From b2844917ad29e967043bea4e187421a6a3f61682 Mon Sep 17 00:00:00 2001 From: Edwin Cheng Date: Sat, 4 Apr 2020 16:04:01 +0800 Subject: Add proc_macro mod (copy from lib_proc_macro) --- .../src/proc_macro/bridge/buffer.rs | 149 +++++++ .../src/proc_macro/bridge/client.rs | 472 +++++++++++++++++++++ .../src/proc_macro/bridge/closure.rs | 27 ++ .../src/proc_macro/bridge/handle.rs | 73 ++++ .../ra_proc_macro_srv/src/proc_macro/bridge/mod.rs | 404 ++++++++++++++++++ .../ra_proc_macro_srv/src/proc_macro/bridge/rpc.rs | 311 ++++++++++++++ .../src/proc_macro/bridge/scoped_cell.rs | 84 ++++ .../src/proc_macro/bridge/server.rs | 323 ++++++++++++++ 8 files changed, 1843 insertions(+) create mode 100644 crates/ra_proc_macro_srv/src/proc_macro/bridge/buffer.rs create mode 100644 crates/ra_proc_macro_srv/src/proc_macro/bridge/client.rs create mode 100644 crates/ra_proc_macro_srv/src/proc_macro/bridge/closure.rs create mode 100644 crates/ra_proc_macro_srv/src/proc_macro/bridge/handle.rs create mode 100644 crates/ra_proc_macro_srv/src/proc_macro/bridge/mod.rs create mode 100644 crates/ra_proc_macro_srv/src/proc_macro/bridge/rpc.rs create mode 100644 crates/ra_proc_macro_srv/src/proc_macro/bridge/scoped_cell.rs create mode 100644 crates/ra_proc_macro_srv/src/proc_macro/bridge/server.rs (limited to 'crates/ra_proc_macro_srv/src/proc_macro/bridge') diff --git a/crates/ra_proc_macro_srv/src/proc_macro/bridge/buffer.rs b/crates/ra_proc_macro_srv/src/proc_macro/bridge/buffer.rs new file mode 100644 index 000000000..dae6ff1d1 --- /dev/null +++ b/crates/ra_proc_macro_srv/src/proc_macro/bridge/buffer.rs @@ -0,0 +1,149 @@ +//! lib-proc-macro Buffer management for same-process client<->server communication. +//! +//! Copy from https://github.com/rust-lang/rust/blob/6050e523bae6de61de4e060facc43dc512adaccd/src/libproc_macro/bridge/buffer.rs +//! augmented with removing unstable features + +use std::io::{self, Write}; +use std::mem; +use std::ops::{Deref, DerefMut}; +use std::slice; + +#[repr(C)] +struct Slice<'a, T> { + data: &'a [T; 0], + len: usize, +} + +unsafe impl<'a, T: Sync> Sync for Slice<'a, T> {} +unsafe impl<'a, T: Sync> Send for Slice<'a, T> {} + +impl<'a, T> Copy for Slice<'a, T> {} +impl<'a, T> Clone for Slice<'a, T> { + fn clone(&self) -> Self { + *self + } +} + +impl<'a, T> From<&'a [T]> for Slice<'a, T> { + fn from(xs: &'a [T]) -> Self { + Slice { data: unsafe { &*(xs.as_ptr() as *const [T; 0]) }, len: xs.len() } + } +} + +impl<'a, T> Deref for Slice<'a, T> { + type Target = [T]; + fn deref(&self) -> &[T] { + unsafe { slice::from_raw_parts(self.data.as_ptr(), self.len) } + } +} + +#[repr(C)] +pub struct Buffer { + data: *mut T, + len: usize, + capacity: usize, + extend_from_slice: extern "C" fn(Buffer, Slice<'_, T>) -> Buffer, + drop: extern "C" fn(Buffer), +} + +unsafe impl Sync for Buffer {} +unsafe impl Send for Buffer {} + +impl Default for Buffer { + fn default() -> Self { + Self::from(vec![]) + } +} + +impl Deref for Buffer { + type Target = [T]; + fn deref(&self) -> &[T] { + unsafe { slice::from_raw_parts(self.data as *const T, self.len) } + } +} + +impl DerefMut for Buffer { + fn deref_mut(&mut self) -> &mut [T] { + unsafe { slice::from_raw_parts_mut(self.data, self.len) } + } +} + +impl Buffer { + pub(super) fn new() -> Self { + Self::default() + } + + pub(super) fn clear(&mut self) { + self.len = 0; + } + + pub(super) fn take(&mut self) -> Self { + mem::take(self) + } + + pub(super) fn extend_from_slice(&mut self, xs: &[T]) { + // Fast path to avoid going through an FFI call. + if let Some(final_len) = self.len.checked_add(xs.len()) { + if final_len <= self.capacity { + let dst = unsafe { slice::from_raw_parts_mut(self.data, self.capacity) }; + dst[self.len..][..xs.len()].copy_from_slice(xs); + self.len = final_len; + return; + } + } + let b = self.take(); + *self = (b.extend_from_slice)(b, Slice::from(xs)); + } +} + +impl Write for Buffer { + fn write(&mut self, xs: &[u8]) -> io::Result { + self.extend_from_slice(xs); + Ok(xs.len()) + } + + fn write_all(&mut self, xs: &[u8]) -> io::Result<()> { + self.extend_from_slice(xs); + Ok(()) + } + + fn flush(&mut self) -> io::Result<()> { + Ok(()) + } +} + +impl Drop for Buffer { + fn drop(&mut self) { + let b = self.take(); + (b.drop)(b); + } +} + +impl From> for Buffer { + fn from(mut v: Vec) -> Self { + let (data, len, capacity) = (v.as_mut_ptr(), v.len(), v.capacity()); + mem::forget(v); + + // This utility function is nested in here because it can *only* + // be safely called on `Buffer`s created by *this* `proc_macro`. + fn to_vec(b: Buffer) -> Vec { + unsafe { + let Buffer { data, len, capacity, .. } = b; + mem::forget(b); + Vec::from_raw_parts(data, len, capacity) + } + } + + extern "C" fn extend_from_slice(b: Buffer, xs: Slice<'_, T>) -> Buffer { + let mut v = to_vec(b); + v.extend_from_slice(&xs); + Buffer::from(v) + } + + extern "C" fn drop(b: Buffer) { + mem::drop(to_vec(b)); + } + + Buffer { data, len, capacity, extend_from_slice, drop } + } +} diff --git a/crates/ra_proc_macro_srv/src/proc_macro/bridge/client.rs b/crates/ra_proc_macro_srv/src/proc_macro/bridge/client.rs new file mode 100644 index 000000000..4b5dc7fd0 --- /dev/null +++ b/crates/ra_proc_macro_srv/src/proc_macro/bridge/client.rs @@ -0,0 +1,472 @@ +//! lib-proc-macro Client-side types. +//! +//! Copy from https://github.com/rust-lang/rust/blob/6050e523bae6de61de4e060facc43dc512adaccd/src/libproc_macro/bridge/client.rs +//! augmented with removing unstable features + +use super::*; + +macro_rules! define_handles { + ( + 'owned: $($oty:ident,)* + 'interned: $($ity:ident,)* + ) => { + #[repr(C)] + #[allow(non_snake_case)] + pub struct HandleCounters { + $($oty: AtomicUsize,)* + $($ity: AtomicUsize,)* + } + + impl HandleCounters { + // FIXME(eddyb) use a reference to the `static COUNTERS`, intead of + // a wrapper `fn` pointer, once `const fn` can reference `static`s. + extern "C" fn get() -> &'static Self { + static COUNTERS: HandleCounters = HandleCounters { + $($oty: AtomicUsize::new(1),)* + $($ity: AtomicUsize::new(1),)* + }; + &COUNTERS + } + } + + // FIXME(eddyb) generate the definition of `HandleStore` in `server.rs`. + #[repr(C)] + #[allow(non_snake_case)] + pub(super) struct HandleStore { + $($oty: handle::OwnedStore,)* + $($ity: handle::InternedStore,)* + } + + impl HandleStore { + pub(super) fn new(handle_counters: &'static HandleCounters) -> Self { + HandleStore { + $($oty: handle::OwnedStore::new(&handle_counters.