diff options
| author | Nathan Chancellor <nathan@kernel.org> | 2026-01-16 16:26:27 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-01-31 16:16:04 -0800 |
| commit | e8d899d301346a5591c9d1af06c3c9b3501cf84b (patch) | |
| tree | 2df38305d05eec39429ce8cec74825807a6a1f06 | |
| parent | 8f1081892d6218d23bf8afb4246217c41f5a9b21 (diff) | |
compiler-clang.h: require LLVM 19.1.0 or higher for __typeof_unqual__
When building the kernel using a version of LLVM between llvmorg-19-init
(the first commit of the LLVM 19 development cycle) and the change in
LLVM that actually added __typeof_unqual__ for all C modes [1], which
might happen during a bisect of LLVM, there is a build failure:
In file included from arch/x86/kernel/asm-offsets.c:9:
In file included from include/linux/crypto.h:15:
In file included from include/linux/completion.h:12:
In file included from include/linux/swait.h:7:
In file included from include/linux/spinlock.h:56:
In file included from include/linux/preempt.h:79:
arch/x86/include/asm/preempt.h:61:2: error: call to undeclared function '__typeof_unqual__'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
61 | raw_cpu_and_4(__preempt_count, ~PREEMPT_NEED_RESCHED);
| ^
arch/x86/include/asm/percpu.h:478:36: note: expanded from macro 'raw_cpu_and_4'
478 | #define raw_cpu_and_4(pcp, val) percpu_binary_op(4, , "and", (pcp), val)
| ^
arch/x86/include/asm/percpu.h:210:3: note: expanded from macro 'percpu_binary_op'
210 | TYPEOF_UNQUAL(_var) pto_tmp__; \
| ^
include/linux/compiler.h:248:29: note: expanded from macro 'TYPEOF_UNQUAL'
248 | # define TYPEOF_UNQUAL(exp) __typeof_unqual__(exp)
| ^
The current logic of CC_HAS_TYPEOF_UNQUAL just checks for a major
version of 19 but half of the 19 development cycle did not have support
for __typeof_unqual__.
Harden the logic of CC_HAS_TYPEOF_UNQUAL to avoid this error by only
using __typeof_unqual__ with a released version of LLVM 19, which is
greater than or equal to 19.1.0 with LLVM's versioning scheme that
matches GCC's [2].
Link: https://github.com/llvm/llvm-project/commit/cc308f60d41744b5920ec2e2e5b25e1273c8704b [1]
Link: https://github.com/llvm/llvm-project/commit/4532617ae420056bf32f6403dde07fb99d276a49 [2]
Link: https://lkml.kernel.org/r/20260116-require-llvm-19-1-for-typeof_unqual-v1-1-3b9a4a4b212b@kernel.org
Fixes: ac053946f5c4 ("compiler.h: introduce TYPEOF_UNQUAL() macro")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Cc: Bill Wendling <morbo@google.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | include/linux/compiler-clang.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h index 7edf1a07b535..e1123dd28486 100644 --- a/include/linux/compiler-clang.h +++ b/include/linux/compiler-clang.h @@ -153,4 +153,4 @@ * Bindgen uses LLVM even if our C compiler is GCC, so we cannot * rely on the auto-detected CONFIG_CC_HAS_TYPEOF_UNQUAL. */ -#define CC_HAS_TYPEOF_UNQUAL (__clang_major__ >= 19) +#define CC_HAS_TYPEOF_UNQUAL (__clang_major__ > 19 || (__clang_major__ == 19 && __clang_minor__ > 0)) |