Add update_visitor::replace

I noticed that most uses of update_visitor::require() were simply
writing the value back to the same place, i.e. foo = require(foo).  The
new replace() method just encapsulates that paradigm, so we don't have
the duplication between the LHS and RHS.

* staptree.h (update_visitor::replace): New.
* elaborate.cxx, staptree.cxx, tapset-mark.cxx, tapset-perfmon.cxx,
  tapset-procfs.cxx, tapset-utrace.cxx, tapsets.cxx: Update all require
  calls that are simply updating the value in-place.

1 files changed, 5 insertions, 0 deletions

diff --git a/staptree.h b/staptree.h
index bc479559..c9b2bdce 100644
--- a/staptree.h
+++ b/staptree.h
@@ -874,6 +874,11 @@ struct update_visitor: public visitor
     targets.push(static_cast<void*>(src));
   }
 
+  template <typename T> void replace (T*& src, bool clearok=false)
+  {
+    src = require(src, clearok);
+  }
+
   virtual ~update_visitor() { assert(targets.empty()); }
 
   virtual void visit_block (block *s);