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-rw-r--r--backport-include/linux/build_bug.h31
1 files changed, 31 insertions, 0 deletions
diff --git a/backport-include/linux/build_bug.h b/backport-include/linux/build_bug.h
new file mode 100644
index 0000000..c883e52
--- /dev/null
+++ b/backport-include/linux/build_bug.h
@@ -0,0 +1,31 @@
+#ifndef __BP_BUILD_BUG_H
+#define __BP_BUILD_BUG_H
+
+#if LINUX_VERSION_IS_GEQ(4,13,0)
+#include_next <linux/build_bug.h>
+#else /* LINUX_VERSION_IS_GEQ(4,13,0) */
+#include <linux/bug.h>
+#endif /* LINUX_VERSION_IS_GEQ(4,13,0) */
+
+#ifndef static_assert
+/**
+ * static_assert - check integer constant expression at build time
+ *
+ * static_assert() is a wrapper for the C11 _Static_assert, with a
+ * little macro magic to make the message optional (defaulting to the
+ * stringification of the tested expression).
+ *
+ * Contrary to BUILD_BUG_ON(), static_assert() can be used at global
+ * scope, but requires the expression to be an integer constant
+ * expression (i.e., it is not enough that __builtin_constant_p() is
+ * true for expr).
+ *
+ * Also note that BUILD_BUG_ON() fails the build if the condition is
+ * true, while static_assert() fails the build if the expression is
+ * false.
+ */
+#define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr)
+#define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
+#endif
+
+#endif /* __BP_BUILD_BUG_H */