The kernel uses `-include` to include include/linux/compiler_types.h
into all translation units (see scripts/Makefile.lib), which #includes
compiler_attributes.h.
arch/powerpc/boot/ uses different compiler flags from the rest of the
kernel. As such, it doesn't contain the definitions from these headers,
and redefines a few that it needs.
For the purpose of enabling -Wimplicit-fallthrough for ppc, include
compiler_types.h via `-include`.
Link: https://github.com/ClangBuiltLinux/linux/issues/236
Signed-off-by: Nick Desaulniers <[email protected]>
---
We could just `#include "include/linux/compiler_types.h"` in the few .c
sources used from lib/ (there are proper header guards in
compiler_types.h).
It was also noted in 6a9dc5fd6170 that we could -D__KERNEL__ and
-include compiler_types.h like the main kernel does, though testing that
produces a whole sea of warnings to cleanup. This approach is minimally
invasive.
arch/powerpc/boot/Makefile | 1 +
arch/powerpc/boot/decompress.c | 1 -
2 files changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index f8ce6d2dde7b..1659963a8f1d 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -31,6 +31,7 @@ endif
BOOTCFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-fno-strict-aliasing -O2 -msoft-float -mno-altivec -mno-vsx \
-pipe -fomit-frame-pointer -fno-builtin -fPIC -nostdinc \
+ -include $(srctree)/include/linux/compiler_attributes.h \
$(LINUXINCLUDE)
ifdef CONFIG_PPC64_BOOT_WRAPPER
diff --git a/arch/powerpc/boot/decompress.c b/arch/powerpc/boot/decompress.c
index 8bf39ef7d2df..6098b879ac97 100644
--- a/arch/powerpc/boot/decompress.c
+++ b/arch/powerpc/boot/decompress.c
@@ -21,7 +21,6 @@
#define STATIC static
#define INIT
-#define __always_inline inline
/*
* The build process will copy the required zlib source files and headers
--
2.29.2.299.gdc1121823c-goog
On Sun, Nov 15, 2020 at 08:35:30PM -0800, Nick Desaulniers wrote:
> The kernel uses `-include` to include include/linux/compiler_types.h
> into all translation units (see scripts/Makefile.lib), which #includes
> compiler_attributes.h.
>
> arch/powerpc/boot/ uses different compiler flags from the rest of the
> kernel. As such, it doesn't contain the definitions from these headers,
> and redefines a few that it needs.
>
> For the purpose of enabling -Wimplicit-fallthrough for ppc, include
> compiler_types.h via `-include`.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/236
> Signed-off-by: Nick Desaulniers <[email protected]>
Acked-by: Gustavo A. R. Silva <[email protected]>
Thanks, Nick.
--
Gustavo
> ---
> We could just `#include "include/linux/compiler_types.h"` in the few .c
> sources used from lib/ (there are proper header guards in
> compiler_types.h).
>
> It was also noted in 6a9dc5fd6170 that we could -D__KERNEL__ and
> -include compiler_types.h like the main kernel does, though testing that
> produces a whole sea of warnings to cleanup. This approach is minimally
> invasive.
>
> arch/powerpc/boot/Makefile | 1 +
> arch/powerpc/boot/decompress.c | 1 -
> 2 files changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
> index f8ce6d2dde7b..1659963a8f1d 100644
> --- a/arch/powerpc/boot/Makefile
> +++ b/arch/powerpc/boot/Makefile
> @@ -31,6 +31,7 @@ endif
> BOOTCFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
> -fno-strict-aliasing -O2 -msoft-float -mno-altivec -mno-vsx \
> -pipe -fomit-frame-pointer -fno-builtin -fPIC -nostdinc \
> + -include $(srctree)/include/linux/compiler_attributes.h \
> $(LINUXINCLUDE)
>
> ifdef CONFIG_PPC64_BOOT_WRAPPER
> diff --git a/arch/powerpc/boot/decompress.c b/arch/powerpc/boot/decompress.c
> index 8bf39ef7d2df..6098b879ac97 100644
> --- a/arch/powerpc/boot/decompress.c
> +++ b/arch/powerpc/boot/decompress.c
> @@ -21,7 +21,6 @@
>
> #define STATIC static
> #define INIT
> -#define __always_inline inline
>
> /*
> * The build process will copy the required zlib source files and headers
> --
> 2.29.2.299.gdc1121823c-goog
>
On Mon, Nov 16, 2020 at 5:35 AM Nick Desaulniers
<[email protected]> wrote:
>
> It was also noted in 6a9dc5fd6170 that we could -D__KERNEL__ and
> -include compiler_types.h like the main kernel does, though testing that
> produces a whole sea of warnings to cleanup. This approach is minimally
> invasive.
I would add a comment noting this as a reminder -- it also helps to
entice a cleanup.
Acked-by: Miguel Ojeda <[email protected]>
Cheers,
Miguel
On Sun, Nov 15, 2020 at 08:35:30PM -0800, Nick Desaulniers wrote:
> The kernel uses `-include` to include include/linux/compiler_types.h
> into all translation units (see scripts/Makefile.lib), which #includes
> compiler_attributes.h.
>
> arch/powerpc/boot/ uses different compiler flags from the rest of the
> kernel. As such, it doesn't contain the definitions from these headers,
> and redefines a few that it needs.
