Make edition per-token, not per-file

More correctly, *also* per-token. Because as it turns out, while the top-level edition affects parsing (I think), the per-token edition affects escaping of identifiers/keywords.

Author: ChayimFriedman2

crates/edition/src/lib.rs

@@ -5,7 +5,8 @@ use std::fmt;
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 #[repr(u8)]
 pub enum Edition {
-    Edition2015,
+    // The syntax context stuff needs the discriminants to start from 0 and be consecutive.
+    Edition2015 = 0,
     Edition2018,
     Edition2021,
     Edition2024,

crates/hir-def/src/body.rs

@@ -15,7 +15,7 @@ use hir_expand::{name::Name, ExpandError, InFile};
 use la_arena::{Arena, ArenaMap, Idx, RawIdx};
 use rustc_hash::FxHashMap;
 use smallvec::SmallVec;
-use span::{Edition, MacroFileId};
+use span::{Edition, MacroFileId, SyntaxContextData};
 use syntax::{ast, AstPtr, SyntaxNodePtr};
 use triomphe::Arc;
 use tt::TextRange;
@@ -37,15 +37,22 @@ use crate::{
 
 /// A wrapper around [`span::SyntaxContextId`] that is intended only for comparisons.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct HygieneId(pub(crate) span::SyntaxContextId);
+pub struct HygieneId(span::SyntaxContextId);
 
 impl HygieneId {
-    pub const ROOT: Self = Self(span::SyntaxContextId::ROOT);
+    // The edition doesn't matter here, we only use this for comparisons and to lookup the macro.
+    pub const ROOT: Self = Self(span::SyntaxContextId::root(Edition::Edition2015));
 
-    pub fn new(ctx: span::SyntaxContextId) -> Self {
+    pub fn new(mut ctx: span::SyntaxContextId) -> Self {
+        // See `Name` for why we're doing that.
+        ctx.remove_root_edition();
         Self(ctx)
     }
 
+    pub(crate) fn lookup(self, db: &dyn DefDatabase) -> SyntaxContextData {
+        db.lookup_intern_syntax_context(self.0)
+    }
+
     pub(crate) fn is_root(self) -> bool {
         self.0.is_root()
     }

crates/hir-def/src/body/lower.rs

@@ -2460,7 +2460,7 @@ impl ExprCollector<'_> {
             None => HygieneId::ROOT,
             Some(span_map) => {
                 let ctx = span_map.span_at(span_start).ctx;
-                HygieneId(self.db.lookup_intern_syntax_context(ctx).opaque_and_semitransparent)
+                HygieneId::new(self.db.lookup_intern_syntax_context(ctx).opaque_and_semitransparent)
             }
         }
     }

crates/hir-def/src/expander.rs

@@ -10,7 +10,7 @@ use hir_expand::{
     ExpandResult, HirFileId, InFile, Lookup, MacroCallId,
 };
 use limit::Limit;
-use span::SyntaxContextId;
+use span::{Edition, SyntaxContextId};
 use syntax::{ast, Parse};
 use triomphe::Arc;
 
@@ -60,7 +60,7 @@ impl Expander {
 
     pub fn syntax_context(&self) -> SyntaxContextId {
         // FIXME:
-        SyntaxContextId::ROOT
+        SyntaxContextId::root(Edition::CURRENT)
     }
 
     pub fn enter_expand<T: ast::AstNode>(

crates/hir-def/src/item_tree/tests.rs

@@ -270,7 +270,7 @@ m!();
             // AstId: 2
             pub macro m2 { ... }
 
-            // AstId: 3, SyntaxContext: 0, ExpandTo: Items
+            // AstId: 3, SyntaxContext: 2, ExpandTo: Items
             m!(...);
         "#]],
     );

crates/hir-def/src/macro_expansion_tests/mbe.rs

@@ -35,9 +35,9 @@ macro_rules! f {
     };
 }
 
-struct#0:[email protected]#1# MyTraitMap2#0:[email protected]#0# {#0:[email protected]#1#
-    map#0:[email protected]#1#:#0:[email protected]#1# #0:[email protected]#1#::#0:[email protected]#1#std#0:[email protected]#1#::#0:[email protected]#1#collections#0:[email protected]#1#::#0:[email protected]#1#HashSet#0:[email protected]#1#<#0:[email protected]#1#(#0:[email protected]#1#)#0:[email protected]#1#>#0:[email protected]#1#,#0:[email protected]#1#
-}#0:[email protected]#1#
+struct#0:[email protected]#4# MyTraitMap2#0:[email protected]#2# {#0:[email protected]#4#
+    map#0:[email protected]#4#:#0:[email protected]#4# #0:[email protected]#4#::#0:[email protected]#4#std#0:[email protected]#4#::#0:[email protected]#4#collections#0:[email protected]#4#::#0:[email protected]#4#HashSet#0:[email protected]#4#<#0:[email protected]#4#(#0:[email protected]#4#)#0:[email protected]#4#>#0:[email protected]#4#,#0:[email protected]#4#
+}#0:[email protected]#4#
 "#]],
     );
 }
@@ -75,12 +75,12 @@ macro_rules! f {
     };
 }
 
