Hi Heinrich, It looks like a bug (or at least an undocumented divergence from GCC) in Clang/LLVM. Or I couldn't find the documentation for it.
Clang uses 'char *': https://github.com/llvm/llvm-project/blob/7faf62a80bfc3a9dfe34133681fcc31f8e8d658b/clang/include/clang/Basic/Builtins.def#L583 GCC uses 'void *': https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html I CCd Clang and GCC lists; maybe they know about that divergence. Cheers, Alex On 12/9/20 7:48 PM, Heinrich Schuchardt wrote: > On 12/9/20 7:34 PM, Alejandro Colomar (man-pages) wrote: >> Hi Heinrich & Michael, >> >> What about the following?: >> >> [ >> NOTES >> GCC provides a similar function, which may be useful on archi‐ >> tectures that lack this system call: >> >> void __builtin___clear_cache(void *begin, void *end); >> ] > > I just checked building with Clang/LLVM. There the arguments are of type > (char *). See the following error output: > > +arch/sandbox/cpu/cache.c:19:26: error: passing 'uint8_t *' (aka > 'unsigned char *') to parameter of type 'char *' converts between > pointers to integer types with different sign [-Werror,-Wpointer-sign] > + __builtin___clear_cache(state->ram_buf, > + ^~~~~~~~~~~~~~ > +arch/sandbox/cpu/cache.c:20:12: error: passing 'uint8_t *' (aka > 'unsigned char *') to parameter of type 'char *' converts between > pointers to integer types with different sign [-Werror,-Wpointer-sign] > + state->ram_buf + state->ram_size); > + ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > Best regards > > Heinrich > >> >> Cheers, >> >> Alex >> >> On 12/9/20 7:04 PM, Heinrich Schuchardt wrote: >>> Hello Michael, >>> >>> function cacheflush() does not exist on many architectures. >>> >>> It would have saved me a lot of time if the man-page had referenced >>> GCC's >>> >>> void __builtin___clear_cache(void *begin, void *end) >>> >>> Maybe you can add it to NOTES. >>> >>> Best regards >>> >>> heirnich >> > -- Alejandro Colomar Linux man-pages comaintainer; http://www.kernel.org/doc/man-pages/ http://www.alejandro-colomar.es _______________________________________________ cfe-users mailing list cfe-users@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-users
