[analyzer] Don't try to evaluate MaterializeTemporaryExpr as a constant.

...and don't consider '0' to be a null pointer constant if it's the
initializer for a float!

Apparently null pointer constant evaluation looks through both
MaterializeTemporaryExpr and ImplicitCastExpr, so we have to be more
careful about types in the callers. For RegionStore this just means giving
up a little more; for ExprEngine this means handling the
MaterializeTemporaryExpr case explicitly.

Follow-up to r180894.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180944 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 2 deletions

diff --git a/lib/StaticAnalyzer/Core/SValBuilder.cpp b/lib/StaticAnalyzer/Core/SValBuilder.cpp
index 652809777c..9d77a3ef58 100644
--- a/lib/StaticAnalyzer/Core/SValBuilder.cpp
+++ b/lib/StaticAnalyzer/Core/SValBuilder.cpp
@@ -268,13 +268,18 @@ Optional<SVal> SValBuilder::getConstantVal(const Expr *E) {
 
   // If we don't have a special case, fall back to the AST's constant evaluator.
   default: {
+    // Don't try to come up with a value for materialized temporaries.
+    if (E->isGLValue())
+      return None;
+
     ASTContext &Ctx = getContext();
     llvm::APSInt Result;
     if (E->EvaluateAsInt(Result, Ctx))
       return makeIntVal(Result);
 
-    if (E->isNullPointerConstant(Ctx, Expr::NPC_ValueDependentIsNotNull))
-      return makeNull();
+    if (Loc::isLocType(E->getType()))
+      if (E->isNullPointerConstant(Ctx, Expr::NPC_ValueDependentIsNotNull))
+        return makeNull();
 
     return None;
   }