1 files changed, 20 insertions, 0 deletions
diff --git a/lib/StaticAnalyzer/Core/ExprEngineC.cpp b/lib/StaticAnalyzer/Core/ExprEngineC.cpp
index 93e598a273..d5555daecd 100644
--- a/lib/StaticAnalyzer/Core/ExprEngineC.cpp
+++ b/lib/StaticAnalyzer/Core/ExprEngineC.cpp
@@ -58,6 +58,26 @@ void ExprEngine::VisitBinaryOperator(const BinaryOperator* B,
       
     if (!B->isAssignmentOp()) {
       StmtNodeBuilder Bldr(*it, Tmp2, *currentBuilderContext);
+
+      if (B->isAdditiveOp()) {
+        // If one of the operands is a location, conjure a symbol for the other
+        // one (offset) if it's unknown so that memory arithmetic always
+        // results in an ElementRegion.
+        // TODO: This can be removed after we enable history tracking with
+        // SymSymExpr.
+        unsigned Count = currentBuilderContext->getCurrentBlockCount();
+        if (isa<Loc>(LeftV) &&
+            RHS->getType()->isIntegerType() && RightV.isUnknown()) {
+          RightV = svalBuilder.getConjuredSymbolVal(RHS, LCtx,
+                                                    RHS->getType(), Count);
+        }
+        if (isa<Loc>(RightV) &&
+            LHS->getType()->isIntegerType() && LeftV.isUnknown()) {
+          LeftV = svalBuilder.getConjuredSymbolVal(LHS, LCtx,
+                                                   LHS->getType(), Count);
+        }
+      }
+
       // Process non-assignments except commas or short-circuited
       // logical expressions (LAnd and LOr).
       SVal Result = evalBinOp(state, Op, LeftV, RightV, B->getType());