Messages in this thread | | | Date | Mon, 27 Apr 2015 16:10:02 -0700 | Subject | Re: [PATCH 1/3] mtd: nand: Add on-die ECC support | From | Brian Norris <> |
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On Mon, Apr 27, 2015 at 3:57 PM, Richard Weinberger <richard@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); }
But:
$ gcc -Wall -Wextra -c b.c b.c: In function ‘test’: b.c:1:1: warning: control reaches end of non-void function [-Wreturn-type] int test() { } ^ $ cat b.c int test() { }
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