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, 49 insertions, 0 deletions

diff --git a/staptree.cxx b/staptree.cxx
index 7a335fc3..9a69d11b 100644
--- a/staptree.cxx
+++ b/staptree.cxx
@@ -332,6 +332,12 @@ void cast_op::print (ostream& o) const
 }
 
 
+void defined_op::print (ostream& o) const
+{
+  o << "@defined(" << *operand << ")";
+}
+
+
 void vardecl::print (ostream& o) const
 {
   o << name;
@@ -1300,6 +1306,14 @@ cast_op::visit (visitor* u)
   u->visit_cast_op(this);
 }
 
+
+void
+defined_op::visit (visitor* u)
+{
+  u->visit_defined_op(this);
+}
+
+
 void
 arrayindex::visit (visitor* u)
 {
@@ -1675,6 +1689,13 @@ traversing_visitor::visit_cast_op (cast_op* e)
 }
 
 void
+traversing_visitor::visit_defined_op (defined_op* e)
+{
+  e->operand->visit (this);
+}
+
+
+void
 traversing_visitor::visit_arrayindex (arrayindex* e)
 {
   for (unsigned i=0; i<e->indexes.size(); i++)
@@ -1789,6 +1810,14 @@ varuse_collecting_visitor::visit_cast_op (cast_op *e)
 }
 
 void
+varuse_collecting_visitor::visit_defined_op (defined_op *e)
+{
+  // XXX
+  functioncall_traversing_visitor::visit_defined_op (e);
+}
+
+
+void
 varuse_collecting_visitor::visit_print_format (print_format* e)
 {
   // NB: Instead of being top-level statements, "print" and "printf"
@@ -2181,6 +2210,13 @@ throwing_visitor::visit_cast_op (cast_op* e)
 }
 
 void
+throwing_visitor::visit_defined_op (defined_op* e)
+{
+  throwone (e->tok);
+}
+
+
+void
 throwing_visitor::visit_arrayindex (arrayindex* e)
 {
   throwone (e->tok);
@@ -2423,6 +2459,13 @@ update_visitor::visit_cast_op (cast_op* e)
 }
 
 void
+update_visitor::visit_defined_op (defined_op* e)
+{
+  replace (e->operand);
+  provide (e);
+}
+
+void
 update_visitor::visit_arrayindex (arrayindex* e)
 {
   replace (e->base);
@@ -2660,6 +2703,12 @@ deep_copy_visitor::visit_cast_op (cast_op* e)
 }
 
 void
+deep_copy_visitor::visit_defined_op (defined_op* e)
+{
+  update_visitor::visit_defined_op(new defined_op(*e));
+}
+
+void
 deep_copy_visitor::visit_arrayindex (arrayindex* e)
 {
   update_visitor::visit_arrayindex(new arrayindex(*e));