-fn#0:[email protected]#0# main#0:[email protected]#0#(#0:[email protected]#0#)#0:[email protected]#0# {#0:[email protected]#0#
-    1#0:[email protected]#0#;#0:[email protected]#0#
-    1.0#0:[email protected]#0#;#0:[email protected]#0#
-    (#0:[email protected]#0#(#0:[email protected]#0#1#0:[email protected]#0#,#0:[email protected]#0# )#0:[email protected]#0#,#0:[email protected]#0# )#0:[email protected]#0#.#0:[email protected]#0#0#0:[email protected]#0#.#0:[email protected]#0#0#0:[email protected]#0#;#0:[email protected]#0#
-    let#0:[email protected]#0# x#0:[email protected]#0# =#0:[email protected]#0# 1#0:[email protected]#0#;#0:[email protected]#0#
-}#0:[email protected]#0#
+fn#0:[email protected]#2# main#0:[email protected]#2#(#0:[email protected]#2#)#0:[email protected]#2# {#0:[email protected]#2#
+    1#0:[email protected]#2#;#0:[email protected]#2#
+    1.0#0:[email protected]#2#;#0:[email protected]#2#
+    (#0:[email protected]#2#(#0:[email protected]#2#1#0:[email protected]#2#,#0:[email protected]#2# )#0:[email protected]#2#,#0:[email protected]#2# )#0:[email protected]#2#.#0:[email protected]#2#0#0:[email protected]#2#.#0:[email protected]#2#0#0:[email protected]#2#;#0:[email protected]#2#
+    let#0:[email protected]#2# x#0:[email protected]#2# =#0:[email protected]#2# 1#0:[email protected]#2#;#0:[email protected]#2#
+}#0:[email protected]#2#
 
 
 "#]],
@@ -171,7 +171,7 @@ fn main(foo: ()) {
     }
 
     fn main(foo: ()) {
-        /* error: unresolved macro unresolved */"helloworld!"#0:[email protected]#0#;
+        /* error: unresolved macro unresolved */"helloworld!"#0:[email protected]#2#;
     }
 }
 
@@ -197,7 +197,7 @@ macro_rules! mk_struct {
 #[macro_use]
 mod foo;
 
-struct#1:[email protected]#1# Foo#0:[email protected]#0#(#1:[email protected]#1#u32#0:[email protected]#0#)#1:[email protected]#1#;#1:[email protected]#1#
+struct#1:[email protected]#4# Foo#0:[email protected]#2#(#1:[email protected]#4#u32#0:[email protected]#2#)#1:[email protected]#4#;#1:[email protected]#4#
 "#]],
     );
 }
@@ -423,10 +423,10 @@ m! { foo, bar }
 macro_rules! m {
     ($($i:ident),*) => ( impl Bar { $(fn $i() {})* } );
 }
-impl#\1# Bar#\1# {#\1#
-    fn#\1# foo#\0#(#\1#)#\1# {#\1#}#\1#
-    fn#\1# bar#\0#(#\1#)#\1# {#\1#}#\1#
-}#\1#
+impl#\4# Bar#\4# {#\4#
+    fn#\4# foo#\2#(#\4#)#\4# {#\4#}#\4#
+    fn#\4# bar#\2#(#\4#)#\4# {#\4#}#\4#
+}#\4#
 "#]],
     );
 }

crates/hir-def/src/macro_expansion_tests/mod.rs

@@ -358,6 +358,7 @@ impl ProcMacroExpander for IdentityWhenValidProcMacroExpander {
         let (parse, _) = syntax_bridge::token_tree_to_syntax_node(
             subtree,
             syntax_bridge::TopEntryPoint::MacroItems,
+            &mut |_| span::Edition::CURRENT,
             span::Edition::CURRENT,
         );
         if parse.errors().is_empty() {

crates/hir-def/src/macro_expansion_tests/proc_macros.rs

@@ -181,9 +181,9 @@ fn foo(&self) {
     self.0. 1;
 }
 
-fn#0:[email protected]#0# foo#0:[email protected]#0#(#0:[email protected]#0#&#0:[email protected]#0#self#0:[email protected]#0# )#0:[email protected]#0# {#0:[email protected]#0#
-    self#0:[email protected]#0# .#0:[email protected]#0#0#0:[email protected]#0#.#0:[email protected]#0#1#0:[email protected]#0#;#0:[email protected]#0#
-}#0:[email protected]#0#"#]],
+fn#0:[email protected]#2# foo#0:[email protected]#2#(#0:[email protected]#2#&#0:[email protected]#2#self#0:[email protected]#2# )#0:[email protected]#2# {#0:[email protected]#2#
+    self#0:[email protected]#2# .#0:[email protected]#2#0#0:[email protected]#2#.#0:[email protected]#2#1#0:[email protected]#2#;#0:[email protected]#2#
+}#0:[email protected]#2#"#]],
     );
 }
 

crates/hir-def/src/nameres/collector.rs

@@ -74,7 +74,7 @@ pub(super) fn collect_defs(db: &dyn DefDatabase, def_map: DefMap, tree_id: TreeI
 
     let proc_macros = if krate.is_proc_macro {
         db.proc_macros()
-            .for_crate(def_map.krate, db.syntax_context(tree_id.file_id()))
+            .for_crate(def_map.krate, db.syntax_context(tree_id.file_id(), krate.edition))
             .unwrap_or_default()
     } else {
         Default::default()

crates/hir-def/src/resolver.rs

@@ -324,7 +324,7 @@ impl Resolver {
 
         if n_segments <= 1 {
             let mut hygiene_info = if !hygiene_id.is_root() {
-                let ctx = db.lookup_intern_syntax_context(hygiene_id.0);
+                let ctx = hygiene_id.lookup(db);
                 ctx.outer_expn.map(|expansion| {
                     let expansion = db.lookup_intern_macro_call(expansion);
                     (ctx.parent, expansion.def)