| Message ID | 1376033802-12826-1-git-send-email-ard.biesheuvel@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Aug 09, 2013 at 09:36:42AM +0200, Ard Biesheuvel wrote: > The C99 types uintXX_t that are usually defined in 'stdint.h' are not as > unambiguous on ARM as you would expect. For the types below, there is a > difference on ARM between GCC built for bare metal ARM, GCC built for glibc > and the kernel itself, which results in build errors if you try to build with > -ffreestanding and include 'stdint.h' (such as when you include 'arm_neon.h' > in order to use NEON intrinsics) > > As the typedefs for these types in 'stdint.h' are based on builtin defines > supplied by GCC, we can tweak these to align with the kernel's idea of those > types, so 'linux/types.h' and 'stdint.h' can be safely included from the same > source file (provided that -ffreestanding is used). > > int32_t uint32_t uintptr_t > bare metal GCC long unsigned long unsigned long > glibc GCC int unsigned int unsigned int > kernel int unsigned int unsigned long > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > > Hi all, > > This is another, less obtrusive way of handling the problem for which I > previously sent an RFC patch 'types.h: use GCC supplied typedefs if appropriate' > In this case, only source files that in fact include stdint.h and are being > built for ARM should be affected. > > Regards, > -- > Ard. > > > arch/arm/include/asm/types.h | 40 ++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 40 insertions(+) > create mode 100644 arch/arm/include/asm/types.h > > diff --git a/arch/arm/include/asm/types.h b/arch/arm/include/asm/types.h > new file mode 100644 > index 0000000..976ac31 > --- /dev/null > +++ b/arch/arm/include/asm/types.h > @@ -0,0 +1,40 @@ > +#ifndef _ASM_TYPES_H > +#define _ASM_TYPES_H > + > +#include <asm-generic/int-ll64.h> > + > +/* > + * The C99 types uintXX_t that are usually defined in 'stdint.h' are not as > + * unambiguous on ARM as you would expect. For the types below, there is a > + * difference on ARM between GCC built for bare metal ARM, GCC built for glibc > + * and the kernel itself, which results in build errors if you try to build with > + * -ffreestanding and include 'stdint.h' (such as when you include 'arm_neon.h' > + * in order to use NEON intrinsics) > + * > + * As the typedefs for these types in 'stdint.h' are based on builtin defines > + * supplied by GCC, we can tweak these to align with the kernel's idea of those > + * types, so 'linux/types.h' and 'stdint.h' can be safely included from the same > + * source file (provided that -ffreestanding is used). > + * > + * int32_t uint32_t uintptr_t > + * bare metal GCC long unsigned long unsigned long > + * glibc GCC int unsigned int unsigned int > + * kernel int unsigned int unsigned long > + */ > + > +#ifdef __INT32__TYPE__ > +#undef __INT32__TYPE__ > +#define __INT32__TYPE__ int > +#endif > + > +#ifdef __UINT32__TYPE__ > +#undef __UINT32__TYPE__ > +#define __UINT32__TYPE__ unsigned int > +#endif > + > +#ifdef __UINTPTR_TYPE__ > +#undef __UINTPTR_TYPE__ > +#define __UINTPTR_TYPE__ unsigned long > +#endif Somebody else might have the opposite problem to ARM, so I'm doubtful about whether it's safe to do this for all arches. The arch maintainers would have to comment on that. This looks ugly in an otherwise generic header. (As a cosmetic thing, you can lose the #ifdefs. #undef doesn't trigger an error of the specified macro doesn't already exist.) Cheers ---Dave
On 9 August 2013 16:14, Dave Martin <Dave.Martin@arm.com> wrote: > On Fri, Aug 09, 2013 at 09:36:42AM +0200, Ard Biesheuvel wrote: [...] > Somebody else might have the opposite problem to ARM, so I'm doubtful > about whether it's safe to do this for all arches. The arch maintainers > would have to comment on that. This looks ugly in an otherwise generic > header. > This is actually under arch/arm so that should not be a problem. In fact, it's a copy of asm-generic/types.h with just the #defines added. > (As a cosmetic thing, you can lose the #ifdefs. #undef doesn't trigger > an error of the specified macro doesn't already exist.) > I am aware of that, but I think it is cleaner not to pollute the namespace if the defines weren't there to begin with. Cheers, Ard.
