From 392159b5618192af5761788d2c7e8256b331ce95 Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <n.nethercote@gmail.com>
Date: Fri, 1 Mar 2024 16:06:29 +1100
Subject: [PATCH] Move `HandleStore` into `server.rs`.

This just moves the server-relevant parts of handles into `server.rs`.
It introduces a new higher-order macro `with_api_handle_types` to avoid
some duplication.

This fixes two `FIXME` comments, and makes things clearer, by not having
server code in `client.rs`.
---
 library/proc_macro/src/bridge/client.rs | 85 ++-----------------------
 library/proc_macro/src/bridge/mod.rs    | 17 +++++
 library/proc_macro/src/bridge/server.rs | 75 +++++++++++++++++++++-
 library/proc_macro/src/bridge/symbol.rs |  8 +--
 4 files changed, 99 insertions(+), 86 deletions(-)

diff --git a/library/proc_macro/src/bridge/client.rs b/library/proc_macro/src/bridge/client.rs
index 52b9ef470dccb..b54f2db88ffc9 100644
--- a/library/proc_macro/src/bridge/client.rs
+++ b/library/proc_macro/src/bridge/client.rs
@@ -5,16 +5,16 @@ use super::*;
 use std::marker::PhantomData;
 use std::sync::atomic::AtomicU32;
 
-macro_rules! define_handles {
+macro_rules! define_client_handles {
     (
         'owned: $($oty:ident,)*
         'interned: $($ity:ident,)*
     ) => {
         #[repr(C)]
         #[allow(non_snake_case)]
-        pub struct HandleCounters {
-            $($oty: AtomicU32,)*
-            $($ity: AtomicU32,)*
+        pub(super) struct HandleCounters {
+            $(pub(super) $oty: AtomicU32,)*
+            $(pub(super) $ity: AtomicU32,)*
         }
 
         impl HandleCounters {
@@ -29,22 +29,6 @@ macro_rules! define_handles {
             }
         }
 
-        // FIXME(eddyb) generate the definition of `HandleStore` in `server.rs`.
-        #[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),)*
-                }
-            }
-        }
-
         $(
             pub(crate) struct $oty {
                 handle: handle::Handle,
@@ -72,53 +56,18 @@ 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 {
@@ -145,22 +94,6 @@ 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 {
@@ -172,15 +105,7 @@ macro_rules! define_handles {
         )*
     }
 }
-define_handles! {
-    'owned:
-    FreeFunctions,
-    TokenStream,
-    SourceFile,
-
-    'interned:
-    Span,
-}
+with_api_handle_types!(define_client_handles);
 
 // FIXME(eddyb) generate these impls by pattern-matching on the
 // names of methods - also could use the presence of `fn drop`
diff --git a/library/proc_macro/src/bridge/mod.rs b/library/proc_macro/src/bridge/mod.rs
index 9b337f23867f4..67c72cf98d405 100644
--- a/library/proc_macro/src/bridge/mod.rs
+++ b/library/proc_macro/src/bridge/mod.rs
@@ -113,6 +113,23 @@ macro_rules! with_api {
     };
 }
 
+// Similar to `with_api`, but only lists the types requiring handles, and they
+// are divided into the two storage categories.
+macro_rules! with_api_handle_types {
+    ($m:ident) => {
+        $m! {
+            'owned:
+            FreeFunctions,
+            TokenStream,
+            SourceFile,
+
+            'interned:
+            Span,
+            // Symbol is handled manually
+        }
+    };
+}
+
 // FIXME(eddyb) this calls `encode` for each argument, but in reverse,
 // to match the ordering in `reverse_decode`.
 macro_rules! reverse_encode {
diff --git a/library/proc_macro/src/bridge/server.rs b/library/proc_macro/src/bridge/server.rs
index 2ea87d866ff3e..8736d1806fbe9 100644
--- a/library/proc_macro/src/bridge/server.rs
+++ b/library/proc_macro/src/bridge/server.rs
@@ -5,8 +5,79 @@ use super::*;
 use std::cell::Cell;
 use std::marker::PhantomData;
 
-// FIXME(eddyb) generate the definition of `HandleStore` in `server.rs`.
-use super::client::HandleStore;
+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;
diff --git a/library/proc_macro/src/bridge/symbol.rs b/library/proc_macro/src/bridge/symbol.rs
index 02225d20b26e1..86ce2cc189588 100644
--- a/library/proc_macro/src/bridge/symbol.rs
+++ b/library/proc_macro/src/bridge/symbol.rs
@@ -109,18 +109,18 @@ impl<S> Encode<S> for Symbol {
     }
 }
 
-impl<S: server::Server> DecodeMut<'_, '_, client::HandleStore<server::MarkedTypes<S>>>
+impl<S: server::Server> DecodeMut<'_, '_, server::HandleStore<server::MarkedTypes<S>>>
     for Marked<S::Symbol, Symbol>
 {
-    fn decode(r: &mut Reader<'_>, s: &mut client::HandleStore<server::MarkedTypes<S>>) -> Self {
+    fn decode(r: &mut Reader<'_>, s: &mut server::HandleStore<server::MarkedTypes<S>>) -> Self {
         Mark::mark(S::intern_symbol(<&str>::decode(r, s)))
     }
 }
 
-impl<S: server::Server> Encode<client::HandleStore<server::MarkedTypes<S>>>
+impl<S: server::Server> Encode<server::HandleStore<server::MarkedTypes<S>>>
     for Marked<S::Symbol, Symbol>
 {
-    fn encode(self, w: &mut Writer, s: &mut client::HandleStore<server::MarkedTypes<S>>) {
+    fn encode(self, w: &mut Writer, s: &mut server::HandleStore<server::MarkedTypes<S>>) {
         S::with_symbol_string(&self.unmark(), |sym| sym.encode(w, s))
     }
 }