diff --git a/crates/edition/src/lib.rs b/crates/edition/src/lib.rs
index c25d5b9557..7e9c94af40 100644
--- a/crates/edition/src/lib.rs
+++ b/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,
diff --git a/crates/hir-def/src/body.rs b/crates/hir-def/src/body.rs
index 433a956ff9..de43924930 100644
--- a/crates/hir-def/src/body.rs
+++ b/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()
     }
diff --git a/crates/hir-def/src/body/lower.rs b/crates/hir-def/src/body/lower.rs
index eed9f9468f..71d8b81236 100644
--- a/crates/hir-def/src/body/lower.rs
+++ b/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)
             }
         }
     }
diff --git a/crates/hir-def/src/expander.rs b/crates/hir-def/src/expander.rs
index 5315c1c6fb..108258d5a1 100644
--- a/crates/hir-def/src/expander.rs
+++ b/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>(
diff --git a/crates/hir-def/src/item_tree/tests.rs b/crates/hir-def/src/item_tree/tests.rs
index 0f53969d6c..735586c049 100644
--- a/crates/hir-def/src/item_tree/tests.rs
+++ b/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!(...);
         "#]],
     );
diff --git a/crates/hir-def/src/macro_expansion_tests/mbe.rs b/crates/hir-def/src/macro_expansion_tests/mbe.rs
index 511626b5ed..8c5bd3b6d3 100644
--- a/crates/hir-def/src/macro_expansion_tests/mbe.rs
+++ b/crates/hir-def/src/macro_expansion_tests/mbe.rs
@@ -35,9 +35,9 @@ macro_rules! f {
     };
 }
 
-struct#0:1@58..64#1# MyTraitMap2#0:2@31..42#0# {#0:1@72..73#1#
-    map#0:1@86..89#1#:#0:1@89..90#1# #0:1@89..90#1#::#0:1@91..93#1#std#0:1@93..96#1#::#0:1@96..98#1#collections#0:1@98..109#1#::#0:1@109..111#1#HashSet#0:1@111..118#1#<#0:1@118..119#1#(#0:1@119..120#1#)#0:1@120..121#1#>#0:1@121..122#1#,#0:1@122..123#1#
-}#0:1@132..133#1#
+struct#0:1@58..64#4# MyTraitMap2#0:2@31..42#2# {#0:1@72..73#4#
+    map#0:1@86..89#4#:#0:1@89..90#4# #0:1@89..90#4#::#0:1@91..93#4#std#0:1@93..96#4#::#0:1@96..98#4#collections#0:1@98..109#4#::#0:1@109..111#4#HashSet#0:1@111..118#4#<#0:1@118..119#4#(#0:1@119..120#4#)#0:1@120..121#4#>#0:1@121..122#4#,#0:1@122..123#4#
+}#0:1@132..133#4#
 "#]],
     );
 }
@@ -75,12 +75,12 @@ macro_rules! f {
     };
 }
 
-fn#0:2@30..32#0# main#0:2@33..37#0#(#0:2@37..38#0#)#0:2@38..39#0# {#0:2@40..41#0#
-    1#0:2@50..51#0#;#0:2@51..52#0#
-    1.0#0:2@61..64#0#;#0:2@64..65#0#
-    (#0:2@74..75#0#(#0:2@75..76#0#1#0:2@76..77#0#,#0:2@77..78#0# )#0:2@78..79#0#,#0:2@79..80#0# )#0:2@80..81#0#.#0:2@81..82#0#0#0:2@82..85#0#.#0:2@82..85#0#0#0:2@82..85#0#;#0:2@85..86#0#
-    let#0:2@95..98#0# x#0:2@99..100#0# =#0:2@101..102#0# 1#0:2@103..104#0#;#0:2@104..105#0#
-}#0:2@110..111#0#
+fn#0:2@30..32#2# main#0:2@33..37#2#(#0:2@37..38#2#)#0:2@38..39#2# {#0:2@40..41#2#
+    1#0:2@50..51#2#;#0:2@51..52#2#
+    1.0#0:2@61..64#2#;#0:2@64..65#2#
+    (#0:2@74..75#2#(#0:2@75..76#2#1#0:2@76..77#2#,#0:2@77..78#2# )#0:2@78..79#2#,#0:2@79..80#2# )#0:2@80..81#2#.#0:2@81..82#2#0#0:2@82..85#2#.#0:2@82..85#2#0#0:2@82..85#2#;#0:2@85..86#2#
+    let#0:2@95..98#2# x#0:2@99..100#2# =#0:2@101..102#2# 1#0:2@103..104#2#;#0:2@104..105#2#
+}#0:2@110..111#2#
 
 
 "#]],
@@ -171,7 +171,7 @@ fn main(foo: ()) {
     }
 
     fn main(foo: ()) {
-        /* error: unresolved macro unresolved */"helloworld!"#0:3@236..321#0#;
+        /* error: unresolved macro unresolved */"helloworld!"#0:3@236..321#2#;
     }
 }
 
@@ -197,7 +197,7 @@ macro_rules! mk_struct {
 #[macro_use]
 mod foo;
 
-struct#1:1@59..65#1# Foo#0:2@32..35#0#(#1:1@70..71#1#u32#0:2@41..44#0#)#1:1@74..75#1#;#1:1@75..76#1#
+struct#1:1@59..65#4# Foo#0:2@32..35#2#(#1:1@70..71#4#u32#0:2@41..44#2#)#1:1@74..75#4#;#1:1@75..76#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#
 "#]],
     );
 }
diff --git a/crates/hir-def/src/macro_expansion_tests/mod.rs b/crates/hir-def/src/macro_expansion_tests/mod.rs
index 5b9ffdf37b..adcf278472 100644
--- a/crates/hir-def/src/macro_expansion_tests/mod.rs
+++ b/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() {
diff --git a/crates/hir-def/src/macro_expansion_tests/proc_macros.rs b/crates/hir-def/src/macro_expansion_tests/proc_macros.rs
index c0178adc9a..70e3e1ed4e 100644
--- a/crates/hir-def/src/macro_expansion_tests/proc_macros.rs
+++ b/crates/hir-def/src/macro_expansion_tests/proc_macros.rs
@@ -181,9 +181,9 @@ fn foo(&self) {
     self.0. 1;
 }
 
-fn#0:1@45..47#0# foo#0:1@48..51#0#(#0:1@51..52#0#&#0:1@52..53#0#self#0:1@53..57#0# )#0:1@57..58#0# {#0:1@59..60#0#
-    self#0:1@65..69#0# .#0:1@69..70#0#0#0:1@70..71#0#.#0:1@71..72#0#1#0:1@73..74#0#;#0:1@74..75#0#
-}#0:1@76..77#0#"#]],
+fn#0:1@45..47#2# foo#0:1@48..51#2#(#0:1@51..52#2#&#0:1@52..53#2#self#0:1@53..57#2# )#0:1@57..58#2# {#0:1@59..60#2#
+    self#0:1@65..69#2# .#0:1@69..70#2#0#0:1@70..71#2#.#0:1@71..72#2#1#0:1@73..74#2#;#0:1@74..75#2#
+}#0:1@76..77#2#"#]],
     );
 }
 
diff --git a/crates/hir-def/src/nameres/collector.rs b/crates/hir-def/src/nameres/collector.rs
index de76257587..988e5e83c8 100644
--- a/crates/hir-def/src/nameres/collector.rs
+++ b/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()
diff --git a/crates/hir-def/src/resolver.rs b/crates/hir-def/src/resolver.rs
index 82da57a9bb..df48ce6737 100644
--- a/crates/hir-def/src/resolver.rs
+++ b/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)
diff --git a/crates/hir-expand/src/builtin/derive_macro.rs b/crates/hir-expand/src/builtin/derive_macro.rs
index 4510a593af..28b6812139 100644
--- a/crates/hir-expand/src/builtin/derive_macro.rs
+++ b/crates/hir-expand/src/builtin/derive_macro.rs
@@ -4,7 +4,7 @@ use intern::sym;
 use itertools::{izip, Itertools};
 use parser::SyntaxKind;
 use rustc_hash::FxHashSet;
-use span::{MacroCallId, Span, SyntaxContextId};
+use span::{Edition, MacroCallId, Span, SyntaxContextId};
 use stdx::never;
 use syntax_bridge::DocCommentDesugarMode;
 use tracing::debug;
@@ -33,7 +33,7 @@ macro_rules! register_builtin {
         }
 
         impl BuiltinDeriveExpander {
-            pub fn expander(&self) -> fn(Span, &tt::TopSubtree) -> ExpandResult<tt::TopSubtree>  {
+            pub fn expander(&self) -> fn(&dyn ExpandDatabase, Span, &tt::TopSubtree) -> ExpandResult<tt::TopSubtree>  {
                 match *self {
                     $( BuiltinDeriveExpander::$trait => $expand, )*
                 }
@@ -58,8 +58,8 @@ impl BuiltinDeriveExpander {
         tt: &tt::TopSubtree,
         span: Span,
     ) -> ExpandResult<tt::TopSubtree> {
-        let span = span_with_def_site_ctxt(db, span, id);
-        self.expander()(span, tt)
+        let span = span_with_def_site_ctxt(db, span, id, Edition::CURRENT);
+        self.expander()(db, span, tt)
     }
 }
 
@@ -226,8 +226,12 @@ struct AdtParam {
 }
 
 // FIXME: This whole thing needs a refactor. Each derive requires its special values, and the result is a mess.
-fn parse_adt(tt: &tt::TopSubtree, call_site: Span) -> Result<BasicAdtInfo, ExpandError> {
-    let (adt, tm) = to_adt_syntax(tt, call_site)?;
+fn parse_adt(
+    db: &dyn ExpandDatabase,
+    tt: &tt::TopSubtree,
+    call_site: Span,
+) -> Result<BasicAdtInfo, ExpandError> {
+    let (adt, tm) = to_adt_syntax(db, tt, call_site)?;
     parse_adt_from_syntax(&adt, &tm, call_site)
 }
 
@@ -382,12 +386,14 @@ fn parse_adt_from_syntax(
 }
 
 fn to_adt_syntax(
+    db: &dyn ExpandDatabase,
     tt: &tt::TopSubtree,
     call_site: Span,
 ) -> Result<(ast::Adt, span::SpanMap<SyntaxContextId>), ExpandError> {
-    let (parsed, tm) = syntax_bridge::token_tree_to_syntax_node(
+    let (parsed, tm) = crate::db::token_tree_to_syntax_node(
+        db,
         tt,
-        syntax_bridge::TopEntryPoint::MacroItems,
+        crate::ExpandTo::Items,
         parser::Edition::CURRENT_FIXME,
     );
     let macro_items = ast::MacroItems::cast(parsed.syntax_node())
@@ -446,12 +452,13 @@ fn name_to_token(
 /// where B1, ..., BN are the bounds given by `bounds_paths`. Z is a phantom type, and
 /// therefore does not get bound by the derived trait.
 fn expand_simple_derive(
+    db: &dyn ExpandDatabase,
     invoc_span: Span,
     tt: &tt::TopSubtree,
     trait_path: tt::TopSubtree,
     make_trait_body: impl FnOnce(&BasicAdtInfo) -> tt::TopSubtree,
 ) -> ExpandResult<tt::TopSubtree> {
-    let info = match parse_adt(tt, invoc_span) {
+    let info = match parse_adt(db, tt, invoc_span) {
         Ok(info) => info,
         Err(e) => {
             return ExpandResult::new(
@@ -520,14 +527,22 @@ fn expand_simple_derive_with_parsed(
     }
 }
 
