Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

More proc macro tweaks #97445

Closed
wants to merge 3 commits into from
Closed

More proc macro tweaks #97445

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
3356d66
Inline and remove `Bridge::enter`.
nnethercote May 18, 2022
0d7dfae
Move `HandleStore` into `server.rs`.
nnethercote May 17, 2022
a59bb6d
Move counters into `server.rs`.
nnethercote May 19, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
198 changes: 43 additions & 155 deletions library/proc_macro/src/bridge/client.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -9,42 +9,6 @@ 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`, instead 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<S: server::Types> {
$($oty: handle::OwnedStore<S::$oty>,)*
$($ity: handle::InternedStore<S::$ity>,)*
}

impl<S: server::Types> HandleStore<S> {
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(crate) struct $oty {
Expand Down Expand Up @@ -73,53 +37,18 @@ macro_rules! define_handles {
}
}

impl<S: server::Types> DecodeMut<'_, '_, HandleStore<server::MarkedTypes<S>>>
for Marked<S::$oty, $oty>
{
fn decode(r: &mut Reader<'_>, s: &mut HandleStore<server::MarkedTypes<S>>) -> Self {
s.$oty.take(handle::Handle::decode(r, &mut ()))
}
}

impl<S> Encode<S> for &$oty {
fn encode(self, w: &mut Writer, s: &mut S) {
self.handle.encode(w, s);
}
}

impl<'s, S: server::Types> Decode<'_, 's, HandleStore<server::MarkedTypes<S>>>
for &'s Marked<S::$oty, $oty>
{
fn decode(r: &mut Reader<'_>, s: &'s HandleStore<server::MarkedTypes<S>>) -> Self {
&s.$oty[handle::Handle::decode(r, &mut ())]
}
}

impl<S> Encode<S> for &mut $oty {
fn encode(self, w: &mut Writer, s: &mut S) {
self.handle.encode(w, s);
}
}

impl<'s, S: server::Types> DecodeMut<'_, 's, HandleStore<server::MarkedTypes<S>>>
for &'s mut Marked<S::$oty, $oty>
{
fn decode(
r: &mut Reader<'_>,
s: &'s mut HandleStore<server::MarkedTypes<S>>
) -> Self {
&mut s.$oty[handle::Handle::decode(r, &mut ())]
}
}

impl<S: server::Types> Encode<HandleStore<server::MarkedTypes<S>>>
for Marked<S::$oty, $oty>
{
fn encode(self, w: &mut Writer, s: &mut HandleStore<server::MarkedTypes<S>>) {
s.$oty.alloc(self).encode(w, s);
}
}

impl<S> DecodeMut<'_, '_, S> for $oty {
fn decode(r: &mut Reader<'_>, s: &mut S) -> Self {
$oty {
Expand Down Expand Up @@ -147,22 +76,6 @@ macro_rules! define_handles {
}
}

impl<S: server::Types> DecodeMut<'_, '_, HandleStore<server::MarkedTypes<S>>>
for Marked<S::$ity, $ity>
{
fn decode(r: &mut Reader<'_>, s: &mut HandleStore<server::MarkedTypes<S>>) -> Self {
s.$ity.copy(handle::Handle::decode(r, &mut ()))
}
}

impl<S: server::Types> Encode<HandleStore<server::MarkedTypes<S>>>
for Marked<S::$ity, $ity>
{
fn encode(self, w: &mut Writer, s: &mut HandleStore<server::MarkedTypes<S>>) {
s.$ity.alloc(self).encode(w, s);
}
}

impl<S> DecodeMut<'_, '_, S> for $ity {
fn decode(r: &mut Reader<'_>, s: &mut S) -> Self {
$ity {
Expand All @@ -174,23 +87,7 @@ macro_rules! define_handles {
)*
}
}
define_handles! {
'owned:
FreeFunctions,
TokenStream,
TokenStreamBuilder,
TokenStreamIter,
Group,
Literal,
SourceFile,
MultiSpan,
Diagnostic,

'interned:
Punct,
Ident,
Span,
}
with_api_types!(define_handles);

// FIXME(eddyb) generate these impls by pattern-matching on the
// names of methods - also could use the presence of `fn drop`
Expand Down Expand Up @@ -323,27 +220,6 @@ impl Bridge<'_> {
})
}

fn enter<R>(self, f: impl FnOnce() -> R) -> R {
let force_show_panics = self.force_show_panics;
// 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 show = BridgeState::with(|state| match state {
BridgeState::NotConnected => true,
BridgeState::Connected(_) | BridgeState::InUse => force_show_panics,
});
if show {
prev(info)
}
}));
});

