Work towards a non-panicing parser (libsyntax)

- Functions in parser.rs return PResult<> rather than panicing
- Other functions in libsyntax call panic! explicitly for now if they rely on panicing behaviour.
- 'panictry!' macro added as scaffolding while converting panicing functions.
  (This does the same as 'unwrap()' but is easier to grep for and turn into try!())
- Leaves panicing wrappers for the following functions so that the
  quote_* macros behave the same:
  - parse_expr, parse_item, parse_pat, parse_arm, parse_ty, parse_stmt

1 files changed, 2 insertions, 2 deletions

diff --git a/src/librustc/session/mod.rs b/src/librustc/session/mod.rs
index 3e3e5e17963..452840310aa 100644
--- a/src/librustc/session/mod.rs
+++ b/src/librustc/session/mod.rs
@@ -68,13 +68,13 @@ impl Session {
         if self.opts.treat_err_as_bug {
             self.span_bug(sp, msg);
         }
-        self.diagnostic().span_fatal(sp, msg)
+        panic!(self.diagnostic().span_fatal(sp, msg))
     }
     pub fn span_fatal_with_code(&self, sp: Span, msg: &str, code: &str) -> ! {
         if self.opts.treat_err_as_bug {
             self.span_bug(sp, msg);
         }
-        self.diagnostic().span_fatal_with_code(sp, msg, code)
+        panic!(self.diagnostic().span_fatal_with_code(sp, msg, code))
     }
     pub fn fatal(&self, msg: &str) -> ! {
         if self.opts.treat_err_as_bug {