-fn copy_expand(span: Span, tt: &tt::TopSubtree) -> ExpandResult<tt::TopSubtree> {
+fn copy_expand(
+    db: &dyn ExpandDatabase,
+    span: Span,
+    tt: &tt::TopSubtree,
+) -> ExpandResult<tt::TopSubtree> {
     let krate = dollar_crate(span);
-    expand_simple_derive(span, tt, quote! {span => #krate::marker::Copy }, |_| quote! {span =>})
+    expand_simple_derive(db, span, tt, quote! {span => #krate::marker::Copy }, |_| quote! {span =>})
 }
 
-fn clone_expand(span: Span, tt: &tt::TopSubtree) -> ExpandResult<tt::TopSubtree> {
+fn clone_expand(
+    db: &dyn ExpandDatabase,
+    span: Span,
+    tt: &tt::TopSubtree,
+) -> ExpandResult<tt::TopSubtree> {
     let krate = dollar_crate(span);
-    expand_simple_derive(span, tt, quote! {span => #krate::clone::Clone }, |adt| {
+    expand_simple_derive(db, span, tt, quote! {span => #krate::clone::Clone }, |adt| {
         if matches!(adt.shape, AdtShape::Union) {
             let star = tt::Punct { char: '*', spacing: ::tt::Spacing::Alone, span };
             return quote! {span =>
@@ -576,9 +591,13 @@ fn and_and(span: Span) -> tt::TopSubtree {
     quote! {span => #and& }
 }
 
-fn default_expand(span: Span, tt: &tt::TopSubtree) -> ExpandResult<tt::TopSubtree> {
+fn default_expand(
+    db: &dyn ExpandDatabase,
+    span: Span,
+    tt: &tt::TopSubtree,
+) -> ExpandResult<tt::TopSubtree> {
     let krate = &dollar_crate(span);
-    expand_simple_derive(span, tt, quote! {span => #krate::default::Default }, |adt| {
+    expand_simple_derive(db, span, tt, quote! {span => #krate::default::Default }, |adt| {
         let body = match &adt.shape {
             AdtShape::Struct(fields) => {
                 let name = &adt.name;
@@ -615,9 +634,13 @@ fn default_expand(span: Span, tt: &tt::TopSubtree) -> ExpandResult<tt::TopSubtre
     })
 }
 
-fn debug_expand(span: Span, tt: &tt::TopSubtree) -> ExpandResult<tt::TopSubtree> {
+fn debug_expand(
+    db: &dyn ExpandDatabase,
+    span: Span,
+    tt: &tt::TopSubtree,
+) -> ExpandResult<tt::TopSubtree> {
     let krate = &dollar_crate(span);
-    expand_simple_derive(span, tt, quote! {span => #krate::fmt::Debug }, |adt| {
+    expand_simple_derive(db, span, tt, quote! {span => #krate::fmt::Debug }, |adt| {
         let for_variant = |name: String, v: &VariantShape| match v {
             VariantShape::Struct(fields) => {
                 let for_fields = fields.iter().map(|it| {
@@ -687,9 +710,13 @@ fn debug_expand(span: Span, tt: &tt::TopSubtree) -> ExpandResult<tt::TopSubtree>
     })
 }
 
-fn hash_expand(span: Span, tt: &tt::TopSubtree) -> ExpandResult<tt::TopSubtree> {
+fn hash_expand(
+    db: &dyn ExpandDatabase,
+    span: Span,
+    tt: &tt::TopSubtree,
+) -> ExpandResult<tt::TopSubtree> {
     let krate = &dollar_crate(span);
-    expand_simple_derive(span, tt, quote! {span => #krate::hash::Hash }, |adt| {
+    expand_simple_derive(db, span, tt, quote! {span => #krate::hash::Hash }, |adt| {
         if matches!(adt.shape, AdtShape::Union) {
             // FIXME: Return expand error here
             return quote! {span =>};
@@ -734,14 +761,22 @@ fn hash_expand(span: Span, tt: &tt::TopSubtree) -> ExpandResult<tt::TopSubtree>
     })
 }
 
-fn eq_expand(span: Span, tt: &tt::TopSubtree) -> ExpandResult<tt::TopSubtree> {
+fn eq_expand(
+    db: &dyn ExpandDatabase,
+    span: Span,
+    tt: &tt::TopSubtree,
+) -> ExpandResult<tt::TopSubtree> {
     let krate = dollar_crate(span);
-    expand_simple_derive(span, tt, quote! {span => #krate::cmp::Eq }, |_| quote! {span =>})
+    expand_simple_derive(db, span, tt, quote! {span => #krate::cmp::Eq }, |_| quote! {span =>})
 }
 
-fn partial_eq_expand(span: Span, tt: &tt::TopSubtree) -> ExpandResult<tt::TopSubtree> {
+fn partial_eq_expand(
+    db: &dyn ExpandDatabase,
+    span: Span,
+    tt: &tt::TopSubtree,
+) -> ExpandResult<tt::TopSubtree> {
     let krate = dollar_crate(span);
-    expand_simple_derive(span, tt, quote! {span => #krate::cmp::PartialEq }, |adt| {
+    expand_simple_derive(db, span, tt, quote! {span => #krate::cmp::PartialEq }, |adt| {
         if matches!(adt.shape, AdtShape::Union) {
             // FIXME: Return expand error here
             return quote! {span =>};
@@ -811,9 +846,13 @@ fn self_and_other_patterns(
     (self_patterns, other_patterns)
 }
 
-fn ord_expand(span: Span, tt: &tt::TopSubtree) -> ExpandResult<tt::TopSubtree> {
+fn ord_expand(
+    db: &dyn ExpandDatabase,
+    span: Span,
+    tt: &tt::TopSubtree,
+) -> ExpandResult<tt::TopSubtree> {
     let krate = &dollar_crate(span);
-    expand_simple_derive(span, tt, quote! {span => #krate::cmp::Ord }, |adt| {
+    expand_simple_derive(db, span, tt, quote! {span => #krate::cmp::Ord }, |adt| {
         fn compare(
             krate: &tt::Ident,
             left: tt::TopSubtree,
@@ -869,9 +908,13 @@ fn ord_expand(span: Span, tt: &tt::TopSubtree) -> ExpandResult<tt::TopSubtree> {
     })
 }
 
-fn partial_ord_expand(span: Span, tt: &tt::TopSubtree) -> ExpandResult<tt::TopSubtree> {
+fn partial_ord_expand(
+    db: &dyn ExpandDatabase,
+    span: Span,
+    tt: &tt::TopSubtree,
+) -> ExpandResult<tt::TopSubtree> {
     let krate = &dollar_crate(span);
-    expand_simple_derive(span, tt, quote! {span => #krate::cmp::PartialOrd }, |adt| {
+    expand_simple_derive(db, span, tt, quote! {span => #krate::cmp::PartialOrd }, |adt| {
         fn compare(
             krate: &tt::Ident,
             left: tt::TopSubtree,
@@ -932,8 +975,12 @@ fn partial_ord_expand(span: Span, tt: &tt::TopSubtree) -> ExpandResult<tt::TopSu
     })
 }
 
-fn coerce_pointee_expand(span: Span, tt: &tt::TopSubtree) -> ExpandResult<tt::TopSubtree> {
-    let (adt, _span_map) = match to_adt_syntax(tt, span) {
+fn coerce_pointee_expand(
+    db: &dyn ExpandDatabase,
+    span: Span,
+    tt: &tt::TopSubtree,
+) -> ExpandResult<tt::TopSubtree> {
+    let (adt, _span_map) = match to_adt_syntax(db, tt, span) {
         Ok(it) => it,
         Err(err) => {
             return ExpandResult::new(tt::TopSubtree::empty(tt::DelimSpan::from_single(span)), err);
diff --git a/crates/hir-expand/src/builtin/fn_macro.rs b/crates/hir-expand/src/builtin/fn_macro.rs
index 5b06de9875..310ddaaf9e 100644
--- a/crates/hir-expand/src/builtin/fn_macro.rs
+++ b/crates/hir-expand/src/builtin/fn_macro.rs
@@ -69,7 +69,7 @@ impl BuiltinFnLikeExpander {
         tt: &tt::TopSubtree,
         span: Span,
     ) -> ExpandResult<tt::TopSubtree> {
-        let span = span_with_def_site_ctxt(db, span, id);
+        let span = span_with_def_site_ctxt(db, span, id, Edition::CURRENT);
         self.expander()(db, id, tt, span)
     }
 
@@ -86,7 +86,7 @@ impl EagerExpander {
         tt: &tt::TopSubtree,
         span: Span,
     ) -> ExpandResult<tt::TopSubtree> {
-        let span = span_with_def_site_ctxt(db, span, id);
+        let span = span_with_def_site_ctxt(db, span, id, Edition::CURRENT);
         self.expander()(db, id, tt, span)
     }
 
@@ -221,7 +221,7 @@ fn assert_expand(
     tt: &tt::TopSubtree,
     span: Span,
 ) -> ExpandResult<tt::TopSubtree> {
-    let call_site_span = span_with_call_site_ctxt(db, span, id);
+    let call_site_span = span_with_call_site_ctxt(db, span, id, Edition::CURRENT);
 
     let mut iter = tt.iter();
 
