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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-07-01 13:55:39 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-07-01 13:55:39 +0200
commit19ed3bb5587b30ace275cb604fb2b9c60dc49de0 (patch)
treee44bf7a63c6df69dacd4ee4501a97618daa5c013 /include/linux/compiler_types.h
parent783100f6ea0ae74a4ff3d616d4bce3b54badf347 (diff)
parent22a40d14b572deb80c0648557f4bd502d7e83826 (diff)
Merge 6.10-rc6 into char-misc-next
We need the char/misc/iio fixes in here as well to build on top of. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/compiler_types.h')
-rw-r--r--include/linux/compiler_types.h23
1 files changed, 23 insertions, 0 deletions
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index 93600de3800b..f14c275950b5 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -143,6 +143,29 @@ static inline void __chk_io_ptr(const volatile void __iomem *ptr) { }
# define __preserve_most
#endif
+/*
+ * Annotating a function/variable with __retain tells the compiler to place
+ * the object in its own section and set the flag SHF_GNU_RETAIN. This flag
+ * instructs the linker to retain the object during garbage-cleanup or LTO
+ * phases.
+ *
+ * Note that the __used macro is also used to prevent functions or data
+ * being optimized out, but operates at the compiler/IR-level and may still
+ * allow unintended removal of objects during linking.
+ *
+ * Optional: only supported since gcc >= 11, clang >= 13
+ *
+ * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-retain-function-attribute
+ * clang: https://clang.llvm.org/docs/AttributeReference.html#retain
+ */
+#if __has_attribute(__retain__) && \
+ (defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || \
+ defined(CONFIG_LTO_CLANG))
+# define __retain __attribute__((__retain__))
+#else
+# define __retain
+#endif
+
/* Compiler specific macros. */
#ifdef __clang__
#include <linux/compiler-clang.h>