Auto merge of #98188 - mystor:fast_group_punct, r=eddyb

proc_macro/bridge: stop using a remote object handle for proc_macro Punct and Group

This is the third part of rust-lang/rust#86822, split off as requested in rust-lang/rust#86822 (review). This patch transforms the `Punct` and `Group` types into structs serialized over IPC rather than handles, making them more efficient to create and manipulate from within proc-macros.

Author: bors

proc_macro/src/bridge/client.rs

@@ -175,14 +175,12 @@ define_handles! {
     'owned:
     FreeFunctions,
     TokenStream,
-    Group,
     Literal,
     SourceFile,
     MultiSpan,
     Diagnostic,
 
     'interned:
-    Punct,
     Ident,
     Span,
 }
@@ -199,12 +197,6 @@ impl Clone for TokenStream {
     }
 }
 
-impl Clone for Group {
-    fn clone(&self) -> Self {
-        self.clone()
-    }
-}
-
 impl Clone for Literal {
     fn clone(&self) -> Self {
         self.clone()

proc_macro/src/bridge/mod.rs

@@ -65,37 +65,19 @@ macro_rules! with_api {
                 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, $S::Literal>,
+                    tree: TokenTree<$S::TokenStream, $S::Span, $S::Ident, $S::Literal>,
                 ) -> $S::TokenStream;
                 fn concat_trees(
                     base: Option<$S::TokenStream>,
-                    trees: Vec<TokenTree<$S::Group, $S::Punct, $S::Ident, $S::Literal>>,
+                    trees: Vec<TokenTree<$S::TokenStream, $S::Span, $S::Ident, $S::Literal>>,
                 ) -> $S::TokenStream;
                 fn concat_streams(
                     base: Option<$S::TokenStream>,
                     streams: Vec<$S::TokenStream>,
                 ) -> $S::TokenStream;
                 fn into_trees(
                     $self: $S::TokenStream
-                ) -> Vec<TokenTree<$S::Group, $S::Punct, $S::Ident, $S::Literal>>;
-            },
-            Group {
-                fn drop($self: $S::Group);
-                fn clone($self: &$S::Group) -> $S::Group;
-                fn new(delimiter: Delimiter, stream: Option<$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) -> $S::Punct;
+                ) -> Vec<TokenTree<$S::TokenStream, $S::Span, $S::Ident, $S::Literal>>;
             },
             Ident {
                 fn new(string: &str, span: $S::Span, is_raw: bool) -> $S::Ident;
@@ -343,6 +325,7 @@ mark_noop! {
     &'_ [u8],
     &'_ str,
     String,
+    u8,
     usize,
     Delimiter,
     Level,
@@ -448,16 +431,49 @@ compound_traits!(
     }
 );
 
+#[derive(Copy, Clone)]
+pub struct DelimSpan<Span> {
+    pub open: Span,
+    pub close: Span,
+    pub entire: Span,
+}
+
+impl<Span: Copy> DelimSpan<Span> {
+    pub fn from_single(span: Span) -> Self {
+        DelimSpan { open: span, close: span, entire: span }
+    }
+}
+
+compound_traits!(struct DelimSpan<Span> { open, close, entire });
+
+#[derive(Clone)]
+pub struct Group<TokenStream, Span> {
+    pub delimiter: Delimiter,
+    pub stream: Option<TokenStream>,
+    pub span: DelimSpan<Span>,
+}
+
+compound_traits!(struct Group<TokenStream, Span> { delimiter, stream, span });
+
+#[derive(Clone)]
+pub struct Punct<Span> {
+    pub ch: u8,
+    pub joint: bool,
+    pub span: Span,
+}
+
+compound_traits!(struct Punct<Span> { ch, joint, span });
+
 #[derive(Clone)]
-pub enum TokenTree<G, P, I, L> {
-    Group(G),
-    Punct(P),
-    Ident(I),
-    Literal(L),
+pub enum TokenTree<TokenStream, Span, Ident, Literal> {
+    Group(Group<TokenStream, Span>),
+    Punct(Punct<Span>),
+    Ident(Ident),
+    Literal(Literal),
 }
 