$oty),)* + $($ity: handle::InternedStore::new(&handle_counters.$ity),)* + } + } + } + + $( + #[repr(C)] + pub struct $oty(pub(crate) handle::Handle); + // impl !Send for $oty {} + // impl !Sync for $oty {} + + // Forward `Drop::drop` to the inherent `drop` method. + impl Drop for $oty { + fn drop(&mut self) { + $oty(self.0).drop(); + } + } + + impl Encode for $oty { + fn encode(self, w: &mut Writer, s: &mut S) { + let handle = self.0; + mem::forget(self); + handle.encode(w, s); + } + } + + impl DecodeMut<'_, '_, HandleStore>> + for Marked + { + fn decode(r: &mut Reader<'_>, s: &mut HandleStore>) -> Self { + s.$oty.take(handle::Handle::decode(r, &mut ())) + } + } + + impl Encode for &$oty { + fn encode(self, w: &mut Writer, s: &mut S) { + self.0.encode(w, s); + } + } + + impl<'s, S: server::Types,> Decode<'_, 's, HandleStore>> + for &'s Marked + { + fn decode(r: &mut Reader<'_>, s: &'s HandleStore>) -> Self { + &s.$oty[handle::Handle::decode(r, &mut ())] + } + } + + impl Encode for &mut $oty { + fn encode(self, w: &mut Writer, s: &mut S) { + self.0.encode(w, s); + } + } + + impl<'s, S: server::Types> DecodeMut<'_, 's, HandleStore>> + for &'s mut Marked + { + fn decode( + r: &mut Reader<'_>, + s: &'s mut HandleStore> + ) -> Self { + &mut s.$oty[handle::Handle::decode(r, &mut ())] + } + } + + impl Encode>> + for Marked + { + fn encode(self, w: &mut Writer, s: &mut HandleStore>) { + s.$oty.alloc(self).encode(w, s); + } + } + + impl DecodeMut<'_, '_, S> for $oty { + fn decode(r: &mut Reader<'_>, s: &mut S) -> Self { + $oty(handle::Handle::decode(r, s)) + } + } + )* + + $( + #[repr(C)] + #[derive(Copy, Clone, PartialEq, Eq, Hash)] + pub(crate) struct $ity(handle::Handle); + // impl !Send for $ity {} + // impl !Sync for $ity {} + + impl Encode for $ity { + fn encode(self, w: &mut Writer, s: &mut S) { + self.0.encode(w, s); + } + } + + impl DecodeMut<'_, '_, HandleStore>> + for Marked + { + fn decode(r: &mut Reader<'_>, s: &mut HandleStore>) -> Self { + s.$ity.copy(handle::Handle::decode(r, &mut ())) + } + } + + impl Encode>> + for Marked + { + fn encode(self, w: &mut Writer, s: &mut HandleStore>) { + s.$ity.alloc(self).encode(w, s); + } + } + + impl DecodeMut<'_, '_, S> for $ity { + fn decode(r: &mut Reader<'_>, s: &mut S) -> Self { + $ity(handle::Handle::decode(r, s)) + } + } + )* + } +} +define_handles! { + 'owned: + TokenStream, + TokenStreamBuilder, + TokenStreamIter, + Group, + Literal, + SourceFile, + MultiSpan, + Diagnostic, + + 'interned: + Punct, + Ident, + Span, +} + +// FIXME(eddyb) generate these impls by pattern-matching on the +// names of methods - also could use the presence of `fn drop` +// to distinguish between 'owned and 'interned, above. +// Alternatively, special 'modes" could be listed of types in with_api +// instead of pattern matching on methods, here and in server decl. + +impl Clone for TokenStream { + fn clone(&self) -> Self { + self.clone() + } +} + +impl Clone for TokenStreamIter { + fn clone(&self) -> Self { + self.clone() + } +} + +impl Clone for Group { + fn clone(&self) -> Self { + self.clone() + } +} + +impl Clone for Literal { + fn clone(&self) -> Self { + self.clone() + } +} + +// FIXME(eddyb) `Literal` should not expose internal `Debug` impls. +impl fmt::Debug for Literal { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.write_str(&self.debug()) + } +} + +impl Clone for SourceFile { + fn clone(&self) -> Self { + self.clone() + } +} + +impl fmt::Debug for Span { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.write_str(&self.debug()) + } +} + +macro_rules! define_client_side { + ($($name:ident { + $(fn $method:ident($($arg:ident: $arg_ty:ty),* $(,)?) $(-> $ret_ty:ty)*;)* + }),* $(,)?) => { + $(impl $name { + #[allow(unused)] + $(pub(crate) fn $method($($arg: $arg_ty),*) $(-> $ret_ty)* { + panic!("hello"); + // Bridge::with(|bridge| { + // let mut b = bridge.cached_buffer.take(); + + // b.clear(); + // api_tags::Method::$name(api_tags::$name::$method).encode(&mut b, &mut ()); + // reverse_encode!(b; $($arg),*); + + // b = bridge.dispatch.call(b); + + // let r = Result::<_, PanicMessage>::decode(&mut &b[..], &mut ()); + + // bridge.cached_buffer = b; + + // r.unwrap_or_else(|e| panic::resume_unwind(e.into())) + // }) + })* + })* + } +} +with_api!(self, self, define_client_side); + +enum BridgeState<'a> { + /// No server is currently connected to this client. + NotConnected, + + /// A server is connected and available for requests. + Connected(Bridge<'a>), + + /// Access to the bridge is being exclusively acquired + /// (e.g., during `BridgeState::with`). + InUse, +} + +enum BridgeStateL {} + +impl<'a> scoped_cell::ApplyL<'a> for BridgeStateL { + type Out = BridgeState<'a>; +} + +thread_local! { + static BRIDGE_STATE: scoped_cell::ScopedCell = + scoped_cell::ScopedCell::new(BridgeState::NotConnected); +} + +impl BridgeState<'_> { + /// Take exclusive control of the thread-local + /// `BridgeState`, and pass it to `f`, mutably. + /// The state will be restored after `f` exits, even + /// by panic, including modifications made to it by `f`. + /// + /// N.B., while `f` is running, the thread-local state + /// is `BridgeState::InUse`. + fn with(f: impl FnOnce(&mut BridgeState<'_>) -> R) -> R { + BRIDGE_STATE.with(|state| { + state.replace(BridgeState::InUse, |mut state| { + // FIXME(#52812) pass `f` directly to `replace` when `RefMutL` is gone + f(&mut *state) + }) + }) + } +} + +impl Bridge<'_> { + fn enter(self, f: impl FnOnce() -> R) -> R { + // Hide the default panic output within `proc_macro` expansions. + // NB. the server can't do this because it may use a different libstd. + static HIDE_PANICS_DURING_EXPANSION: Once = Once::new(); + HIDE_PANICS_DURING_EXPANSION.call_once(|| { + let prev = panic::take_hook(); + panic::set_hook(Box::new(move |info| { + let hide = BridgeState::with(|state| match state { + BridgeState::NotConnected => false, + BridgeState::Connected(_) | BridgeState::InUse => true, + }); + if !hide { + prev(info) + } + })); + }); + + BRIDGE_STATE.with(|state| state.set(BridgeState::Connected(self), f)) + } + + fn with(f: impl FnOnce(&mut Bridge<'_>) -> R) -> R { + BridgeState::with(|state| match state { + BridgeState::NotConnected => { + panic!