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

From: Joe Perches <joe@perches.com>
To: Nick Desaulniers <ndesaulniers@google.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>,
	"Paul E . McKenney" <paulmck@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Lai Jiangshan <jiangshanlai@gmail.com>,
	Josh Triplett <josh@joshtriplett.org>,
	Kees Cook <keescook@chromium.org>,
	LKML <linux-kernel@vger.kernel.org>,
	rcu@vger.kernel.org,
	Clang-Built-Linux ML <clang-built-linux@googlegroups.com>,
	Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
	Michael Ellerman <mpe@ellerman.id.au>
Subject: Re: [RFC PATCH next-20200930] treewide: Convert macro and uses of __section(foo) to __section("foo")
Date: Wed, 30 Sep 2020 15:06:51 -0700	[thread overview]
Message-ID: <417ffa3fd3fba5d4a481db6a0b0c9b48cbbb17c4.camel@perches.com> (raw)
In-Reply-To: <CAKwvOdkhyvTpY6pHT+CLSsBFuKRWsXucjbwN_tyJAsryZXvG1A@mail.gmail.com>

On Wed, 2020-09-30 at 14:40 -0700, Nick Desaulniers wrote:
> On Wed, Sep 30, 2020 at 12:16 PM Joe Perches <joe@perches.com> 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@perches.com>
> > ---
> > 
> > This is the current output from the script against next-20200930
> > attached in this link:
> > 
> > https://lore.kernel.org/lkml/0e582a7f5144a33f465978d97701f9b3dcc377f3.camel@perches.com/
> > 
> > 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?

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");