On Fri, Aug 09, 2013 at 04:18:30PM +0200, Ard Biesheuvel wrote: > On 9 August 2013 16:14, Dave Martin <Dave.Martin@arm.com> wrote: > > On Fri, Aug 09, 2013 at 09:36:42AM +0200, Ard Biesheuvel wrote: > > [...] > > > Somebody else might have the opposite problem to ARM, so I'm doubtful > > about whether it's safe to do this for all arches. The arch maintainers > > would have to comment on that. This looks ugly in an otherwise generic > > header. > > > > This is actually under arch/arm so that should not be a problem. In > fact, it's a copy of asm-generic/types.h with just the #defines added. Duh. Misread your patch, sorry about that. > > (As a cosmetic thing, you can lose the #ifdefs. #undef doesn't trigger > > an error of the specified macro doesn't already exist.) > > > > I am aware of that, but I think it is cleaner not to pollute the > namespace if the defines weren't there to begin with. Ah, I see what you mean. Yes, that makes sense. I'd read the #ifdefs as just being there to avoid redefinition errors. I'll leave the thread for other people to comment, but this looks like a reasonable thing to do for now. Because the kernel is not a hosted C environment, we shouldn't be including any foreign headers which care about the distinction, except for GCC's own headers like arm_neon.h. Cheers ---Dave
Kinda-acked-by Dave Martin, anyone else care to comment? On 9 August 2013 09:36, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: > The C99 types uintXX_t that are usually defined in 'stdint.h' are not as > unambiguous on ARM as you would expect. For the types below, there is a > difference on ARM between GCC built for bare metal ARM, GCC built for glibc > and the kernel itself, which results in build errors if you try to build with > -ffreestanding and include 'stdint.h' (such as when you include 'arm_neon.h' > in order to use NEON intrinsics) > > As the typedefs for these types in 'stdint.h' are based on builtin defines > supplied by GCC, we can tweak these to align with the kernel's idea of those > types, so 'linux/types.h' and 'stdint.h' can be safely included from the same > source file (provided that -ffreestanding is used). > > int32_t uint32_t uintptr_t > bare metal GCC long unsigned long unsigned long > glibc GCC int unsigned int unsigned int > kernel int unsigned int unsigned long > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > > Hi all, > > This is another, less obtrusive way of handling the problem for which I > previously sent an RFC patch 'types.h: use GCC supplied typedefs if appropriate' > In this case, only source files that in fact include stdint.h and are being > built for ARM should be affected. > > Regards, > -- > Ard. > > > arch/arm/include/asm/types.h | 40 ++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 40 insertions(+) > create mode 100644 arch/arm/include/asm/types.h > > diff --git a/arch/arm/include/asm/types.h b/arch/arm/include/asm/types.h > new file mode 100644 > index 0000000..976ac31 > --- /dev/null > +++ b/arch/arm/include/asm/types.h > @@ -0,0 +1,40 @@ > +#ifndef _ASM_TYPES_H > +#define _ASM_TYPES_H > + > +#include <asm-generic/int-ll64.h> > + > +/* > + * The C99 types uintXX_t that are usually defined in 'stdint.h' are not as > + * unambiguous on ARM as you would expect. For the types below, there is a > + * difference on ARM between GCC built for bare metal ARM, GCC built for glibc > + * and the kernel itself, which results in build errors if you try to build with > + * -ffreestanding and include 'stdint.h' (such as when you include 'arm_neon.h' > + * in order to use NEON intrinsics) > + * > + * As the typedefs for these types in 'stdint.h' are based on builtin defines > + * supplied by GCC, we can tweak these to align with the kernel's idea of those > + * types, so 'linux/types.h' and 'stdint.h' can be safely included from the same > + * source file (provided that -ffreestanding is used). > + * > + * int32_t uint32_t uintptr_t > + * bare metal GCC long unsigned long unsigned long > + * glibc GCC int unsigned int unsigned int > + * kernel int unsigned int unsigned long > + */ > + > +#ifdef __INT32__TYPE__ > +#undef __INT32__TYPE__ > +#define __INT32__TYPE__ int > +#endif > + > +#ifdef __UINT32__TYPE__ > +#undef __UINT32__TYPE__ > +#define __UINT32__TYPE__ unsigned int > +#endif > + > +#ifdef __UINTPTR_TYPE__ > +#undef __UINTPTR_TYPE__ > +#define __UINTPTR_TYPE__ unsigned long > +#endif > + > +#endif /* _ASM_TYPES_H */ > -- > 1.8.1.2 >
On Tue, 13 Aug 2013, Ard Biesheuvel wrote: > Kinda-acked-by Dave Martin, anyone else care to comment? > Acked-by: Nicolas Pitre <nico@linaro.org> > On 9 August 2013 09:36, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: > > The C99 types uintXX_t that are usually defined in 'stdint.h' are not as > > unambiguous on ARM as you would expect. For the types below, there is a > > difference on ARM between GCC built for bare metal ARM, GCC built for glibc > > and the kernel itself, which results in build errors if you try to build with > > -ffreestanding and include 'stdint.h' (such as when you include 'arm_neon.h' > > in order to use NEON intrinsics) > > > > As the typedefs for these types in 'stdint.h' are based on builtin defines > > supplied by GCC, we can tweak these to align with the kernel's