Change CheckDeadStores to use Expr::isNullPointerConstant, which will correctly determine whether an expression is a null pointer constant.

Patch by Kovarththanan Rajaratnam!

llvm-svn: 89621

1 files changed, 5 insertions, 6 deletions

diff --git a/clang/lib/Analysis/CheckDeadStores.cpp b/clang/lib/Analysis/CheckDeadStores.cpp
index d5cb7ca7fdd..dd70ed7f2c1 100644
--- a/clang/lib/Analysis/CheckDeadStores.cpp
+++ b/clang/lib/Analysis/CheckDeadStores.cpp
@@ -134,16 +134,15 @@ public:
 
       if (DeclRefExpr* DR = dyn_cast<DeclRefExpr>(B->getLHS()))
         if (VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
-          Expr* RHS = B->getRHS()->IgnoreParenCasts();
-
           // Special case: check for assigning null to a pointer.
           //  This is a common form of defensive programming.
           if (VD->getType()->isPointerType()) {
-            if (IntegerLiteral* L = dyn_cast<IntegerLiteral>(RHS))
-              // FIXME: Probably should have an Expr::isNullPointerConstant.
-              if (L->getValue() == 0)
-                return;
+            if (B->getRHS()->isNullPointerConstant(Ctx,
+                                              Expr::NPC_ValueDependentIsNull))
+              return;
           }
+
+          Expr* RHS = B->getRHS()->IgnoreParenCasts();
           // Special case: self-assignments.  These are often used to shut up
           //  "unused variable" compiler warnings.
           if (DeclRefExpr* RhsDR = dyn_cast<DeclRefExpr>(RHS))