Hi Martin, I sent you an email, but I received a "delivery failure". If you're reading this from a list, could you answer, please? Thanks, Alex On 12/14/20 11:34 PM, Alejandro Colomar (man-pages) wrote: > Hello Martin, > > Thanks for the correction! > Then the prototypes that changes from 'char *' to 'void *' in r269082 > were not exposed to the user, right? > I guess then those are just internal implementation where GCC did use > 'char *'. > > Where is the actual prototype exposed to the user declared? > > Thanks, > > Alex > > P.S.: Michael, wait for a patch revision (v6). > > On 12/14/20 10:13 PM, Martin Sebor wrote: >> On 12/11/20 11:14 AM, Alejandro Colomar (man-pages) via Gcc wrote: >>> It looks like GCC recently moved from 'char *' to 'void *'. >>> This SO question[1] (4 years ago) quotes the GCC docs >>> and they had 'char *'. >> >> __builtin___clear_cache in GCC has always been declared to take >> void*. The signature in the manual was recently corrected to match >> the implementation, i.e., from char* to void*, in r269082. >> >> Martin >> >>> Maybe Clang hasn't noticed the change. >>> I'll report a bug. >>> >>> [1]: https://stackoverflow.com/q/35741814/6872717 >>> >>> On 12/9/20 8:15 PM, Alejandro Colomar (man-pages) wrote: >>>> 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; https://www.kernel.org/doc/man-pages/ http://www.alejandro-colomar.es/