("procedural macro API is used outside of a procedural macro"); + } + BridgeState::InUse => { + panic!("procedural macro API is used while it's already in use"); + } + BridgeState::Connected(bridge) => f(bridge), + }) + } +} + +/// A client-side "global object" (usually a function pointer), +/// which may be using a different `proc_macro` from the one +/// used by the server, but can be interacted with compatibly. +/// +/// N.B., `F` must have FFI-friendly memory layout (e.g., a pointer). +/// The call ABI of function pointers used for `F` doesn't +/// need to match between server and client, since it's only +/// passed between them and (eventually) called by the client. +#[repr(C)] +#[derive(Copy, Clone)] +pub struct Client { + // FIXME(eddyb) use a reference to the `static COUNTERS`, intead of + // a wrapper `fn` pointer, once `const fn` can reference `static`s. + pub(super) get_handle_counters: extern "C" fn() -> &'static HandleCounters, + pub(super) run: extern "C" fn(Bridge<'_>, F) -> Buffer, + pub(super) f: F, +} + +/// Client-side helper for handling client panics, entering the bridge, +/// deserializing input and serializing output. +// FIXME(eddyb) maybe replace `Bridge::enter` with this? +fn run_client DecodeMut<'a, 's, ()>, R: Encode<()>>( + mut bridge: Bridge<'_>, + f: impl FnOnce(A) -> R, +) -> Buffer { + // The initial `cached_buffer` contains the input. + let mut b = bridge.cached_buffer.take(); + + panic::catch_unwind(panic::AssertUnwindSafe(|| { + bridge.enter(|| { + let reader = &mut &b[..]; + let input = A::decode(reader, &mut ()); + + // Put the `cached_buffer` back in the `Bridge`, for requests. + Bridge::with(|bridge| bridge.cached_buffer = b.take()); + + let output = f(input); + + // Take the `cached_buffer` back out, for the output value. + b = Bridge::with(|bridge| bridge.cached_buffer.take()); + + // HACK(eddyb) Separate encoding a success value (`Ok(output)`) + // from encoding a panic (`Err(e: PanicMessage)`) to avoid + // having handles outside the `bridge.enter(|| ...)` scope, and + // to catch panics that could happen while encoding the success. + // + // Note that panics should be impossible beyond this point, but + // this is defensively trying to avoid any accidental panicking + // reaching the `extern "C"` (which should `abort` but may not + // at the moment, so this is also potentially preventing UB). + b.clear(); + Ok::<_, ()>(output).encode(&mut b, &mut ()); + }) + })) + .map_err(PanicMessage::from) + .unwrap_or_else(|e| { + b.clear(); + Err::<(), _>(e).encode(&mut b, &mut ()); + }); + b +} + +impl Client crate::TokenStream> { + pub fn expand1(f: fn(crate::TokenStream) -> crate::TokenStream) -> Self { + extern "C" fn run( + bridge: Bridge<'_>, + f: impl FnOnce(crate::TokenStream) -> crate::TokenStream, + ) -> Buffer { + run_client(bridge, |input| f(crate::TokenStream(input)).0) + } + Client { get_handle_counters: HandleCounters::get, run, f } + } +} + +impl Client crate::TokenStream> { + pub fn expand2(f: fn(crate::TokenStream, crate::TokenStream) -> crate::TokenStream) -> Self { + extern "C" fn run( + bridge: Bridge<'_>, + f: impl FnOnce(crate::TokenStream, crate::TokenStream) -> crate::TokenStream, + ) -> Buffer { + run_client(bridge, |(input, input2)| { + f(crate::TokenStream(input), crate::TokenStream(input2)).0 + }) + } + Client { get_handle_counters: HandleCounters::get, run, f } + } +} + +#[repr(C)] +#[derive(Copy, Clone)] +pub enum ProcMacro { + CustomDerive { + trait_name: &'static str, + attributes: &'static [&'static str], + client: Client crate::TokenStream>, + }, + + Attr { + name: &'static str, + client: Client crate::TokenStream>, + }, + + Bang { + name: &'static str, + client: Client crate::TokenStream>, + }, +} + +impl std::fmt::Debug for ProcMacro { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + write!(f, "ProcMacro {{ name: {} }}", self.name()) + } +} + +impl ProcMacro { + pub fn name(&self) -> &'static str { + match self { + ProcMacro::CustomDerive { trait_name, .. } => trait_name, + ProcMacro::Attr { name, .. } => name, + ProcMacro::Bang { name, .. } => name, + } + } + + pub fn custom_derive( + trait_name: &'static str, + attributes: &'static [&'static str], + expand: fn(crate::TokenStream) -> crate::TokenStream, + ) -> Self { + ProcMacro::CustomDerive { trait_name, attributes, client: Client::expand1(expand) } + } + + pub fn attr( + name: &'static str, + expand: fn(crate::TokenStream, crate::TokenStream) -> crate::TokenStream, + ) -> Self { + ProcMacro::Attr { name, client: Client::expand2(expand) } + } + + pub fn bang(name: &'static str, expand: fn(crate::TokenStream) -> crate::TokenStream) -> Self { + ProcMacro::Bang { name, client: Client::expand1(expand) } + } +} diff --git a/crates/ra_proc_macro_srv/src/proc_macro/bridge/closure.rs b/crates/ra_proc_macro_srv/src/proc_macro/bridge/closure.rs new file mode 100644 index 000000000..b8addff4a --- /dev/null +++ b/crates/ra_proc_macro_srv/src/proc_macro/bridge/closure.rs @@ -0,0 +1,27 @@ +//! lib-proc-macro Closure type (equivalent to `&mut dyn FnMut(A) -> R`) that's `repr(C)`. +//! +//! Copy from https://github.com/rust-lang/rust/blob/6050e523bae6de61de4e060facc43dc512adaccd/src/libproc_macro/bridge/closure.rs# +//! augmented with removing unstable features + +#[repr(C)] +pub struct Closure<'a, A, R> { + call: unsafe extern "C" fn(&mut Env, A) -> R, + env: &'a mut Env, +} + +struct Env; + +impl<'a, A, R, F: FnMut(A) -> R> From<&'a mut F> for Closure<'a, A, R> { + fn from(f: &'a mut F) -> Self { + unsafe extern "C" fn call R>(env: &mut Env, arg: A) -> R { + (*(env as *mut _ as *mut F))(arg) + } + Closure { call: call::, env: unsafe { &mut *(f as *mut _ as *mut Env) } } + } +} + +impl<'a, A, R> Closure<'a, A, R> { + pub fn call(&mut self, arg: A) -> R { + unsafe { (self.call)(self.env, arg) } + } +} diff --git a/crates/ra_proc_macro_srv/src/proc_macro/bridge/handle.rs b/crates/ra_proc_macro_srv/src/proc_macro/bridge/handle.rs new file mode 100644 index 000000000..a2f77b5ac --- /dev/null +++ b/crates/ra_proc_macro_srv/src/proc_macro/bridge/handle.rs @@ -0,0 +1,73 @@ +//! lib-proc-macro Server-side handles and storage for per-handle data. +//! +//! Copy from https://github.com/rust-lang/rust/blob/6050e523bae6de61de4e060facc43dc512adaccd/src/libproc_macro/bridge/handle.rs +//! augmented with removing unstable features + +use std::collections::{BTreeMap, HashMap}; +use std::hash::Hash; +use std::num::NonZeroU32; +use std::ops::{Index, IndexMut}; +use std::sync::atomic::{AtomicUsize, Ordering}; + +pub(super) type Handle = NonZeroU32; + +pub(super) struct OwnedStore { + counter: &'static AtomicUsize, + data: BTreeMap, +} + +impl OwnedStore { + pub(super) fn new(counter: &'static AtomicUsize) -> Self { + // Ensure the handle counter isn't 0, which would panic later, + // when `NonZeroU32::new` (aka `Handle::new`) is called in `alloc`. + assert_ne!