On Tue, 1 Dec 2020 at 21:00, Nick Desaulniers <[email protected]> wrote: > > On Tue, Dec 1, 2020 at 7:21 AM Marco Elver <[email protected]> wrote: > > > > The C11 _Static_assert() keyword may be used at module scope, and we > > need to teach genksyms about it to not abort with an error. We currently > > have a growing number of static_assert() (but also direct usage of > > _Static_assert()) users at module scope: > > > > git grep -E '^_Static_assert\(|^static_assert\(' | grep -v '^tools' > > | wc -l > > 135 > > > > More recently, when enabling CONFIG_MODVERSIONS with CONFIG_KCSAN, we > > observe a number of warnings: > > > > WARNING: modpost: EXPORT symbol "<..all kcsan symbols..>" [vmlinux] > > [...] > > > > When running a preprocessed source through 'genksyms -w' a number of > > syntax errors point at usage of static_assert()s. In the case of > > kernel/kcsan/encoding.h, new static_assert()s had been introduced which > > used expressions that appear to cause genksyms to not even be able to > > recover from the syntax error gracefully (as it appears was the case > > previously). > > > > Therefore, make genksyms ignore all _Static_assert() and the contained > > expression. With the fix, usage of _Static_assert() no longer cause > > "syntax error" all over the kernel, and the above modpost warnings for > > KCSAN are gone, too. > > > > Signed-off-by: Marco Elver <[email protected]> > > Ah, genksyms...if only there were a library that we could use to parse > C code...:P
Hehe -- another usecase for using that library ;-) If only we could require LLVM be present even when building the rest of the kernel with GCC. I guess this works, for now. Until the next new keyword that is used at module scope... > Acked-by: Nick Desaulniers <[email protected]> Thanks!
