new: 增加一些编译器相关的宏

kernel/common/compiler_attributes.h

@@ -0,0 +1,22 @@
+#pragma once
+
+// 当函数的返回值未被使用时，编译器抛出警告信息
+#define __must_check __attribute__((__warn_unused_result__))
+#define __force __attribute__((force))
+// 无返回值的属性
+#define __noreturn __attribute__((__noreturn__))
+/*
+ * 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
+
+typedef uint8_t __attribute__((__may_alias__)) __u8_alias_t;
+typedef uint16_t __attribute__((__may_alias__)) __u16_alias_t;
+typedef uint32_t __attribute__((__may_alias__)) __u32_alias_t;
+typedef uint64_t __attribute__((__may_alias__)) __u64_alias_t;