| Message ID | 1330431110-22020-1-git-send-email-fabio.estevam@freescale.com |
|---|---|
| State | New |
| Headers | show |
On Tue, Feb 28, 2012 at 09:11:50AM -0300, Fabio Estevam wrote: > Fix the following build error: > > arch/arm/mach-imx/cpu_op-mx51.c: In function 'mx51_get_cpu_op': > arch/arm/mach-imx/cpu_op-mx51.c:27: error: implicit declaration of function 'BUILD_BUG_ON_ZERO' I think having the asm/bug.h replaced with linux/bug.h in linux/kernel.h would be a better solution. > > Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> > --- > This applies against linux-next > > arch/arm/mach-imx/cpu_op-mx51.c | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/arch/arm/mach-imx/cpu_op-mx51.c b/arch/arm/mach-imx/cpu_op-mx51.c > index 9d34c3d..9a4f77a 100644 > --- a/arch/arm/mach-imx/cpu_op-mx51.c > +++ b/arch/arm/mach-imx/cpu_op-mx51.c > @@ -14,6 +14,7 @@ > #include <linux/types.h> > #include <mach/hardware.h> > #include <linux/kernel.h> > +#include <linux/bug.h> > > static struct cpu_op mx51_cpu_op[] = { > { > -- > 1.7.1 > > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Tue, Feb 28, 2012 at 9:53 AM, Russell King - ARM Linux <linux@arm.linux.org.uk> wrote: > I think having the asm/bug.h replaced with linux/bug.h in linux/kernel.h > would be a better solution. commit 6f863554 (kernel.h: doesn't explicitly use bug.h, so don't include it. ), which appears in linux-next, has removed asm/debug.h from linux/kernel.h. I should have pointed this commit ID in my commit log. Regards, Fabio Estevam
On Tue, Feb 28, 2012 at 10:03:33AM -0300, Fabio Estevam wrote: > On Tue, Feb 28, 2012 at 9:53 AM, Russell King - ARM Linux > <linux@arm.linux.org.uk> wrote: > > > I think having the asm/bug.h replaced with linux/bug.h in linux/kernel.h > > would be a better solution. > > commit 6f863554 (kernel.h: doesn't explicitly use bug.h, so don't > include it. ), which appears in linux-next, has removed asm/debug.h > from linux/kernel.h. > > I should have pointed this commit ID in my commit log. No, this is not a fix, and it probably makes things worse. linux/kernel.h _does_ use bug stuff - in ARRAY_SIZE(). ARRAY_SIZE() uses __must_be_array(), which is defined in linux/compiler-gcc.h, which is obtained via linux/compiler.h and linux/linkage.h. linux/compiler-gcc.h defines __must_be_array() to be: #define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0])) and BUILD_BUG_ON_ZERO used to be in linux/kernel.h but got moved to linux/bug.h. Hence why people are seeing build breakage with ARRAY_SIZE(). The answer is not to start scattering lots of .c files with linux/bug.h includes, but to fix linux/kernel.h.
On 2/28/12, Russell King - ARM Linux <linux@arm.linux.org.uk> wrote: > On Tue, Feb 28, 2012 at 10:03:33AM -0300, Fabio Estevam wrote: >> On Tue, Feb 28, 2012 at 9:53 AM, Russell King - ARM Linux >> <linux@arm.linux.org.uk> wrote: >> >> > I think having the asm/bug.h replaced with linux/bug.h in linux/kernel.h >> > would be a better solution. >> >> commit 6f863554 (kernel.h: doesn't explicitly use bug.h, so don't >> include it. ), which appears in linux-next, has removed asm/debug.h >> from linux/kernel.h. >> >> I should have pointed this commit ID in my commit log. > > No, this is not a fix, and it probably makes things worse. > > linux/kernel.h _does_ use bug stuff - in ARRAY_SIZE(). > > ARRAY_SIZE() uses __must_be_array(), which is defined in > linux/compiler-gcc.h, > which is obtained via linux/compiler.h and linux/linkage.h. > > linux/compiler-gcc.h defines __must_be_array() to be: > #define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0])) > > and BUILD_BUG_ON_ZERO used to be in linux/kernel.h but got moved to > linux/bug.h. > > Hence why people are seeing build breakage with ARRAY_SIZE(). > > The answer is not to start scattering lots of .c files with linux/bug.h > includes, but to fix linux/kernel.h. This makes sense, thanks. Will submit a patch for lkml shortly.
[Re: [PATCH] ARM: mx51: Fix build error due to missing include of <linux/bug.h>] On 28/02/2012 (Tue 13:21) Russell King - ARM Linux wrote: [...] > The answer is not to start scattering lots of .c files with linux/bug.h > includes, but to fix linux/kernel.h. Hi Russell, I understand your concerns, and had I found myself "buggering" lots of .c files, I would have backed away and said to myself, "OK, this really isn't going to work - we really can't do this." But to put some metrics to it, after building for about 10 different arch and all their defconfigs, I only had to change about twenty[1] of the approximately sixteen thousand .c files in the kernel. That is about 0.125% -- which is one of the things that made me think "Hey, we can really do this cleanup!" Including this file, there were only two .c files in all of arch/arm that were using bug somehow. So I think having kernel.h not require bug.h is completely do-able. But in the end, I'm not welded to the idea. I think it is a win, but I'm not going to kick up a big stink if Linus or Andrew say they don't think it is of value, and would rather not rock the boat. Thanks, Paul. -- [1] https://lkml.org/lkml/2012/1/26/521
On Tue, Feb 28, 2012 at 06:52:45PM -0500, Paul Gortmaker wrote: > [Re: [PATCH] ARM: mx51: Fix build error due to missing include of <linux/bug.h>] On 28/02/2012 (Tue 13:21) Russell King - ARM Linux wrote: > > [...] > > > The answer is not to start scattering lots of .c files with linux/bug.h > > includes, but to fix linux/kernel.h. > > Hi Russell, > > I understand your concerns, and had I found myself "buggering" lots > of .c files, I would have backed away and said to myself, "OK, this > really isn't going to work - we really can't do this." > > But to put some metrics to it, after building for about 10 different > arch and all their defconfigs, I only had to change about twenty[1] of > the approximately sixteen thousand .c files in the kernel. I think there's more than that - I've seen two reports for other files which have needed fixing so far, and I wouldn't be surprised if there's more. I guess we'll see in coming weeks how it pans out, but my gut feeling is that this is going to cause a fair number of build problems.
diff --git a/arch/arm/mach-imx/cpu_op-mx51.c b/arch/arm/mach-imx/cpu_op-mx51.c index 9d34c3d..9a4f77a 100644 --- a/arch/arm/mach-imx/cpu_op-mx51.c +++ b/arch/arm/mach-imx/cpu_op-mx51.c @@ -14,6 +14,7 @@ #include <linux/types.h> #include <mach/hardware.h> #include <linux/kernel.h> +#include <linux/bug.h> static struct cpu_op mx51_cpu_op[] = { {
Fix the following build error: arch/arm/mach-imx/cpu_op-mx51.c: In function 'mx51_get_cpu_op': arch/arm/mach-imx/cpu_op-mx51.c:27: error: implicit declaration of function 'BUILD_BUG_ON_ZERO' Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> --- This applies against linux-next arch/arm/mach-imx/cpu_op-mx51.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)