
213 .field("suffix", &format_args!("{:?}", &self.suffix()))
214 .field("span", &self.span())
219 impl Clone for SourceFile {
220 fn clone(&self) -> Self {
225 impl fmt::Debug for Span {
226 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
227 f.write_str(&self.debug())
231 macro_rules! define_client_side {
233 $(fn $method:ident($($arg:ident: $arg_ty:ty),* $(,)?) $(-> $ret_ty:ty)*;)*
236 $(pub(crate) fn $method($($arg: $arg_ty),*) $(-> $ret_ty)* {
237 Bridge::with(|bridge| {
238 let mut b = bridge.cached_buffer.take();
241 api_tags::Method::$name(api_tags::$name::$method).encode(&mut b, &mut ());
242 reverse_encode!(b; $($arg),*);
244 b = bridge.dispatch.call(b);
246 let r = Result::<_, PanicMessage>::decode(&mut &b[..], &mut ());
248 bridge.cached_buffer = b;
250 r.unwrap_or_else(|e| panic::resume_unwind(e.into()))
256 with_api!(self, self, define_client_side);
258 enum BridgeState<'a> {
259 /// No server is currently connected to this client.
262 /// A server is connected and available for requests.
263 Connected(Bridge<'a>),
265 /// Access to the bridge is being exclusively acquired
266 /// (e.g., during `BridgeState::with`).
272 impl<'a> scoped_cell::ApplyL<'a> for BridgeStateL {
273 type Out = BridgeState<'a>;
277 static BRIDGE_STATE: scoped_cell::ScopedCell<BridgeStateL> =
278 scoped_cell::ScopedCell::new(BridgeState::NotConnected);
281 impl BridgeState<'_> {
282 /// Take exclusive control of the thread-local
283 /// `BridgeState`, and pass it to `f`, mutably.
284 /// The state will be restored after `f` exits, even
285 /// by panic, including modifications made to it by `f`.
287 /// N.B., while `f` is running, the thread-local state
288 /// is `BridgeState::InUse`.
289 fn with<R>(f: impl FnOnce(&mut BridgeState<'_>) -> R) -> R {
290 BRIDGE_STATE.with(|state| {
291 state.replace(BridgeState::InUse, |mut state| {
292 // FIXME(#52812) pass `f` directly to `replace` when `RefMutL` is gone
300 pub(crate) fn is_available() -> bool {
301 BridgeState::with(|state| match state {
302 BridgeState::Connected(_) | BridgeState::InUse => true,
303 BridgeState::NotConnected => false,
307 fn enter<R>(self, f: impl FnOnce() -> R) -> R {
308 let force_show_panics = self.force_show_panics;
309 // Hide the default panic output within `proc_macro` expansions.
310 // NB. the server can't do this because it may use a different libstd.
311 static HIDE_PANICS_DURING_EXPANSION: Once = Once::new();
312 HIDE_PANICS_DURING_EXPANSION.call_once(|| {
313 let prev = panic::take_hook();
314 panic::set_hook(Box::new(move |info| {
315 let show = BridgeState::with(|state| match state {
316 BridgeState::NotConnected => true,
317 BridgeState::Connected(_) | BridgeState::InUse => force_show_panics,
325 BRIDGE_STATE.with(|state| state.set(BridgeState::Connected(self), f))
328 fn with<R>(f: impl FnOnce(&mut Bridge<'_>) -> R) -> R {
329 BridgeState::with(|state| match state {
330 BridgeState::NotConnected => {
331 panic!("procedural macro API is used outside of a procedural macro");
333 BridgeState::InUse => {
334 panic!("procedural macro API is used while it's already in use");
336 BridgeState::Connected(bridge) => f(bridge),
341 /// A client-side "global object" (usually a function pointer),
342 /// which may be using a different `proc_macro` from the one
343 /// used by the server, but can be interacted with compatibly.
345 /// N.B., `F` must have FFI-friendly memory layout (e.g., a pointer).
346 /// The call ABI of function pointers used for `F` doesn't
347 /// need to match between server and client, since it's only
348 /// passed between them and (eventually) called by the client.
350 #[derive(Copy, Clone)]
351 pub struct Client<F> {
352 // FIXME(eddyb) use a reference to the `static COUNTERS`, instead of
353 // a wrapper `fn` pointer, once `const fn` can reference `static`s.
