Enhance analyzer reasoning about sending messages to nil. A nil receiver returns 0 for scalars of size <= sizeof(void*).

llvm-svn: 68629

1 files changed, 20 insertions, 0 deletions

diff --git a/clang/lib/Analysis/SVals.cpp b/clang/lib/Analysis/SVals.cpp
index b642857c502..c5900b30cd8 100644
--- a/clang/lib/Analysis/SVals.cpp
+++ b/clang/lib/Analysis/SVals.cpp
@@ -202,6 +202,22 @@ SVal loc::ConcreteInt::EvalBinOp(BasicValueFactory& BasicVals,
 }
 
 //===----------------------------------------------------------------------===//
+// Utility methods for constructing SVals.
+//===----------------------------------------------------------------------===//
+
+SVal SVal::MakeZero(BasicValueFactory &BasicVals, QualType T) {
+  if (Loc::IsLocType(T))
+    return Loc::MakeNull(BasicVals);
+
+  if (T->isIntegerType())
+    return NonLoc::MakeVal(BasicVals, 0, T);
+  
+  // FIXME: Handle floats.
+  // FIXME: Handle structs.
+  return UnknownVal();  
+}
+
+//===----------------------------------------------------------------------===//
 // Utility methods for constructing Non-Locs.
 //===----------------------------------------------------------------------===//
 
@@ -314,6 +330,10 @@ Loc Loc::MakeVal(AddrLabelExpr* E) { return loc::GotoLabel(E->getLabel()); }
 
 Loc Loc::MakeVal(SymbolRef sym) { return loc::SymbolVal(sym); }
 
+Loc Loc::MakeNull(BasicValueFactory &BasicVals) {
+  return loc::ConcreteInt(BasicVals.getZeroWithPtrWidth());
+}
+
 //===----------------------------------------------------------------------===//
 // Pretty-Printing.
 //===----------------------------------------------------------------------===//