PR11005: @defined($tvar) predicate, part 1

* staptree.h (defined_op): New class.
* all files: Extend all visitors as appropriate, mostly
  dummy/pass-through implementation.
* parse.cxx (parse_target_symbol): New function, factored out
  of parse_symbol().
  (parse_define_op): New function.
* NEWS: Mention it.
* parse.h: Corresponding changes.
* tapsets.cxx (var_expanding_visitor::visit_defined_op):
  Implement @defined() semantics.
  (dwarf_var_expanding_visitor::visit_target_symbol): Adjust.
* tapset-utrace.c (visit_target_symbol_arg): Avoid crashes
  on $argZZZ.
* tapsets.cxx (sdt_var_expanding_visitor): Ditto.
* semok/thirtysix.stp: New test.

1 files changed, 3 insertions, 1 deletions

diff --git a/parse.h b/parse.h
index 0ff8664c..8f34442a 100644
--- a/parse.h
+++ b/parse.h
@@ -1,5 +1,5 @@
 // -*- C++ -*-
-// Copyright (C) 2005-2007 Red Hat Inc.
+// Copyright (C) 2005-2010 Red Hat Inc.
 // Copyright (C) 2007 Bull S.A.S
 //
 // This file is part of systemtap, and is free software.  You can
@@ -188,6 +188,8 @@ private: // nonterminals
   continue_statement* parse_continue_statement ();
   indexable* parse_indexable ();
   const token *parse_hist_op_or_bare_name (hist_op *&hop, std::string &name);
+  target_symbol *parse_target_symbol (const token* t);
+  expression* parse_defined_op (const token* t);
   expression* parse_expression ();
   expression* parse_assignment ();
   expression* parse_ternary ();