@@ -342,7 +342,7 @@ fn panic_expand(
     span: Span,
 ) -> ExpandResult<tt::TopSubtree> {
     let dollar_crate = dollar_crate(span);
-    let call_site_span = span_with_call_site_ctxt(db, span, id);
+    let call_site_span = span_with_call_site_ctxt(db, span, id, Edition::CURRENT);
 
     let mac = if use_panic_2021(db, call_site_span) {
         sym::panic_2021.clone()
@@ -373,7 +373,7 @@ fn unreachable_expand(
     span: Span,
 ) -> ExpandResult<tt::TopSubtree> {
     let dollar_crate = dollar_crate(span);
-    let call_site_span = span_with_call_site_ctxt(db, span, id);
+    let call_site_span = span_with_call_site_ctxt(db, span, id, Edition::CURRENT);
 
     let mac = if use_panic_2021(db, call_site_span) {
         sym::unreachable_2021.clone()
diff --git a/crates/hir-expand/src/builtin/quote.rs b/crates/hir-expand/src/builtin/quote.rs
index 6c1abc2620..fcd242bb49 100644
--- a/crates/hir-expand/src/builtin/quote.rs
+++ b/crates/hir-expand/src/builtin/quote.rs
@@ -225,7 +225,7 @@ mod tests {
     use ::tt::IdentIsRaw;
     use expect_test::expect;
     use intern::Symbol;
-    use span::{SpanAnchor, SyntaxContextId, ROOT_ERASED_FILE_AST_ID};
+    use span::{Edition, SpanAnchor, SyntaxContextId, ROOT_ERASED_FILE_AST_ID};
     use syntax::{TextRange, TextSize};
 
     use super::quote;
@@ -239,7 +239,7 @@ mod tests {
             ),
             ast_id: ROOT_ERASED_FILE_AST_ID,
         },
-        ctx: SyntaxContextId::ROOT,
+        ctx: SyntaxContextId::root(Edition::CURRENT),
     };
 
     #[test]
@@ -276,8 +276,8 @@ mod tests {
         assert_eq!(quoted.to_string(), "hello");
         let t = format!("{quoted:#?}");
         expect![[r#"
-            SUBTREE $$ 937550:0@0..0#0 937550:0@0..0#0
-              IDENT   hello 937550:0@0..0#0"#]]
+            SUBTREE $$ 937550:0@0..0#2 937550:0@0..0#2
+              IDENT   hello 937550:0@0..0#2"#]]
         .assert_eq(&t);
     }
 
diff --git a/crates/hir-expand/src/db.rs b/crates/hir-expand/src/db.rs
index f4e80ef9e2..b7804f888a 100644
--- a/crates/hir-expand/src/db.rs
+++ b/crates/hir-expand/src/db.rs
@@ -5,7 +5,7 @@ use either::Either;
 use limit::Limit;
 use mbe::MatchedArmIndex;
 use rustc_hash::FxHashSet;
-use span::{AstIdMap, EditionedFileId, Span, SyntaxContextData, SyntaxContextId};
+use span::{AstIdMap, Edition, EditionedFileId, Span, SyntaxContextData, SyntaxContextId};
 use syntax::{ast, AstNode, Parse, SyntaxElement, SyntaxError, SyntaxNode, SyntaxToken, T};
 use syntax_bridge::{syntax_node_to_token_tree, DocCommentDesugarMode};
 use triomphe::Arc;
@@ -136,12 +136,12 @@ pub trait ExpandDatabase: SourceDatabase {
         macro_call: MacroCallId,
     ) -> Option<Arc<ExpandResult<Arc<[SyntaxError]>>>>;
     #[ra_salsa::transparent]
-    fn syntax_context(&self, file: HirFileId) -> SyntaxContextId;
+    fn syntax_context(&self, file: HirFileId, edition: Edition) -> SyntaxContextId;
 }
 
-fn syntax_context(db: &dyn ExpandDatabase, file: HirFileId) -> SyntaxContextId {
+fn syntax_context(db: &dyn ExpandDatabase, file: HirFileId, edition: Edition) -> SyntaxContextId {
     match file.repr() {
-        HirFileIdRepr::FileId(_) => SyntaxContextId::ROOT,
+        HirFileIdRepr::FileId(_) => SyntaxContextId::root(edition),
         HirFileIdRepr::MacroFile(m) => {
             db.macro_arg_considering_derives(m.macro_call_id, &m.macro_call_id.lookup(db).kind)
                 .2
@@ -273,9 +273,9 @@ pub fn expand_speculative(
                 loc.krate,
                 &tt,
                 attr_arg.as_ref(),
-                span_with_def_site_ctxt(db, span, actual_macro_call),
-                span_with_call_site_ctxt(db, span, actual_macro_call),
-                span_with_mixed_site_ctxt(db, span, actual_macro_call),
+                span_with_def_site_ctxt(db, span, actual_macro_call, loc.def.edition),
+                span_with_call_site_ctxt(db, span, actual_macro_call, loc.def.edition),
+                span_with_mixed_site_ctxt(db, span, actual_macro_call, loc.def.edition),
             )
         }
         MacroDefKind::BuiltInAttr(_, it) if it.is_derive() => {
@@ -300,7 +300,7 @@ pub fn expand_speculative(
 
     fixup::reverse_fixups(&mut speculative_expansion.value, &undo_info);
     let (node, rev_tmap) =
-        token_tree_to_syntax_node(&speculative_expansion.value, expand_to, loc.def.edition);
+        token_tree_to_syntax_node(db, &speculative_expansion.value, expand_to, loc.def.edition);
 
     let syntax_node = node.syntax_node();
     let token = rev_tmap
@@ -346,6 +346,7 @@ fn parse_macro_expansion(
         macro_expand(db, macro_file.macro_call_id, loc);
 
     let (parse, mut rev_token_map) = token_tree_to_syntax_node(
+        db,
         match &tt {
             CowArc::Arc(it) => it,
             CowArc::Owned(it) => it,
@@ -699,9 +700,9 @@ fn expand_proc_macro(
             loc.krate,
             &macro_arg,
             attr_arg,
-            span_with_def_site_ctxt(db, span, id),
-            span_with_call_site_ctxt(db, span, id),
-            span_with_mixed_site_ctxt(db, span, id),
+            span_with_def_site_ctxt(db, span, id, loc.def.edition),
+            span_with_call_site_ctxt(db, span, id, loc.def.edition),
+            span_with_mixed_site_ctxt(db, span, id, loc.def.edition),
         )
     };
 
@@ -715,7 +716,8 @@ fn expand_proc_macro(
     ExpandResult { value: Arc::new(tt), err }
 }
 
-fn token_tree_to_syntax_node(
+pub(crate) fn token_tree_to_syntax_node(
+    db: &dyn ExpandDatabase,
     tt: &tt::TopSubtree,
     expand_to: ExpandTo,
     edition: parser::Edition,
@@ -727,7 +729,12 @@ fn token_tree_to_syntax_node(
         ExpandTo::Type => syntax_bridge::TopEntryPoint::Type,
         ExpandTo::Expr => syntax_bridge::TopEntryPoint::Expr,
     };
-    syntax_bridge::token_tree_to_syntax_node(tt, entry_point, edition)
+    syntax_bridge::token_tree_to_syntax_node(
+        tt,
+        entry_point,
+        &mut |ctx| ctx.lookup(db).edition,
+        edition,
+    )
 }
 
 fn check_tt_count(tt: &tt::TopSubtree) -> Result<(), ExpandResult<()>> {
@@ -751,5 +758,7 @@ fn check_tt_count(tt: &tt::TopSubtree) -> Result<(), ExpandResult<()>> {
 }
 
 fn setup_syntax_context_root(db: &dyn ExpandDatabase) {
-    db.intern_syntax_context(SyntaxContextData::root());
+    for edition in Edition::iter() {
+        db.intern_syntax_context(SyntaxContextData::root(edition));
+    }
 }
diff --git a/crates/hir-expand/src/declarative.rs b/crates/hir-expand/src/declarative.rs
index d1c39f32ca..fef77acb7b 100644
--- a/crates/hir-expand/src/declarative.rs
+++ b/crates/hir-expand/src/declarative.rs
@@ -2,7 +2,7 @@
 
 use base_db::CrateId;
 use intern::sym;
-use span::{Edition, MacroCallId, Span, SyntaxContextId};
+use span::{Edition, HirFileIdRepr, MacroCallId, Span, SyntaxContextId};
 use stdx::TupleExt;
 use syntax::{ast, AstNode};
 use syntax_bridge::DocCommentDesugarMode;
@@ -20,6 +20,7 @@ use crate::{
 pub struct DeclarativeMacroExpander {
     pub mac: mbe::DeclarativeMacro,
     pub transparency: Transparency,
+    edition: Edition,
 }
 
 impl DeclarativeMacroExpander {
@@ -40,7 +41,7 @@ impl DeclarativeMacroExpander {
                 .mac
                 .expand(
                     &tt,
-                    |s| s.ctx = apply_mark(db, s.ctx, call_id, self.transparency),
+                    |s| s.ctx = apply_mark(db, s.ctx, call_id, self.transparency, self.edition),
                     span,
                     loc.def.edition,
                 )
@@ -159,6 +160,10 @@ impl DeclarativeMacroExpander {
                 transparency(&macro_def).unwrap_or(Transparency::Opaque),
             ),
         };
-        Arc::new(DeclarativeMacroExpander { mac, transparency })
+        let edition = ctx_edition(match id.file_id.repr() {
+            HirFileIdRepr::MacroFile(macro_file) => macro_file.macro_call_id.lookup(db).ctxt,
+            HirFileIdRepr::FileId(file) => SyntaxContextId::root(file.edition()),
+        });
+        Arc::new(DeclarativeMacroExpander { mac, transparency, edition })
     }
 }
diff --git a/crates/hir-expand/src/files.rs b/crates/hir-expand/src/files.rs
index 8c04d05402..13ddb0d4ac 100644
--- a/crates/hir-expand/src/files.rs
+++ b/crates/hir-expand/src/files.rs
@@ -380,14 +380,14 @@ impl InFile<TextRange> {
     ) -> (FileRange, SyntaxContextId) {
         match self.file_id.repr() {
             HirFileIdRepr::FileId(file_id) => {
-                (FileRange { file_id, range: self.value }, SyntaxContextId::ROOT)
+                (FileRange { file_id, range: self.value }, SyntaxContextId::root(file_id.edition()))
             }
             HirFileIdRepr::MacroFile(mac_file) => {
                 match map_node_range_up(db, &db.expansion_span_map(mac_file), self.value) {
                     Some(it) => it,
                     None => {
                         let loc = db.lookup_intern_macro_call(mac_file.macro_call_id);
-                        (loc.kind.original_call_range(db), SyntaxContextId::ROOT)
+                        (loc.kind.original_call_range(db), SyntaxContextId::root(loc.def.edition))
                     }
                 }
             }
@@ -432,9 +432,10 @@ impl InFile<TextRange> {
         db: &dyn db::ExpandDatabase,
     ) -> Option<(FileRange, SyntaxContextId)> {
         match self.file_id.repr() {
-            HirFileIdRepr::FileId(file_id) => {
-                Some((FileRange { file_id, range: self.value }, SyntaxContextId::ROOT))
-            }
+            HirFileIdRepr::FileId(file_id) => Some((
+                FileRange { file_id, range: self.value },
+                SyntaxContextId::root(file_id.edition()),
+            )),
             HirFileIdRepr::MacroFile(mac_file) => {
                 map_node_range_up(db, &db.expansion_span_map(mac_file), self.value)
             }
diff --git a/crates/hir-expand/src/fixup.rs b/crates/hir-expand/src/fixup.rs
index 90012dd1f7..00fad67578 100644
--- a/crates/hir-expand/src/fixup.rs
+++ b/crates/hir-expand/src/fixup.rs
@@ -380,7 +380,7 @@ pub(crate) fn reverse_fixups(tt: &mut TopSubtree, undo_info: &SyntaxFixupUndoInf
         let span = |file_id| Span {
             range: TextRange::empty(TextSize::new(0)),
             anchor: SpanAnchor { file_id, ast_id: ROOT_ERASED_FILE_AST_ID },
-            ctx: SyntaxContextId::ROOT,
+            ctx: SyntaxContextId::root(span::Edition::Edition2015),
         };
         delimiter.open = span(delimiter.open.anchor.file_id);
         delimiter.close = span(delimiter.close.anchor.file_id);
@@ -554,6 +554,7 @@ mod tests {
         let (parse, _) = syntax_bridge::token_tree_to_syntax_node(
             &tt,
             syntax_bridge::TopEntryPoint::MacroItems,
+            &mut |_| parser::Edition::CURRENT,
             parser::Edition::CURRENT,
         );
         assert!(
diff --git a/crates/hir-expand/src/hygiene.rs b/crates/hir-expand/src/hygiene.rs
index f48de807c2..fe05af0ac9 100644
--- a/crates/hir-expand/src/hygiene.rs
+++ b/crates/hir-expand/src/hygiene.rs
@@ -24,26 +24,37 @@
 
 use std::iter;
 
