Class ExpressionAnalyzer

lib/vf_analyzers.cpp:1244–1357

};

struct ExpressionAnalyzer : SingleValueFlowAnalyzer {
    const Token* expr;
    bool local = true;
    bool unknown{};
    bool dependOnThis{};
    bool uniqueExprId{};

    ExpressionAnalyzer(const Token* e, ValueFlow::Value val, const Settings& s)
        : SingleValueFlowAnalyzer(std::move(val), s),
        expr(e)
    {

        assert(e && e->exprId() != 0 && "Not a valid expression");
        dependOnThis = exprDependsOnThis(expr);
        setupExprVarIds(expr);
        if (value.isSymbolicValue()) {
            dependOnThis |= exprDependsOnThis(value.tokvalue);
            setupExprVarIds(value.tokvalue);
        }
        uniqueExprId =
            expr->isUniqueExprId() && (Token::Match(expr, "%cop%") || !isVariableChanged(expr, 0, s));
    }

    static bool nonLocal(const Variable* var, bool deref) {
        return !var || (!var->isLocal() && !var->isArgument()) || (deref && var->isArgument() && var->isPointer()) ||
               var->isStatic() || var->isReference() || var->isExtern();
    }

    void setupExprVarIds(const Token* start, int depth = 0) {
        if (depth > settings.vfOptions.maxExprVarIdDepth) {
            // TODO: add bailout message
            return;
        }
        visitAstNodes(start, [&](const Token* tok) {
            const bool top = depth == 0 && tok == start;
            const bool ispointer = astIsPointer(tok) || astIsSmartPointer(tok) || astIsIterator(tok);
            if (!top || !ispointer || value.indirect != 0) {
                for (const ValueFlow::Value& v : tok->values()) {
                    if (!(v.isLocalLifetimeValue() || (ispointer && v.isSymbolicValue() && v.isKnown())))
                        continue;
                    if (!v.tokvalue)
                        continue;
                    if (v.tokvalue == tok)
                        continue;
                    setupExprVarIds(v.tokvalue, depth + 1);
                }
            }
            if (depth == 0 && tok->isIncompleteVar()) {
                // TODO: Treat incomplete var as global, but we need to update
                // the alias variables to just expr ids instead of requiring
                // Variable
                unknown = true;
                return ChildrenToVisit::none;
            }
            if (tok->varId() > 0) {
                varids[tok->varId()] = tok->variable();
                if (!Token::simpleMatch(tok->previous(), ".")) {
                    const Variable* var = tok->variable();