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authorNick Desaulniers <ndesaulniers@google.com>2021-08-02 22:23:20 +0200
committerMiguel Ojeda <ojeda@kernel.org>2021-09-09 01:14:28 +0200
commitb83a908498d68fafca931e1276e145b339cac5fb (patch)
tree2795a8bbc93b56fd96b8663d6b1b97d321d713eb /include
parentMAINTAINERS: add Nick as Reviewer for compiler_attributes.h (diff)
downloadlinux-b83a908498d68fafca931e1276e145b339cac5fb.tar.xz
linux-b83a908498d68fafca931e1276e145b339cac5fb.zip
compiler_attributes.h: move __compiletime_{error|warning}
Clang 14 will add support for __attribute__((__error__(""))) and __attribute__((__warning__(""))). To make use of these in __compiletime_error and __compiletime_warning (as used by BUILD_BUG and friends) for newer clang and detect/fallback for older versions of clang, move these to compiler_attributes.h and guard them with __has_attribute preprocessor guards. Link: https://reviews.llvm.org/D106030 Link: https://bugs.llvm.org/show_bug.cgi?id=16428 Link: https://github.com/ClangBuiltLinux/linux/issues/1173 Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> [Reworded, landed in Clang 14] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/compiler-gcc.h3
-rw-r--r--include/linux/compiler_attributes.h24
-rw-r--r--include/linux/compiler_types.h6
3 files changed, 24 insertions, 9 deletions
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 5d97ef738a57..61c1479688db 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -43,9 +43,6 @@
#define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
-#define __compiletime_warning(message) __attribute__((__warning__(message)))
-#define __compiletime_error(message) __attribute__((__error__(message)))
-
#if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
#define __latent_entropy __attribute__((latent_entropy))
#endif
diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h
index 7b1fa5c30169..f4df9e5a8c76 100644
--- a/include/linux/compiler_attributes.h
+++ b/include/linux/compiler_attributes.h
@@ -30,6 +30,7 @@
# define __GCC4_has_attribute___assume_aligned__ (__GNUC_MINOR__ >= 9)
# define __GCC4_has_attribute___copy__ 0
# define __GCC4_has_attribute___designated_init__ 0
+# define __GCC4_has_attribute___error__ 1
# define __GCC4_has_attribute___externally_visible__ 1
# define __GCC4_has_attribute___no_caller_saved_registers__ 0
# define __GCC4_has_attribute___noclone__ 1
@@ -38,6 +39,7 @@
# define __GCC4_has_attribute___no_sanitize_undefined__ (__GNUC_MINOR__ >= 9)
# define __GCC4_has_attribute___no_sanitize_coverage__ 0
# define __GCC4_has_attribute___fallthrough__ 0
+# define __GCC4_has_attribute___warning__ 1
#endif
/*
@@ -138,6 +140,17 @@
#endif
/*
+ * Optional: only supported since clang >= 14.0
+ *
+ * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-error-function-attribute
+ */
+#if __has_attribute(__error__)
+# define __compiletime_error(msg) __attribute__((__error__(msg)))
+#else
+# define __compiletime_error(msg)
+#endif
+
+/*
* Optional: not supported by clang
*
* gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-externally_005fvisible-function-attribute
@@ -287,6 +300,17 @@
#define __must_check __attribute__((__warn_unused_result__))
/*
+ * Optional: only supported since clang >= 14.0
+ *
+ * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-warning-function-attribute
+ */
+#if __has_attribute(__warning__)
+# define __compiletime_warning(msg) __attribute__((__warning__(msg)))
+#else
+# define __compiletime_warning(msg)
+#endif
+
+/*
* gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-weak-function-attribute
* gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-weak-variable-attribute
*/
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index d29bda7f6ebd..8246d0caffa6 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -294,12 +294,6 @@ struct ftrace_likely_data {
#ifndef __compiletime_object_size
# define __compiletime_object_size(obj) -1
#endif
-#ifndef __compiletime_warning
-# define __compiletime_warning(message)
-#endif
-#ifndef __compiletime_error
-# define __compiletime_error(message)
-#endif
#ifdef __OPTIMIZE__
# define __compiletime_assert(condition, msg, prefix, suffix) \