 compound_traits!(
-    enum TokenTree<G, P, I, L> {
+    enum TokenTree<TokenStream, Span, Ident, Literal> {
         Group(tt),
         Punct(tt),
         Ident(tt),
@@ -468,12 +484,12 @@ compound_traits!(
 /// Globals provided alongside the initial inputs for a macro expansion.
 /// Provides values such as spans which are used frequently to avoid RPC.
 #[derive(Clone)]
-pub struct ExpnGlobals<S> {
-    pub def_site: S,
-    pub call_site: S,
-    pub mixed_site: S,
+pub struct ExpnGlobals<Span> {
+    pub def_site: Span,
+    pub call_site: Span,
+    pub mixed_site: Span,
 }
 
 compound_traits!(
-    struct ExpnGlobals<Sp> { def_site, call_site, mixed_site }
+    struct ExpnGlobals<Span> { def_site, call_site, mixed_site }
 );

proc_macro/src/bridge/server.rs

@@ -8,8 +8,6 @@ use super::client::HandleStore;
 pub trait Types {
     type FreeFunctions: 'static;
     type TokenStream: 'static + Clone;
-    type Group: 'static + Clone;
-    type Punct: 'static + Copy + Eq + Hash;
     type Ident: 'static + Copy + Eq + Hash;
     type Literal: 'static + Clone;
     type SourceFile: 'static + Clone;

proc_macro/src/lib.rs

@@ -212,8 +212,8 @@ pub use quote::{quote, quote_span};
 fn tree_to_bridge_tree(
     tree: TokenTree,
 ) -> bridge::TokenTree<
-    bridge::client::Group,
-    bridge::client::Punct,
+    bridge::client::TokenStream,
+    bridge::client::Span,
     bridge::client::Ident,
     bridge::client::Literal,
 > {
@@ -238,8 +238,8 @@ impl From<TokenTree> for TokenStream {
 struct ConcatTreesHelper {
     trees: Vec<
         bridge::TokenTree<
-            bridge::client::Group,
-            bridge::client::Punct,
+            bridge::client::TokenStream,
+            bridge::client::Span,
             bridge::client::Ident,
             bridge::client::Literal,
         >,
@@ -365,8 +365,8 @@ pub mod token_stream {
     pub struct IntoIter(
         std::vec::IntoIter<
             bridge::TokenTree<
-                bridge::client::Group,
-                bridge::client::Punct,
+                bridge::client::TokenStream,
+                bridge::client::Span,
                 bridge::client::Ident,
                 bridge::client::Literal,
             >,
@@ -788,7 +788,7 @@ impl fmt::Display for TokenTree {
 /// A `Group` internally contains a `TokenStream` which is surrounded by `Delimiter`s.
 #[derive(Clone)]
 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
-pub struct Group(bridge::client::Group);
+pub struct Group(bridge::Group<bridge::client::TokenStream, bridge::client::Span>);
 
 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
 impl !Send for Group {}
@@ -825,13 +825,17 @@ impl Group {
     /// method below.
     #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
     pub fn new(delimiter: Delimiter, stream: TokenStream) -> Group {
-        Group(bridge::client::Group::new(delimiter, stream.0))
+        Group(bridge::Group {
+            delimiter,
+            stream: stream.0,
+            span: bridge::DelimSpan::from_single(Span::call_site().0),
+        })
     }
 
     /// Returns the delimiter of this `Group`
     #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
     pub fn delimiter(&self) -> Delimiter {
-        self.0.delimiter()
+        self.0.delimiter
     }
 
     /// Returns the `TokenStream` of tokens that are delimited in this `Group`.
@@ -840,7 +844,7 @@ impl Group {
     /// returned above.
     #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
     pub fn stream(&self) -> TokenStream {
-        TokenStream(Some(self.0.stream()))
+        TokenStream(self.0.stream.clone())
     }
 
