PR10831: Remember derived "aliases" in the probe chain

SDT and label probes are not really final probe types themselves, but
rather they get translated into some other final type.  This patch
preserves this relationship as if SDT and label probes were dynamically
generated aliases.

* elaborate.cxx (probe::create_alias): New, fake an alias_derived_probe.
* tapsets.cxx (query_label): Append the label name as an alias.
  (sdt_query::handle_query_module): Let convert_location do the alias.
  (sdt_query::convert_location): Translate the location using an alias.
* main.cxx (printscript): Elaborate the derivation debug dump.

1 files changed, 1 insertions, 0 deletions

diff --git a/staptree.h b/staptree.h
index f357eb28..67349b8e 100644
--- a/staptree.h
+++ b/staptree.h
@@ -681,6 +681,7 @@ struct probe
   virtual void printsig (std::ostream &o) const;
   virtual void collect_derivation_chain (std::vector<probe*> &probes_list);
   virtual const probe_alias *get_alias () const { return 0; }
+  virtual probe* create_alias(probe_point* l, probe_point* a);
   virtual probe* basest () { return this; }
   virtual ~probe() {}
   bool privileged;