Last week I committed a patch to check for enum comparisons which are invalid in C++. Today I committed a patch to check for enum conversions during function calls which are invalid in C++. These new warnings are enabled by -Wc++-compat.
I have not fixed every gcc backend to compile without producing any of the new warnings. I have fixed some: arm, i386, ia64, mips, pa, rs6000, s390, sparc, spu. This covers all the primary and secondary platforms, plus spu which I had to touch because I changed a target vector which it implements. Adding these warnings to -Wc++-compat may break bootstrap for other platforms, and may cause additional warnings when building cross-compilers. I would like to ask the maintainers for backends which I did not mention to bootstrap their targets if possible, and/or to build them with a newly built mainline compiler, to see if there are new warnings about C++ compatibility. These warnings are normally straightforward to fix. For warnings related to calling gen_rtx_EXPR_LIST to add a register note, change the code to use the add_reg_note function instead. I am willing to help fix any backends which have trouble with the new warnings. However, I do not plan to build every backend myself. There will be some more improvements to -Wc++-compat coming, causing more warnings on existing gcc code, and I plan to follow this same procedure. Ian