     /// Returns the span for the delimiters of this token stream, spanning the
@@ -852,7 +856,7 @@ impl Group {
     /// ```
     #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
     pub fn span(&self) -> Span {
-        Span(self.0.span())
+        Span(self.0.span.entire)
     }
 
     /// Returns the span pointing to the opening delimiter of this group.
@@ -863,7 +867,7 @@ impl Group {
     /// ```
     #[stable(feature = "proc_macro_group_span", since = "1.55.0")]
     pub fn span_open(&self) -> Span {
-        Span(self.0.span_open())
+        Span(self.0.span.open)
     }
 
     /// Returns the span pointing to the closing delimiter of this group.
@@ -874,7 +878,7 @@ impl Group {
     /// ```
     #[stable(feature = "proc_macro_group_span", since = "1.55.0")]
     pub fn span_close(&self) -> Span {
-        Span(self.0.span_close())
+        Span(self.0.span.close)
     }
 
     /// Configures the span for this `Group`'s delimiters, but not its internal
@@ -885,7 +889,7 @@ impl Group {
     /// tokens at the level of the `Group`.
     #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
     pub fn set_span(&mut self, span: Span) {
-        self.0.set_span(span.0);
+        self.0.span = bridge::DelimSpan::from_single(span.0);
     }
 }
 
@@ -925,7 +929,7 @@ impl fmt::Debug for Group {
 /// forms of `Spacing` returned.
 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
 #[derive(Clone)]
-pub struct Punct(bridge::client::Punct);
+pub struct Punct(bridge::Punct<bridge::client::Span>);
 
 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
 impl !Send for Punct {}
@@ -958,13 +962,24 @@ impl Punct {
     /// which can be further configured with the `set_span` method below.
     #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
     pub fn new(ch: char, spacing: Spacing) -> Punct {
-        Punct(bridge::client::Punct::new(ch, spacing))
+        const LEGAL_CHARS: &[char] = &[
+            '=', '<', '>', '!', '~', '+', '-', '*', '/', '%', '^', '&', '|', '@', '.', ',', ';',
+            ':', '#', '$', '?', '\'',
+        ];
+        if !LEGAL_CHARS.contains(&ch) {
+            panic!("unsupported character `{:?}`", ch);
+        }
+        Punct(bridge::Punct {
+            ch: ch as u8,
+            joint: spacing == Spacing::Joint,
+            span: Span::call_site().0,
+        })
     }
 
     /// Returns the value of this punctuation character as `char`.
     #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
     pub fn as_char(&self) -> char {
-        self.0.as_char()
+        self.0.ch as char
     }
 
     /// Returns the spacing of this punctuation character, indicating whether it's immediately
@@ -973,28 +988,19 @@ impl Punct {
     /// (`Alone`) so the operator has certainly ended.
     #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
     pub fn spacing(&self) -> Spacing {
-        self.0.spacing()
+        if self.0.joint { Spacing::Joint } else { Spacing::Alone }
     }
 
     /// Returns the span for this punctuation character.
     #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
     pub fn span(&self) -> Span {
-        Span(self.0.span())
+        Span(self.0.span)
     }
 
     /// Configure the span for this punctuation character.
     #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
     pub fn set_span(&mut self, span: Span) {
-        self.0 = self.0.with_span(span.0);
-    }
-}
-
-// N.B., the bridge only provides `to_string`, implement `fmt::Display`
-// based on it (the reverse of the usual relationship between the two).
-#[stable(feature = "proc_macro_lib", since = "1.15.0")]
-impl ToString for Punct {
-    fn to_string(&self) -> String {
-        TokenStream::from(TokenTree::from(self.clone())).to_string()
+        self.0.span = span.0;
     }
 }
 
@@ -1003,7 +1009,7 @@ impl ToString for Punct {
 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
 impl fmt::Display for Punct {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.write_str(&self.to_string())
+        write!(f, "{}", self.as_char())
     }
 }