Clang supports the 'require_explicit_initialization' attribute on struct fields to indicate that a field must be initialized explicitly by the user when the object is constructed. When an aggregate initializer or uninitialized variable omits an annotated field, Clang emits a -Wuninitialized-explicit-init warning (enabled by default).
Add the __require_explicit_initialization macro to include/linux/compiler_attributes.h (which is included by include/linux/compiler_types.h and include/linux/compiler.h) so kernel structs with error-prone initialization (such as mandatory callbacks or cleanup handlers) can enforce explicit initialization at compile time, as discussed at the Linux Plumbers Conference. Also teach Sphinx (Documentation/conf.py), kernel-doc (tools/lib/python/kdoc/xforms_lists.py), and checkpatch.pl about the new attribute macro. Link: https://lpc.events/event/20/contributions/2392/ Assisted-by: Antigravity:gemini-3.1-pro Signed-off-by: Ian Rogers <[email protected]> --- Documentation/conf.py | 1 + include/linux/compiler_attributes.h | 11 +++++++++++ scripts/checkpatch.pl | 1 + tools/lib/python/kdoc/xforms_lists.py | 1 + 4 files changed, 14 insertions(+) diff --git a/Documentation/conf.py b/Documentation/conf.py index 5ab26ce89daf..3e5cb9ca0970 100644 --- a/Documentation/conf.py +++ b/Documentation/conf.py @@ -203,6 +203,7 @@ c_id_attributes = [ "__noreturn", "__packed", "__pure", + "__require_explicit_initialization", "__section", "__always_unused", "__maybe_unused", diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h index 476c4c560d17..60522ab80c5a 100644 --- a/include/linux/compiler_attributes.h +++ b/include/linux/compiler_attributes.h @@ -322,6 +322,17 @@ */ #define __pure __attribute__((__pure__)) +/* + * Optional: not supported by gcc + * + * clang: https://clang.llvm.org/docs/AttributeReference.html#require-explicit-initialization + */ +#if __has_attribute(__require_explicit_initialization__) +# define __require_explicit_initialization __attribute__((__require_explicit_initialization__)) +#else +# define __require_explicit_initialization +#endif + /* * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-section-function-attribute * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-section-variable-attribute diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 8a7787d228a6..4a3ae6b0100a 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -6871,6 +6871,7 @@ sub process { "noreturn" => "__noreturn", "packed" => "__packed", "pure" => "__pure", + "require_explicit_initialization" => "__require_explicit_initialization", "section" => "__section", "used" => "__used", "weak" => "__weak" diff --git a/tools/lib/python/kdoc/xforms_lists.py b/tools/lib/python/kdoc/xforms_lists.py index e3dda2fe8a53..32066fbbe763 100644 --- a/tools/lib/python/kdoc/xforms_lists.py +++ b/tools/lib/python/kdoc/xforms_lists.py @@ -36,6 +36,7 @@ class CTransforms: (CMatch("CRYPTO_MINALIGN_ATTR"), ""), (CMatch("__private"), ""), (CMatch("__rcu"), ""), + (CMatch("__require_explicit_initialization"), ""), (CMatch("____cacheline_aligned_in_smp"), ""), (CMatch("____cacheline_aligned"), ""), (CMatch("__cacheline_group_(?:begin|end)"), ""), -- 2.56.0.385.gd3acb90ef8-goog
