From e4edc161f20ccbc77fffb7ceb60ebb6102cbd747 Mon Sep 17 00:00:00 2001
From: Dylan MacKenzie <ecstaticmorse@gmail.com>
Date: Wed, 2 Sep 2020 14:54:55 -0700
Subject: [PATCH] Give name to extra `Span` in `LiveDrop` error

---
 compiler/rustc_mir/src/transform/check_consts/ops.rs        | 6 ++++--
 .../src/transform/check_consts/post_drop_elaboration.rs     | 2 +-
 compiler/rustc_mir/src/transform/check_consts/validation.rs | 2 +-
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/compiler/rustc_mir/src/transform/check_consts/ops.rs b/compiler/rustc_mir/src/transform/check_consts/ops.rs
index ff27d0c3a921..4af355310ae2 100644
--- a/compiler/rustc_mir/src/transform/check_consts/ops.rs
+++ b/compiler/rustc_mir/src/transform/check_consts/ops.rs
@@ -148,7 +148,9 @@ fn emit_error(&self, ccx: &ConstCx<'_, '_>, span: Span) {
 impl NonConstOp for InlineAsm {}
 
 #[derive(Debug)]
-pub struct LiveDrop(pub Option<Span>);
+pub struct LiveDrop {
+    pub dropped_at: Option<Span>,
+}
 impl NonConstOp for LiveDrop {
     fn emit_error(&self, ccx: &ConstCx<'_, '_>, span: Span) {
         let mut diagnostic = struct_span_err!(
@@ -158,7 +160,7 @@ fn emit_error(&self, ccx: &ConstCx<'_, '_>, span: Span) {
             "destructors cannot be evaluated at compile-time"
         );
         diagnostic.span_label(span, format!("{}s cannot evaluate destructors", ccx.const_kind()));
-        if let Some(span) = self.0 {
+        if let Some(span) = self.dropped_at {
             diagnostic.span_label(span, "value is dropped here");
         }
         diagnostic.emit();
diff --git a/compiler/rustc_mir/src/transform/check_consts/post_drop_elaboration.rs b/compiler/rustc_mir/src/transform/check_consts/post_drop_elaboration.rs
index 55075b3ab5e9..a2e5c905612a 100644
--- a/compiler/rustc_mir/src/transform/check_consts/post_drop_elaboration.rs
+++ b/compiler/rustc_mir/src/transform/check_consts/post_drop_elaboration.rs
@@ -52,7 +52,7 @@ fn deref(&self) -> &Self::Target {
 
 impl CheckLiveDrops<'mir, 'tcx> {
     fn check_live_drop(&self, span: Span) {
-        ops::non_const(self.ccx, ops::LiveDrop(None), span);
+        ops::non_const(self.ccx, ops::LiveDrop { dropped_at: None }, span);
     }
 }
 
diff --git a/compiler/rustc_mir/src/transform/check_consts/validation.rs b/compiler/rustc_mir/src/transform/check_consts/validation.rs
index e8411b121e39..ebba7f29663e 100644
--- a/compiler/rustc_mir/src/transform/check_consts/validation.rs
+++ b/compiler/rustc_mir/src/transform/check_consts/validation.rs
@@ -576,7 +576,7 @@ fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location
 
                 if needs_drop {
                     self.check_op_spanned(
-                        ops::LiveDrop(Some(terminator.source_info.span)),
+                        ops::LiveDrop { dropped_at: Some(terminator.source_info.span) },
                         err_span,
                     );
                 }