Re: [PATCH 12/11] pragma once: scripted treewide conversion

[Darrick J. Wong]

On Sun, Feb 28, 2021 at 08:11:54PM +0300, Alexey Dobriyan wrote:
> [  Bcc a lot of lists so that people understand what's this is all         ]
> [  about without creating uber-cc-thread.                                  ]
> [  Apologies if I missed your subsystem                                    ]
> [  Please see [PATCH 11/11: pragma once: conversion script (in Python 2)]  ]
> 
> Hi, Linus.
> 
> Please run the script below from top-level directory, it will convert
> most kernel headers to #pragma once directive advancing them into
> 21-st century.
> 
> The advantages are:
> 
> * less LOC
> 
> 	18087 files changed, 18878 insertions(+), 99804 deletions(-)
> 	= -81 kLOC (give or take)
> 
> * less mental tax on developers forced to name things which aren't even
>   real code

I don't find include guards to be much of a mental tax, but it sure
would be nice to see exactly what the changes would look like...

> * less junk in preprocessor hashtables and editors/IDEs autocompletion
>   lists
> 
> There are two bit exceptions: UAPI headers and ACPICA.
> Given ubiquity of #pragma once, I personally think even these subsystems
> should be converted in the future.
> 
> Compile tested on alpha, arc, arm, arm64, h8300, ia64, m68k, microblaze,
> mips, nios2, parisc, powerpc, riscv, s390, sh, sparc, um-i386, um-x86_64,
> i386, x86_64, xtensa (allnoconfig, all defconfigs, allmodconfig with or
> without SMP/DEBUG_KERNEL + misc stuff).
> 
> Not compile tested on csky, hexagon, nds32, openrisc. 
> 
> Love,
> 	Alexey
> 
> Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
> 
> 
> 
> #!/bin/sh -x
> find . -type f -name '*.h' -print	|\
> LC_ALL=C sort				|\
> sed -e 's#^./##g'			|\
> xargs ./scripts/pragma-once.py

...because I can't find this script in upstream git, so I can't really
tell for myself what the changes to xfs would look like.  The thing I
need to know is, what will changes to fs/xfs/libxfs/ look like when we
port that to userspace?

Does this introduce any minimum compiler version requirements?

--D

> 
> find . -type d -name 'uapi' | xargs git checkout -f
> git checkout -f arch/alpha/include/asm/cmpxchg.h
> git checkout -f arch/arm/mach-imx/hardware.h
> git checkout -f arch/arm/mach-ixp4xx/include/mach/hardware.h
> git checkout -f arch/arm/mach-sa1100/include/mach/hardware.h
> git checkout -f arch/mips/include/asm/mips-cps.h
> git checkout -f arch/x86/boot/boot.h
> git checkout -f arch/x86/boot/ctype.h
> git checkout -f arch/x86/include/asm/cpufeatures.h
> git checkout -f arch/x86/include/asm/disabled-features.h
> git checkout -f arch/x86/include/asm/required-features.h
> git checkout -f arch/x86/include/asm/vmxfeatures.h
> git checkout -f arch/x86/include/asm/vvar.h
> git checkout -f drivers/acpi/acpica/
> git checkout -f drivers/gpu/drm/amd/pm/inc/vega10_ppsmc.h
> git checkout -f drivers/gpu/drm/amd/pm/powerplay/ppsmc.h
> git checkout -f drivers/input/misc/yealink.h
> git checkout -f drivers/media/usb/dvb-usb-v2/mxl111sf-demod.h
> git checkout -f drivers/media/usb/dvb-usb-v2/mxl111sf-tuner.h
> git checkout -f drivers/pcmcia/yenta_socket.h
> git checkout -f drivers/staging/rtl8723bs/include/hal_com_h2c.h
> git checkout -f include/linux/acpi.h
> git checkout -f include/linux/bitops.h
> git checkout -f include/linux/compiler_types.h
> git checkout -f include/linux/device.h
> git checkout -f include/linux/kbuild.h
> git checkout -f include/linux/libfdt_env.h
> git checkout -f include/linux/local_lock.h
> git checkout -f include/linux/spinlock.h
> git checkout -f include/linux/spinlock_api_smp.h
> git checkout -f include/linux/spinlock_types.h
> git checkout -f include/linux/tracepoint.h
> git checkout -f mm/gup_test.h
> git checkout -f net/batman-adv/main.h
> git checkout -f scripts/dtc/
> git checkout -f tools/include/linux/bitops.h
> git checkout -f tools/include/linux/compiler.h
> git checkout -f tools/testing/selftests/clone3/clone3_selftests.h
> git checkout -f tools/testing/selftests/futex/include/atomic.h
> git checkout -f tools/testing/selftests/futex/include/futextest.h
> git checkout -f tools/testing/selftests/futex/include/logging.h
> git checkout -f tools/testing/selftests/kselftest.h
> git checkout -f tools/testing/selftests/kselftest_harness.h
> git checkout -f tools/testing/selftests/pidfd/pidfd.h
> git checkout -f tools/testing/selftests/x86/helpers.h