(counter.load(Ordering::SeqCst), 0); + + OwnedStore { counter, data: BTreeMap::new() } + } +} + +impl OwnedStore { + pub(super) fn alloc(&mut self, x: T) -> Handle { + let counter = self.counter.fetch_add(1, Ordering::SeqCst); + let handle = Handle::new(counter as u32).expect("`proc_macro` handle counter overflowed"); + assert!(self.data.insert(handle, x).is_none()); + handle + } + + pub(super) fn take(&mut self, h: Handle) -> T { + self.data.remove(&h).expect("use-after-free in `proc_macro` handle") + } +} + +impl Index for OwnedStore { + type Output = T; + fn index(&self, h: Handle) -> &T { + self.data.get(&h).expect("use-after-free in `proc_macro` handle") + } +} + +impl IndexMut for OwnedStore { + fn index_mut(&mut self, h: Handle) -> &mut T { + self.data.get_mut(&h).expect("use-after-free in `proc_macro` handle") + } +} + +pub(super) struct InternedStore { + owned: OwnedStore, + interner: HashMap, +} + +impl InternedStore { + pub(super) fn new(counter: &'static AtomicUsize) -> Self { + InternedStore { owned: OwnedStore::new(counter), interner: HashMap::new() } + } + + pub(super) fn alloc(&mut self, x: T) -> Handle { + let owned = &mut self.owned; + *self.interner.entry(x).or_insert_with(|| owned.alloc(x)) + } + + pub(super) fn copy(&mut self, h: Handle) -> T { + self.owned[h] + } +} diff --git a/crates/ra_proc_macro_srv/src/proc_macro/bridge/mod.rs b/crates/ra_proc_macro_srv/src/proc_macro/bridge/mod.rs new file mode 100644 index 000000000..6ae3926b2 --- /dev/null +++ b/crates/ra_proc_macro_srv/src/proc_macro/bridge/mod.rs @@ -0,0 +1,404 @@ +//! lib-proc-macro Internal interface for communicating between a `proc_macro` client +//! +//! Copy from https://github.com/rust-lang/rust/blob/6050e523bae6de61de4e060facc43dc512adaccd/src/libproc_macro/bridge/mod.rs +//! augmented with removing unstable features +//! +//! Internal interface for communicating between a `proc_macro` client +//! (a proc macro crate) and a `proc_macro` server (a compiler front-end). +//! +//! Serialization (with C ABI buffers) and unique integer handles are employed +//! to allow safely interfacing between two copies of `proc_macro` built +//! (from the same source) by different compilers with potentially mismatching +//! Rust ABIs (e.g., stage0/bin/rustc vs stage1/bin/rustc during bootstrap). + +#![deny(unsafe_code)] + +pub use crate::proc_macro::{Delimiter, Level, LineColumn, Spacing}; +use std::fmt; +use std::hash::Hash; +use std::marker; +use std::mem; +use std::ops::Bound; +use std::panic; +use std::sync::atomic::AtomicUsize; +use std::sync::Once; +use std::thread; + +/// Higher-order macro describing the server RPC API, allowing automatic +/// generation of type-safe Rust APIs, both client-side and server-side. +/// +/// `with_api!(MySelf, my_self, my_macro)` expands to: +/// ```rust,ignore (pseudo-code) +/// my_macro! { +/// // ... +/// Literal { +/// // ... +/// fn character(ch: char) -> MySelf::Literal; +/// // ... +/// fn span(my_self: &MySelf::Literal) -> MySelf::Span; +/// fn set_span(my_self: &mut MySelf::Literal, span: MySelf::Span); +/// }, +/// // ... +/// } +/// ``` +/// +/// The first two arguments serve to customize the arguments names +/// and argument/return types, to enable several different usecases: +/// +/// If `my_self` is just `self`, then each `fn` signature can be used +/// as-is for a method. If it's anything else (`self_` in practice), +/// then the signatures don't have a special `self` argument, and +/// can, therefore, have a different one introduced. +/// +/// If `MySelf` is just `Self`, then the types are only valid inside +/// a trait or a trait impl, where the trait has associated types +/// for each of the API types. If non-associated types are desired, +/// a module name (`self` in practice) can be used instead of `Self`. +macro_rules! with_api { + ($S:ident, $self:ident, $m:ident) => { + $m! { + TokenStream { + fn drop($self: $S::TokenStream); + fn clone($self: &$S::TokenStream) -> $S::TokenStream; + fn new() -> $S::TokenStream; + fn is_empty($self: &$S::TokenStream) -> bool; + fn from_str(src: &str) -> $S::TokenStream; + fn to_string($self: &$S::TokenStream) -> String; + fn from_token_tree( + tree: TokenTree<$S::Group, $S::Punct, $S::Ident, $S::Literal>, + ) -> $S::TokenStream; + fn into_iter($self: $S::TokenStream) -> $S::TokenStreamIter; + }, + TokenStreamBuilder { + fn drop($self: $S::TokenStreamBuilder); + fn new() -> $S::TokenStreamBuilder; + fn push($self: &mut $S::TokenStreamBuilder, stream: $S::TokenStream); + fn build($self: $S::TokenStreamBuilder) -> $S::TokenStream; + }, + TokenStreamIter { + fn drop($self: $S::TokenStreamIter); + fn clone($self: &$S::TokenStreamIter) -> $S::TokenStreamIter; + fn next( + $self: &mut $S::TokenStreamIter, + ) -> Option>; + }, + Group { + fn drop($self: $S::Group); + fn clone($self: &$S::Group) -> $S::Group; + fn new(delimiter: Delimiter, stream: $S::TokenStream) -> $S::Group; + fn delimiter($self: &$S::Group) -> Delimiter; + fn stream($self: &$S::Group) -> $S::TokenStream; + fn span($self: &$S::Group) -> $S::Span; + fn span_open($self: &$S::Group) -> $S::Span; + fn span_close($self: &$S::Group) -> $S::Span; + fn set_span($self: &mut $S::Group, span: $S::Span); + }, + Punct { + fn new(ch: char, spacing: Spacing) -> $S::Punct; + fn as_char($self: $S::Punct) -> char; + fn spacing($self: $S::Punct) -> Spacing; + fn span($self: $S::Punct) -> $S::Span; + fn with_span($self: $S::Punct, span: $S::Span) -> $S::Punct; + }, + Ident { + fn new(string: &str, span: $S::Span, is_raw: bool) -> $S::Ident; + fn span($self: $S::Ident) -> $S::Span; + fn with_span($self: $S::Ident, span: $S::Span) -> $S::Ident; + }, + Literal { + fn drop($self: $S::Literal); + fn clone($self: &$S::Literal) -> $S::Literal; + // FIXME(eddyb) `Literal` should not expose internal `Debug` impls. + fn debug($self: &$S::Literal) -> String; + fn integer(n: &str) -> $S::Literal; + fn typed_integer(n: &str, kind: &str) -> $S::Literal; + fn float(n: &str) -> $S::Literal; + fn f32(n: &str) -> $S::Literal; + fn f64(n: &str) -> $S::Literal; + fn string(string: &str) -> $S::Literal; + fn character(ch: char) -> $S::Literal; + fn byte_string(bytes: &[u8]) -> $S::Literal; + fn span($self: &$S::Literal) -> $S::Span; + fn set_span($self: &mut $S::Literal, span: $S::Span); + fn subspan( + $self: &$S::Literal, + start: Bound, + end: Bound, + ) -> Option<$S::Span>; + }, + SourceFile { + fn drop($self: $S::SourceFile); + fn clone($self: &$S::SourceFile) -> $S::SourceFile; + fn eq($self: &$S::SourceFile, other: &$S::SourceFile) -> bool; + fn path($self: &$S::SourceFile) -> String; + fn is_real($self: &$S::SourceFile) -> bool; + }, + MultiSpan { + fn drop($self: $S::MultiSpan); + fn new() -> $S::MultiSpan; + fn push($self: &mut $S::MultiSpan, span: $S::Span); + }, + Diagnostic { + fn drop($self: $S::Diagnostic); + fn new(level: Level, msg: &str, span: $S::MultiSpan) -> $S::Diagnostic; + fn sub( + $self: &mut $S::Diagnostic, + level: Level, + msg: &str, + span: $S::MultiSpan, + ); + fn emit($self: $S::Diagnostic); + }, + Span { + fn debug($self: $S::Span) -> String; + fn def_site() -> $S::Span; + fn call_site() -> $S::Span; + fn mixed_site() -> $S::Span; + fn source_file($self: $S::Span) -> $S::SourceFile; + fn parent($self: $S::Span) -> Option<$S::Span>; + fn source($self: $S::Span) -> $S::Span; + fn start($self: $S::Span) -> LineColumn; + fn end($self: $S::Span) -> LineColumn; + fn join($self: $S::Span, other: $S::Span) -> Option<$S::Span>; + fn resolved_at($self: $S::Span, at: $S::Span) -> $S::Span; + fn source_text($self: $S::Span) -> Option; + }, + } + }; +} + +// FIXME(eddyb) this calls `encode` for each argument, but in reverse, +// to avoid borrow conflicts from borrows started by `&mut` arguments. +macro_rules! reverse_encode { + ($writer:ident;) => {}; + ($writer:ident; $first:ident $(, $rest:ident)*) => { + reverse_encode!($writer; $($rest),*); + $first.encode(&mut $writer, &mut ()); + } +} + +// FIXME(eddyb) this calls `decode` for each argument, but in reverse, +// to avoid borrow conflicts from borrows started by `&mut` arguments. +macro_rules! reverse_decode { + ($reader:ident, $s:ident;) => {}; + ($reader:ident, $s:ident; $first:ident: $first_ty:ty $(, $rest:ident: $rest_ty:ty)*) => { + reverse_decode!($reader, $s; $($rest: $rest_ty),*); + let $first = <$first_ty>::decode(&mut $reader, $s); + } +} + +#[allow(unsafe_code)] +mod buffer; +#[forbid(unsafe_code)] +pub mod client; +#[allow(unsafe_code)] +mod closure; +#[forbid(unsafe_code)] +mod handle; +#[macro_use] +#[forbid(unsafe_code)] +mod rpc; +#[allow(unsafe_code)] +mod scoped_cell; +#[forbid(unsafe_code)] +pub mod server; + +use buffer::Buffer; +pub use rpc::PanicMessage; +use rpc::{Decode, DecodeMut, Encode, Reader, Writer}; + +/// An active connection between a server and a client. +/// The server creates the bridge (`Bridge::run_server` in `server.rs`), +/// then passes it to the client through the function pointer in the `run` +/// field of `client::Client`. The client holds its copy of the `Bridge` +/// in TLS during its execution (`Bridge::{enter, with}` in `client.rs`). +#[repr(C)] +pub struct Bridge<'a> { + /// Reusable buffer (only `clear`-ed, never shrunk), primarily + /// used for making requests, but also for passing input to client. + cached_buffer: Buffer, + + /// Server-side function that the client uses to make requests. + dispatch: closure::Closure<'a, Buffer, Buffer>, +} + +#[forbid(unsafe_code)] +#[allow(non_camel_case_types)] +mod api_tags { + use super::rpc::{DecodeMut, Encode, Reader, Writer}; + + macro_rules! declare_tags { + ($($name:ident { + $(fn $method:ident($($arg:ident: $arg_ty:ty),* $(,)?) $(-> $ret_ty:ty)*;)* + }),* $(,)?) => { + $( + pub(super) enum $name { + $($method),* + } + rpc_encode_decode!(enum $name { $($method),* }); + )* + + + pub(super) enum Method { + $($name($name)),* + } + rpc_encode_decode!(enum Method { $($name(m)),* }); + } + } + with_api!(self, self, declare_tags); +} + +/// Helper to wrap associated types to allow trait impl dispatch. +/// That is, normally a pair of impls for `T::Foo` and `T::Bar` +/// can overlap, but if the impls are, instead, on types like +/// `Marked` and `Marked`, they can't. +trait Mark { + type Unmarked; + fn mark(unmarked: Self::Unmarked) -> Self; +} + +/// Unwrap types wrapped by `Mark::mark` (see `Mark` for details). +trait Unmark { + type Unmarked; + fn unmark(self) -> Self::Unmarked; +} + +#[derive(Copy, Clone, PartialEq, Eq, Hash)] +struct Marked { + value: T, + _marker: marker::PhantomData, +} + +impl Mark for Marked { + type Unmarked = T; + fn mark(unmarked: Self::Unmarked) -> Self { + Marked { value: unmarked, _marker: marker::PhantomData } + } +} +impl Unmark for Marked { + type Unmarked = T; + fn unmark(self) -> Self::Unmarked { + self.value + } +} +impl<'a, T, M> Unmark for &'a Marked { + type Unmarked = &'a T; + fn unmark(self) -> Self::Unmarked { + &self.value + } +} +impl<'a, T, M> Unmark for &'a mut Marked { + type Unmarked = &'a mut T; + fn unmark(self) -> Self::Unmarked { + &mut self.value + } +} + +impl Mark for Option { + type Unmarked = Option; + fn mark(unmarked: Self::Unmarked) -> Self { + unmarked.map(T::mark) + } +} +impl Unmark for Option { + type Unmarked = Option; + fn unmark(self) -> Self::Unmarked { + self.map(T::unmark) + } +} + +macro_rules! mark_noop { + ($($ty:ty),* $(,)?) => { + $( + impl Mark for $ty { + type Unmarked = Self; + fn mark(unmarked: Self::Unmarked) -> Self { + unmarked + } + } + impl Unmark for $ty { + type Unmarked = Self; + fn unmark(self) -> Self::Unmarked { + self + } + } + )* + } +} +mark_noop! { + (), + bool, + char, + &'_ [u8], + &'_ str, + String, + Delimiter, + Level, + LineColumn, + Spacing, + Bound, +} + +rpc_encode_decode!( + enum Delimiter { + Parenthesis, + Brace, + Bracket, + None, + } +); +rpc_encode_decode!( + enum Level { + Error, + Warning, + Note, + Help, + } +); +rpc_encode_decode!(struct LineColumn { line, column }); +rpc_encode_decode!