354 pub(super) get_handle_counters: extern "C" fn() -> &'static HandleCounters,
355 pub(super) run: extern "C" fn(Bridge<'_>, F) -> Buffer<u8>,
359 /// Client-side helper for handling client panics, entering the bridge,
360 /// deserializing input and serializing output.
361 // FIXME(eddyb) maybe replace `Bridge::enter` with this?
362 fn run_client<A: for<'a, 's> DecodeMut<'a, 's, ()>, R: Encode<()>>(
363 mut bridge: Bridge<'_>,
364 f: impl FnOnce(A) -> R,
366 // The initial `cached_buffer` contains the input.
367 let mut b = bridge.cached_buffer.take();
369 panic::catch_unwind(panic::AssertUnwindSafe(|| {
371 let reader = &mut &b[..];
372 let input = A::decode(reader, &mut ());
374 // Put the `cached_buffer` back in the `Bridge`, for requests.
375 Bridge::with(|bridge| bridge.cached_buffer = b.take());
377 let output = f(input);
379 // Take the `cached_buffer` back out, for the output value.
380 b = Bridge::with(|bridge| bridge.cached_buffer.take());
382 // HACK(eddyb) Separate encoding a success value (`Ok(output)`)
383 // from encoding a panic (`Err(e: PanicMessage)`) to avoid
384 // having handles outside the `bridge.enter(|| ...)` scope, and
385 // to catch panics that could happen while encoding the success.
387 // Note that panics should be impossible beyond this point, but
388 // this is defensively trying to avoid any accidental panicking
389 // reaching the `extern "C"` (which should `abort` but may not
390 // at the moment, so this is also potentially preventing UB).
392 Ok::<_, ()>(output).encode(&mut b, &mut ());
395 .map_err(PanicMessage::from)
396 .unwrap_or_else(|e| {
398 Err::<(), _>(e).encode(&mut b, &mut ());
403 impl Client<fn(crate::TokenStream) -> crate::TokenStream> {
404 #[rustc_allow_const_fn_unstable(const_fn)]
405 pub const fn expand1(f: fn(crate::TokenStream) -> crate::TokenStream) -> Self {
408 f: impl FnOnce(crate::TokenStream) -> crate::TokenStream,
410 run_client(bridge, |input| f(crate::TokenStream(input)).0)
412 Client { get_handle_counters: HandleCounters::get, run, f }
416 impl Client<fn(crate::TokenStream, crate::TokenStream) -> crate::TokenStream> {
417 #[rustc_allow_const_fn_unstable(const_fn)]
418 pub const fn expand2(
419 f: fn(crate::TokenStream, crate::TokenStream) -> crate::TokenStream,
423 f: impl FnOnce(crate::TokenStream, crate::TokenStream) -> crate::TokenStream,
425 run_client(bridge, |(input, input2)| {
426 f(crate::TokenStream(input), crate::TokenStream(input2)).0
429 Client { get_handle_counters: HandleCounters::get, run, f }
434 #[derive(Copy, Clone)]
437 trait_name: &'static str,
438 attributes: &'static [&'static str],
439 client: Client<fn(crate::TokenStream) -> crate::TokenStream>,
444 client: Client<fn(crate::TokenStream, crate::TokenStream) -> crate::TokenStream>,
449 client: Client<fn(crate::TokenStream) -> crate::TokenStream>,
454 pub fn name(&self) -> &'static str {
456 ProcMacro::CustomDerive { trait_name, .. } => trait_name,
457 ProcMacro::Attr { name, .. } => name,
458 ProcMacro::Bang { name, .. } => name,
462 #[rustc_allow_const_fn_unstable(const_fn)]
463 pub const fn custom_derive(
464 trait_name: &'static str,
465 attributes: &'static [&'static str],
466 expand: fn(crate::TokenStream) -> crate::TokenStream,
468 ProcMacro::CustomDerive { trait_name, attributes, client: Client::expand1(expand) }
471 #[rustc_allow_const_fn_unstable(const_fn)]
474 expand: fn(crate::TokenStream, crate::TokenStream) -> crate::TokenStream,
476 ProcMacro::Attr { name, client: Client::expand2(expand) }
479 #[rustc_allow_const_fn_unstable(const_fn)]
482 expand: fn(crate::TokenStream) -> crate::TokenStream,
484 ProcMacro::Bang { name, client: Client::expand1(expand) }