Actual behaviour:

Using QBENCHMARK with newer Clang compiler with -Wreserved-identifier option triggers a compiler warning:

mycppfile.cpp:580:9: warning: identifier '_iteration_controller' is reserved because it starts with '_' [clang-diagnostic-reserved-identifier]
         QBENCHMARK
         ^
/usr/include/x86_64-linux-gnu/qt5/QtTest/qbenchmark.h:77:47: note: expanded from macro 'QBENCHMARK'
         for (QTest::QBenchmarkIterationController __iteration_controller;
         ^

Expected behaviour:

Using QBENCHMARK does not trigger any compiler warnings.