( + enum Spacing { + Alone, + Joint, + } +); + +#[derive(Clone)] +pub enum TokenTree { + Group(G), + Punct(P), + Ident(I), + Literal(L), +} + +impl Mark for TokenTree { + type Unmarked = TokenTree; + fn mark(unmarked: Self::Unmarked) -> Self { + match unmarked { + TokenTree::Group(tt) => TokenTree::Group(G::mark(tt)), + TokenTree::Punct(tt) => TokenTree::Punct(P::mark(tt)), + TokenTree::Ident(tt) => TokenTree::Ident(I::mark(tt)), + TokenTree::Literal(tt) => TokenTree::Literal(L::mark(tt)), + } + } +} +impl Unmark for TokenTree { + type Unmarked = TokenTree; + fn unmark(self) -> Self::Unmarked { + match self { + TokenTree::Group(tt) => TokenTree::Group(tt.unmark()), + TokenTree::Punct(tt) => TokenTree::Punct(tt.unmark()), + TokenTree::Ident(tt) => TokenTree::Ident(tt.unmark()), + TokenTree::Literal(tt) => TokenTree::Literal(tt.unmark()), + } + } +} + +rpc_encode_decode!( + enum TokenTree { + Group(tt), + Punct(tt), + Ident(tt), + Literal(tt), + } +); diff --git a/crates/ra_proc_macro_srv/src/proc_macro/bridge/rpc.rs b/crates/ra_proc_macro_srv/src/proc_macro/bridge/rpc.rs new file mode 100644 index 000000000..3528d5c99 --- /dev/null +++ b/crates/ra_proc_macro_srv/src/proc_macro/bridge/rpc.rs @@ -0,0 +1,311 @@ +//! lib-proc-macro Serialization for client-server communication. +//! +//! Copy from https://github.com/rust-lang/rust/blob/6050e523bae6de61de4e060facc43dc512adaccd/src/libproc_macro/bridge/rpc.rs +//! augmented with removing unstable features +//! +//! Serialization for client-server communication. + +use std::any::Any; +use std::char; +use std::io::Write; +use std::num::NonZeroU32; +use std::ops::Bound; +use std::str; + +pub(super) type Writer = super::buffer::Buffer; + +pub(super) trait Encode: Sized { + fn encode(self, w: &mut Writer, s: &mut S); +} + +pub(super) type Reader<'a> = &'a [u8]; + +pub(super) trait Decode<'a, 's, S>: Sized { + fn decode(r: &mut Reader<'a>, s: &'s S) -> Self; +} + +pub(super) trait DecodeMut<'a, 's, S>: Sized { + fn decode(r: &mut Reader<'a>, s: &'s mut S) -> Self; +} + +macro_rules! rpc_encode_decode { + (le $ty:ty) => { + impl Encode for $ty { + fn encode(self, w: &mut Writer, _: &mut S) { + w.write_all(&self.to_le_bytes()).unwrap(); + } + } + + impl DecodeMut<'_, '_, S> for $ty { + fn decode(r: &mut Reader<'_>, _: &mut S) -> Self { + const N: usize = ::std::mem::size_of::<$ty>(); + + let mut bytes = [0; N]; + bytes.copy_from_slice(&r[..N]); + *r = &r[N..]; + + Self::from_le_bytes(bytes) + } + } + }; + (struct $name:ident { $($field:ident),* $(,)? }) => { + impl Encode for $name { + fn encode(self, w: &mut Writer, s: &mut S) { + $(self.$field.encode(w, s);)* + } + } + + impl DecodeMut<'_, '_, S> for $name { + fn decode(r: &mut Reader<'_>, s: &mut S) -> Self { + $name { + $($field: DecodeMut::decode(r, s)),* + } + } + } + }; + (enum $name:ident $(<$($T:ident),+>)? { $($variant:ident $(($field:ident))*),* $(,)? }) => { + impl),+)?> Encode for $name $(<$($T),+>)? { + fn encode(self, w: &mut Writer, s: &mut S) { + // HACK(eddyb): `Tag` enum duplicated between the + // two impls as there's no other place to stash it. + #[allow(non_upper_case_globals)] + mod tag { + #[repr(u8)] enum Tag { $($variant),* } + + $(pub const $variant: u8 = Tag::$variant as u8;)* + } + + match self { + $($name::$variant $(($field))* => { + tag::$variant.encode(w, s); + $($field.encode(w, s);)* + })* + } + } + } + + impl<'a, S, $($($T: for<'s> DecodeMut<'a, 's, S>),+)?> DecodeMut<'a, '_, S> + for $name $(<$($T),+>)? + { + fn decode(r: &mut Reader<'a>, s: &mut S) -> Self { + // HACK(eddyb): `Tag` enum duplicated between the + // two impls as there's no other place to stash it. + #[allow(non_upper_case_globals)] + mod tag { + #[repr(u8)] enum Tag { $($variant),* } + + $(pub const $variant: u8 = Tag::$variant as u8;)* + } + + match u8::decode(r, s) { + $(tag::$variant => { + $(let $field = DecodeMut::decode(r, s);)* + $name::$variant $(($field))* + })* + _ => unreachable!(), + } + } + } + } +} + +impl Encode for () { + fn encode(self, _: &mut Writer, _: &mut S) {} +} + +impl DecodeMut<'_, '_, S> for () { + fn decode(_: &mut Reader<'_>, _: &mut S) -> Self {} +} + +impl Encode for u8 { + fn encode(self, w: &mut Writer, _: &mut S) { + w.write_all(&[self]).unwrap(); + } +} + +impl DecodeMut<'_, '_, S> for u8 { + fn decode(r: &mut Reader<'_>, _: &mut S) -> Self { + let x = r[0]; + *r = &r[1..]; + x + } +} + +rpc_encode_decode!(le u32); +rpc_encode_decode!(le usize); + +impl Encode for bool { + fn encode(self, w: &mut Writer, s: &mut S) { + (self as u8).encode(w, s); + } +} + +impl DecodeMut<'_, '_, S> for bool { + fn decode(r: &mut Reader<'_>, s: &mut S) -> Self { + match u8::decode(r, s) { + 0 => false, + 1 => true, + _ => unreachable!(), + } + } +} + +impl Encode for char { + fn encode(self, w: &mut Writer, s: &mut S) { + (self as u32).encode(w, s); + } +} + +impl DecodeMut<'_, '_, S> for char { + fn decode(r: &mut Reader<'_>, s: &mut S) -> Self { + char::from_u32(u32::decode(r, s)).unwrap() + } +} + +impl Encode for NonZeroU32 { + fn encode(self, w: &mut Writer, s: &mut S) { + self.get().encode(w, s); + } +} + +impl DecodeMut<'_, '_, S> for NonZeroU32 { + fn decode(r: &mut Reader<'_>, s: &mut S) -> Self { + Self::new(u32::decode(r, s)).unwrap() + } +} + +impl, B: Encode> Encode for (A, B) { + fn encode(self, w: &mut Writer, s: &mut S) { + self.0.encode(w, s); + self.1.encode(w, s); + } +} + +impl<'a, S, A: for<'s> DecodeMut<'a, 's, S>, B: for<'s> DecodeMut<'a, 's, S>> DecodeMut<'a, '_, S> + for (A, B) +{ + fn decode(r: &mut Reader<'a>, s: &mut S) -> Self { + (DecodeMut::decode(r, s), DecodeMut::decode(r, s)) + } +} + +rpc_encode_decode!( + enum Bound { + Included(x), + Excluded(x), + Unbounded, + } +); + +rpc_encode_decode!( + enum Option { + None, + Some(x), + } +); + +rpc_encode_decode!