Re: [RFC PATCH next-20200930] treewide: Convert macro and uses of __section(foo) to __section("foo")

From: Joe Perches
Date: Wed Sep 30 2020 - 18:25:41 EST


On Wed, 2020-09-30 at 15:20 -0700, Nick Desaulniers wrote:
> On Wed, Sep 30, 2020 at 3:06 PM Joe Perches <joe@xxxxxxxxxxx> wrote:
> > On Wed, 2020-09-30 at 14:40 -0700, Nick Desaulniers wrote:
> > > On Wed, Sep 30, 2020 at 12:16 PM Joe Perches <joe@xxxxxxxxxxx> wrote:
> > > > Use a more generic form for __section that requires quotes to avoid
> > > > complications with clang and gcc differences.
> > > >
> > > > Remove the quote operator # from compiler_attributes.h __section macro.
> > > >
> > > > Convert all unquoted __section(foo) uses to quoted __section("foo").
> > > > Also convert __attribute__((section("foo"))) uses to __section("foo")
> > > > even if the __attribute__ has multiple list entry forms.
> > > >
> > > > Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
> > > > ---
> > > >
> > > > This is the current output from the script against next-20200930
> > > > attached in this link:
> > > >
> > > > https://lore.kernel.org/lkml/0e582a7f5144a33f465978d97701f9b3dcc377f3.camel@xxxxxxxxxxx/
> > > >
> > > > It might be useful to run the script immediately before
> > > > the next -rc1.
> > >
> > > $ ARCH=powerpc CROSS_COMPILE=powerpc64le-linux-gnu- make CC=clang -j71
> > > powernv_defconfig
> > > $ ARCH=powerpc CROSS_COMPILE=powerpc64le-linux-gnu- make CC=clang -j71
> > > ...
> > > arch/powerpc/boot/main.c:193:44: error: expected ';' after top level declarator
> > > static char cmdline[BOOT_COMMAND_LINE_SIZE]
> >
> > The script does not convert files in
> >
> > scripts/
> > tools/
> > uapi/
> > and include/linux/compiler_attributes.h
> >
> > It otherwise assumes that any __attribute__((__section__
> > use should be converted to __section.
> >
> > If this ppc file is the only file outside of the
> > listed exclusions, I can either exclude it directly
> > or add compiler.h to it.
> >
> > You have a preference?
>
> If compiler_types.h which includes compiler_attributes.h is being
> implicitly including by Kbuild add `-include` flags to most
> translation units in the kernel, it would be nice to be able to use it
> everywhere. I consider open coded __attribute__'s a portability bug.
> So including the header in arch/powerpc/boot/*.c would be my
> preference.
>
> > Perhaps these are also possible files that need exclusions:
> >
> > ./arch/x86/boot/video.h:#define __videocard struct card_info __section(".videocards") __attribute__((used))
> > ./arch/x86/boot/compressed/pgtable_64.c:unsigned long *trampoline_32bit __section(".data");
> > ./arch/x86/boot/tty.c:static void __section(".inittext") serial_putchar(int ch)
> > ./arch/x86/boot/tty.c:static void __section(".inittext") bios_putchar(int ch)
> > ./arch/x86/boot/tty.c:void __section(".inittext") putchar(int ch)
> > ./arch/x86/boot/tty.c:void __section(".inittext") puts(const char *str)
> > ./arch/s390/boot/startup.c:static struct diag210 _diag210_tmp_dma __section(".dma.data");
> > ./arch/powerpc/boot/main.c: __section("__builtin_cmdline");
> > ./arch/powerpc/boot/ps3.c: __section("__builtin_cmdline");
> >
> >
>

no ppc cross compiler here, so can't test but maybe:
---
arch/powerpc/boot/main.c | 2 ++
arch/powerpc/boot/ps3.c | 2 ++
2 files changed, 4 insertions(+)

diff --git a/arch/powerpc/boot/main.c b/arch/powerpc/boot/main.c
index 6a5b937a7f5c..ce6e27798f79 100644
--- a/arch/powerpc/boot/main.c
+++ b/arch/powerpc/boot/main.c
@@ -6,6 +6,8 @@
*/
#include <stdarg.h>
#include <stddef.h>
+#include <linux/compiler.h>
+
#include "elf.h"
#include "page.h"
#include "string.h"
diff --git a/arch/powerpc/boot/ps3.c b/arch/powerpc/boot/ps3.c
index a71714b454b1..86ca9c30562a 100644
--- a/arch/powerpc/boot/ps3.c
+++ b/arch/powerpc/boot/ps3.c
@@ -8,6 +8,8 @@

#include <stdarg.h>
#include <stddef.h>
+#include <linux/compiler.h>
+
#include "types.h"
#include "elf.h"
#include "string.h"