Streamlining exception handling macros a little bit.

* eval.c (op_unwind_protect): Use uw_simple_catch_begin,
and remove the uw_catch (exsym, exvals) clause. Put
explicit braces around the unwind code even though it
is only one statement.

* match.c (do_txeval): Got rid of empty uw_unwind clause.
This is not needed any longer.
(v_try): Got rid of explicit uw_do_unwind calls.

* unwind.h (uw_simple_catch_begin): New macro.
(uw_do_unwind): Macro removed.
(uw_catch): Added goto uw_unwind_label at the front.
This way if the previous clause falls through,
control goes to the unwind logic.
(uw_unwind): Got rid of initial break. Previous
clause should fall through to unwind logic,
whether it is the main clause, or one of the catches.
(uw_catch_end): Default case aborts, because
we don't expect this.

1 files changed, 2 insertions, 2 deletions

diff --git a/match.c b/match.c
index 09d34dec..4e060df0 100644
--- a/match.c
+++ b/match.c
@@ -1366,6 +1366,8 @@ static val do_txeval(val spec, val form, val bindings, val allow_unbound)
 
       sem_error(spec, lit("~a"), exc, nao);
     }
+
+    uw_unwind { }
   }
   uw_catch_end;
 
@@ -2748,7 +2750,6 @@ static val v_try(match_files_ctx *c)
     uw_catch_begin(catch_syms, exsym, exvals);
 
     result = match_files(mf_spec(*c, try_clause));
-    uw_do_unwind;
 
     uw_catch(exsym, exvals) {
       {
@@ -2807,7 +2808,6 @@ static val v_try(match_files_ctx *c)
           }
         }
       }
-      uw_do_unwind;
     }
 
     uw_unwind {