Set flow direction

Author: web-flow

lib/valueflow.cpp

@@ -5861,9 +5861,9 @@ static void valueFlowSubFunction(const TokenList& tokenlist,
                         continue;
                 }
 
-                if (argvar->isReference() && isVariableChanged(argvar, settings)) {
+                if (argvar->isReference()) {
                     argvalues.remove_if([](const ValueFlow::Value& v) {
-                        return !v.isUninitValue();
+                        return v.isReverse();
                     });
                 }
 

lib/vf_analyzers.cpp

@@ -1606,6 +1606,7 @@ ValuePtr<Analyzer> makeAnalyzer(const Token* exprTok, ValueFlow::Value value, co
 
 ValuePtr<Analyzer> makeReverseAnalyzer(const Token* exprTok, ValueFlow::Value value, const Settings& settings)
 {
+    value.setFlow(ValueFlow::Value::Flow::REVERSE);
     if (value.isContainerSizeValue())
         return ContainerExpressionAnalyzer(exprTok, std::move(value), settings);
     return ExpressionAnalyzer(exprTok, std::move(value), settings);

lib/vfvalue.cpp

@@ -27,7 +27,9 @@
 
 namespace ValueFlow {
     Value::Value(const Token *c, MathLib::bigint val, Bound b)
-        : bound(b),
+        : valueType(ValueType::INT),
+        bound(b),
+        flow(Flow::UNKNOWN),
         safe(false),
         conditional(false),
         macro(false),

lib/vfvalue.h

@@ -45,7 +45,9 @@ namespace ValueFlow
         enum class Bound : std::uint8_t { Upper, Lower, Point };
 
         explicit Value(MathLib::bigint val = 0, Bound b = Bound::Point) :
+            valueType(ValueType::INT),
             bound(b),
+            flow(Flow::UNKNOWN),
             safe(false),
             conditional(false),
             macro(false),
@@ -212,7 +214,7 @@ namespace ValueFlow
             ITERATOR_START,
             ITERATOR_END,
             SYMBOLIC
-        } valueType = ValueType::INT;
+        } valueType : 4;
         bool isIntValue() const {
             return valueType == ValueType::INT;
         }
@@ -267,7 +269,15 @@ namespace ValueFlow
         }
 
         /** The value bound  */
-        Bound bound = Bound::Point;
+        Bound bound : 2;
+
+        enum class Flow : std::uint8_t {
+            UNKNOWN,
+            FORWARD,
+            REVERSE
+        } flow : 2;
+        bool isReverse() const { return flow == Flow::REVERSE; }
+        void setFlow(Flow f) { flow = f; }
 
         /** value relies on safe checking */
         // cppcheck-suppress premium-misra-cpp-2023-12.2.1