use std::cell::Cell;
use std::marker::PhantomData;
use super::*;
macro_rules! define_server_handles {
(
'owned: $($oty:ident,)*
'interned: $($ity:ident,)*
) => {
#[allow(non_snake_case)]
pub(super) struct HandleStore<S: Types> {
$($oty: handle::OwnedStore<S::$oty>,)*
$($ity: handle::InternedStore<S::$ity>,)*
}
impl<S: Types> HandleStore<S> {
fn new(handle_counters: &'static client::HandleCounters) -> Self {
HandleStore {
$($oty: handle::OwnedStore::new(&handle_counters.$oty),)*
$($ity: handle::InternedStore::new(&handle_counters.$ity),)*
}
}
}
$(
impl<S: Types> Encode<HandleStore<MarkedTypes<S>>> for Marked<S::$oty, client::$oty> {
fn encode(self, w: &mut Writer, s: &mut HandleStore<MarkedTypes<S>>) {
s.$oty.alloc(self).encode(w, s);
}
}
impl<S: Types> DecodeMut<'_, '_, HandleStore<MarkedTypes<S>>>
for Marked<S::$oty, client::$oty>
{
fn decode(r: &mut Reader<'_>, s: &mut HandleStore<MarkedTypes<S>>) -> Self {
s.$oty.take(handle::Handle::decode(r, &mut ()))
}
}
impl<'s, S: Types> Decode<'_, 's, HandleStore<MarkedTypes<S>>>
for &'s Marked<S::$oty, client::$oty>
{
fn decode(r: &mut Reader<'_>, s: &'s HandleStore<MarkedTypes<S>>) -> Self {
&s.$oty[handle::Handle::decode(r, &mut ())]
}
}
impl<'s, S: Types> DecodeMut<'_, 's, HandleStore<MarkedTypes<S>>>
for &'s mut Marked<S::$oty, client::$oty>
{
fn decode(
r: &mut Reader<'_>,
s: &'s mut HandleStore<MarkedTypes<S>>
) -> Self {
&mut s.$oty[handle::Handle::decode(r, &mut ())]
}
}
)*
$(
impl<S: Types> Encode<HandleStore<MarkedTypes<S>>> for Marked<S::$ity, client::$ity> {
fn encode(self, w: &mut Writer, s: &mut HandleStore<MarkedTypes<S>>) {
s.$ity.alloc(self).encode(w, s);
}
}
impl<S: Types> DecodeMut<'_, '_, HandleStore<MarkedTypes<S>>>
for Marked<S::$ity, client::$ity>
{
fn decode(r: &mut Reader<'_>, s: &mut HandleStore<MarkedTypes<S>>) -> Self {
s.$ity.copy(handle::Handle::decode(r, &mut ()))
}
}
)*
}
}
with_api_handle_types!(define_server_handles);
pub trait Types {
type FreeFunctions: 'static;
type TokenStream: 'static + Clone;
type SourceFile: 'static + Clone;
type Span: 'static + Copy + Eq + Hash;
type Symbol: 'static;
}
macro_rules! associated_fn {
(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 $name: Types {
$(associated_fn!(fn $method(&mut self, $($arg: $arg_ty),*) $(-> $ret_ty)?);)*
})*
pub trait Server: Types $(+ $name)* {
fn globals(&mut self) -> ExpnGlobals<Self::Span>;
fn intern_symbol(ident: &str) -> Self::Symbol;
fn with_symbol_string(symbol: &Self::Symbol, f: impl FnOnce(&str));
}
}
}
with_api!(Self, self_, declare_server_traits);
pub(super) struct MarkedTypes<S: Types>(S);
impl<S: Server> Server for MarkedTypes<S> {
fn globals(&mut self) -> ExpnGlobals<Self::Span> {
<_>::mark(Server::globals(&mut self.0))
}
fn intern_symbol(ident: &str) -> Self::Symbol {
<_>::mark(S::intern_symbol(ident))
}
fn with_symbol_string(symbol: &Self::Symbol, f: impl FnOnce(&str)) {
S::with_symbol_string(symbol.unmark(), f)
}
}
macro_rules! define_mark_types_impls {
($($name:ident {
$(fn $method:ident($($arg:ident: $arg_ty:ty),* $(,)?) $(-> $ret_ty:ty)?;)*
}),* $(,)?) => {
impl<S: Types> Types for MarkedTypes<S> {
$(type $name = Marked<S::$name, client::$name>;)*
}
$(impl<S: $name> $name for MarkedTypes<S> {
$(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<S: Types> {
handle_store: HandleStore<S>,
server: S,
}
macro_rules! define_dispatcher_impl {
($($name:ident {
$(fn $method:ident($($arg:ident: $arg_ty:ty),* $(,)?) $(-> $ret_ty:ty)?;)*
}),* $(,)?) => {
pub trait DispatcherTrait {
$(type $name;)*
fn dispatch(&mut self, buf: Buffer) -> Buffer;
}
impl<S: Server> DispatcherTrait for Dispatcher<MarkedTypes<S>> {
$(type $name = <MarkedTypes<S> as Types>::$name;)*
fn dispatch(&mut self, mut buf: Buffer) -> Buffer {
let Dispatcher { handle_store, server } = self;
let mut reader = &buf[..];
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),*)
};
let r = if thread::panicking() {
Ok(call_method())
} else {
panic::catch_unwind(panic::AssertUnwindSafe(call_method))
.map_err(PanicMessage::from)
};
buf.clear();
r.encode(&mut buf, handle_store);
})*
}),*
}
buf
}
}
}
}
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(BridgeConfig<'_>) -> Buffer,
force_show_panics: bool,
) -> Buffer;
}
thread_local! {
static ALREADY_RUNNING_SAME_THREAD: Cell<bool> = const { Cell::new(false) };
}
struct RunningSameThreadGuard(());
impl RunningSameThreadGuard {
fn new() -> Self {
