Updates requested in the review.

Author: marek-trtik

src/taint-slicer/irept_instrument.cpp

@@ -13,25 +13,25 @@ Date: May 2017
 
 #include <taint-slicer/irept_instrument.h>
 
-static bool are_equal(const irept l, const irept r)
-{
-  return &l.read()==&r.read();
-}
+// WARNING: 'irept' does not support equality check and its explicit use
+// in functions below was not appreciated (see PR #132). Equivalence
+// checks are thus used. And so, in case of performance issues in the
+// instrumenter focus your attention also to profiling of these checks.
 
 irept instrument(const irept irep, const instrumenter_fnt &instrumenter)
 {
   bool modified=false;
 
   irept::subt new_sub;
-  for(const irept sub : irep.get_sub())
+  for(const irept &sub : irep.get_sub())
   {
     new_sub.push_back(instrument(sub, instrumenter));
-    if(!are_equal(new_sub.back(), sub))
+    if(new_sub.back()!=sub)
       modified=true;
   }
 
   irept::named_subt new_named_sub;
-  for(const irept::named_subt::value_type name_sub : irep.get_named_sub())
+  for(const irept::named_subt::value_type &name_sub : irep.get_named_sub())
   {
     const auto it_bool=
       new_named_sub.insert(
@@ -40,12 +40,12 @@ irept instrument(const irept irep, const instrumenter_fnt &instrumenter)
           instrument(name_sub.second, instrumenter)
         });
     assert(it_bool.second);
-    if(!are_equal(it_bool.first->second, name_sub.second))
+    if(it_bool.first->second!=name_sub.second)
       modified=true;
   }
 
   irept::named_subt new_comments;
-  for(const irept::named_subt::value_type name_sub : irep.get_comments())
+  for(const irept::named_subt::value_type &name_sub : irep.get_comments())
   {
     const auto it_bool=
       new_comments.insert(
@@ -54,7 +54,7 @@ irept instrument(const irept irep, const instrumenter_fnt &instrumenter)
           instrument(name_sub.second, instrumenter)
         });
     assert(it_bool.second);
-    if(!are_equal(it_bool.first->second, name_sub.second))
+    if(it_bool.first->second!=name_sub.second)
       modified=true;
   }
 
@@ -69,55 +69,57 @@ irept instrument(const irept irep, const instrumenter_fnt &instrumenter)
   return instrumenter(irep);
 }
 
-irept instrument_using_pivot(
+irept instrument_using_guide(
   const irept pivot,
   const irept irep,
-  const pivot_instrumenter_fnt &instrumenter)
+  const guide_instrumenter_fnt &instrumenter)
 {
   bool modified=false;
 
   irept::subt new_sub;
   for(auto pit=pivot.get_sub().cbegin(), iit=irep.get_sub().cbegin();
       pit!=pivot.get_sub().cend() && iit!=irep.get_sub().cend(); ++pit, ++iit)
   {
-    new_sub.push_back(instrument_using_pivot(*pit, *iit, instrumenter));
-    if(!are_equal(new_sub.back(), *iit))
+    new_sub.push_back(instrument_using_guide(*pit, *iit, instrumenter));
+    if(new_sub.back()!=*iit)
       modified=true;
   }
 
   irept::named_subt new_named_sub;
-  for(auto pit=pivot.get_named_sub().cbegin(),
-           iit=irep.get_named_sub().cbegin();
-      pit!=pivot.get_named_sub().cend() &&
+  for(auto iit=irep.get_named_sub().cbegin();
       iit!=irep.get_named_sub().cend();
-      ++pit, ++iit)
+      ++iit)
   {
+    const auto pit=pivot.get_named_sub().find(iit->first);
     const auto it_bool=
       new_named_sub.insert(
         {
           iit->first,
-          instrument_using_pivot(pit->second, iit->second, instrumenter)
+          pit!=pivot.get_named_sub().cend() ?
+            instrument_using_guide(pit->second, iit->second, instrumenter):
+            iit->second
         });
     assert(it_bool.second);
-    if(!are_equal(it_bool.first->second, iit->second))
+    if(it_bool.first->second!=iit->second)
       modified=true;
   }
 