BRIDGE_STATE.with(|state| state.set(BridgeState::Connected(self), f))
}

fn with<R>(f: impl FnOnce(&mut Bridge<'_>) -> R) -> R {
BridgeState::with(|state| match state {
BridgeState::NotConnected => {
Expand All @@ -370,10 +246,6 @@ impl Bridge<'_> {
/// and forcing the use of APIs that take/return `S::TokenStream`, server-side.
#[repr(C)]
pub struct Client<I, O> {
// FIXME(eddyb) use a reference to the `static COUNTERS`, instead 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<'_>) -> Buffer,

pub(super) _marker: PhantomData<fn(I) -> O>,
Expand All @@ -388,7 +260,6 @@ impl<I, O> Clone for Client<I, O> {

/// 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<A: for<'a, 's> DecodeMut<'a, 's, ()>, R: Encode<()>>(
mut bridge: Bridge<'_>,
f: impl FnOnce(A) -> R,
Expand All @@ -397,29 +268,48 @@ fn run_client<A: for<'a, 's> DecodeMut<'a, 's, ()>, R: Encode<()>>(
let mut buf = bridge.cached_buffer.take();

panic::catch_unwind(panic::AssertUnwindSafe(|| {
bridge.enter(|| {
let reader = &mut &buf[..];
let input = A::decode(reader, &mut ());

// Put the `cached_buffer` back in the `Bridge`, for requests.
Bridge::with(|bridge| bridge.cached_buffer = buf.take());

let output = f(input);

// Take the `cached_buffer` back out, for the output value.
buf = 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 might not
// at the moment, so this is also potentially preventing UB).
buf.clear();
Ok::<_, ()>(output).encode(&mut buf, &mut ());
let force_show_panics = bridge.force_show_panics;
// 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 show = BridgeState::with(|state| match state {
BridgeState::NotConnected => true,
BridgeState::Connected(_) | BridgeState::InUse => force_show_panics,
});
if show {
prev(info)
}
}));
});

BRIDGE_STATE.with(|state| {
state.set(BridgeState::Connected(bridge), || {
let reader = &mut &buf[..];
let input = A::decode(reader, &mut ());

// Put the `cached_buffer` back in the `Bridge`, for requests.
Bridge::with(|bridge| bridge.cached_buffer = buf.take());

let output = f(input);

// Take the `cached_buffer` back out, for the output value.
buf = 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 might not
// at the moment, so this is also potentially preventing UB).
buf.clear();
Ok::<_, ()>(output).encode(&mut buf, &mut ());
})
})
}))
.map_err(PanicMessage::from)
Expand All @@ -433,7 +323,6 @@ fn run_client<A: for<'a, 's> DecodeMut<'a, 's, ()>, R: Encode<()>>(
impl Client<crate::TokenStream, crate::TokenStream> {
pub const fn expand1(f: impl Fn(crate::TokenStream) -> crate::TokenStream + Copy) -> Self {
Client {
get_handle_counters: HandleCounters::get,
run: super::selfless_reify::reify_to_extern_c_fn_hrt_bridge(move |bridge| {
run_client(bridge, |input| f(crate::TokenStream(input)).0)
}),
Expand All @@ -447,7 +336,6 @@ impl Client<(crate::TokenStream, crate::TokenStream), crate::TokenStream> {
f: impl Fn(crate::TokenStream, crate::TokenStream) -> crate::TokenStream + Copy,
) -> Self {
Client {
get_handle_counters: HandleCounters::get,
run: super::selfless_reify::reify_to_extern_c_fn_hrt_bridge(move |bridge| {
run_client(bridge, |(input, input2)| {
f(crate::TokenStream(input), crate::TokenStream(input2)).0
Expand Down
24 changes: 24 additions & 0 deletions library/proc_macro/src/bridge/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -175,6 +175,30 @@ macro_rules! with_api {
};
}

// Similar to `with_api`, but only lists the types, and they are divided into
// the two storage categories.
macro_rules! with_api_types {
($m:ident) => {
$m! {
'owned:
FreeFunctions,
TokenStream,
TokenStreamBuilder,
TokenStreamIter,
Group,
Literal,
SourceFile,
MultiSpan,
Diagnostic,

'interned:
Punct,
Ident,
Span,
}
};
}

// FIXME(eddyb) this calls `encode` for each argument, but in reverse,
// to match the ordering in `reverse_decode`.
macro_rules! reverse_encode {
Expand Down
Loading