PR tree-optimization/18815

[pf3gnuchains/gcc-fork.git] / gcc / gimple-low.c

diff --git a/gcc/gimple-low.c b/gcc/gimple-low.c
index 6e60aeb..f3e70ee 100644 (file)
--- a/gcc/gimple-low.c
+++ b/gcc/gimple-low.c
@@ -291,15 +291,16 @@ try_catch_may_fallthru (tree stmt)
       return false;
 
     case EH_FILTER_EXPR:
-      /* If the exception does not match EH_FILTER_TYPES, we will
-        execute EH_FILTER_FAILURE, and we will fall through if that
-        falls through.  If the exception does match EH_FILTER_TYPES,
-        we will fall through.  We don't know which exceptions may be
-        generated, so we just check for EH_FILTER_TYPES being NULL,
-        in which case we know that that the exception does not
-        match.  */
-      return (EH_FILTER_TYPES (tsi_stmt (i)) != NULL
-             || block_may_fallthru (EH_FILTER_FAILURE (tsi_stmt (i))));
+      /* The exception filter expression only matters if there is an
+        exception.  If the exception does not match EH_FILTER_TYPES,
+        we will execute EH_FILTER_FAILURE, and we will fall through
+        if that falls through.  If the exception does match
+        EH_FILTER_TYPES, the stack unwinder will continue up the
+        stack, so we will not fall through.  We don't know whether we
+        will throw an exception which matches EH_FILTER_TYPES or not,
+        so we just ignore EH_FILTER_TYPES and assume that we might
+        throw an exception which doesn't match.  */
+      return block_may_fallthru (EH_FILTER_FAILURE (tsi_stmt (i)));
 
     default:
       /* This case represents statements to be executed when an