On Mon, Nov 2, 2015 at 4:43 AM, Joerg Sonnenberger via cfe-commits <cfe-commits@lists.llvm.org> wrote: > On Sun, Nov 01, 2015 at 08:48:53PM -0500, Aaron Ballman via cfe-commits wrote: >> On Sun, Nov 1, 2015 at 2:31 PM, Joerg Sonnenberger via cfe-commits >> <cfe-commits@lists.llvm.org> wrote: >> > On Tue, Oct 27, 2015 at 06:10:26PM +0000, Samuel Benzaquen via cfe-commits >> > wrote: >> >> sbenza added a comment. >> >> >> >> In http://reviews.llvm.org/D14096#275902, @xazax.hun wrote: >> >> >> >> > There is already a similar check in the Google package. What are the >> >> > differences between those two checks? What is the reason we can not >> >> > just register that check into the core guidelines module? >> >> >> >> >> >> That other check discourages c-style cast in favor of C++ style casts, >> >> even if it is a reinterpret_cast. It simply replaces the cstyle cast with >> >> an equivalent C++ one. It is basically a stylistic check. >> >> >> >> This check will warn unsafe cstyle casts, while allowing safe ones like >> >> int->uint casts. >> >> This one is a safety related check. >> > >> > Looking back to the discussion about the C++ style casts, this argument >> > makes no sense. For C++ code, reinterpret_cast is clearly preferable >> > over C-style casts for all but code size reasons. There seems to be no >> > consideration about "safe" uses with reinterpret_cast, so why should >> > C-style casts >> > be different? >> >> "Clearly preferable" is kind of debatable, but I don't disagree with >> your statement. That being said, this checker isn't concerned with >> C++-style casts, so I'm not certain I understand what you would like >> to see changed with this checker. Can you elaborate? > > Let me reverse that. Do the core guidelines really define a set of > "safe" C-style casts and don't have the equivalent for C++ casts? The > latter is what I took from the follow-up on the introduction of the C++ > cast checkers.
Okay, that makes more sense to me -- thank you for the clarification. My understanding is that the core guidelines define a set of "safe" C-style casts and don't have the equivalent for C++ casts. That seems like a good bug report to file with the core guidelines folks (https://github.com/isocpp/CppCoreGuidelines/issues). I agree that it seems strange that a C-style cast resulting in reinterpret_cast is safe and not diagnosed, while the same effective cast spelled with reinterpret_cast is diagnosed. ~Aaron > > Joerg > _______________________________________________ > cfe-commits mailing list > cfe-commits@lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
