[PATCH v2 2/6] compiler.h: Introduce TYPEOF_UNQUAL() macro
From: Uros Bizjak <hidden>
Date: 2024-12-05 15:43:01
Also in:
linux-arch, linux-bcachefs, linux-mm, lkml
Subsystem:
sparse checker, the rest · Maintainers:
Chris Li, Linus Torvalds
Define TYPEOF_UNQUAL() to use __typeof_unqual__() as typeof operator when available, to return unqualified type of the expression. Current version of sparse doesn't know anything about __typeof_unqual__() operator. Avoid the usage of __typeof_unqual__() when sparse checking is active to prevent sparse errors with unknowing keyword. Signed-off-by: Uros Bizjak <redacted> Acked-by: Nadav Amit <redacted> Cc: Thomas Gleixner <redacted> Cc: Dennis Zhou <dennis@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Christoph Lameter <redacted> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Brian Gerst <redacted> Cc: Denys Vlasenko <redacted> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org --- include/linux/compiler.h | 13 +++++++++++++ init/Kconfig | 3 +++ 2 files changed, 16 insertions(+)
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 469a64dd6495..ec0429d7a153 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h@@ -321,6 +321,19 @@ static inline void *offset_to_ptr(const int *off) */ #define prevent_tail_call_optimization() mb() +/* + * Define TYPEOF_UNQUAL() to use __typeof_unqual__() as typeof + * operator when available, to return unqualified type of the exp. + * + * XXX: Remove test for __CHECKER__ once + * sparse learns about __typeof_unqual__. + */ +#if defined(CONFIG_CC_HAS_TYPEOF_UNQUAL) && !defined(__CHECKER__) +# define TYPEOF_UNQUAL(exp) __typeof_unqual__(exp) +#else +# define TYPEOF_UNQUAL(exp) __typeof__(exp) +#endif + #include <asm/rwonce.h> #endif /* __LINUX_COMPILER_H */
diff --git a/init/Kconfig b/init/Kconfig
index a20e6efd3f0f..c1f9eb3d5f2e 100644
--- a/init/Kconfig
+++ b/init/Kconfig@@ -894,6 +894,9 @@ config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH config CC_HAS_INT128 def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT +config CC_HAS_TYPEOF_UNQUAL + def_bool $(success,echo 'int foo (int a) { __typeof_unqual__(a) b = a; return b; }' | $(CC) -x c - -S -o /dev/null) + config CC_IMPLICIT_FALLTHROUGH string default "-Wimplicit-fallthrough=5" if CC_IS_GCC && $(cc-option,-Wimplicit-fallthrough=5)
--
2.42.0