idea of those > > types, so 'linux/types.h' and 'stdint.h' can be safely included from the same > > source file (provided that -ffreestanding is used). > > > > int32_t uint32_t uintptr_t > > bare metal GCC long unsigned long unsigned long > > glibc GCC int unsigned int unsigned int > > kernel int unsigned int unsigned long > > > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > > --- > > > > Hi all, > > > > This is another, less obtrusive way of handling the problem for which I > > previously sent an RFC patch 'types.h: use GCC supplied typedefs if appropriate' > > In this case, only source files that in fact include stdint.h and are being > > built for ARM should be affected. > > > > Regards, > > -- > > Ard. > > > > > > arch/arm/include/asm/types.h | 40 ++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 40 insertions(+) > > create mode 100644 arch/arm/include/asm/types.h > > > > diff --git a/arch/arm/include/asm/types.h b/arch/arm/include/asm/types.h > > new file mode 100644 > > index 0000000..976ac31 > > --- /dev/null > > +++ b/arch/arm/include/asm/types.h > > @@ -0,0 +1,40 @@ > > +#ifndef _ASM_TYPES_H > > +#define _ASM_TYPES_H > > + > > +#include <asm-generic/int-ll64.h> > > + > > +/* > > + * The C99 types uintXX_t that are usually defined in 'stdint.h' are not as > > + * unambiguous on ARM as you would expect. For the types below, there is a > > + * difference on ARM between GCC built for bare metal ARM, GCC built for glibc > > + * and the kernel itself, which results in build errors if you try to build with > > + * -ffreestanding and include 'stdint.h' (such as when you include 'arm_neon.h' > > + * in order to use NEON intrinsics) > > + * > > + * As the typedefs for these types in 'stdint.h' are based on builtin defines > > + * supplied by GCC, we can tweak these to align with the kernel's idea of those > > + * types, so 'linux/types.h' and 'stdint.h' can be safely included from the same > > + * source file (provided that -ffreestanding is used). > > + * > > + * int32_t uint32_t uintptr_t > > + * bare metal GCC long unsigned long unsigned long > > + * glibc GCC int unsigned int unsigned int > > + * kernel int unsigned int unsigned long > > + */ > > + > > +#ifdef __INT32__TYPE__ > > +#undef __INT32__TYPE__ > > +#define __INT32__TYPE__ int > > +#endif > > + > > +#ifdef __UINT32__TYPE__ > > +#undef __UINT32__TYPE__ > > +#define __UINT32__TYPE__ unsigned int > > +#endif > > + > > +#ifdef __UINTPTR_TYPE__ > > +#undef __UINTPTR_TYPE__ > > +#define __UINTPTR_TYPE__ unsigned long > > +#endif > > + > > +#endif /* _ASM_TYPES_H */ > > -- > > 1.8.1.2 > > >
diff --git a/arch/arm/include/asm/types.h b/arch/arm/include/asm/types.h new file mode 100644 index 0000000..976ac31 --- /dev/null +++ b/arch/arm/include/asm/types.h @@ -0,0 +1,40 @@ +#ifndef _ASM_TYPES_H +#define _ASM_TYPES_H + +#include <asm-generic/int-ll64.h> + +/* + * The C99 types uintXX_t that are usually defined in 'stdint.h' are not as + * unambiguous on ARM as you would expect. For the types below, there is a + * difference on ARM between GCC built for bare metal ARM, GCC built for glibc + * and the kernel itself, which results in build errors if you try to build with + * -ffreestanding and include 'stdint.h' (such as when you include 'arm_neon.h' + * in order to use NEON intrinsics) + * + * As the typedefs for these types in 'stdint.h' are based on builtin defines + * supplied by GCC, we can tweak these to align with the kernel's idea of those + * types, so 'linux/types.h' and 'stdint.h' can be safely included from the same + * source file (provided that -ffreestanding is used). + * + * int32_t uint32_t uintptr_t + * bare metal GCC long unsigned long unsigned long + * glibc GCC int unsigned int unsigned int + * kernel int unsigned int unsigned long + */ + +#ifdef __INT32__TYPE__ +#undef __INT32__TYPE__ +#define __INT32__TYPE__ int +#endif + +#ifdef __UINT32__TYPE__ +#undef __UINT32__TYPE__ +#define __UINT32__TYPE__ unsigned int +#endif + +#ifdef __UINTPTR_TYPE__ +#undef __UINTPTR_TYPE__ +#define __UINTPTR_TYPE__ unsigned long +#endif + +#endif /* _ASM_TYPES_H */
The C99 types uintXX_t that are usually defined in 'stdint.h' are not as unambiguous on ARM as you would expect. For the types below, there is a difference on ARM between GCC built for bare metal ARM, GCC built for glibc and the kernel itself, which results in build errors if you try to build with -ffreestanding and include 'stdint.h' (such as when you include 'arm_neon.h' in order to use NEON intrinsics) As the typedefs for these types in 'stdint.h' are based on builtin defines supplied by GCC, we can tweak these to align with the kernel's idea of those types, so 'linux/types.h' and 'stdint.h' can be safely included from the same source file (provided that -ffreestanding is used). int32_t uint32_t uintptr_t bare metal GCC long unsigned long unsigned long glibc GCC int unsigned int unsigned int kernel int unsigned int unsigned long Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- Hi all, This is another, less obtrusive way of handling the problem for which I previously sent an RFC patch 'types.h: use GCC supplied typedefs if appropriate' In this case, only source files that in fact include stdint.h and are being built for ARM should be affected. Regards,