Remove SyntaxContext trait

crates/mbe/src/syntax_bridge.rs

@@ -11,7 +11,7 @@
 };
 use tt::{
     buffer::{Cursor, TokenBuffer},
-    Span, SyntaxContext,
+    Span,
 };
 
 use crate::{to_parser_input::to_parser_input, tt_iter::TtIter};
@@ -37,7 +37,6 @@ fn span_for(&self, range: TextRange) -> S {
 
 /// Dummy things for testing where spans don't matter.
 pub(crate) mod dummy_test_span_utils {
-    use tt::SyntaxContext;
 
     use super::*;
 
@@ -53,9 +52,6 @@ pub(crate) mod dummy_test_span_utils {
 
     #[derive(Debug, Copy, Clone, PartialEq, Eq)]
     pub struct DummyTestSyntaxContext;
-    impl SyntaxContext for DummyTestSyntaxContext {
-        const DUMMY: Self = DummyTestSyntaxContext;
-    }
 
     pub struct DummyTestSpanMap;
 
@@ -82,7 +78,7 @@ pub fn syntax_node_to_token_tree<Ctx, SpanMap>(
 ) -> tt::Subtree<SpanData<Ctx>>
 where
     SpanData<Ctx>: Span,
-    Ctx: SyntaxContext,
+    Ctx: Copy,
     SpanMap: SpanMapper<SpanData<Ctx>>,
 {
     let mut c = Converter::new(node, map, Default::default(), Default::default(), span);
@@ -102,7 +98,7 @@ pub fn syntax_node_to_token_tree_modified<Ctx, SpanMap>(
 where
     SpanMap: SpanMapper<SpanData<Ctx>>,
     SpanData<Ctx>: Span,
-    Ctx: SyntaxContext,
+    Ctx: Copy,
 {
     let mut c = Converter::new(node, map, append, remove, call_site);
     convert_tokens(&mut c)
@@ -128,7 +124,7 @@ pub fn token_tree_to_syntax_node<Ctx>(
 ) -> (Parse<SyntaxNode>, SpanMap<SpanData<Ctx>>)
 where
     SpanData<Ctx>: Span,
-    Ctx: SyntaxContext,
+    Ctx: Copy,
 {
     let buffer = match tt {
         tt::Subtree {
@@ -165,7 +161,7 @@ pub fn parse_to_token_tree<Ctx>(
 ) -> Option<tt::Subtree<SpanData<Ctx>>>
 where
     SpanData<Ctx>: Span,
-    Ctx: SyntaxContext,
+    Ctx: Copy,
 {
     let lexed = parser::LexedStr::new(text);
     if lexed.errors().next().is_some() {
@@ -531,7 +527,7 @@ fn to_text(&self, ctx: &StaticRawConverter<'_, S>) -> SmolStr {
     }
 }
 
-impl<Ctx: SyntaxContext> TokenConverter<SpanData<Ctx>> for RawConverter<'_, Ctx>
+impl<Ctx: Copy> TokenConverter<SpanData<Ctx>> for RawConverter<'_, Ctx>
 where
     SpanData<Ctx>: Span,
 {

crates/proc-macro-api/src/msg/flat.rs

@@ -54,9 +54,7 @@ fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
     }
 }
 
-impl tt::Span for TokenId {
-    const DUMMY: Self = TokenId(!0);
-}
+impl tt::Span for TokenId {}
 
 #[derive(Serialize, Deserialize, Debug)]
 pub struct FlatTree {

crates/tt/src/lib.rs

@@ -11,34 +11,10 @@
 pub use smol_str::SmolStr;
 pub use text_size::{TextRange, TextSize};
 
-pub trait Span: std::fmt::Debug + Copy + Sized + Eq {
-    // FIXME: Should not exist. Dummy spans will always be wrong if they leak somewhere. Instead,
-    // the call site or def site spans should be used in relevant places, its just that we don't
-    // expose those everywhere in the yet.
-    #[deprecated = "dummy spans will panic if surfaced incorrectly, as such they should be replaced appropriately"]
-    const DUMMY: Self;
-}
+pub trait Span: std::fmt::Debug + Copy + Sized + Eq {}
 
-pub trait SyntaxContext: std::fmt::Debug + Copy + Sized + Eq {
-    #[deprecated = "dummy spans will panic if surfaced incorrectly, as such they should be replaced appropriately"]
-    const DUMMY: Self;
-}
-
-impl<Ctx: SyntaxContext> Span for span::SpanData<Ctx> {
-    #[allow(deprecated)]
-    const DUMMY: Self = span::SpanData {
-        range: TextRange::empty(TextSize::new(0)),
-        anchor: span::SpanAnchor {
-            file_id: span::FileId::BOGUS,
-            ast_id: span::ROOT_ERASED_FILE_AST_ID,
-        },
-        ctx: Ctx::DUMMY,
-    };
-}
-
-impl SyntaxContext for span::SyntaxContextId {
-    const DUMMY: Self = Self::ROOT;
-}
+impl<Ctx> Span for span::SpanData<Ctx> where span::SpanData<Ctx>: std::fmt::Debug + Copy + Sized + Eq
+{}
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum TokenTree<S> {