-use span::{MacroCallId, Span, SyntaxContextData, SyntaxContextId};
+use span::{Edition, MacroCallId, Span, SyntaxContextData, SyntaxContextId};
 
 use crate::db::{ExpandDatabase, InternSyntaxContextQuery};
 
 pub use span::Transparency;
 
-pub fn span_with_def_site_ctxt(db: &dyn ExpandDatabase, span: Span, expn_id: MacroCallId) -> Span {
-    span_with_ctxt_from_mark(db, span, expn_id, Transparency::Opaque)
+pub fn span_with_def_site_ctxt(
+    db: &dyn ExpandDatabase,
+    span: Span,
+    expn_id: MacroCallId,
+    edition: Edition,
+) -> Span {
+    span_with_ctxt_from_mark(db, span, expn_id, Transparency::Opaque, edition)
 }
 
-pub fn span_with_call_site_ctxt(db: &dyn ExpandDatabase, span: Span, expn_id: MacroCallId) -> Span {
-    span_with_ctxt_from_mark(db, span, expn_id, Transparency::Transparent)
+pub fn span_with_call_site_ctxt(
+    db: &dyn ExpandDatabase,
+    span: Span,
+    expn_id: MacroCallId,
+    edition: Edition,
+) -> Span {
+    span_with_ctxt_from_mark(db, span, expn_id, Transparency::Transparent, edition)
 }
 
 pub fn span_with_mixed_site_ctxt(
     db: &dyn ExpandDatabase,
     span: Span,
     expn_id: MacroCallId,
+    edition: Edition,
 ) -> Span {
-    span_with_ctxt_from_mark(db, span, expn_id, Transparency::SemiTransparent)
+    span_with_ctxt_from_mark(db, span, expn_id, Transparency::SemiTransparent, edition)
 }
 
 fn span_with_ctxt_from_mark(
@@ -51,8 +62,12 @@ fn span_with_ctxt_from_mark(
     span: Span,
     expn_id: MacroCallId,
     transparency: Transparency,
+    edition: Edition,
 ) -> Span {
-    Span { ctx: apply_mark(db, SyntaxContextId::ROOT, expn_id, transparency), ..span }
+    Span {
+        ctx: apply_mark(db, SyntaxContextId::root(edition), expn_id, transparency, edition),
+        ..span
+    }
 }
 
 pub(super) fn apply_mark(
@@ -60,9 +75,10 @@ pub(super) fn apply_mark(
     ctxt: SyntaxContextId,
     call_id: MacroCallId,
     transparency: Transparency,
+    edition: Edition,
 ) -> SyntaxContextId {
     if transparency == Transparency::Opaque {
-        return apply_mark_internal(db, ctxt, call_id, transparency);
+        return apply_mark_internal(db, ctxt, call_id, transparency, edition);
     }
 
     let call_site_ctxt = db.lookup_intern_macro_call(call_id).ctxt;
@@ -73,7 +89,7 @@ pub(super) fn apply_mark(
     };
 
     if call_site_ctxt.is_root() {
-        return apply_mark_internal(db, ctxt, call_id, transparency);
+        return apply_mark_internal(db, ctxt, call_id, transparency, edition);
     }
 
     // Otherwise, `expn_id` is a macros 1.0 definition and the call site is in a
@@ -86,9 +102,9 @@ pub(super) fn apply_mark(
     //
     // See the example at `test/ui/hygiene/legacy_interaction.rs`.
     for (call_id, transparency) in ctxt.marks(db) {
-        call_site_ctxt = apply_mark_internal(db, call_site_ctxt, call_id, transparency);
+        call_site_ctxt = apply_mark_internal(db, call_site_ctxt, call_id, transparency, edition);
     }
-    apply_mark_internal(db, call_site_ctxt, call_id, transparency)
+    apply_mark_internal(db, call_site_ctxt, call_id, transparency, edition)
 }
 
 fn apply_mark_internal(
@@ -96,6 +112,7 @@ fn apply_mark_internal(
     ctxt: SyntaxContextId,
     call_id: MacroCallId,
     transparency: Transparency,
+    edition: Edition,
 ) -> SyntaxContextId {
     use base_db::ra_salsa;
 
@@ -108,13 +125,14 @@ fn apply_mark_internal(
     if transparency >= Transparency::Opaque {
         let parent = opaque;
         opaque = ra_salsa::plumbing::get_query_table::<InternSyntaxContextQuery>(db).get_or_insert(
-            (parent, call_id, transparency),
+            (parent, call_id, transparency, edition),
             |new_opaque| SyntaxContextData {
                 outer_expn: call_id,
                 outer_transparency: transparency,
                 parent,
                 opaque: new_opaque,
                 opaque_and_semitransparent: new_opaque,
+                edition,
             },
         );
     }
@@ -123,13 +141,14 @@ fn apply_mark_internal(
         let parent = opaque_and_semitransparent;
         opaque_and_semitransparent =
             ra_salsa::plumbing::get_query_table::<InternSyntaxContextQuery>(db).get_or_insert(
-                (parent, call_id, transparency),
+                (parent, call_id, transparency, edition),
                 |new_opaque_and_semitransparent| SyntaxContextData {
                     outer_expn: call_id,
                     outer_transparency: transparency,
                     parent,
                     opaque,
                     opaque_and_semitransparent: new_opaque_and_semitransparent,
+                    edition,
                 },
             );
     }
@@ -141,6 +160,7 @@ fn apply_mark_internal(
         parent,
         opaque,
         opaque_and_semitransparent,
+        edition,
     })
 }
 
diff --git a/crates/hir-expand/src/mod_path.rs b/crates/hir-expand/src/mod_path.rs
index 7ecf521987..876919f3ed 100644
--- a/crates/hir-expand/src/mod_path.rs
+++ b/crates/hir-expand/src/mod_path.rs
@@ -273,10 +273,9 @@ fn convert_path(
                 res
             }
         }
-        ast::PathSegmentKind::SelfTypeKw => ModPath::from_segments(
-            PathKind::Plain,
-            Some(Name::new_symbol(sym::Self_.clone(), SyntaxContextId::ROOT)),
-        ),
+        ast::PathSegmentKind::SelfTypeKw => {
+            ModPath::from_segments(PathKind::Plain, Some(Name::new_symbol_root(sym::Self_.clone())))
+        }
         ast::PathSegmentKind::CrateKw => ModPath::from_segments(PathKind::Crate, iter::empty()),
         ast::PathSegmentKind::SelfKw => handle_super_kw(0)?,
         ast::PathSegmentKind::SuperKw => handle_super_kw(1)?,
diff --git a/crates/hir-expand/src/name.rs b/crates/hir-expand/src/name.rs
index 267d545833..54a61a096d 100644
--- a/crates/hir-expand/src/name.rs
+++ b/crates/hir-expand/src/name.rs
@@ -80,11 +80,20 @@ impl Name {
         Name { symbol: Symbol::intern(text), ctx: () }
     }
 
-    pub fn new(text: &str, ctx: SyntaxContextId) -> Name {
+    pub fn new(text: &str, mut ctx: SyntaxContextId) -> Name {
+        // For comparisons etc. we remove the edition, because sometimes we search for some `Name`
+        // and we don't know which edition it came from.
+        // Can't do that for all `SyntaxContextId`s because it breaks Salsa.
+        ctx.remove_root_edition();
         _ = ctx;
         Self::new_text(text)
     }
 
+    pub fn new_root(text: &str) -> Name {
+        // The edition doesn't matter for hygiene.
+        Self::new(text, SyntaxContextId::root(Edition::Edition2015))
+    }
+
     pub fn new_tuple_field(idx: usize) -> Name {
         Name { symbol: Symbol::intern(&idx.to_string()), ctx: () }
     }
diff --git a/crates/hir/src/attrs.rs b/crates/hir/src/attrs.rs
index a23fdf1b39..01cb040bdf 100644
--- a/crates/hir/src/attrs.rs
+++ b/crates/hir/src/attrs.rs
@@ -12,7 +12,6 @@ use hir_def::{
 };
 use hir_expand::{mod_path::PathKind, name::Name};
 use hir_ty::{db::HirDatabase, method_resolution};
-use span::SyntaxContextId;
 
 use crate::{
     Adt, AsAssocItem, AssocItem, BuiltinType, Const, ConstParam, DocLinkDef, Enum, ExternCrateDecl,
@@ -328,9 +327,7 @@ fn doc_modpath_from_str(link: &str) -> Option<ModPath> {
         };
         let parts = first_segment.into_iter().chain(parts).map(|segment| match segment.parse() {
             Ok(idx) => Name::new_tuple_field(idx),
-            Err(_) => {
-                Name::new(segment.split_once('<').map_or(segment, |it| it.0), SyntaxContextId::ROOT)
-            }
+            Err(_) => Name::new_root(segment.split_once('<').map_or(segment, |it| it.0)),
         });
         Some(ModPath::from_segments(kind, parts))
     };
diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index fe4b255d3c..ac109be5ef 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -83,7 +83,7 @@ use itertools::Itertools;
 use nameres::diagnostics::DefDiagnosticKind;
 use rustc_hash::FxHashSet;
 use smallvec::SmallVec;
-use span::{Edition, EditionedFileId, FileId, MacroCallId, SyntaxContextId};
+use span::{Edition, EditionedFileId, FileId, MacroCallId};
 use stdx::{format_to, impl_from, never};
 use syntax::{
     ast::{self, HasAttrs as _, HasGenericParams, HasName},
@@ -4824,7 +4824,7 @@ impl Type {
         let iterator_trait = db.lang_item(self.env.krate, LangItem::Iterator)?.as_trait()?;
         let iterator_item = db
             .trait_data(iterator_trait)
-            .associated_type_by_name(&Name::new_symbol(sym::Item.clone(), SyntaxContextId::ROOT))?;
+            .associated_type_by_name(&Name::new_symbol_root(sym::Item.clone()))?;
         self.normalize_trait_assoc_type(db, &[], iterator_item.into())
     }
 
diff --git a/crates/hir/src/semantics.rs b/crates/hir/src/semantics.rs
index 7f44f396bf..7414735016 100644
--- a/crates/hir/src/semantics.rs
+++ b/crates/hir/src/semantics.rs
@@ -959,7 +959,10 @@ impl<'db> SemanticsImpl<'db> {
                 process_expansion_for_token(&mut stack, include)?;
             }
             None => {
-                stack.push((file_id.into(), smallvec![(token, SyntaxContextId::ROOT)]));
+                stack.push((
+                    file_id.into(),
+                    smallvec![(token, SyntaxContextId::root(file_id.edition()))],
+                ));
             }
         }
 
