On Mon, Oct 22, 2018 at 10:50 AM Bernd Petrovitsch <bernd@xxxxxxxxxxxxxxxxxxx> wrote: > > Hi all! > > On 22/10/18 13:07, Miguel Ojeda wrote: > > On Mon, Oct 22, 2018 at 12:54 PM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > >> > >> Doing both is super ugly. Let's just do comments until Eclipse gets > >> updated. > > Yes, "Eclipse" as the IDE. > > And yes but IMHO better super ugly than loosing the warning - YMMV. > > For the archives: I have Eclipse Photon/June 2016 here. And "no break" > is the (default) string in a comment used by Eclipse (it can be > customized and is actually a regexp but it must be in a comment). > > >> I had wanted to move to the attribute because that would simplify things > >> in Smatch but it's not a huge deal to delay for another year. > > > > I can re-send them later on, no problem. On the other hand, doing the > > changes will push tools to get updated sooner ;-) > > > > If tools were doing something as fancy as comment parsing for > > diagnostics, they should have been updated with the attribute support > > (either gcc's or C++17's) -- it has been more than a year now since > > gcc 7.1 and the C++17 final draft. (Note that this does not apply for > > things like clang, since they weren't doing comment parsing to begin > > with.) > > That would be nice. And if they agree on the same texts (or accept per > default all somewhat widely used and/or old ones). > > After stumbling over > https://stackoverflow.com/questions/16935935/how-do-i-turn-off-a-static-code-analysis-warning-on-a-line-by-line-warning-in-cd, > looking into Eclipses Window -> Preferences -> C/C++ -> Code Analysis -> > "No break at the end of case" screen (that's the screenshot there) and I > tried various things: > > Preface: > I have > ---- snip ---- > #define __fallthrough __attribute__((fallthrough)) > ---- snip ---- > for gcc >= 7 (because clang doesn't know it and I had also older > gcc's in use before). > > So: > - Adding a comment to the #define doesn't change anything for Eclipse. > - Eclipse looks *only* in comments for the string/regexp given > the warnings configuration (and that comment must be on the line > directly before the "case"). > - Eclipse understands [[fallthrough]] out-of-the-box though (which > is C++11 AFAIK) as does g++-7 (I use -std=gnu++17 - most of the > sources are C++, but not all) and clang++-6 (all the current standard > Ubuntu-18.06/Bionic packages). > Eclipse "accepts" [[fallthrough]] only in C++ sources (and not in C > sources). > - Neither gcc nor clang understand [[fallthrough]] (so it's probably a > no-go for the Kernel with C89 anyways). > > MfG, > Bernd > > PS: clang++ errors with "fallthrough annotation in unreachable code" if > [[fallthrough]] is after an assert(). clang-devs there, please, the > fallthrough doesn't really generated code (I hope;-). > I have lots of switch()es which catch undefined values (for enums > et. al.) with "default"+assert() and fall through to the most safe > case (for the deployed version). Can you send me a link to a simple reproducer in godbolt (godbolt.org) and we'll take a look? > -- > "I dislike type abstraction if it has no real reason. And saving > on typing is not a good reason - if your typing speed is the main > issue when you're coding, you're doing something seriously wrong." > - Linus Torvalds -- Thanks, ~Nick Desaulniers
