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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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e468f5c06b
This is an effort to disentangle the include/linux/compiler*.h headers and bring them up to date. The main idea behind the series is to use feature checking macros (i.e. __has_attribute) instead of compiler version checks (e.g. GCC_VERSION), which are compiler-agnostic (so they can be shared, reducing the size of compiler-specific headers) and version-agnostic. Other related improvements have been performed in the headers as well, which on top of the use of __has_attribute it has amounted to a significant simplification of these headers (e.g. GCC_VERSION is now only guarding a few non-attribute macros). This series should also help the efforts to support compiling the kernel with clang and icc. A fair amount of documentation and comments have also been added, clarified or removed; and the headers are now more readable, which should help kernel developers in general. The series was triggered due to the move to gcc >= 4.6. In turn, this series has also triggered Sparse to gain the ability to recognize __has_attribute on its own. Finally, the __nonstring variable attribute series has been also applied on top; plus two related patches from Nick Desaulniers for unreachable() that came a bit afterwards. -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEPjU5OPd5QIZ9jqqOGXyLc2htIW0FAlvNpywACgkQGXyLc2ht IW1aiQ/+P8SJOa3GkiH37/nrIbk/wgMNytbs+gxE5YPaU1DP74Mn1prJ4XhQQic9 /mt8GnitZwzEHWdsGEUk+ZQwnIa7ZEAmpecbAF206AMRbNxa14T5YwBx4bqWFjZp sP4zPTHt3JCKL8TM+z26o152UbF2kc4WSxHjEjSFaqEnR2E5D0MwFeGPzc8fgWmS pNyn3CidzB0TS1UF008YXhiJO6HIhFNPyhPawlhwbbdsdlhZ4u0JmwfqP4EvjRFM kyzdQ9CDe+AgTTD9Y8HhtoUClaa7SJzFWNzpKIJMWt8jpKWYZQ/+WtwKg2cf+v3M uwktcs3RI1dYrjcITLz4VJ0oVaRFnyGgXvMP4yqWQx429hqnd09WXhMioXQ1htoI H0vpPIAPsK+dqVA9sP3JzMq4h6+dE7P364lkbThbVpYAGKZ52qaLt9ixT1mw1Q9f a683ji6o02IVOGUNZ/3KAb5MqdhewNEDdZILZYRfm4AL1Em3WW9QVtIosHPviLgc 16VjA02wKdxIcg+1LZMTNhfybztnSCf7SuQurpH1zEqFDGzrXwB7nYFplEY7DrrD cqhOA1fMQa++oQR+D40QDoY2ybqPOyvJG7z17pvtt+6jXep4yy2a3Bxf+ClK0nto 5yT7v9ikXJr84FOkk7OvktLlAWvcykvAdfvDepBZhpqhuX82tHY= =Y8WB -----END PGP SIGNATURE----- Merge tag 'compiler-attributes-for-linus-4.20-rc1' of https://github.com/ojeda/linux Pull compiler attribute updates from Miguel Ojeda: "This is an effort to disentangle the include/linux/compiler*.h headers and bring them up to date. The main idea behind the series is to use feature checking macros (i.e. __has_attribute) instead of compiler version checks (e.g. GCC_VERSION), which are compiler-agnostic (so they can be shared, reducing the size of compiler-specific headers) and version-agnostic. Other related improvements have been performed in the headers as well, which on top of the use of __has_attribute it has amounted to a significant simplification of these headers (e.g. GCC_VERSION is now only guarding a few non-attribute macros). This series should also help the efforts to support compiling the kernel with clang and icc. A fair amount of documentation and comments have also been added, clarified or removed; and the headers are now more readable, which should help kernel developers in general. The series was triggered due to the move to gcc >= 4.6. In turn, this series has also triggered Sparse to gain the ability to recognize __has_attribute on its own. Finally, the __nonstring variable attribute series has been also applied on top; plus two related patches from Nick Desaulniers for unreachable() that came a bit afterwards" * tag 'compiler-attributes-for-linus-4.20-rc1' of https://github.com/ojeda/linux: compiler-gcc: remove comment about gcc 4.5 from unreachable() compiler.h: update definition of unreachable() Compiler Attributes: ext4: remove local __nonstring definition Compiler Attributes: auxdisplay: panel: use __nonstring Compiler Attributes: enable -Wstringop-truncation on W=1 (gcc >= 8) Compiler Attributes: add support for __nonstring (gcc >= 8) Compiler Attributes: add MAINTAINERS entry Compiler Attributes: add Doc/process/programming-language.rst Compiler Attributes: remove uses of __attribute__ from compiler.h Compiler Attributes: KENTRY used twice the "used" attribute Compiler Attributes: use feature checks instead of version checks Compiler Attributes: add missing SPDX ID in compiler_types.h Compiler Attributes: remove unneeded sparse (__CHECKER__) tests Compiler Attributes: homogenize __must_be_array Compiler Attributes: remove unneeded tests Compiler Attributes: always use the extra-underscores syntax Compiler Attributes: remove unused attributes
76 lines
2.7 KiB
Makefile
76 lines
2.7 KiB
Makefile
# SPDX-License-Identifier: GPL-2.0
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# ==========================================================================
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#
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# make W=... settings
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#
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# W=1 - warnings that may be relevant and does not occur too often
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# W=2 - warnings that occur quite often but may still be relevant
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# W=3 - the more obscure warnings, can most likely be ignored
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#
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# $(call cc-option, -W...) handles gcc -W.. options which
