PR10102: tolerate the failure related to optional probe

This patch will make stap silently accept the
failure related to optional probe. It puts try/catch
around find_and_build which can cover most probe types.
The specific treatment for dwarf_derived_probe in
commit ed82b7c902d6a2e26452ec51c9cdb9665dbf9e97 is
reverted.

1 files changed, 12 insertions, 4 deletions

diff --git a/elaborate.cxx b/elaborate.cxx
index 53f2a8f6..6fb3f197 100644
--- a/elaborate.cxx
+++ b/elaborate.cxx
@@ -406,9 +406,6 @@ match_node::find_and_build (systemtap_session& s,
       sub_map_iterator_t i = sub.find (match);
       if (i == sub.end()) // no match
         {
-          if (loc->optional) /* PR10102: to tolerate mismatched optional probe */
-		return;
-
           string alternatives;
           for (sub_map_iterator_t i = sub.begin(); i != sub.end(); i++)
             alternatives += string(" ") + i->first.str();
@@ -633,7 +630,18 @@ derive_probes (systemtap_session& s,
           // and set a flag on the copy permanently.
           bool old_loc_opt = loc->optional;
           loc->optional = loc->optional || optional;
-          s.pattern_root->find_and_build (s, p, loc, 0, dps); // <-- actual derivation!
+          try
+	    {
+	      s.pattern_root->find_and_build (s, p, loc, 0, dps); // <-- actual derivation!
+	    }
+          catch (const semantic_error& e)
+	    {
+              if (!loc->optional)
+                throw semantic_error(e);
+              else /* tolerate failure for optional probe */
+	        continue;
+	    }
+
           loc->optional = old_loc_opt;
           unsigned num_atend = dps.size();