Introduce and use `SyntaxContext::outer_expn_info()`.

It reduces two `hygiene_data` accesses to one on some hot paths.

2 files changed, 4 insertions, 5 deletions

diff --git a/src/librustc_lint/builtin.rs b/src/librustc_lint/builtin.rs
index d184c671bba..44b727c6925 100644
--- a/src/librustc_lint/builtin.rs
+++ b/src/librustc_lint/builtin.rs
@@ -158,7 +158,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NonShorthandFieldPatterns {
                 if fieldpat.node.is_shorthand {
                     continue;
                 }
-                if fieldpat.span.ctxt().outer().expn_info().is_some() {
+                if fieldpat.span.ctxt().outer_expn_info().is_some() {
                     // Don't lint if this is a macro expansion: macro authors
                     // shouldn't have to worry about this kind of style issue
                     // (Issue #49588)
@@ -1003,7 +1003,7 @@ impl UnreachablePub {
         let mut applicability = Applicability::MachineApplicable;
         match vis.node {
             hir::VisibilityKind::Public if !cx.access_levels.is_reachable(id) => {
-                if span.ctxt().outer().expn_info().is_some() {
+                if span.ctxt().outer_expn_info().is_some() {
                     applicability = Applicability::MaybeIncorrect;
                 }
                 let def_span = cx.tcx.sess.source_map().def_span(span);
diff --git a/src/librustc_lint/unused.rs b/src/librustc_lint/unused.rs
index 34f7e04c164..036820c6d7f 100644
--- a/src/librustc_lint/unused.rs
+++ b/src/librustc_lint/unused.rs
@@ -391,9 +391,8 @@ impl EarlyLintPass for UnusedParens {
                 // trigger in situations that macro authors shouldn't have to care about, e.g.,
                 // when a parenthesized token tree matched in one macro expansion is matched as
                 // an expression in another and used as a fn/method argument (Issue #47775)
-                if e.span.ctxt().outer().expn_info()
-                    .map_or(false, |info| info.call_site.ctxt().outer()
-                            .expn_info().is_some()) {
+                if e.span.ctxt().outer_expn_info()
+                    .map_or(false, |info| info.call_site.ctxt().outer_expn_info().is_some()) {
                         return;
                 }
                 let msg = format!("{} argument", call_kind);