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# are not supported by all versions of the compiler
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# ==========================================================================
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KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned)
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ifeq ("$(origin W)", "command line")
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export KBUILD_ENABLE_EXTRA_GCC_CHECKS := $(W)
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endif
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ifdef KBUILD_ENABLE_EXTRA_GCC_CHECKS
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warning- := $(empty)
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warning-1 := -Wextra -Wunused -Wno-unused-parameter
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warning-1 += -Wmissing-declarations
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warning-1 += -Wmissing-format-attribute
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warning-1 += $(call cc-option, -Wmissing-prototypes)
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warning-1 += -Wold-style-definition
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warning-1 += $(call cc-option, -Wmissing-include-dirs)
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warning-1 += $(call cc-option, -Wunused-but-set-variable)
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warning-1 += $(call cc-option, -Wunused-const-variable)
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warning-1 += $(call cc-option, -Wpacked-not-aligned)
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warning-1 += $(call cc-option, -Wstringop-truncation)
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warning-1 += $(call cc-disable-warning, missing-field-initializers)
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warning-1 += $(call cc-disable-warning, sign-compare)
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warning-2 := -Waggregate-return
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warning-2 += -Wcast-align
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warning-2 += -Wdisabled-optimization
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warning-2 += -Wnested-externs
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warning-2 += -Wshadow
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warning-2 += $(call cc-option, -Wlogical-op)
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warning-2 += $(call cc-option, -Wmissing-field-initializers)
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warning-2 += $(call cc-option, -Wsign-compare)
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warning-2 += $(call cc-option, -Wmaybe-uninitialized)
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warning-2 += $(call cc-option, -Wunused-macros)
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warning-3 := -Wbad-function-cast
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warning-3 += -Wcast-qual
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warning-3 += -Wconversion
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warning-3 += -Wpacked
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warning-3 += -Wpadded
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warning-3 += -Wpointer-arith
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warning-3 += -Wredundant-decls
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warning-3 += -Wswitch-default
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warning-3 += $(call cc-option, -Wpacked-bitfield-compat)
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warning := $(warning-$(findstring 1, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
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warning += $(warning-$(findstring 2, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
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warning += $(warning-$(findstring 3, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
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ifeq ("$(strip $(warning))","")
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$(error W=$(KBUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown)
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endif
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KBUILD_CFLAGS += $(warning)
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else
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ifeq ($(cc-name),clang)
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KBUILD_CFLAGS += $(call cc-disable-warning, initializer-overrides)
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KBUILD_CFLAGS += $(call cc-disable-warning, unused-value)
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KBUILD_CFLAGS += $(call cc-disable-warning, format)
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KBUILD_CFLAGS += $(call cc-disable-warning, sign-compare)
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KBUILD_CFLAGS += $(call cc-disable-warning, format-zero-length)
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KBUILD_CFLAGS += $(call cc-disable-warning, uninitialized)
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endif
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endif
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