rustc_span: return an impl Iterator instead of a Vec from macro_backtrace.

2 files changed, 6 insertions, 6 deletions

diff --git a/src/librustc_errors/emitter.rs b/src/librustc_errors/emitter.rs
index 49c8be28292..f9e23e96fa8 100644
--- a/src/librustc_errors/emitter.rs
+++ b/src/librustc_errors/emitter.rs
@@ -343,8 +343,9 @@ pub trait Emitter {
             if call_sp != *sp && !always_backtrace {
                 before_after.push((*sp, call_sp));
             }
-            let backtrace_len = sp.macro_backtrace().len();
-            for (i, trace) in sp.macro_backtrace().iter().rev().enumerate() {
+            let macro_backtrace: Vec<_> = sp.macro_backtrace().collect();
+            let backtrace_len = macro_backtrace.len();
+            for (i, trace) in macro_backtrace.iter().rev().enumerate() {
                 // Only show macro locations that are local
                 // and display them like a span_note
                 if trace.def_site.is_dummy() {
@@ -398,8 +399,7 @@ pub trait Emitter {
                 continue;
             }
             if sm.span_to_filename(sp_label.span.clone()).is_macros() && !always_backtrace {
-                let v = sp_label.span.macro_backtrace();
-                if let Some(use_site) = v.last() {
+                if let Some(use_site) = sp_label.span.macro_backtrace().last() {
                     before_after.push((sp_label.span.clone(), use_site.call_site.clone()));
                 }
             }
diff --git a/src/librustc_errors/json.rs b/src/librustc_errors/json.rs
index 21be9527b6c..3ddf9b09893 100644
--- a/src/librustc_errors/json.rs
+++ b/src/librustc_errors/json.rs
@@ -309,7 +309,7 @@ impl DiagnosticSpan {
         // backtrace ourselves, but the `macro_backtrace` helper makes
         // some decision, such as dropping some frames, and I don't
         // want to duplicate that logic here.
-        let backtrace = span.macro_backtrace().into_iter();
+        let backtrace = span.macro_backtrace();
         DiagnosticSpan::from_span_full(span, is_primary, label, suggestion, backtrace, je)
     }
 
@@ -318,7 +318,7 @@ impl DiagnosticSpan {
         is_primary: bool,
         label: Option<String>,
         suggestion: Option<(&String, Applicability)>,
-        mut backtrace: vec::IntoIter<ExpnData>,
+        mut backtrace: impl Iterator<Item = ExpnData>,
         je: &JsonEmitter,
     ) -> DiagnosticSpan {
         let start = je.sm.lookup_char_pos(span.lo());