( + enum Result { + Ok(x), + Err(e), + } +); + +impl Encode for &[u8] { + fn encode(self, w: &mut Writer, s: &mut S) { + self.len().encode(w, s); + w.write_all(self).unwrap(); + } +} + +impl<'a, S> DecodeMut<'a, '_, S> for &'a [u8] { + fn decode(r: &mut Reader<'a>, s: &mut S) -> Self { + let len = usize::decode(r, s); + let xs = &r[..len]; + *r = &r[len..]; + xs + } +} + +impl Encode for &str { + fn encode(self, w: &mut Writer, s: &mut S) { + self.as_bytes().encode(w, s); + } +} + +impl<'a, S> DecodeMut<'a, '_, S> for &'a str { + fn decode(r: &mut Reader<'a>, s: &mut S) -> Self { + str::from_utf8(<&[u8]>::decode(r, s)).unwrap() + } +} + +impl Encode for String { + fn encode(self, w: &mut Writer, s: &mut S) { + self[..].encode(w, s); + } +} + +impl DecodeMut<'_, '_, S> for String { + fn decode(r: &mut Reader<'_>, s: &mut S) -> Self { + <&str>::decode(r, s).to_string() + } +} + +/// Simplied version of panic payloads, ignoring +/// types other than `&'static str` and `String`. +#[derive(Debug)] +pub enum PanicMessage { + StaticStr(&'static str), + String(String), + Unknown, +} + +impl From> for PanicMessage { + fn from(payload: Box) -> Self { + if let Some(s) = payload.downcast_ref::<&'static str>() { + return PanicMessage::StaticStr(s); + } + if let Ok(s) = payload.downcast::() { + return PanicMessage::String(*s); + } + PanicMessage::Unknown + } +} + +impl Into> for PanicMessage { + fn into(self) -> Box { + match self { + PanicMessage::StaticStr(s) => Box::new(s), + PanicMessage::String(s) => Box::new(s), + PanicMessage::Unknown => { + struct UnknownPanicMessage; + Box::new(UnknownPanicMessage) + } + } + } +} + +impl PanicMessage { + pub fn as_str(&self) -> Option<&str> { + match self { + PanicMessage::StaticStr(s) => Some(s), + PanicMessage::String(s) => Some(s), + PanicMessage::Unknown => None, + } + } +} + +impl Encode for PanicMessage { + fn encode(self, w: &mut Writer, s: &mut S) { + self.as_str().encode(w, s); + } +} + +impl DecodeMut<'_, '_, S> for PanicMessage { + fn decode(r: &mut Reader<'_>, s: &mut S) -> Self { + match Option::::decode(r, s) { + Some(s) => PanicMessage::String(s), + None => PanicMessage::Unknown, + } + } +} diff --git a/crates/ra_proc_macro_srv/src/proc_macro/bridge/scoped_cell.rs b/crates/ra_proc_macro_srv/src/proc_macro/bridge/scoped_cell.rs new file mode 100644 index 000000000..6ef7ea43c --- /dev/null +++ b/crates/ra_proc_macro_srv/src/proc_macro/bridge/scoped_cell.rs @@ -0,0 +1,84 @@ +//! lib-proc-macro `Cell` variant for (scoped) existential lifetimes. +//! +//! Copy from https://github.com/rust-lang/rust/blob/6050e523bae6de61de4e060facc43dc512adaccd/src/libproc_macro/bridge/scoped_cell.rs#L1 +//! augmented with removing unstable features + +use std::cell::Cell; +use std::mem; +use std::ops::{Deref, DerefMut}; + +/// Type lambda application, with a lifetime. +#[allow(unused_lifetimes)] +pub trait ApplyL<'a> { + type Out; +} + +/// Type lambda taking a lifetime, i.e., `Lifetime -> Type`. +pub trait LambdaL: for<'a> ApplyL<'a> {} + +impl ApplyL<'a>> LambdaL for T {} + +// HACK(eddyb) work around projection limitations with a newtype +// FIXME(#52812) replace with `&'a mut >::Out` +pub struct RefMutL<'a, 'b, T: LambdaL>(&'a mut >::Out); + +impl<'a, 'b, T: LambdaL> Deref for RefMutL<'a, 'b, T> { + type Target = >::Out; + fn deref(&self) -> &Self::Target { + self.0 + } +} + +impl<'a, 'b, T: LambdaL> DerefMut for RefMutL<'a, 'b, T> { + fn deref_mut(&mut self) -> &mut Self::Target { + self.0 + } +} + +pub struct ScopedCell(Cell<>::Out>); + +impl ScopedCell { + pub fn new(value: >::Out) -> Self { + ScopedCell(Cell::new(value)) + } + + /// Sets the value in `self` to `replacement` while + /// running `f`, which gets the old value, mutably. + /// The old value will be restored after `f` exits, even + /// by panic, including modifications made to it by `f`. + pub fn replace<'a, R>( + &self, + replacement: >::Out, + f: impl for<'b, 'c> FnOnce(RefMutL<'b, 'c, T>) -> R, + ) -> R { + /// Wrapper that ensures that the cell always gets filled + /// (with the original state, optionally changed by `f`), + /// even if `f` had panicked. + struct PutBackOnDrop<'a, T: LambdaL> { + cell: &'a ScopedCell, + value: Option<>::Out>, + } + + impl<'a, T: LambdaL> Drop for PutBackOnDrop<'a, T> { + fn drop(&mut self) { + self.cell.0.set(self.value.take().unwrap()); + } + } + + let mut put_back_on_drop = PutBackOnDrop { + cell: self, + value: Some(self.0.replace(unsafe { + let erased = mem::transmute_copy(&replacement); + mem::forget(replacement); + erased + })), + }; + + f(RefMutL(put_back_on_drop.value.as_mut().unwrap())) + } + + /// Sets the value in `self` to `value` while running `f`. + pub fn set(&self, value: >::Out, f: impl FnOnce() -> R) -> R { + self.replace(value, |_| f()) + } +} diff --git a/crates/ra_proc_macro_srv/src/proc_macro/bridge/server.rs b/crates/ra_proc_macro_srv/src/proc_macro/bridge/server.rs new file mode 100644 index 000000000..45d41ac02 --- /dev/null +++ b/crates/ra_proc_macro_srv/src/proc_macro/bridge/server.rs @@ -0,0 +1,323 @@ +//! lib-proc-macro server-side traits +//! +//! Copy from https://github.com/rust-lang/rust/blob/6050e523bae6de61de4e060facc43dc512adaccd/src/libproc_macro/bridge/server.rs +//! augmented with removing unstable features + +use super::*; + +// FIXME(eddyb) generate the definition of `HandleStore` in `server.rs`. +use super::client::HandleStore; + +/// Declare an associated item of one of the traits below, optionally +/// adjusting it (i.e., adding bounds to types and default bodies to methods). +macro_rules! associated_item { + (type TokenStream) => + (type TokenStream: 'static + Clone;); + (type TokenStreamBuilder) => + (type TokenStreamBuilder: 'static;); + (type TokenStreamIter) => + (type TokenStreamIter: 'static + Clone;); + (type Group) => + (type Group: 'static + Clone;); + (type Punct) => + (type Punct: 'static + Copy + Eq + Hash;); + (type Ident) => + (type Ident: 'static + Copy + Eq + Hash;); + (type Literal) => + (type Literal: 'static + Clone;); + (type SourceFile) => + (type SourceFile: 'static + Clone;); + (type MultiSpan) => + (type MultiSpan: 'static;); + (type Diagnostic) => + (type Diagnostic: 'static;); + (type Span) => + (type Span: 'static + Copy + Eq + Hash;); + (fn drop(&mut self, $arg:ident: $arg_ty:ty)) => + (fn drop(&mut self, $arg: $arg_ty) { mem::drop($arg) }); + (fn clone(&mut self, $arg:ident: $arg_ty:ty) -> $ret_ty:ty) => + (fn clone(&mut self, $arg: $arg_ty) -> $ret_ty { $arg.clone() }); + ($($item:tt)*) => ($($item)*;) +} + +macro_rules! declare_server_traits { + ($($name:ident { + $(fn $method:ident($($arg:ident: $arg_ty:ty),* $(,)?) $(-> $ret_ty:ty)?;)* + }),* $(,)?) => { + pub trait Types { + $(associated_item!(type $name);)* + } + + $(pub trait $name: Types { + $(associated_item!(fn $method(&mut self, $($arg: $arg_ty),*) $(-> $ret_ty)?);)* + })* + + pub trait Server: Types $(+ $name)* {} + impl Server for S {} + } +} +with_api!