rollup merge of #20258: sanxiyn/show-span-2

diff --cc src/librustc/session/config.rs
Simple merge

diff --cc src/librustc/session/mod.rs
index 770e8d73ec7614f70ceb16982a5bdd7f9838f72a,9a6275401adc81e22b662bc80eabd9559d5e5d41..abb780615ae7b8170f6f8801dd660e3368417683
--- 1/src/librustc/session/mod.rs
--- 2/src/librustc/session/mod.rs
+++ b/src/librustc/session/mod.rs
@@@ -201,12 -199,9 +201,12 @@@ impl Session 
      pub fn no_landing_pads(&self) -> bool {
          self.debugging_opt(config::NO_LANDING_PADS)
      }
-     pub fn show_span(&self) -> bool {
-         self.debugging_opt(config::SHOW_SPAN)
+     pub fn unstable_options(&self) -> bool {
+         self.debugging_opt(config::UNSTABLE_OPTIONS)
      }
 +    pub fn print_enum_sizes(&self) -> bool {
 +        self.debugging_opt(config::PRINT_ENUM_SIZES)
 +    }
      pub fn sysroot<'a>(&'a self) -> &'a Path {
          match self.opts.maybe_sysroot {
              Some (ref sysroot) => sysroot,

diff --cc src/librustc_driver/driver.rs
index 9540c3fa3d7e817ff692ba791c255b916b1ca0c2,5e563ae9d6dfa9b47e5663a40c2c8ba033961655..f5c29a6b30b3069f7fe9f02859cc033d44ddf451
--- 1/src/librustc_driver/driver.rs
--- 2/src/librustc_driver/driver.rs
+++ b/src/librustc_driver/driver.rs
@@@ -143,11 -132,14 +143,11 @@@ pub fn phase_1_parse_input(sess: &Sessi
      });
  
      if sess.opts.debugging_opts & config::AST_JSON_NOEXPAND != 0 {
 -        let mut stdout = io::BufferedWriter::new(io::stdout());
 -        let mut json = json::PrettyEncoder::new(&mut stdout);
 -        // unwrapping so IoError isn't ignored
 -        krate.encode(&mut json).unwrap();
 +        println!("{}", json::as_json(&krate));
      }
  
-     if sess.show_span() {
-         syntax::show_span::run(sess.diagnostic(), &krate);
+     if let Some(ref s) = sess.opts.show_span {
+         syntax::show_span::run(sess.diagnostic(), s.as_slice(), &krate);
      }
  
      krate

diff --cc src/librustc_driver/lib.rs
Simple merge