let already_running = ALREADY_RUNNING_SAME_THREAD.replace(true);
assert!(
!already_running,
"same-thread nesting (\"reentrance\") of proc macro executions is not supported"
);
RunningSameThreadGuard(())
}
}
impl Drop for RunningSameThreadGuard {
fn drop(&mut self) {
ALREADY_RUNNING_SAME_THREAD.set(false);
}
}
pub struct MaybeCrossThread<P> {
cross_thread: bool,
marker: PhantomData<P>,
}
impl<P> MaybeCrossThread<P> {
pub const fn new(cross_thread: bool) -> Self {
MaybeCrossThread { cross_thread, marker: PhantomData }
}
}
impl<P> ExecutionStrategy for MaybeCrossThread<P>
where
P: MessagePipe<Buffer> + Send + 'static,
{
fn run_bridge_and_client(
&self,
dispatcher: &mut impl DispatcherTrait,
input: Buffer,
run_client: extern "C" fn(BridgeConfig<'_>) -> Buffer,
force_show_panics: bool,
) -> Buffer {
if self.cross_thread || ALREADY_RUNNING_SAME_THREAD.get() {
<CrossThread<P>>::new().run_bridge_and_client(
dispatcher,
input,
run_client,
force_show_panics,
)
} else {
SameThread.run_bridge_and_client(dispatcher, input, run_client, force_show_panics)
}
}
}
pub struct SameThread;
impl ExecutionStrategy for SameThread {
fn run_bridge_and_client(
&self,
dispatcher: &mut impl DispatcherTrait,
input: Buffer,
run_client: extern "C" fn(BridgeConfig<'_>) -> Buffer,
force_show_panics: bool,
) -> Buffer {
let _guard = RunningSameThreadGuard::new();
let mut dispatch = |buf| dispatcher.dispatch(buf);
run_client(BridgeConfig {
input,
dispatch: (&mut dispatch).into(),
force_show_panics,
_marker: marker::PhantomData,
})
}
}
pub struct CrossThread<P>(PhantomData<P>);
impl<P> CrossThread<P> {
pub const fn new() -> Self {
CrossThread(PhantomData)
}
}
impl<P> ExecutionStrategy for CrossThread<P>
where
P: MessagePipe<Buffer> + Send + 'static,
{
fn run_bridge_and_client(
&self,
dispatcher: &mut impl DispatcherTrait,
input: Buffer,
run_client: extern "C" fn(BridgeConfig<'_>) -> Buffer,
force_show_panics: bool,
) -> Buffer {
let (mut server, mut client) = P::new();
let join_handle = thread::spawn(move || {
let mut dispatch = |b: Buffer| -> Buffer {
client.send(b);
client.recv().expect("server died while client waiting for reply")
};
run_client(BridgeConfig {
input,
dispatch: (&mut dispatch).into(),
force_show_panics,
_marker: marker::PhantomData,
})
});
while let Some(b) = server.recv() {
server.send(dispatcher.dispatch(b));
}
join_handle.join().unwrap()
}
}
pub trait MessagePipe<T>: Sized {
fn new() -> (Self, Self);
fn send(&mut self, value: T);
fn recv(&mut self) -> Option<T>;
}
fn run_server<
S: Server,
I: Encode<HandleStore<MarkedTypes<S>>>,
O: for<'a, 's> DecodeMut<'a, 's, HandleStore<MarkedTypes<S>>>,
>(
strategy: &impl ExecutionStrategy,
handle_counters: &'static client::HandleCounters,
server: S,
input: I,
run_client: extern "C" fn(BridgeConfig<'_>) -> Buffer,
force_show_panics: bool,
) -> Result<O, PanicMessage> {
let mut dispatcher =
Dispatcher { handle_store: HandleStore::new(handle_counters), server: MarkedTypes(server) };
let globals = dispatcher.server.globals();
let mut buf = Buffer::new();
(globals, input).encode(&mut buf, &mut dispatcher.handle_store);
buf = strategy.run_bridge_and_client(&mut dispatcher, buf, run_client, force_show_panics);
Result::decode(&mut &buf[..], &mut dispatcher.handle_store)
}
impl client::Client<crate::TokenStream, crate::TokenStream> {
pub fn run<S>(
&self,
strategy: &impl ExecutionStrategy,
server: S,
input: S::TokenStream,
force_show_panics: bool,
) -> Result<S::TokenStream, PanicMessage>
where
S: Server,
S::TokenStream: Default,
{
let client::Client { handle_counters, run, _marker } = *self;
run_server(
strategy,
handle_counters,
server,
<MarkedTypes<S> as Types>::TokenStream::mark(input),
run,
force_show_panics,
)
.map(|s| <Option<<MarkedTypes<S> as Types>::TokenStream>>::unmark(s).unwrap_or_default())
}
}
impl client::Client<(crate::TokenStream, crate::TokenStream), crate::TokenStream> {
pub fn run<S>(
&self,
strategy: &impl ExecutionStrategy,
server: S,
input: S::TokenStream,
input2: S::TokenStream,
force_show_panics: bool,
) -> Result<S::TokenStream, PanicMessage>
where
S: Server,
S::TokenStream: Default,
{
let client::Client { handle_counters, run, _marker } = *self;
run_server(
strategy,
handle_counters,
server,
(
<MarkedTypes<S> as Types>::TokenStream::mark(input),
<MarkedTypes<S> as Types>::TokenStream::mark(input2),
),
run,
force_show_panics,
)
.map(|s| <Option<<MarkedTypes<S> as Types>::TokenStream>>::unmark(s).unwrap_or_default())
}
}