@@ -1571,7 +1574,7 @@ impl<'db> SemanticsImpl<'db> {
             self.db.upcast(),
             &ModPath::from_segments(
                 hir_def::path::PathKind::Plain,
-                segments.into_iter().map(|it| Name::new(&it, SyntaxContextId::ROOT)),
+                segments.into_iter().map(|it| Name::new_root(&it)),
             ),
         );
         Some(items.iter_items().map(|(item, _)| item.into()))
diff --git a/crates/ide-diagnostics/src/handlers/no_such_field.rs b/crates/ide-diagnostics/src/handlers/no_such_field.rs
index e5d871975b..0f126a1a65 100644
--- a/crates/ide-diagnostics/src/handlers/no_such_field.rs
+++ b/crates/ide-diagnostics/src/handlers/no_such_field.rs
@@ -399,4 +399,38 @@ fn f(s@m::Struct {
 "#,
         )
     }
+
+    #[test]
+    fn editions_between_macros() {
+        check_diagnostics(
+            r#"
+//- /edition2015.rs crate:edition2015 edition:2015
+#[macro_export]
+macro_rules! pass_expr_thorough {
+    ($e:expr) => { $e };
+}
+
+//- /edition2018.rs crate:edition2018 deps:edition2015 edition:2018
+async fn bar() {}
+async fn foo() {
+    edition2015::pass_expr_thorough!(bar().await);
+}
+        "#,
+        );
+        check_diagnostics(
+            r#"
+//- /edition2018.rs crate:edition2018 edition:2018
+pub async fn bar() {}
+#[macro_export]
+macro_rules! make_await {
+    () => { async { $crate::bar().await }; };
+}
+
+//- /edition2015.rs crate:edition2015 deps:edition2018 edition:2015
+fn foo() {
+    edition2018::make_await!();
+}
+        "#,
+        );
+    }
 }
diff --git a/crates/mbe/src/lib.rs b/crates/mbe/src/lib.rs
index 6abf56d4b3..bebd29ef74 100644
--- a/crates/mbe/src/lib.rs
+++ b/crates/mbe/src/lib.rs
@@ -369,7 +369,8 @@ pub fn expect_fragment<'t>(
 ) -> ExpandResult<tt::TokenTreesView<'t, Span>> {
     use ::parser;
     let buffer = tt_iter.remaining();
-    let parser_input = to_parser_input(edition, buffer);
+    // FIXME: Pass the correct edition per token. Due to the split between mbe and hir-expand it's complicated.
+    let parser_input = to_parser_input(buffer, &mut |_ctx| edition);
     let tree_traversal = entry_point.parse(&parser_input, edition);
     let mut cursor = buffer.cursor();
     let mut error = false;
diff --git a/crates/mbe/src/tests.rs b/crates/mbe/src/tests.rs
index e63ad113ff..fb68d35a4c 100644
--- a/crates/mbe/src/tests.rs
+++ b/crates/mbe/src/tests.rs
@@ -26,7 +26,7 @@ fn check_(
             file_id: EditionedFileId::new(FileId::from_raw(0), def_edition),
             ast_id: ErasedFileAstId::from_raw(0),
         },
-        SyntaxContextId::ROOT,
+        SyntaxContextId::root(Edition::CURRENT),
         decl,
     )
     .unwrap();
@@ -39,16 +39,20 @@ fn check_(
         file_id: EditionedFileId::new(FileId::from_raw(1), call_edition),
         ast_id: ErasedFileAstId::from_raw(0),
     };
-    let arg_tt =
-        syntax_bridge::parse_to_token_tree(call_edition, call_anchor, SyntaxContextId::ROOT, arg)
-            .unwrap();
+    let arg_tt = syntax_bridge::parse_to_token_tree(
+        call_edition,
+        call_anchor,
+        SyntaxContextId::root(Edition::CURRENT),
+        arg,
+    )
+    .unwrap();
     let res = mac.expand(
         &arg_tt,
         |_| (),
         Span {
             range: TextRange::up_to(TextSize::of(arg)),
             anchor: call_anchor,
-            ctx: SyntaxContextId::ROOT,
+            ctx: SyntaxContextId::root(Edition::CURRENT),
         },
         def_edition,
     );
@@ -59,7 +63,12 @@ fn check_(
     if render_debug {
         format_to!(expect_res, "{:#?}\n\n", res.value.0);
     }
-    let (node, _) = syntax_bridge::token_tree_to_syntax_node(&res.value.0, parse, def_edition);
+    let (node, _) = syntax_bridge::token_tree_to_syntax_node(
+        &res.value.0,
+        parse,
+        &mut |_| def_edition,
+        def_edition,
+    );
     format_to!(
         expect_res,
         "{}",
@@ -106,25 +115,25 @@ fn token_mapping_smoke_test() {
 struct MyTraitMap2
 "#,
         expect![[r#"
-            SUBTREE $$ 1:0@0..20#0 1:0@0..20#0
-              IDENT   struct 0:0@34..40#0
-              IDENT   MyTraitMap2 1:0@8..19#0
-              SUBTREE {} 0:0@48..49#0 0:0@100..101#0
-                IDENT   map 0:0@58..61#0
-                PUNCH   : [alone] 0:0@61..62#0
-                PUNCH   : [joint] 0:0@63..64#0
-                PUNCH   : [alone] 0:0@64..65#0
-                IDENT   std 0:0@65..68#0
-                PUNCH   : [joint] 0:0@68..69#0
-                PUNCH   : [alone] 0:0@69..70#0
-                IDENT   collections 0:0@70..81#0
-                PUNCH   : [joint] 0:0@81..82#0
-                PUNCH   : [alone] 0:0@82..83#0
-                IDENT   HashSet 0:0@83..90#0
-                PUNCH   < [alone] 0:0@90..91#0
-                SUBTREE () 0:0@91..92#0 0:0@92..93#0
-                PUNCH   > [joint] 0:0@93..94#0
-                PUNCH   , [alone] 0:0@94..95#0
+            SUBTREE $$ 1:0@0..20#2 1:0@0..20#2
+              IDENT   struct 0:0@34..40#2
+              IDENT   MyTraitMap2 1:0@8..19#2
+              SUBTREE {} 0:0@48..49#2 0:0@100..101#2
+                IDENT   map 0:0@58..61#2
+                PUNCH   : [alone] 0:0@61..62#2
+                PUNCH   : [joint] 0:0@63..64#2
+                PUNCH   : [alone] 0:0@64..65#2
+                IDENT   std 0:0@65..68#2
+                PUNCH   : [joint] 0:0@68..69#2
+                PUNCH   : [alone] 0:0@69..70#2
+                IDENT   collections 0:0@70..81#2
+                PUNCH   : [joint] 0:0@81..82#2
+                PUNCH   : [alone] 0:0@82..83#2
+                IDENT   HashSet 0:0@83..90#2
+                PUNCH   < [alone] 0:0@90..91#2
+                SUBTREE () 0:0@91..92#2 0:0@92..93#2
+                PUNCH   > [joint] 0:0@93..94#2
+                PUNCH   , [alone] 0:0@94..95#2
 
             struct MyTraitMap2 {
                 map: ::std::collections::HashSet<()>,
@@ -153,28 +162,28 @@ fn main() {
 }
 "#,
         expect![[r#"
-            SUBTREE $$ 1:0@0..63#0 1:0@0..63#0
-              IDENT   fn 1:0@1..3#0
-              IDENT   main 1:0@4..8#0
-              SUBTREE () 1:0@8..9#0 1:0@9..10#0
-              SUBTREE {} 1:0@11..12#0 1:0@61..62#0
-                LITERAL Integer 1 1:0@17..18#0
-                PUNCH   ; [alone] 1:0@18..19#0
-                LITERAL Float 1.0 1:0@24..27#0
-                PUNCH   ; [alone] 1:0@27..28#0
-                SUBTREE () 1:0@33..34#0 1:0@39..40#0
-                  SUBTREE () 1:0@34..35#0 1:0@37..38#0
-                    LITERAL Integer 1 1:0@35..36#0
-                    PUNCH   , [alone] 1:0@36..37#0
-                  PUNCH   , [alone] 1:0@38..39#0
-                PUNCH   . [alone] 1:0@40..41#0
-                LITERAL Float 0.0 1:0@41..44#0
-                PUNCH   ; [alone] 1:0@44..45#0
-                IDENT   let 1:0@50..53#0
-                IDENT   x 1:0@54..55#0
-                PUNCH   = [alone] 1:0@56..57#0
-                LITERAL Integer 1 1:0@58..59#0
-                PUNCH   ; [alone] 1:0@59..60#0
+            SUBTREE $$ 1:0@0..63#2 1:0@0..63#2
+              IDENT   fn 1:0@1..3#2
+              IDENT   main 1:0@4..8#2
+              SUBTREE () 1:0@8..9#2 1:0@9..10#2
+              SUBTREE {} 1:0@11..12#2 1:0@61..62#2
+                LITERAL Integer 1 1:0@17..18#2
+                PUNCH   ; [alone] 1:0@18..19#2
+                LITERAL Float 1.0 1:0@24..27#2
+                PUNCH   ; [alone] 1:0@27..28#2
+                SUBTREE () 1:0@33..34#2 1:0@39..40#2
+                  SUBTREE () 1:0@34..35#2 1:0@37..38#2
+                    LITERAL Integer 1 1:0@35..36#2
+                    PUNCH   , [alone] 1:0@36..37#2
+                  PUNCH   , [alone] 1:0@38..39#2
+                PUNCH   . [alone] 1:0@40..41#2
+                LITERAL Float 0.0 1:0@41..44#2
+                PUNCH   ; [alone] 1:0@44..45#2
+                IDENT   let 1:0@50..53#2
+                IDENT   x 1:0@54..55#2
+                PUNCH   = [alone] 1:0@56..57#2
+                LITERAL Integer 1 1:0@58..59#2
+                PUNCH   ; [alone] 1:0@59..60#2
 
             fn main(){
                 1;
@@ -200,14 +209,14 @@ fn expr_2021() {
     const { 1 },
 "#,
         expect![[r#"
-            SUBTREE $$ 1:0@0..25#0 1:0@0..25#0
-              IDENT   _ 1:0@5..6#0
-              PUNCH   ; [joint] 0:0@36..37#0
-              SUBTREE () 0:0@34..35#0 0:0@34..35#0
-                IDENT   const 1:0@12..17#0
-                SUBTREE {} 1:0@18..19#0 1:0@22..23#0
-                  LITERAL Integer 1 1:0@20..21#0
-              PUNCH   ; [alone] 0:0@39..40#0
+            SUBTREE $$ 1:0@0..25#2 1:0@0..25#2
+              IDENT   _ 1:0@5..6#2
+              PUNCH   ; [joint] 0:0@36..37#2
+              SUBTREE () 0:0@34..35#2 0:0@34..35#2
+                IDENT   const 1:0@12..17#2
+                SUBTREE {} 1:0@18..19#2 1:0@22..23#2
+                  LITERAL Integer 1 1:0@20..21#2
+              PUNCH   ; [alone] 0:0@39..40#2
 