   irept::named_subt new_comments;
-  for(auto pit=pivot.get_comments().cbegin(),
-           iit=irep.get_comments().cbegin();
-      pit!=pivot.get_comments().cend() &&
+  for(auto iit=irep.get_comments().cbegin();
       iit!=irep.get_comments().cend();
-      ++pit, ++iit)
+      ++iit)
   {
+    auto pit=pivot.get_comments().find(iit->first);
     const auto it_bool=
       new_comments.insert(
         {
           iit->first,
-          instrument_using_pivot(pit->second, iit->second, instrumenter)
+          pit!=pivot.get_comments().cend() ?
+            instrument_using_guide(pit->second, iit->second, instrumenter):
+            iit->second
         });
     assert(it_bool.second);
-    if(!are_equal(it_bool.first->second, iit->second))
+    if(it_bool.first->second!=iit->second)
       modified=true;
   }
 

src/taint-slicer/irept_instrument.h

@@ -27,7 +27,7 @@ proces of "irept" hierarchical and shared data structures.
 /// functions looking only into the passed instance (i.e. not into
 /// 'irept' hierarchy below the passed instance).
 typedef std::function<irept(irept)> instrumenter_fnt;
-typedef std::function<irept(irept, irept)> pivot_instrumenter_fnt;
+typedef std::function<irept(irept, irept)> guide_instrumenter_fnt;
 
 /*******************************************************************\
 
@@ -42,13 +42,7 @@ typedef std::function<irept(irept, irept)> pivot_instrumenter_fnt;
   the hierarchy it calls the passed instrumenter. The result of the
   function is a new 'irept' hierarchy constructed from the original
   one by traversing it bottom-up and by applying the instrumenter on
-  each visited node. It is possible that in the end the new hierarchy
-  shares some nodes with the original hierarchy. Namely, a node in the
-  new hierarchy is NOT a node of the original hierarchy only if
-  (a) The instrumenter returned for that node a new (different) node,
-  (b) The instrumenter returned for that node the same node, but in the
-      sub-hierarchy under that node there is a node for which the case (a)
-      was applied.
+  each visited node.
 
 \*******************************************************************/
 irept instrument(const irept irep, const instrumenter_fnt &instrumenter);
@@ -62,22 +56,23 @@ irept instrument(const irept irep, const instrumenter_fnt &instrumenter);
  Outputs:
 
  Purpose:
-  The function builds an instrumented copy of a passed hierarchy of
+  Builds an instrumented copy of a passed hierarchy of
   'irept's in the same way as the function 'instrument' above. However,
-  this version allows the user to also specify a 'pivot' hierarchy of
-  'irept's providing more refined instrumentation. For instance, the
-  instrumenter is called only on that topological part of the hierarchy
-  matching the topology of the pivot. Also, the instrumenter called for
-  some node may use the corresponding pivot node to decide how the
+  this version allows the user to also specify a 'guide' hierarchy of
+  'irept's providing more refined instrumentation.
+  The instrumenter is called only on that topological part of the hierarchy
+  matching the topology of the guide. Positional and named operands not present
+  in the guide irep are left unaltered. Also, the instrumenter called for
+  some node may use the corresponding guide node to decide how the
   instrumentation will be performed. For example, imagine two nodes of
   the exactly the same kind of the instrumenter passed with the different
-  kinds of pivot nodes. The intrumenter may then return nodes of different
-  kinds (according to kinds of pivot nodes).
+  kinds of guide nodes. The intrumenter may then return nodes of different
+  kinds (according to kinds of guide nodes).
 
 \*******************************************************************/
-irept instrument_using_pivot(
-  const irept pivot,
+irept instrument_using_guide(
+  const irept guide,
   const irept irep,
-  const pivot_instrumenter_fnt &instrumenter);
+  const guide_instrumenter_fnt &instrumenter);
 
 #endif