(Self, self_, declare_server_traits); + +pub(super) struct MarkedTypes(S); + +macro_rules! define_mark_types_impls { + ($($name:ident { + $(fn $method:ident($($arg:ident: $arg_ty:ty),* $(,)?) $(-> $ret_ty:ty)?;)* + }),* $(,)?) => { + impl Types for MarkedTypes { + $(type $name = Marked;)* + } + + $(impl $name for MarkedTypes { + $(fn $method(&mut self, $($arg: $arg_ty),*) $(-> $ret_ty)? { + <_>::mark($name::$method(&mut self.0, $($arg.unmark()),*)) + })* + })* + } +} +with_api!(Self, self_, define_mark_types_impls); + +struct Dispatcher { + handle_store: HandleStore, + server: S, +} + +macro_rules! define_dispatcher_impl { + ($($name:ident { + $(fn $method:ident($($arg:ident: $arg_ty:ty),* $(,)?) $(-> $ret_ty:ty)?;)* + }),* $(,)?) => { + // FIXME(eddyb) `pub` only for `ExecutionStrategy` below. + pub trait DispatcherTrait { + // HACK(eddyb) these are here to allow `Self::$name` to work below. + $(type $name;)* + fn dispatch(&mut self, b: Buffer) -> Buffer; + } + + impl DispatcherTrait for Dispatcher> { + $(type $name = as Types>::$name;)* + fn dispatch(&mut self, mut b: Buffer) -> Buffer { + let Dispatcher { handle_store, server } = self; + + let mut reader = &b[..]; + match api_tags::Method::decode(&mut reader, &mut ()) { + $(api_tags::Method::$name(m) => match m { + $(api_tags::$name::$method => { + let mut call_method = || { + reverse_decode!(reader, handle_store; $($arg: $arg_ty),*); + $name::$method(server, $($arg),*) + }; + // HACK(eddyb) don't use `panic::catch_unwind` in a panic. + // If client and server happen to use the same `libstd`, + // `catch_unwind` asserts that the panic counter was 0, + // even when the closure passed to it didn't panic. + let r = if thread::panicking() { + Ok(call_method()) + } else { + panic::catch_unwind(panic::AssertUnwindSafe(call_method)) + .map_err(PanicMessage::from) + }; + + b.clear(); + r.encode(&mut b, handle_store); + })* + }),* + } + b + } + } + } +} +with_api!(Self, self_, define_dispatcher_impl); + +pub trait ExecutionStrategy { + fn run_bridge_and_client( + &self, + dispatcher: &mut impl DispatcherTrait, + input: Buffer, + run_client: extern "C" fn(Bridge<'_>, D) -> Buffer, + client_data: D, + ) -> Buffer; +} + +pub struct SameThread; + +impl ExecutionStrategy for SameThread { + fn run_bridge_and_client( + &self, + dispatcher: &mut impl DispatcherTrait, + input: Buffer, + run_client: extern "C" fn(Bridge<'_>, D) -> Buffer, + client_data: D, + ) -> Buffer { + let mut dispatch = |b| dispatcher.dispatch(b); + + run_client(Bridge { cached_buffer: input, dispatch: (&mut dispatch).into() }, client_data) + } +} + +// NOTE(eddyb) Two implementations are provided, the second one is a bit +// faster but neither is anywhere near as fast as same-thread execution. + +pub struct CrossThread1; + +impl ExecutionStrategy for CrossThread1 { + fn run_bridge_and_client( + &self, + dispatcher: &mut impl DispatcherTrait, + input: Buffer, + run_client: extern "C" fn(Bridge<'_>, D) -> Buffer, + client_data: D, + ) -> Buffer { + use std::sync::mpsc::channel; + + let (req_tx, req_rx) = channel(); + let (res_tx, res_rx) = channel(); + + let join_handle = thread::spawn(move || { + let mut dispatch = |b| { + req_tx.send(b).unwrap(); + res_rx.recv().unwrap() + }; + + run_client( + Bridge { cached_buffer: input, dispatch: (&mut dispatch).into() }, + client_data, + ) + }); + + for b in req_rx { + res_tx.send(dispatcher.dispatch(b)).unwrap(); + } + + join_handle.join().unwrap() + } +} + +pub struct CrossThread2; + +impl ExecutionStrategy for CrossThread2 { + fn run_bridge_and_client( + &self, + dispatcher: &mut impl DispatcherTrait, + input: Buffer, + run_client: extern "C" fn(Bridge<'_>, D) -> Buffer, + client_data: D, + ) -> Buffer { + use std::sync::{Arc, Mutex}; + + enum State { + Req(T), + Res(T), + } + + let mut state = Arc::new(Mutex::new(State::Res(Buffer::new()))); + + let server_thread = thread::current(); + let state2 = state.clone(); + let join_handle = thread::spawn(move || { + let mut dispatch = |b| { + *state2.lock().unwrap() = State::Req(b); + server_thread.unpark(); + loop { + thread::park(); + if let State::Res(b) = &mut *state2.lock().unwrap() { + break b.take(); + } + } + }; + + let r = run_client( + Bridge { cached_buffer: input, dispatch: (&mut dispatch).into() }, + client_data, + ); + + // Wake up the server so it can exit the dispatch loop. + drop(state2); + server_thread.unpark(); + + r + }); + + // Check whether `state2` was dropped, to know when to stop. + while Arc::get_mut(&mut state).is_none() { + thread::park(); + let mut b = match &mut *state.lock().unwrap() { + State::Req(b) => b.take(), + _ => continue, + }; + b = dispatcher.dispatch(b.take()); + *state.lock().unwrap() = State::Res(b); + join_handle.thread().unpark(); + } + + join_handle.join().unwrap() + } +} + +fn run_server< + S: Server, + I: Encode>>, + O: for<'a, 's> DecodeMut<'a, 's, HandleStore>>, + D: Copy + Send + 'static, +>( + strategy: &impl ExecutionStrategy, + handle_counters: &'static client::HandleCounters, + server: S, + input: I, + run_client: extern "C" fn(Bridge<'_>, D) -> Buffer, + client_data: D, +) -> Result { + let mut dispatcher = + Dispatcher { handle_store: HandleStore::new(handle_counters), server: MarkedTypes(server) }; + + let mut b = Buffer::new(); + input.encode(&mut b, &mut dispatcher.handle_store); + + b = strategy.run_bridge_and_client(&mut dispatcher, b, run_client, client_data); + + Result::decode(&mut &b[..], &mut dispatcher.handle_store) +} + +impl client::Client crate::TokenStream> { + pub fn run( + &self, + strategy: &impl ExecutionStrategy, + server: S, + input: S::TokenStream, + ) -> Result { + let client::Client { get_handle_counters, run, f } = *self; + run_server( + strategy, + get_handle_counters(), + server, + as Types>::TokenStream::mark(input), + run, + f, + ) + .map( as Types>::TokenStream::unmark) + } +} + +impl client::Client crate::TokenStream> { + pub fn run( + &self, + strategy: &impl ExecutionStrategy, + server: S, + input: S::TokenStream, + input2: S::TokenStream, + ) -> Result { + let client::Client { get_handle_counters, run, f } = *self; + run_server( + strategy, + get_handle_counters(), + server, + ( + as Types>::TokenStream::mark(input), + as Types>::TokenStream::mark(input2), + ), + run, + f, + ) + .map( as Types>::TokenStream::unmark) + } +} -- cgit v1.2.3