void WritingToTemporary::VisitStmt()

in src/checks/level0/writing-to-temporary.cpp [55:116]
50 lines of code
20 McCabe index (conditional complexity)

void WritingToTemporary::VisitStmt(clang::Stmt *stmt)
{
    auto *callExpr = dyn_cast<CallExpr>(stmt);
    if (!callExpr) {
        return;
    }

    if (shouldIgnoreFile(stmt->getBeginLoc())) {
        return;
    }

    // For a chain like getFoo().setBar(), returns {setBar(), getFoo()}
    std::vector<CallExpr *> callExprs = Utils::callListForChain(callExpr); // callExpr is the call to setBar()
    if (callExprs.size() < 2) {
        return;
    }

    CallExpr *firstCallToBeEvaluated = callExprs.at(callExprs.size() - 1); // This is the call to getFoo()
    FunctionDecl *firstFunc = firstCallToBeEvaluated->getDirectCallee();
    if (!firstFunc) {
        return;
    }

    CallExpr *secondCallToBeEvaluated = callExprs.at(callExprs.size() - 2); // This is the call to setBar()
    FunctionDecl *secondFunc = secondCallToBeEvaluated->getDirectCallee();
    if (!secondFunc) {
        return;
    }

    auto *secondMethod = dyn_cast<CXXMethodDecl>(secondFunc);
    if (!secondMethod || secondMethod->isConst() || secondMethod->isStatic()) {
        return;
    }

    CXXRecordDecl *record = secondMethod->getParent();
    if (!record || isDisallowedClass(record->getNameAsString())) {
        return;
    }

    QualType qt = firstFunc->getReturnType();
    const Type *firstFuncReturnType = qt.getTypePtrOrNull();
    if (!firstFuncReturnType || firstFuncReturnType->isPointerType() || firstFuncReturnType->isReferenceType()) {
        return;
    }

    qt = secondFunc->getReturnType();
    const Type *secondFuncReturnType = qt.getTypePtrOrNull();
    if (!secondFuncReturnType || !secondFuncReturnType->isVoidType()) {
        return;
    }

    if (!m_widenCriteria && !isKnownType(record->getNameAsString()) && !clazy::startsWith(secondFunc->getNameAsString(), "set")) {
        return;
    }

    const std::string &methodName = secondMethod->getQualifiedNameAsString();
    if (isDisallowedMethod(methodName)) {
        return;
    }

    emitWarning(stmt->getBeginLoc(), "Call to temporary is a no-op: " + methodName);
}