| Message ID | 20201121194339.52290-1-masahiroy@kernel.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | compiler_attribute: remove CONFIG_ENABLE_MUST_CHECK | expand |
On Sat, Nov 21, 2020 at 8:44 PM Masahiro Yamada <masahiroy@kernel.org> wrote: > > Our goal is to always enable __must_check where appreciate, so this > CONFIG option is no longer needed. This would be great. It also implies we can then move it to `compiler_attributes.h` since it does not depend on config options anymore. We should also rename it to `__nodiscard`, since that is the standardized name (coming soon to C2x and in C++ for years). Cc'ing the Clang folks too to make them aware. Cheers, Miguel
On Sun, Nov 22, 2020 at 5:45 AM Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> wrote: > > On Sat, Nov 21, 2020 at 8:44 PM Masahiro Yamada <masahiroy@kernel.org> wrote: > > > > Our goal is to always enable __must_check where appreciate, so this > > CONFIG option is no longer needed. > > This would be great. It also implies we can then move it to > `compiler_attributes.h` since it does not depend on config options > anymore. > > We should also rename it to `__nodiscard`, since that is the > standardized name (coming soon to C2x and in C++ for years). > > Cc'ing the Clang folks too to make them aware. > I can move it to compiler_attribute.h This attribute is supported by gcc, clang, and icc. https://godbolt.org/z/ehd6so I can send v2. I do not mind renaming, but it should be done in a separate patch.
On Mon, Nov 23, 2020 at 4:37 AM Masahiro Yamada <masahiroy@kernel.org> wrote: > > I can move it to compiler_attribute.h > > This attribute is supported by gcc, clang, and icc. > https://godbolt.org/z/ehd6so > > I can send v2. > > I do not mind renaming, but it should be done in a separate patch. Of course -- sorry, I didn't mean we had to do them now, i.e. we can do the move and the rename later on, if you prefer. Cheers, Miguel
On Sat, Nov 21, 2020 at 8:44 PM Masahiro Yamada <masahiroy@kernel.org> wrote: > > Revert commit cebc04ba9aeb ("add CONFIG_ENABLE_MUST_CHECK"). > > A lot of warn_unused_result warnings existed in 2006, but until now > they have been fixed thanks to people doing allmodconfig tests. > > Our goal is to always enable __must_check where appreciate, so this > CONFIG option is no longer needed. > > I see a lot of defconfig (arch/*/configs/*_defconfig) files having: > > # CONFIG_ENABLE_MUST_CHECK is not set > > I did not touch them for now since it would be a big churn. If arch > maintainers want to clean them up, please go ahead. > > Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Picked it up through compiler-attributes with the "appreciate" typo fixed on my end. I did a quick compile-test with a minimal config. Let's see if the -next bots complain... Thanks! Cheers, Miguel
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index ac3fa37a84f9..02f6d3fbad9d 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -110,11 +110,7 @@ struct ftrace_likely_data { unsigned long constant; }; -#ifdef CONFIG_ENABLE_MUST_CHECK #define __must_check __attribute__((__warn_unused_result__)) -#else -#define __must_check -#endif #if defined(CC_USING_HOTPATCH) #define notrace __attribute__((hotpatch(0, 0))) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c789b39ed527..cb8ef4fd0d02 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -286,14 +286,6 @@ config GDB_SCRIPTS endif # DEBUG_INFO -config ENABLE_MUST_CHECK - bool "Enable __must_check logic" - default y - help - Enable the __must_check logic in the kernel build. Disable this to - suppress the "warning: ignoring return value of 'foo', declared with - attribute warn_unused_result" messages. - config FRAME_WARN int "Warn for stack frames larger than" range 0 8192 diff --git a/tools/testing/selftests/wireguard/qemu/debug.config b/tools/testing/selftests/wireguard/qemu/debug.config index b50c2085c1ac..fe07d97df9fa 100644 --- a/tools/testing/selftests/wireguard/qemu/debug.config +++ b/tools/testing/selftests/wireguard/qemu/debug.config @@ -1,5 +1,4 @@ CONFIG_LOCALVERSION="-debug" -CONFIG_ENABLE_MUST_CHECK=y CONFIG_FRAME_POINTER=y CONFIG_STACK_VALIDATION=y CONFIG_DEBUG_KERNEL=y
Revert commit cebc04ba9aeb ("add CONFIG_ENABLE_MUST_CHECK"). A lot of warn_unused_result warnings existed in 2006, but until now they have been fixed thanks to people doing allmodconfig tests. Our goal is to always enable __must_check where appreciate, so this CONFIG option is no longer needed. I see a lot of defconfig (arch/*/configs/*_defconfig) files having: # CONFIG_ENABLE_MUST_CHECK is not set I did not touch them for now since it would be a big churn. If arch maintainers want to clean them up, please go ahead. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> --- include/linux/compiler_types.h | 4 ---- lib/Kconfig.debug | 8 -------- tools/testing/selftests/wireguard/qemu/debug.config | 1 - 3 files changed, 13 deletions(-)