From: Hauke Mehrtens <hauke@hauke-m.de>
To: backports@vger.kernel.org
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Subject: [PATCH 3/3] headers: stddef.h: Add struct_group
Date: Mon, 22 Jan 2024 22:33:08 +0100 [thread overview]
Message-ID: <20240122213308.149303-3-hauke@hauke-m.de> (raw)
In-Reply-To: <20240122213308.149303-1-hauke@hauke-m.de>
Add the struct_group from Linux.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
---
backport/backport-include/linux/stddef.h | 77 ++++++++++++++++++++++++
1 file changed, 77 insertions(+)
diff --git a/backport/backport-include/linux/stddef.h b/backport/backport-include/linux/stddef.h
index a0765ef3..5a73ec71 100644
--- a/backport/backport-include/linux/stddef.h
+++ b/backport/backport-include/linux/stddef.h
@@ -56,4 +56,81 @@
__DECLARE_FLEX_ARRAY(TYPE, NAME)
#endif
+#ifndef __struct_group
+/**
+ * __struct_group() - Create a mirrored named and anonyomous struct
+ *
+ * @TAG: The tag name for the named sub-struct (usually empty)
+ * @NAME: The identifier name of the mirrored sub-struct
+ * @ATTRS: Any struct attributes (usually empty)
+ * @MEMBERS: The member declarations for the mirrored structs
+ *
+ * Used to create an anonymous union of two structs with identical layout
+ * and size: one anonymous and one named. The former's members can be used
+ * normally without sub-struct naming, and the latter can be used to
+ * reason about the start, end, and size of the group of struct members.
+ * The named struct can also be explicitly tagged for layer reuse, as well
+ * as both having struct attributes appended.
+ */
+#define __struct_group(TAG, NAME, ATTRS, MEMBERS...) \
+ union { \
+ struct { MEMBERS } ATTRS; \
+ struct TAG { MEMBERS } ATTRS NAME; \
+ }
+#endif
+
+#ifndef struct_group
+/**
+ * struct_group() - Wrap a set of declarations in a mirrored struct
+ *
+ * @NAME: The identifier name of the mirrored sub-struct
+ * @MEMBERS: The member declarations for the mirrored structs
+ *
+ * Used to create an anonymous union of two structs with identical
+ * layout and size: one anonymous and one named. The former can be
+ * used normally without sub-struct naming, and the latter can be
+ * used to reason about the start, end, and size of the group of
+ * struct members.
+ */
+#define struct_group(NAME, MEMBERS...) \
+ __struct_group(/* no tag */, NAME, /* no attrs */, MEMBERS)
+#endif /* struct_group */
+
+#ifndef struct_group_attr
+/**
+ * struct_group_attr() - Create a struct_group() with trailing attributes
+ *
+ * @NAME: The identifier name of the mirrored sub-struct
+ * @ATTRS: Any struct attributes to apply
+ * @MEMBERS: The member declarations for the mirrored structs
+ *
+ * Used to create an anonymous union of two structs with identical
+ * layout and size: one anonymous and one named. The former can be
+ * used normally without sub-struct naming, and the latter can be
+ * used to reason about the start, end, and size of the group of
+ * struct members. Includes structure attributes argument.
+ */
+#define struct_group_attr(NAME, ATTRS, MEMBERS...) \
+ __struct_group(/* no tag */, NAME, ATTRS, MEMBERS)
+#endif /* struct_group_attr */
+
+#ifndef struct_group_tagged
+/**
+ * struct_group_tagged() - Create a struct_group with a reusable tag
+ *
+ * @TAG: The tag name for the named sub-struct
+ * @NAME: The identifier name of the mirrored sub-struct
+ * @MEMBERS: The member declarations for the mirrored structs
+ *
+ * Used to create an anonymous union of two structs with identical
+ * layout and size: one anonymous and one named. The former can be
+ * used normally without sub-struct naming, and the latter can be
+ * used to reason about the start, end, and size of the group of
+ * struct members. Includes struct tag argument for the named copy,
+ * so the specified layout can be reused later.
+ */
+#define struct_group_tagged(TAG, NAME, MEMBERS...) \
+ __struct_group(TAG, NAME, /* no attrs */, MEMBERS)
+#endif /* struct_group_tagged */
+
#endif /* __BACKPORT_LINUX_STDDEF_H */
--
2.43.0
prev parent reply other threads:[~2024-01-22 21:33 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-22 21:33 [PATCH 1/3] patches: Refresh on top of kernel 5.15.147 Hauke Mehrtens
2024-01-22 21:33 ` [PATCH 2/3] backports: Add usb_check_bulk_endpoints() Hauke Mehrtens
2024-01-22 21:33 ` Hauke Mehrtens [this message]
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