             _;
             (const  {
@@ -228,13 +237,13 @@ fn expr_2021() {
         expect![[r#"
             ExpandError {
                 inner: (
-                    1:0@5..6#0,
+                    1:0@5..6#2,
                     NoMatchingRule,
                 ),
             }
 
-            SUBTREE $$ 1:0@0..8#0 1:0@0..8#0
-              PUNCH   ; [alone] 0:0@39..40#0
+            SUBTREE $$ 1:0@0..8#2 1:0@0..8#2
+              PUNCH   ; [alone] 0:0@39..40#2
 
             ;"#]],
     );
@@ -252,13 +261,13 @@ fn expr_2021() {
         expect![[r#"
             ExpandError {
                 inner: (
-                    1:0@5..10#0,
+                    1:0@5..10#2,
                     NoMatchingRule,
                 ),
             }
 
-            SUBTREE $$ 1:0@0..18#0 1:0@0..18#0
-              PUNCH   ; [alone] 0:0@39..40#0
+            SUBTREE $$ 1:0@0..18#2 1:0@0..18#2
+              PUNCH   ; [alone] 0:0@39..40#2
 
             ;"#]],
     );
@@ -278,26 +287,26 @@ fn expr_2021() {
     break 'foo bar,
 "#,
         expect![[r#"
-            SUBTREE $$ 1:0@0..76#0 1:0@0..76#0
-              LITERAL Integer 4 1:0@5..6#0
-              PUNCH   ; [joint] 0:0@41..42#0
-              LITERAL Str literal 1:0@12..21#0
-              PUNCH   ; [joint] 0:0@41..42#0
-              SUBTREE () 0:0@39..40#0 0:0@39..40#0
-                IDENT   funcall 1:0@27..34#0
-                SUBTREE () 1:0@34..35#0 1:0@35..36#0
-              PUNCH   ; [joint] 0:0@41..42#0
-              SUBTREE () 0:0@39..40#0 0:0@39..40#0
-                IDENT   future 1:0@42..48#0
-                PUNCH   . [alone] 1:0@48..49#0
-                IDENT   await 1:0@49..54#0
-              PUNCH   ; [joint] 0:0@41..42#0
-              SUBTREE () 0:0@39..40#0 0:0@39..40#0
-                IDENT   break 1:0@60..65#0
-                PUNCH   ' [joint] 1:0@66..67#0
-                IDENT   foo 1:0@67..70#0
-                IDENT   bar 1:0@71..74#0
-              PUNCH   ; [alone] 0:0@44..45#0
+            SUBTREE $$ 1:0@0..76#2 1:0@0..76#2
+              LITERAL Integer 4 1:0@5..6#2
+              PUNCH   ; [joint] 0:0@41..42#2
+              LITERAL Str literal 1:0@12..21#2
+              PUNCH   ; [joint] 0:0@41..42#2
+              SUBTREE () 0:0@39..40#2 0:0@39..40#2
+                IDENT   funcall 1:0@27..34#2
+                SUBTREE () 1:0@34..35#2 1:0@35..36#2
+              PUNCH   ; [joint] 0:0@41..42#2
+              SUBTREE () 0:0@39..40#2 0:0@39..40#2
+                IDENT   future 1:0@42..48#2
+                PUNCH   . [alone] 1:0@48..49#2
+                IDENT   await 1:0@49..54#2
+              PUNCH   ; [joint] 0:0@41..42#2
+              SUBTREE () 0:0@39..40#2 0:0@39..40#2
+                IDENT   break 1:0@60..65#2
+                PUNCH   ' [joint] 1:0@66..67#2
+                IDENT   foo 1:0@67..70#2
+                IDENT   bar 1:0@71..74#2
+              PUNCH   ; [alone] 0:0@44..45#2
 
             4;
             "literal";
@@ -319,13 +328,13 @@ fn expr_2021() {
         expect![[r#"
             ExpandError {
                 inner: (
-                    1:0@5..6#0,
+                    1:0@5..6#2,
                     NoMatchingRule,
                 ),
             }
 
-            SUBTREE $$ 1:0@0..8#0 1:0@0..8#0
-              PUNCH   ; [alone] 0:0@44..45#0
+            SUBTREE $$ 1:0@0..8#2 1:0@0..8#2
+              PUNCH   ; [alone] 0:0@44..45#2
 
             ;"#]],
     );
diff --git a/crates/proc-macro-api/src/legacy_protocol/msg.rs b/crates/proc-macro-api/src/legacy_protocol/msg.rs
index 6ea8db9a90..4b831e4ace 100644
--- a/crates/proc-macro-api/src/legacy_protocol/msg.rs
+++ b/crates/proc-macro-api/src/legacy_protocol/msg.rs
@@ -159,7 +159,7 @@ type ProtocolWrite<W: Write> = for<'o, 'msg> fn(out: &'o mut W, msg: &'msg str)
 #[cfg(test)]
 mod tests {
     use intern::{sym, Symbol};
-    use span::{ErasedFileAstId, Span, SpanAnchor, SyntaxContextId, TextRange, TextSize};
+    use span::{Edition, ErasedFileAstId, Span, SpanAnchor, SyntaxContextId, TextRange, TextSize};
     use tt::{
         Delimiter, DelimiterKind, Ident, Leaf, Literal, Punct, Spacing, TopSubtree,
         TopSubtreeBuilder,
@@ -180,12 +180,12 @@ mod tests {
             open: Span {
                 range: TextRange::empty(TextSize::new(0)),
                 anchor,
-                ctx: SyntaxContextId::ROOT,
+                ctx: SyntaxContextId::root(Edition::CURRENT),
             },
             close: Span {
                 range: TextRange::empty(TextSize::new(19)),
                 anchor,
-                ctx: SyntaxContextId::ROOT,
+                ctx: SyntaxContextId::root(Edition::CURRENT),
             },
             kind: DelimiterKind::Invisible,
         });
@@ -196,7 +196,7 @@ mod tests {
                 span: Span {
                     range: TextRange::at(TextSize::new(0), TextSize::of("struct")),
                     anchor,
-                    ctx: SyntaxContextId::ROOT,
+                    ctx: SyntaxContextId::root(Edition::CURRENT),
                 },
                 is_raw: tt::IdentIsRaw::No,
             }
@@ -208,7 +208,7 @@ mod tests {
                 span: Span {
                     range: TextRange::at(TextSize::new(5), TextSize::of("r#Foo")),
                     anchor,
-                    ctx: SyntaxContextId::ROOT,
+                    ctx: SyntaxContextId::root(Edition::CURRENT),
                 },
                 is_raw: tt::IdentIsRaw::Yes,
             }
@@ -219,7 +219,7 @@ mod tests {
             span: Span {
                 range: TextRange::at(TextSize::new(10), TextSize::of("\"Foo\"")),
                 anchor,
-                ctx: SyntaxContextId::ROOT,
+                ctx: SyntaxContextId::root(Edition::CURRENT),
             },
             kind: tt::LitKind::Str,
             suffix: None,
@@ -229,7 +229,7 @@ mod tests {
             span: Span {
                 range: TextRange::at(TextSize::new(13), TextSize::of('@')),
                 anchor,
-                ctx: SyntaxContextId::ROOT,
+                ctx: SyntaxContextId::root(Edition::CURRENT),
             },
             spacing: Spacing::Joint,
         }));
@@ -238,7 +238,7 @@ mod tests {
             Span {
                 range: TextRange::at(TextSize::new(14), TextSize::of('{')),
                 anchor,
-                ctx: SyntaxContextId::ROOT,
+                ctx: SyntaxContextId::root(Edition::CURRENT),
             },
         );
         builder.push(Leaf::Literal(Literal {
@@ -246,7 +246,7 @@ mod tests {
             span: Span {
                 range: TextRange::at(TextSize::new(15), TextSize::of("0u32")),
                 anchor,
-                ctx: SyntaxContextId::ROOT,
+                ctx: SyntaxContextId::root(Edition::CURRENT),
             },
             kind: tt::LitKind::Integer,
             suffix: Some(sym::u32.clone()),
@@ -254,7 +254,7 @@ mod tests {
         builder.close(Span {
             range: TextRange::at(TextSize::new(19), TextSize::of('}')),
             anchor,
-            ctx: SyntaxContextId::ROOT,
+            ctx: SyntaxContextId::root(Edition::CURRENT),
         });
 
         builder.build()
diff --git a/crates/proc-macro-srv/src/server_impl/rust_analyzer_span.rs b/crates/proc-macro-srv/src/server_impl/rust_analyzer_span.rs
index beaebf3330..c7614849e0 100644
--- a/crates/proc-macro-srv/src/server_impl/rust_analyzer_span.rs
+++ b/crates/proc-macro-srv/src/server_impl/rust_analyzer_span.rs
@@ -440,7 +440,7 @@ mod tests {
                 file_id: EditionedFileId::current_edition(FileId::from_raw(0)),
                 ast_id: span::ErasedFileAstId::from_raw(0),
             },
-            ctx: SyntaxContextId::ROOT,
+            ctx: SyntaxContextId::root(span::Edition::CURRENT),
         };
         let s = TokenStream {
             token_trees: vec![
@@ -482,7 +482,7 @@ mod tests {
                 file_id: EditionedFileId::current_edition(FileId::from_raw(0)),
                 ast_id: span::ErasedFileAstId::from_raw(0),
             },
-            ctx: SyntaxContextId::ROOT,
+            ctx: SyntaxContextId::root(span::Edition::CURRENT),
         };
         let subtree_paren_a = vec![
             tt::TokenTree::Subtree(tt::Subtree {
diff --git a/crates/proc-macro-srv/src/tests/mod.rs b/crates/proc-macro-srv/src/tests/mod.rs
index dc6e71163b..15de88ea65 100644
--- a/crates/proc-macro-srv/src/tests/mod.rs
+++ b/crates/proc-macro-srv/src/tests/mod.rs
@@ -12,7 +12,7 @@ fn test_derive_empty() {
         "DeriveEmpty",
         r#"struct S;"#,
         expect!["SUBTREE $$ 1 1"],
-        expect!["SUBTREE $$ 42:2@0..100#0 42:2@0..100#0"],
+        expect!["SUBTREE $$ 42:2@0..100#2 42:2@0..100#2"],
     );
 }
 