>
> For the purpose of enabling -Wimplicit-fallthrough for ppc, include
> compiler_types.h via `-include`.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/236
> Signed-off-by: Nick Desaulniers <[email protected]>
Reviewed-by: Nathan Chancellor <[email protected]>
Tested-by: Nathan Chancellor <[email protected]>
> ---
> We could just `#include "include/linux/compiler_types.h"` in the few .c
> sources used from lib/ (there are proper header guards in
> compiler_types.h).
>
> It was also noted in 6a9dc5fd6170 that we could -D__KERNEL__ and
> -include compiler_types.h like the main kernel does, though testing that
> produces a whole sea of warnings to cleanup. This approach is minimally
> invasive.
>
> arch/powerpc/boot/Makefile | 1 +
> arch/powerpc/boot/decompress.c | 1 -
> 2 files changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
> index f8ce6d2dde7b..1659963a8f1d 100644
> --- a/arch/powerpc/boot/Makefile
> +++ b/arch/powerpc/boot/Makefile
> @@ -31,6 +31,7 @@ endif
> BOOTCFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
> -fno-strict-aliasing -O2 -msoft-float -mno-altivec -mno-vsx \
> -pipe -fomit-frame-pointer -fno-builtin -fPIC -nostdinc \
> + -include $(srctree)/include/linux/compiler_attributes.h \
> $(LINUXINCLUDE)
>
> ifdef CONFIG_PPC64_BOOT_WRAPPER
> diff --git a/arch/powerpc/boot/decompress.c b/arch/powerpc/boot/decompress.c
> index 8bf39ef7d2df..6098b879ac97 100644
> --- a/arch/powerpc/boot/decompress.c
> +++ b/arch/powerpc/boot/decompress.c
> @@ -21,7 +21,6 @@
>
> #define STATIC static
> #define INIT
> -#define __always_inline inline
>
> /*
> * The build process will copy the required zlib source files and headers
> --
> 2.29.2.299.gdc1121823c-goog
>
On Sun, Nov 15, 2020 at 08:35:30PM -0800, Nick Desaulniers wrote:
> The kernel uses `-include` to include include/linux/compiler_types.h
> into all translation units (see scripts/Makefile.lib), which #includes
> compiler_attributes.h.
>
> arch/powerpc/boot/ uses different compiler flags from the rest of the
> kernel. As such, it doesn't contain the definitions from these headers,
> and redefines a few that it needs.
>
> For the purpose of enabling -Wimplicit-fallthrough for ppc, include
> compiler_types.h via `-include`.
This should be "compiler_attributes.h".
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/236
> Signed-off-by: Nick Desaulniers <[email protected]>
> ---
> We could just `#include "include/linux/compiler_types.h"` in the few .c
> sources used from lib/ (there are proper header guards in
> compiler_types.h).
>
> It was also noted in 6a9dc5fd6170 that we could -D__KERNEL__ and
> -include compiler_types.h like the main kernel does, though testing that
> produces a whole sea of warnings to cleanup. This approach is minimally
> invasive.
>
> arch/powerpc/boot/Makefile | 1 +
> arch/powerpc/boot/decompress.c | 1 -
> 2 files changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
> index f8ce6d2dde7b..1659963a8f1d 100644
> --- a/arch/powerpc/boot/Makefile
> +++ b/arch/powerpc/boot/Makefile
> @@ -31,6 +31,7 @@ endif
> BOOTCFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
> -fno-strict-aliasing -O2 -msoft-float -mno-altivec -mno-vsx \
> -pipe -fomit-frame-pointer -fno-builtin -fPIC -nostdinc \
> + -include $(srctree)/include/linux/compiler_attributes.h \
> $(LINUXINCLUDE)
>
> ifdef CONFIG_PPC64_BOOT_WRAPPER
> diff --git a/arch/powerpc/boot/decompress.c b/arch/powerpc/boot/decompress.c
> index 8bf39ef7d2df..6098b879ac97 100644
> --- a/arch/powerpc/boot/decompress.c
> +++ b/arch/powerpc/boot/decompress.c
> @@ -21,7 +21,6 @@
>
> #define STATIC static
> #define INIT
> -#define __always_inline inline
>
> /*
> * The build process will copy the required zlib source files and headers
> --
> 2.29.2.299.gdc1121823c-goog
>
Nick Desaulniers <[email protected]> writes:
> The kernel uses `-include` to include include/linux/compiler_types.h
> into all translation units (see scripts/Makefile.lib), which #includes
> compiler_attributes.h.
>
> arch/powerpc/boot/ uses different compiler flags from the rest of the
> kernel. As such, it doesn't contain the definitions from these headers,
> and redefines a few that it needs.
>
> For the purpose of enabling -Wimplicit-fallthrough for ppc, include
> compiler_types.h via `-include`.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/236
> Signed-off-by: Nick Desaulniers <[email protected]>
> ---
> We could just `#include "include/linux/compiler_types.h"` in the few .c
> sources used from lib/ (there are proper header guards in
> compiler_types.h).
>
> It was also noted in 6a9dc5fd6170 that we could -D__KERNEL__ and
> -include compiler_types.h like the main kernel does, though testing that
> produces a whole sea of warnings to cleanup. This approach is minimally
> invasive.
>
> arch/powerpc/boot/Makefile | 1 +
> arch/powerpc/boot/decompress.c | 1 -
> 2 files changed, 1 insertion(+), 1 deletion(-)
Acked-by: Michael Ellerman <[email protected]>
cheers