The Compiler Attributes series 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 4 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. You can also fetch it from: https://github.com/ojeda/linux/tree/compiler-attributes-v3 Enjoy! Cheers, Miguel Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> Cc: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx> Cc: Eli Friedman <efriedma@xxxxxxxxxxxxxx> Cc: Christopher Li <sparse@xxxxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> Cc: Joe Perches <joe@xxxxxxxxxxx> Cc: Dominique Martinet <asmadeus@xxxxxxxxxxxxx> Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: linux-sparse@xxxxxxxxxxxxxxx Cc: linux-doc@xxxxxxxxxxxxxxx Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@xxxxxxxxx> v2 -> v3: New: * Remove duplicated "used" attribute in KENTRY * Silence sparse warnings on __has_attribute & simplify the macro block * Add Documentation/process/programming-language.rst * Improve _attribute.h description * Improve some commit descriptions * Add Reviewed-by's/Acked-by's/Suggested-by's (hopefully I didn't miss anybody!) * Rebase on top of v4.19-rc2 * Cc Rasmus, Luc From reviews: * Fix __attribute_const__ rename typo (Nick) * Add SPDX identifier to _attributes.h (Nick) * Add SPDX identifier to _types.h (Greg) * Remove __attribute__ uses from compiler.h (Nick) * Tweak clang doc comments (Nick) * Move __naked out of -gcc.h to be shared (Arnd) * Use __name__ syntax instead (Rasmus) * Update sparse description (Luc) * Remove __CHECKER__ test from __must_be_array (Luc) * Add note on __has_attribute regarding sparse (Luc) * Cc linux-sparse (Luc) It is quite a lot of stuff changed this time around, I hope I haven't missed anything said in the emails. Please take a look! Compile-tested for a while on (x86_64, gcc-7.3, allmodconfig). Miguel Ojeda (12): Compiler Attributes: remove unused attributes Compiler Attributes: always use the extra-underscores syntax Compiler Attributes: remove unneeded tests Compiler Attributes: homogenize __must_be_array Compiler Attributes: naked was fixed in gcc 4.6 Compiler Attributes: naked can be shared Compiler Attributes: remove unneeded sparse (__CHECKER__) tests Compiler Attributes: add missing SPDX ID in compiler_types.h Compiler Attributes: use feature checks instead of version checks Compiler Attributes: KENTRY used twice the "used" attribute Compiler Attributes: remove uses of __attribute__ from compiler.h Compiler Attributes: add Doc/process/programming-language.rst Documentation/process/index.rst | 1 + .../process/programming-language.rst | 44 ++++ include/linux/compiler-clang.h | 5 - include/linux/compiler-gcc.h | 84 +----- include/linux/compiler-intel.h | 9 - include/linux/compiler.h | 19 +- include/linux/compiler_attributes.h | 239 ++++++++++++++++++ include/linux/compiler_types.h | 101 ++------ 8 files changed, 314 insertions(+), 188 deletions(-) create mode 100644 Documentation/process/programming-language.rst create mode 100644 include/linux/compiler_attributes.h -- 2.17.1
