Small cleanup

Author: estebank

Diff for: compiler/rustc_errors/src/emitter.rs

@@ -10,7 +10,7 @@
 use Destination::*;
 
 use rustc_span::source_map::SourceMap;
-use rustc_span::{FileLines, SourceFile, Span};
+use rustc_span::{DesugaringKind, FileLines, SourceFile, Span};
 
 use crate::snippet::{Annotation, AnnotationType, Line, MultilineAnnotation, Style, StyledString};
 use crate::styled_buffer::StyledBuffer;
@@ -400,12 +400,13 @@ pub trait Emitter: Translate {
             // entries we don't want to print, to make sure the indices being
             // printed are contiguous (or omitted if there's only one entry).
             let macro_backtrace: Vec<_> = sp.macro_backtrace().collect();
-            for (i, trace) in macro_backtrace.iter().rev().enumerate() {
-                if trace.def_site.is_dummy() {
-                    continue;
-                }
-
-                if always_backtrace && !matches!(trace.kind, ExpnKind::Inlined) {
+            for (i, trace) in macro_backtrace.iter().rev().enumerate().filter(|(_, trace)| {
+                !matches!(
+                    trace.kind,
+                    ExpnKind::Inlined | ExpnKind::Desugaring(DesugaringKind::Resize)
+                ) && !trace.def_site.is_dummy()
+            }) {
+                if always_backtrace {
                     new_labels.push((
                         trace.def_site,
                         format!(

Diff for: compiler/rustc_lint/src/methods.rs

@@ -36,7 +36,7 @@ declare_lint_pass!(TemporaryCStringAsPtr => [TEMPORARY_CSTRING_AS_PTR]);
 
 fn in_macro(span: Span) -> bool {
     if span.from_expansion() {
-        !matches!(span.ctxt().outer_expn_data().kind, ExpnKind::Desugaring(..))
+        !matches!(span.peel_ctxt().ctxt().outer_expn_data().kind, ExpnKind::Desugaring(..))
     } else {
         false
     }

Diff for: compiler/rustc_middle/src/lint.rs

@@ -466,7 +466,7 @@ pub fn struct_lint_level(
 /// This is used to test whether a lint should not even begin to figure out whether it should
 /// be reported on the current node.
 pub fn in_external_macro(sess: &Session, span: Span) -> bool {
-    let expn_data = span.ctxt().outer_expn_data();
+    let expn_data = span.peel_ctxt().ctxt().outer_expn_data();
     match expn_data.kind {
         ExpnKind::Inlined
         | ExpnKind::Root

Diff for: compiler/rustc_span/src/lib.rs

@@ -610,7 +610,7 @@ impl Span {
             {
                 true
             }
-            ExpnKind::Desugaring(DesugaringKind::Resize) | ExpnKind::Desugaring(_) => {
+            ExpnKind::Desugaring(_) => {
                 self.parent_callsite().unwrap().can_be_used_for_suggestions()
             }
             ExpnKind::Macro(..) => false,
@@ -761,7 +761,7 @@ impl Span {
 
     /// Checks if this span arises from a compiler desugaring of kind `kind`.
     pub fn is_desugaring(self, kind: DesugaringKind) -> bool {
-        match self.ctxt().outer_expn_data().kind {
+        match self.peel_ctxt().ctxt().outer_expn_data().kind {
             ExpnKind::Desugaring(k) => k == kind,
             _ => false,
         }
@@ -770,7 +770,7 @@ impl Span {
     /// Returns the compiler desugaring that created this span, or `None`
     /// if this span is not from a desugaring.
     pub fn desugaring_kind(self) -> Option<DesugaringKind> {
-        match self.ctxt().outer_expn_data().kind {
+        match self.peel_ctxt().ctxt().outer_expn_data().kind {
             ExpnKind::Desugaring(k) => Some(k),
             _ => None,
         }

Diff for: compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs

@@ -956,7 +956,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             .join(", ");
 
         if matches!(obligation.cause.code(), ObligationCauseCode::FunctionArgumentObligation { .. })
-            && match obligation.cause.span.ctxt().outer_expn_data().kind {
+            && match obligation.cause.span.peel_ctxt().ctxt().outer_expn_data().kind {
                 ExpnKind::Root
                 | ExpnKind::AstPass(_)
                 | ExpnKind::Desugaring(_)
@@ -1249,7 +1249,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         {
             obligation.cause.code()
         } else if let ExpnKind::Desugaring(DesugaringKind::ForLoop) =
-            span.ctxt().outer_expn_data().kind
+            span.peel_ctxt().ctxt().outer_expn_data().kind
         {
             obligation.cause.code()
         } else {
@@ -1324,7 +1324,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                     // }
                     // ```
                     if !matches!(
-                        span.ctxt().outer_expn_data().kind,
+                        span.peel_ctxt().ctxt().outer_expn_data().kind,
                         ExpnKind::Root | ExpnKind::Desugaring(DesugaringKind::ForLoop)
                     ) {
                         return false;