@@ -29,12 +29,12 @@ fn test_derive_error() {
                 LITERAL Str #[derive(DeriveError)] struct S ; 1
               PUNCH   ; [alone] 1"#]],
         expect![[r#"
-            SUBTREE $$ 42:2@0..100#0 42:2@0..100#0
-              IDENT   compile_error 42:2@0..100#0
-              PUNCH   ! [alone] 42:2@0..100#0
-              SUBTREE () 42:2@0..100#0 42:2@0..100#0
-                LITERAL Str #[derive(DeriveError)] struct S ; 42:2@0..100#0
-              PUNCH   ; [alone] 42:2@0..100#0"#]],
+            SUBTREE $$ 42:2@0..100#2 42:2@0..100#2
+              IDENT   compile_error 42:2@0..100#2
+              PUNCH   ! [alone] 42:2@0..100#2
+              SUBTREE () 42:2@0..100#2 42:2@0..100#2
+                LITERAL Str #[derive(DeriveError)] struct S ; 42:2@0..100#2
+              PUNCH   ; [alone] 42:2@0..100#2"#]],
     );
 }
 
@@ -53,14 +53,14 @@ fn test_fn_like_macro_noop() {
               PUNCH   , [alone] 1
               SUBTREE [] 1 1"#]],
         expect![[r#"
-            SUBTREE $$ 42:2@0..100#0 42:2@0..100#0
-              IDENT   ident 42:2@0..5#0
-              PUNCH   , [alone] 42:2@5..6#0
-              LITERAL Integer 0 42:2@7..8#0
-              PUNCH   , [alone] 42:2@8..9#0
-              LITERAL Integer 1 42:2@10..11#0
-              PUNCH   , [alone] 42:2@11..12#0
-              SUBTREE [] 42:2@13..14#0 42:2@14..15#0"#]],
+            SUBTREE $$ 42:2@0..100#2 42:2@0..100#2
+              IDENT   ident 42:2@0..5#2
+              PUNCH   , [alone] 42:2@5..6#2
+              LITERAL Integer 0 42:2@7..8#2
+              PUNCH   , [alone] 42:2@8..9#2
+              LITERAL Integer 1 42:2@10..11#2
+              PUNCH   , [alone] 42:2@11..12#2
+              SUBTREE [] 42:2@13..14#2 42:2@14..15#2"#]],
     );
 }
 
@@ -75,10 +75,10 @@ fn test_fn_like_macro_clone_ident_subtree() {
               PUNCH   , [alone] 1
               SUBTREE [] 1 1"#]],
         expect![[r#"
-            SUBTREE $$ 42:2@0..100#0 42:2@0..100#0
-              IDENT   ident 42:2@0..5#0
-              PUNCH   , [alone] 42:2@5..6#0
-              SUBTREE [] 42:2@7..8#0 42:2@7..8#0"#]],
+            SUBTREE $$ 42:2@0..100#2 42:2@0..100#2
+              IDENT   ident 42:2@0..5#2
+              PUNCH   , [alone] 42:2@5..6#2
+              SUBTREE [] 42:2@7..8#2 42:2@7..8#2"#]],
     );
 }
 
@@ -91,8 +91,8 @@ fn test_fn_like_macro_clone_raw_ident() {
             SUBTREE $$ 1 1
               IDENT   r#async 1"#]],
         expect![[r#"
-            SUBTREE $$ 42:2@0..100#0 42:2@0..100#0
-              IDENT   r#async 42:2@0..7#0"#]],
+            SUBTREE $$ 42:2@0..100#2 42:2@0..100#2
+              IDENT   r#async 42:2@0..7#2"#]],
     );
 }
 
@@ -105,8 +105,8 @@ fn test_fn_like_fn_like_span_join() {
             SUBTREE $$ 1 1
               IDENT   r#joined 1"#]],
         expect![[r#"
-            SUBTREE $$ 42:2@0..100#0 42:2@0..100#0
-              IDENT   r#joined 42:2@0..11#0"#]],
+            SUBTREE $$ 42:2@0..100#2 42:2@0..100#2
+              IDENT   r#joined 42:2@0..11#2"#]],
     );
 }
 
@@ -121,10 +121,10 @@ fn test_fn_like_fn_like_span_ops() {
               IDENT   resolved_at_def_site 1
               IDENT   start_span 1"#]],
         expect![[r#"
-            SUBTREE $$ 42:2@0..100#0 42:2@0..100#0
-              IDENT   set_def_site 41:1@0..150#0
-              IDENT   resolved_at_def_site 42:2@13..33#0
-              IDENT   start_span 42:2@34..34#0"#]],
+            SUBTREE $$ 42:2@0..100#2 42:2@0..100#2
+              IDENT   set_def_site 41:1@0..150#2
+              IDENT   resolved_at_def_site 42:2@13..33#2
+              IDENT   start_span 42:2@34..34#2"#]],
     );
 }
 
@@ -143,14 +143,14 @@ fn test_fn_like_mk_literals() {
               LITERAL Integer 123i64 1
               LITERAL Integer 123 1"#]],
         expect![[r#"
-            SUBTREE $$ 42:2@0..100#0 42:2@0..100#0
-              LITERAL ByteStr byte_string 42:2@0..100#0
-              LITERAL Char c 42:2@0..100#0
-              LITERAL Str string 42:2@0..100#0
-              LITERAL Float 3.14f64 42:2@0..100#0
-              LITERAL Float 3.14 42:2@0..100#0
-              LITERAL Integer 123i64 42:2@0..100#0
-              LITERAL Integer 123 42:2@0..100#0"#]],
+            SUBTREE $$ 42:2@0..100#2 42:2@0..100#2
+              LITERAL ByteStr byte_string 42:2@0..100#2
+              LITERAL Char c 42:2@0..100#2
+              LITERAL Str string 42:2@0..100#2
+              LITERAL Float 3.14f64 42:2@0..100#2
+              LITERAL Float 3.14 42:2@0..100#2
+              LITERAL Integer 123i64 42:2@0..100#2
+              LITERAL Integer 123 42:2@0..100#2"#]],
     );
 }
 
@@ -164,9 +164,9 @@ fn test_fn_like_mk_idents() {
               IDENT   standard 1
               IDENT   r#raw 1"#]],
         expect![[r#"
-            SUBTREE $$ 42:2@0..100#0 42:2@0..100#0
-              IDENT   standard 42:2@0..100#0
-              IDENT   r#raw 42:2@0..100#0"#]],
+            SUBTREE $$ 42:2@0..100#2 42:2@0..100#2
+              IDENT   standard 42:2@0..100#2
+              IDENT   r#raw 42:2@0..100#2"#]],
     );
 }
 
@@ -198,27 +198,27 @@ fn test_fn_like_macro_clone_literals() {
               PUNCH   , [alone] 1
               LITERAL CStr null 1"#]],
         expect![[r#"
-            SUBTREE $$ 42:2@0..100#0 42:2@0..100#0
-              LITERAL Integer 1u16 42:2@0..4#0
-              PUNCH   , [alone] 42:2@4..5#0
-              LITERAL Integer 2_u32 42:2@6..11#0
-              PUNCH   , [alone] 42:2@11..12#0
-              PUNCH   - [alone] 42:2@13..14#0
-              LITERAL Integer 4i64 42:2@14..18#0
-              PUNCH   , [alone] 42:2@18..19#0
-              LITERAL Float 3.14f32 42:2@20..27#0
-              PUNCH   , [alone] 42:2@27..28#0
-              LITERAL Str hello bridge 42:2@29..43#0
-              PUNCH   , [alone] 42:2@43..44#0
-              LITERAL Str suffixedsuffix 42:2@45..61#0
-              PUNCH   , [alone] 42:2@61..62#0
-              LITERAL StrRaw(2) raw 42:2@63..73#0
-              PUNCH   , [alone] 42:2@73..74#0
-              LITERAL Char a 42:2@75..78#0
-              PUNCH   , [alone] 42:2@78..79#0
-              LITERAL Byte b 42:2@80..84#0
-              PUNCH   , [alone] 42:2@84..85#0
-              LITERAL CStr null 42:2@86..93#0"#]],
+            SUBTREE $$ 42:2@0..100#2 42:2@0..100#2
+              LITERAL Integer 1u16 42:2@0..4#2
+              PUNCH   , [alone] 42:2@4..5#2
+              LITERAL Integer 2_u32 42:2@6..11#2
+              PUNCH   , [alone] 42:2@11..12#2
+              PUNCH   - [alone] 42:2@13..14#2
+              LITERAL Integer 4i64 42:2@14..18#2
+              PUNCH   , [alone] 42:2@18..19#2
+              LITERAL Float 3.14f32 42:2@20..27#2
+              PUNCH   , [alone] 42:2@27..28#2
+              LITERAL Str hello bridge 42:2@29..43#2
+              PUNCH   , [alone] 42:2@43..44#2
+              LITERAL Str suffixedsuffix 42:2@45..61#2
+              PUNCH   , [alone] 42:2@61..62#2
+              LITERAL StrRaw(2) raw 42:2@63..73#2
+              PUNCH   , [alone] 42:2@73..74#2
+              LITERAL Char a 42:2@75..78#2
+              PUNCH   , [alone] 42:2@78..79#2
+              LITERAL Byte b 42:2@80..84#2
+              PUNCH   , [alone] 42:2@84..85#2
+              LITERAL CStr null 42:2@86..93#2"#]],
     );
 }
 
