Method isVariableUsage

lib/checkuninitvar.cpp:1154–1354

}

const Token* CheckUninitVarImpl::isVariableUsage(const Token *vartok, const Library& library, bool pointer, Alloc alloc, int indirect)
{
    const bool cpp = vartok->isCpp();
    const Token *valueExpr = vartok;   // non-dereferenced , no address of value as variable
    while (Token::Match(valueExpr->astParent(), ".|::") && astIsRhs(valueExpr))
        valueExpr = valueExpr->astParent();
    // stuff we ignore..
    while (valueExpr->astParent()) {
        // *&x
        if (valueExpr->astParent()->isUnaryOp("&") && valueExpr->astParent()->astParent() && valueExpr->astParent()->astParent()->isUnaryOp("*"))
            valueExpr = valueExpr->astParent()->astParent();
        // (type &)x
        else if (valueExpr->astParent()->isCast() && valueExpr->astParent()->isUnaryOp("(") && Token::simpleMatch(valueExpr->astParent()->link()->previous(), "& )"))
            valueExpr = valueExpr->astParent();
        // designated initializers: {.x | { ... , .x
        else if (Token::simpleMatch(valueExpr->astParent(), ".") &&
                 Token::Match(valueExpr->astParent()->previous(), ",|{"))
            valueExpr = valueExpr->astParent();
        else
            break;
    }
    if (!pointer) {
        if (Token::Match(vartok, "%name% [.(]") && vartok->variable() && !vartok->variable()->isPointer())
            return nullptr;
        while (Token::simpleMatch(valueExpr->astParent(), ".") && astIsLhs(valueExpr) && valueExpr->astParent()->valueType() && valueExpr->astParent()->valueType()->pointer == 0)
            valueExpr = valueExpr->astParent();
    }
    const Token *derefValue = nullptr; // dereferenced value expression
    if (alloc != NO_ALLOC) {
        const int arrayDim = (vartok->variable() && vartok->variable()->isArray()) ? vartok->variable()->dimensions().size() : 1;
        int deref = 0;
        derefValue = valueExpr;
        while (Token::Match(derefValue->astParent(), "+|-|*|[|.") ||
               (derefValue->astParent() && derefValue->astParent()->isCast()) ||
               (deref < arrayDim && Token::simpleMatch(derefValue->astParent(), "&") && derefValue->astParent()->isBinaryOp())) {
            const Token * const derefValueParent = derefValue->astParent();
            if (derefValueParent->str() == "*") {
                if (derefValueParent->isUnaryOp("*"))
                    ++deref;
                else
                    break;
            } else if (derefValueParent->str() == "[") {
                if (astIsLhs(derefValue))
                    ++deref;
                else
                    break;
            } else if (Token::Match(derefValueParent, "[+-]")) {
                if (deref >= arrayDim)
                    break;
            } else if (derefValueParent->str() == ".")
                ++deref;
            derefValue = derefValueParent;
            if (deref < arrayDim)
                valueExpr = derefValue;
        }
        if (deref < arrayDim) {
            // todo compare deref with array dimensions
            derefValue = nullptr;