Implement lazy "copying" of structures and arrays in RegionStore. While

RegionStore already lazily abstracted the contents of arrays and structs, when
doing an assignment from one array/struct to another we did an explicit
element-wise copy, which resulted in a loss of laziness and huge performance
problem when analyzing many code bases.

Now RegionStoreManager handles such assignments using a new SVal could
'LazyCompoundSVal', which basically means the value of a given struct or array
(a MemRegion*) in a specific state (GRState). When we do a load from a field
whose encompassing struct binds to a LazyCompoundSVal, we essentially do a field
lookup in the original structure. This means we have essentially zero copying of
data for structs/arrays and everything stays lazy.

llvm-svn: 78268

1 files changed, 15 insertions, 1 deletions

diff --git a/clang/lib/Analysis/SVals.cpp b/clang/lib/Analysis/SVals.cpp
index 5ac18a15065..c597ba459e7 100644
--- a/clang/lib/Analysis/SVals.cpp
+++ b/clang/lib/Analysis/SVals.cpp
@@ -158,6 +158,14 @@ void SVal::symbol_iterator::expand() {
   assert(false && "unhandled expansion case");
 }
 
+const GRState *nonloc::LazyCompoundVal::getState() const {
+  return static_cast<const LazyCompoundValData*>(Data)->getState();
+}
+
+const TypedRegion *nonloc::LazyCompoundVal::getRegion() const {
+  return static_cast<const LazyCompoundValData*>(Data)->getRegion();
+}
+
 //===----------------------------------------------------------------------===//
 // Other Iterators.
 //===----------------------------------------------------------------------===//
@@ -289,7 +297,13 @@ void NonLoc::dumpToStream(llvm::raw_ostream& os) const {
       }
       os << "}";
       break;
-    }      
+    }
+    case nonloc::LazyCompoundValKind: {
+      const nonloc::LazyCompoundVal &C = *cast<nonloc::LazyCompoundVal>(this);
+      os << "lazyCompoundVal{" << (void*) C.getState() << ',' << C.getRegion()
+         << '}';
+      break;
+    }            
     default:
       assert (false && "Pretty-printed not implemented for this NonLoc.");
       break;