On Tue, 27 Jun 2023 12:22:43 GMT, Daniel Jeliński <djelin...@openjdk.org> wrote:
> Please review this attempt to fix ignored-qualifiers warning. > > Example warnings: > > src/hotspot/share/oops/method.hpp:413:19: warning: 'volatile' type qualifier > on return type has no effect [-Wignored-qualifiers] > CompiledMethod* volatile code() const; > ^~~~~~~~~ > > > src/hotspot/share/jfr/periodic/jfrModuleEvent.cpp:65:20: warning: type > qualifiers ignored on cast result type [-Wignored-qualifiers] > 65 | event.set_source((const ModuleEntry* const)from_module); > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > > The proposed fix removes the ignored qualifiers. > In a few AD files I replaced `const` with `constexpr` where I noticed that > the method is returning a compile-time constant, and other platforms use > `constexpr` on the same method. > > Release, debug and slowdebug builds on Aarch64 / x64 and Mac / Linux complete > without errors. Cross-compile GHA builds also pass. David: I think this part of the spec is relevant here: > A non-class non-array prvalue cannot be > [cv-qualified](https://en.cppreference.com/w/cpp/language/cv), [...]. (Note: > a function call or cast expression may result in a prvalue of non-class > cv-qualified type, but the cv-qualifier is generally immediately stripped > out.) [source](https://en.cppreference.com/w/cpp/language/value_category) given that the cv qualifiers are immediately stripped by the compiler, there's no point in providing them. In the particular volatile pointer case: the function performs a volatile read to get the pointer value (address). That address can then be used in a non-volatile manner. Kim: I realize that it's a big change, so thank you very much for reviewing it anyway! I was prepared to split it up, just wanted to know if this warning is something we want to fix. ------------- PR Comment: https://git.openjdk.org/jdk/pull/14674#issuecomment-1611905364
