[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.

llvm-svn: 180944

2 files changed, 15 insertions, 3 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
index 0d5fb1785b3..bfe4e15a715 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -741,6 +741,13 @@ void ExprEngine::Visit(const Stmt *S, ExplodedNode *Pred,
       const CXXDefaultArgExpr *DefaultE = cast<CXXDefaultArgExpr>(S);
       const Expr *ArgE = DefaultE->getExpr();
 
+      bool IsTemporary = false;
+      if (const MaterializeTemporaryExpr *MTE =
+            dyn_cast<MaterializeTemporaryExpr>(ArgE)) {
+        ArgE = MTE->GetTemporaryExpr();
+        IsTemporary = true;
+      }
+
       Optional<SVal> ConstantVal = svalBuilder.getConstantVal(ArgE);
       if (!ConstantVal)
         ConstantVal = UnknownVal();
@@ -749,7 +756,7 @@ void ExprEngine::Visit(const Stmt *S, ExplodedNode *Pred,
            I != E; ++I) {
         ProgramStateRef State = (*I)->getState();
         State = State->BindExpr(DefaultE, LCtx, *ConstantVal);
-        if (DefaultE->isGLValue())
+        if (IsTemporary)
           State = createTemporaryRegionIfNeeded(State, LCtx, DefaultE,
                                                 DefaultE);
         Bldr2.generateNode(S, *I, State);
diff --git a/clang/lib/StaticAnalyzer/Core/SValBuilder.cpp b/clang/lib/StaticAnalyzer/Core/SValBuilder.cpp
index 652809777cf..9d77a3ef58f 100644
--- a/clang/lib/StaticAnalyzer/Core/SValBuilder.cpp
+++ b/clang/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;
   }