From b8de01c0d9806da3fc276329e251df81a3ec3886 Mon Sep 17 00:00:00 2001
From: Ryan Prichard <ryan.prichard@gmail.com>
Date: Sun, 5 Apr 2015 18:15:38 -0700
Subject: [PATCH] Remove the vestigial ExtCtxt::print_backtrace function.

It was added in 2011-08-05 and reduced to a no-op ten days later.
---
 src/libsyntax/ext/base.rs       | 10 ----------
 src/libsyntax/ext/log_syntax.rs |  2 --
 2 files changed, 12 deletions(-)

diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index 71fba789ff835..88b119bb9e115 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -603,7 +603,6 @@ impl<'a> ExtCtxt<'a> {
             None => self.bug("missing top span")
         })
     }
-    pub fn print_backtrace(&self) { }
     pub fn backtrace(&self) -> ExpnId { self.backtrace }
     pub fn original_span(&self) -> Span {
         let mut expn_id = self.backtrace;
@@ -698,7 +697,6 @@ impl<'a> ExtCtxt<'a> {
     ///   substitute; we never hit resolve/type-checking so the dummy
     ///   value doesn't have to match anything)
     pub fn span_fatal(&self, sp: Span, msg: &str) -> ! {
-        self.print_backtrace();
         self.parse_sess.span_diagnostic.span_fatal(sp, msg);
     }
 
@@ -708,35 +706,27 @@ impl<'a> ExtCtxt<'a> {
     /// Compilation will be stopped in the near future (at the end of
     /// the macro expansion phase).
     pub fn span_err(&self, sp: Span, msg: &str) {
-        self.print_backtrace();
         self.parse_sess.span_diagnostic.span_err(sp, msg);
     }
     pub fn span_warn(&self, sp: Span, msg: &str) {
-        self.print_backtrace();
         self.parse_sess.span_diagnostic.span_warn(sp, msg);
     }
     pub fn span_unimpl(&self, sp: Span, msg: &str) -> ! {
-        self.print_backtrace();
         self.parse_sess.span_diagnostic.span_unimpl(sp, msg);
     }
     pub fn span_bug(&self, sp: Span, msg: &str) -> ! {
-        self.print_backtrace();
         self.parse_sess.span_diagnostic.span_bug(sp, msg);
     }
     pub fn span_note(&self, sp: Span, msg: &str) {
-        self.print_backtrace();
         self.parse_sess.span_diagnostic.span_note(sp, msg);
     }
     pub fn span_help(&self, sp: Span, msg: &str) {
-        self.print_backtrace();
         self.parse_sess.span_diagnostic.span_help(sp, msg);
     }
     pub fn fileline_help(&self, sp: Span, msg: &str) {
-        self.print_backtrace();
         self.parse_sess.span_diagnostic.fileline_help(sp, msg);
     }
     pub fn bug(&self, msg: &str) -> ! {
-        self.print_backtrace();
         self.parse_sess.span_diagnostic.handler().bug(msg);
     }
     pub fn trace_macros(&self) -> bool {
diff --git a/src/libsyntax/ext/log_syntax.rs b/src/libsyntax/ext/log_syntax.rs
index 8173dd93f7468..9869108952c5e 100644
--- a/src/libsyntax/ext/log_syntax.rs
+++ b/src/libsyntax/ext/log_syntax.rs
@@ -26,8 +26,6 @@ pub fn expand_syntax_ext<'cx>(cx: &'cx mut base::ExtCtxt,
         return base::DummyResult::any(sp);
     }
 
-    cx.print_backtrace();
-
     println!("{}", print::pprust::tts_to_string(tts));
 
     // any so that `log_syntax` can be invoked as an expression and item.