Make ExpnData fields krate and orig_id private

These fields are only used by hygiene serialized, and should not be
accessed by anything outside of `rustc_span`.

compiler/rustc_ast_lowering/src/lib.rs

@@ -57,7 +57,7 @@ use rustc_session::lint::{builtin::BARE_TRAIT_OBJECTS, BuiltinLintDiagnostics, L
 use rustc_session::parse::ParseSess;
 use rustc_session::Session;
 use rustc_span::hygiene::ExpnId;
-use rustc_span::source_map::{respan, DesugaringKind, ExpnData, ExpnKind};
+use rustc_span::source_map::{respan, DesugaringKind};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::Span;
 
@@ -743,10 +743,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         span: Span,
         allow_internal_unstable: Option<Lrc<[Symbol]>>,
     ) -> Span {
-        span.fresh_expansion(ExpnData {
-            allow_internal_unstable,
-            ..ExpnData::default(ExpnKind::Desugaring(reason), span, self.sess.edition(), None)
-        })
+        span.mark_with_reason(allow_internal_unstable, reason, self.sess.edition())
     }
 
     fn with_anonymous_lifetime_mode<R>(

compiler/rustc_expand/src/base.rs

@@ -12,7 +12,7 @@ use rustc_data_structures::sync::{self, Lrc};
 use rustc_errors::{DiagnosticBuilder, ErrorReported};
 use rustc_parse::{self, nt_to_tokenstream, parser, MACRO_ARGUMENTS};
 use rustc_session::{parse::ParseSess, Limit, Session};
-use rustc_span::def_id::{DefId, LOCAL_CRATE};
+use rustc_span::def_id::DefId;
 use rustc_span::edition::Edition;
 use rustc_span::hygiene::{AstPass, ExpnData, ExpnId, ExpnKind};
 use rustc_span::source_map::SourceMap;
@@ -842,19 +842,17 @@ impl SyntaxExtension {
         descr: Symbol,
         macro_def_id: Option<DefId>,
     ) -> ExpnData {
-        ExpnData {
-            kind: ExpnKind::Macro(self.macro_kind(), descr),
+        ExpnData::new(
+            ExpnKind::Macro(self.macro_kind(), descr),
             parent,
             call_site,
-            def_site: self.span,
-            allow_internal_unstable: self.allow_internal_unstable.clone(),
-            allow_internal_unsafe: self.allow_internal_unsafe,
-            local_inner_macros: self.local_inner_macros,
-            edition: self.edition,
+            self.span,
+            self.allow_internal_unstable.clone(),
+            self.allow_internal_unsafe,
+            self.local_inner_macros,
+            self.edition,
             macro_def_id,
-            krate: LOCAL_CRATE,
-            orig_id: None,
-        }
+        )
     }
 }
 

compiler/rustc_expand/src/expand.rs

@@ -1020,15 +1020,16 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
         // with exception of the derive container case which is not resolved and can get
         // its expansion data immediately.
         let expn_data = match &kind {
-            InvocationKind::DeriveContainer { item, .. } => Some(ExpnData {
-                parent: self.cx.current_expansion.id,
-                ..ExpnData::default(
+            InvocationKind::DeriveContainer { item, .. } => {
+                let mut expn_data = ExpnData::default(
                     ExpnKind::Macro(MacroKind::Attr, sym::derive),
                     item.span(),
                     self.cx.sess.parse_sess.edition,
                     None,
-                )
-            }),
+                );
+                expn_data.parent = self.cx.current_expansion.id;
+                Some(expn_data)
+            }
             _ => None,
         };
         let expn_id = ExpnId::fresh(expn_data);

compiler/rustc_mir/src/transform/inline.rs

@@ -742,11 +742,11 @@ impl<'a, 'tcx> MutVisitor<'tcx> for Integrator<'a, 'tcx> {
     }
 
     fn visit_span(&mut self, span: &mut Span) {
+        let mut expn_data =
+            ExpnData::default(ExpnKind::Inlined, *span, self.tcx.sess.edition(), None);
+        expn_data.def_site = self.body_span;
         // Make sure that all spans track the fact that they were inlined.
-        *span = self.callsite_span.fresh_expansion(ExpnData {
-            def_site: self.body_span,
-            ..ExpnData::default(ExpnKind::Inlined, *span, self.tcx.sess.edition(), None)
-        });
+        *span = self.callsite_span.fresh_expansion(expn_data);
     }
 
     fn visit_place(&mut self, place: &mut Place<'tcx>, context: PlaceContext, location: Location) {

compiler/rustc_span/src/hygiene.rs

@@ -650,6 +650,20 @@ impl Span {
             self.with_ctxt(data.apply_mark(SyntaxContext::root(), expn_id, transparency))
         })
     }
+
+    /// Reuses the span but adds information like the kind of the desugaring and features that are
+    /// allowed inside this span.
+    pub fn mark_with_reason(
+        self,
+        allow_internal_unstable: Option<Lrc<[Symbol]>>,
+        reason: DesugaringKind,
+        edition: Edition,
+    ) -> Span {
+        self.fresh_expansion(ExpnData {
+            allow_internal_unstable,
+            ..ExpnData::default(ExpnKind::Desugaring(reason), self, edition, None)
+        })
+    }
 }
 
 /// A subset of properties from both macro definition and macro call available through global data.
@@ -699,21 +713,47 @@ pub struct ExpnData {
     /// created locally - when our serialized metadata is decoded,
     /// foreign `ExpnId`s will have their `ExpnData` looked up
     /// from the crate specified by `Crate
-    pub krate: CrateNum,
+    krate: CrateNum,
     /// The raw that this `ExpnData` had in its original crate.
     /// An `ExpnData` can be created before being assigned an `ExpnId`,
     /// so this might be `None` until `set_expn_data` is called
     // This is used only for serialization/deserialization purposes:
     // two `ExpnData`s that differ only in their `orig_id` should
     // be considered equivalent.
     #[stable_hasher(ignore)]
-    pub orig_id: Option<u32>,
+    orig_id: Option<u32>,
 }
 
 // This would require special handling of `orig_id` and `parent`
 impl !PartialEq for ExpnData {}
 
 impl ExpnData {
+    pub fn new(
+        kind: ExpnKind,
+        parent: ExpnId,
+        call_site: Span,
+        def_site: Span,
+        allow_internal_unstable: Option<Lrc<[Symbol]>>,
+        allow_internal_unsafe: bool,
+        local_inner_macros: bool,
+        edition: Edition,
+        macro_def_id: Option<DefId>,
+    ) -> ExpnData {
+        ExpnData {
+            kind,
+            parent,
+            call_site,
+            def_site,
+            allow_internal_unstable,
+            allow_internal_unsafe,
+            local_inner_macros,
+            edition,
+            macro_def_id,
+            krate: LOCAL_CRATE,
+            orig_id: None,
+        }
+    }
+
     /// Constructs expansion data with default properties.
     pub fn default(
         kind: ExpnKind,