With Xcode4.5, llvm/clang:
Apple clang version 4.1 (tags/Apple/clang-421.11.66) (based on LLVM 3.1svn)
Thread model: posix
we use -fcheck-new in our compiler settings which has been triggering this clang warning:
clang: warning: argument unused during compilation: ‘-fcheck-new’
We wonder if this gcc setting is not supported by clang.
gcc spec seems to say that without this the only mechanism against heap allocation returning null pointers
is through exceptions. However, we disabled exceptions for performance requirements. So this setting
is important to us.
Currently we have to use -Qunused-arguments to suppress the warnings, but
the real question is whether or not it is safe to work without -fcheck-new if it’s not supported by clang.
From web search, we also found the following links which implies that it could be a bug in LLVM/clang:
If -fcheck-new is an important feature for you (and not a workaround for an old gcc problem), please feel free to file a bug at [http://llvm.org/bugs/](http://llvm.org/bugs/)
- Except for the -fcheck-new option, Clang seems to understand all the other compiler options used during the HotSpot build process. For -fcheck-new a warning is issued advertising that the option will be ignored. So I just removed it frommake/linux/makefiles/clang.make. I have also removed obvious workarounds for some older GCC versions in the new Clang files which were derived from their corresponding GCC counterparts.
There was a longer discussion around the fix for the CHECK macros about one and a half years ago. I started a patch that time but than somehow forgot about it. Now with the new compiler (and the old warnings) I remembered about it. I hope to get it done this time and to send it out for review soon. Thank you for the offer to take care about it.
Anybody has any comments?