@@ -239,12 +239,12 @@ fn test_attr_macro() {
                 LITERAL Str #[attr_error(some arguments)] mod m {} 1
               PUNCH   ; [alone] 1"#]],
         expect![[r#"
-            SUBTREE $$ 42:2@0..100#0 42:2@0..100#0
-              IDENT   compile_error 42:2@0..100#0
-              PUNCH   ! [alone] 42:2@0..100#0
-              SUBTREE () 42:2@0..100#0 42:2@0..100#0
-                LITERAL Str #[attr_error(some arguments)] mod m {} 42:2@0..100#0
-              PUNCH   ; [alone] 42:2@0..100#0"#]],
+            SUBTREE $$ 42:2@0..100#2 42:2@0..100#2
+              IDENT   compile_error 42:2@0..100#2
+              PUNCH   ! [alone] 42:2@0..100#2
+              SUBTREE () 42:2@0..100#2 42:2@0..100#2
+                LITERAL Str #[attr_error(some arguments)] mod m {} 42:2@0..100#2
+              PUNCH   ; [alone] 42:2@0..100#2"#]],
     );
 }
 
diff --git a/crates/proc-macro-srv/src/tests/utils.rs b/crates/proc-macro-srv/src/tests/utils.rs
index 37d51050f3..42f0a7f59b 100644
--- a/crates/proc-macro-srv/src/tests/utils.rs
+++ b/crates/proc-macro-srv/src/tests/utils.rs
@@ -76,7 +76,7 @@ fn assert_expand_impl(
             file_id: EditionedFileId::current_edition(FileId::from_raw(41)),
             ast_id: ErasedFileAstId::from_raw(1),
         },
-        ctx: SyntaxContextId::ROOT,
+        ctx: SyntaxContextId::root(span::Edition::CURRENT),
     };
     let call_site = Span {
         range: TextRange::new(0.into(), 100.into()),
@@ -84,7 +84,7 @@ fn assert_expand_impl(
             file_id: EditionedFileId::current_edition(FileId::from_raw(42)),
             ast_id: ErasedFileAstId::from_raw(2),
         },
-        ctx: SyntaxContextId::ROOT,
+        ctx: SyntaxContextId::root(span::Edition::CURRENT),
     };
     let mixed_site = call_site;
 
diff --git a/crates/span/src/hygiene.rs b/crates/span/src/hygiene.rs
index 87a948df55..6becc8e41e 100644
--- a/crates/span/src/hygiene.rs
+++ b/crates/span/src/hygiene.rs
@@ -26,7 +26,7 @@ use crate::InternId;
 #[cfg(feature = "ra-salsa")]
 use ra_salsa::{InternId, InternValue};
 
-use crate::MacroCallId;
+use crate::{Edition, MacroCallId};
 
 /// Interned [`SyntaxContextData`].
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
@@ -59,11 +59,20 @@ impl fmt::Display for SyntaxContextId {
 }
 
 impl SyntaxContextId {
+    #[inline]
+    pub fn remove_root_edition(&mut self) {
+        if self.is_root() {
+            *self = Self::root(Edition::Edition2015);
+        }
+    }
+
     /// The root context, which is the parent of all other contexts. All [`FileId`]s have this context.
-    pub const ROOT: Self = SyntaxContextId(unsafe { InternId::new_unchecked(0) });
+    pub const fn root(edition: Edition) -> Self {
+        SyntaxContextId(unsafe { InternId::new_unchecked(edition as u32) })
+    }
 
     pub fn is_root(self) -> bool {
-        self == Self::ROOT
+        self.into_u32() <= Edition::LATEST as u32
     }
 
     /// Deconstruct a `SyntaxContextId` into a raw `u32`.
@@ -89,6 +98,7 @@ pub struct SyntaxContextData {
     // per crate. Though that is likely not a problem as `MacroCallId`s are already crate calling dependent.
     pub outer_expn: Option<MacroCallId>,
     pub outer_transparency: Transparency,
+    pub edition: Edition,
     pub parent: SyntaxContextId,
     /// This context, but with all transparent and semi-transparent expansions filtered away.
     pub opaque: SyntaxContextId,
@@ -98,10 +108,10 @@ pub struct SyntaxContextData {
 
 #[cfg(feature = "ra-salsa")]
 impl InternValue for SyntaxContextData {
-    type Key = (SyntaxContextId, Option<MacroCallId>, Transparency);
+    type Key = (SyntaxContextId, Option<MacroCallId>, Transparency, Edition);
 
     fn into_key(&self) -> Self::Key {
-        (self.parent, self.outer_expn, self.outer_transparency)
+        (self.parent, self.outer_expn, self.outer_transparency, self.edition)
     }
 }
 
@@ -118,13 +128,14 @@ impl std::fmt::Debug for SyntaxContextData {
 }
 
 impl SyntaxContextData {
-    pub fn root() -> Self {
+    pub fn root(edition: Edition) -> Self {
         SyntaxContextData {
             outer_expn: None,
             outer_transparency: Transparency::Opaque,
-            parent: SyntaxContextId::ROOT,
-            opaque: SyntaxContextId::ROOT,
-            opaque_and_semitransparent: SyntaxContextId::ROOT,
+            parent: SyntaxContextId::root(edition),
+            opaque: SyntaxContextId::root(edition),
+            opaque_and_semitransparent: SyntaxContextId::root(edition),
+            edition,
         }
     }
 }
diff --git a/crates/span/src/map.rs b/crates/span/src/map.rs
index 66bbce1859..dc35de67fd 100644
--- a/crates/span/src/map.rs
+++ b/crates/span/src/map.rs
@@ -208,7 +208,7 @@ impl RealSpanMap {
         Span {
             range: range - offset,
             anchor: SpanAnchor { file_id: self.file_id, ast_id },
-            ctx: SyntaxContextId::ROOT,
+            ctx: SyntaxContextId::root(self.file_id.edition()),
         }
     }
 }
diff --git a/crates/syntax-bridge/src/lib.rs b/crates/syntax-bridge/src/lib.rs
index ed8b1908d6..19801c49e4 100644
--- a/crates/syntax-bridge/src/lib.rs
+++ b/crates/syntax-bridge/src/lib.rs
@@ -1,6 +1,6 @@
 //! Conversions between [`SyntaxNode`] and [`tt::TokenTree`].
 
-use std::fmt;
+use std::{fmt, hash::Hash};
 
 use intern::Symbol;
 use rustc_hash::{FxHashMap, FxHashSet};
@@ -58,7 +58,7 @@ pub mod dummy_test_span_utils {
             ),
             ast_id: span::ROOT_ERASED_FILE_AST_ID,
         },
-        ctx: SyntaxContextId::ROOT,
+        ctx: SyntaxContextId::root(Edition::CURRENT),
     };
 
     pub struct DummyTestSpanMap;
@@ -74,7 +74,7 @@ pub mod dummy_test_span_utils {
                     ),
                     ast_id: span::ROOT_ERASED_FILE_AST_ID,
                 },
-                ctx: SyntaxContextId::ROOT,
+                ctx: SyntaxContextId::root(Edition::CURRENT),
             }
         }
     }
@@ -141,15 +141,16 @@ where
 pub fn token_tree_to_syntax_node<Ctx>(
     tt: &tt::TopSubtree<SpanData<Ctx>>,
     entry_point: parser::TopEntryPoint,
-    edition: parser::Edition,
+    span_to_edition: &mut dyn FnMut(Ctx) -> Edition,
+    top_edition: Edition,
 ) -> (Parse<SyntaxNode>, SpanMap<Ctx>)
 where
-    SpanData<Ctx>: Copy + fmt::Debug,
-    Ctx: PartialEq,
+    Ctx: Copy + fmt::Debug + PartialEq + PartialEq + Eq + Hash,
 {
     let buffer = tt.view().strip_invisible();
-    let parser_input = to_parser_input(edition, buffer);
-    let parser_output = entry_point.parse(&parser_input, edition);
+    let parser_input = to_parser_input(buffer, span_to_edition);
+    // It matters what edition we parse with even when we escape all identifiers correctly.
+    let parser_output = entry_point.parse(&parser_input, top_edition);
     let mut tree_sink = TtTreeSink::new(buffer.cursor());
     for event in parser_output.iter() {
         match event {
diff --git a/crates/syntax-bridge/src/to_parser_input.rs b/crates/syntax-bridge/src/to_parser_input.rs
index 1bbb05f550..0dcb2be316 100644
--- a/crates/syntax-bridge/src/to_parser_input.rs
+++ b/crates/syntax-bridge/src/to_parser_input.rs
@@ -2,17 +2,20 @@
 //! format that works for our parser.
 
 use std::fmt;
+use std::hash::Hash;
 
-use span::Edition;
+use rustc_hash::FxHashMap;
+use span::{Edition, SpanData};
 use syntax::{SyntaxKind, SyntaxKind::*, T};
 
-pub fn to_parser_input<S: Copy + fmt::Debug>(
-    edition: Edition,
-    buffer: tt::TokenTreesView<'_, S>,
+pub fn to_parser_input<Ctx: Copy + fmt::Debug + PartialEq + Eq + Hash>(
+    buffer: tt::TokenTreesView<'_, SpanData<Ctx>>,
+    span_to_edition: &mut dyn FnMut(Ctx) -> Edition,
 ) -> parser::Input {
     let mut res = parser::Input::default();
 
     let mut current = buffer.cursor();
+    let mut syntax_context_to_edition_cache = FxHashMap::default();
 
     while !current.eof() {
         let tt = current.token_tree();
@@ -57,20 +60,25 @@ pub fn to_parser_input<S: Copy + fmt::Debug>(
                             res.was_joint();
                         }
                     }
-                    tt::Leaf::Ident(ident) => match ident.sym.as_str() {
-                        "_" => res.push(T![_]),
-                        i if i.starts_with('\'') => res.push(LIFETIME_IDENT),
-                        _ if ident.is_raw.yes() => res.push(IDENT),
-                        text => match SyntaxKind::from_keyword(text, edition) {
-                            Some(kind) => res.push(kind),
-                            None => {
-                                let contextual_keyword =
-                                    SyntaxKind::from_contextual_keyword(text, edition)
-                                        .unwrap_or(SyntaxKind::IDENT);
-                                res.push_ident(contextual_keyword);
-                            }
-                        },
-                    },
+                    tt::Leaf::Ident(ident) => {
+                        let edition = *syntax_context_to_edition_cache
+                            .entry(ident.span.ctx)
+                            .or_insert_with(|| span_to_edition(ident.span.ctx));
+                        match ident.sym.as_str() {
+                            "_" => res.push(T![_]),
+                            i if i.starts_with('\'') => res.push(LIFETIME_IDENT),
+                            _ if ident.is_raw.yes() => res.push(IDENT),
+                            text => match SyntaxKind::from_keyword(text, edition) {
+                                Some(kind) => res.push(kind),
+                                None => {
+                                    let contextual_keyword =
+                                        SyntaxKind::from_contextual_keyword(text, edition)
+                                            .unwrap_or(SyntaxKind::IDENT);
+                                    res.push_ident(contextual_keyword);
+                                }
+                            },
+                        }
+                    }
                     tt::Leaf::Punct(punct) => {
                         let kind = SyntaxKind::from_char(punct.char)
                             .unwrap_or_else(|| panic!("{punct:#?} is not a valid punct"));