From 3f6b3bbace466f4be1311192f335c4c7792a83d2 Mon Sep 17 00:00:00 2001
From: Esteban Küber <esteban@kuber.com.ar>
Date: Thu, 10 May 2018 09:09:58 -0700
Subject: Improve format string errors

 - Point at format string position inside the formatting string
 - Explain that argument names can't start with an underscore
---
 src/libsyntax_pos/lib.rs | 7 +++++++
 1 file changed, 7 insertions(+)

(limited to 'src/libsyntax_pos')

diff --git a/src/libsyntax_pos/lib.rs b/src/libsyntax_pos/lib.rs
index 8b4a3ea26a1..e1693ff4db6 100644
--- a/src/libsyntax_pos/lib.rs
+++ b/src/libsyntax_pos/lib.rs
@@ -427,6 +427,13 @@ impl Span {
         )
     }
 
+    pub fn from_inner_byte_pos(self, start: usize, end: usize) -> Span {
+        let span = self.data();
+        Span::new(span.lo + BytePos::from_usize(start),
+                  span.lo + BytePos::from_usize(end),
+                  span.ctxt)
+    }
+
     #[inline]
     pub fn apply_mark(self, mark: Mark) -> Span {
         let span = self.data();
-- 
cgit 1.4.1-3-g733a5