Am 28.04.2015 um 01:10 schrieb Brian Norris: > On Mon, Apr 27, 2015 at 3:57 PM, Richard Weinberger <rich...@nod.at> wrote: >> Am 28.04.2015 um 00:53 schrieb Brian Norris: >>> On Tue, Apr 28, 2015 at 12:42:18AM +0200, Richard Weinberger wrote: >>>> Am 28.04.2015 um 00:36 schrieb Ben Shelton: >>>>>>> When I build this without CONFIG_MTD_NAND_ECC_ON_DIE enabled, I get the >>>>>>> following warning here: >>>>>>> >>>>>>> In file included from drivers/mtd/nand/nand_base.c:46:0: >>>>>>> include/linux/mtd/nand_ondie.h: In function 'nand_read_subpage_on_die': >>>>>>> include/linux/mtd/nand_ondie.h:28:1: warning: no return statement in >>>>>>> function returning non-void [-Wreturn-type] >>>>>>> include/linux/mtd/nand_ondie.h: In function 'nand_read_page_on_die': >>>>>>> include/linux/mtd/nand_ondie.h:34:1: warning: no return statement in >>>>>>> function returning non-void [-Wreturn-type] >>>>>>> >>>>>>> Perhaps return an error code here, even though you'll never get past >>>>>>> the BUG()? >>>>>> >>>>>> What gcc is this? >>>>>> gcc 4.8 here does not warn, I thought it is smart enough that this >>>>>> function does never >>>>>> return. Can it be that your .config has CONFIG_BUG=n? >>>>>> Anyway, this functions clearly needs a return statement. :) >>>>> >>>>> gcc 4.7.2, and you are correct that I had CONFIG_BUG off. :) >>>> >>>> Yeah, just noticed that BUG() with CONFIG_BUG=n does not have >>>> a nonreturn attribute. So, gcc cannot know... >>> >>> But it's an obvious infinite loop... all of my toolchains (4.2, 4.5, >>> 4.6, 4.8) are able to compile this without complaining (gcc -Wall): >>> >>> int test() { do { } while (1); } >> >> Not here. gcc 4.8 warns on that. >> As soon I add __attribute__ ((noreturn)) it does not longer complain. > > Huh? Maybe I have a crazy modified gcc. > > $ gcc --version > gcc (Ubuntu 4.8.2-19ubuntu1) 4.8.2 > Copyright (C) 2013 Free Software Foundation, Inc. > This is free software; see the source for copying conditions. There is NO > warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. > > $ gcc -Wall -Wextra -c a.c > $ cat a.c > int test() { do {} while (1); }
Make test static and gcc will warn. Thanks, //richard -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/