From edef02286ee855045120854cdff646ce034a7474 Mon Sep 17 00:00:00 2001
From: fslongjin <longjin@RinGoTek.cn>
Date: Wed, 28 Sep 2022 23:11:34 +0800
Subject: [PATCH] =?UTF-8?q?=E6=96=B0=E5=A2=9E=E9=94=99=E8=AF=AF=E5=88=A4?=
 =?UTF-8?q?=E6=96=AD=E7=9A=84=E5=AE=8F=EF=BC=8C=E4=BB=A5=E5=8F=8A=E8=BF=94?=
 =?UTF-8?q?=E5=9B=9E=E5=80=BC=E4=BD=BF=E7=94=A8=E6=A3=80=E6=B5=8B?=
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---
 kernel/common/compiler.h |  7 ++++++-
 kernel/common/err.h      | 30 ++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 kernel/common/err.h

diff --git a/kernel/common/compiler.h b/kernel/common/compiler.h
index 9265fa14..60da65d8 100644
--- a/kernel/common/compiler.h
+++ b/kernel/common/compiler.h
@@ -9,4 +9,9 @@
 // 内存屏障
 #define barrier() __asm__ __volatile__("" :: \
                                            : "memory");
-#endif
\ No newline at end of file
+#endif
+
+// 编译器属性
+
+// 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__))
\ No newline at end of file
diff --git a/kernel/common/err.h b/kernel/common/err.h
new file mode 100644
index 00000000..cd3c33c3
--- /dev/null
+++ b/kernel/common/err.h
@@ -0,0 +1,30 @@
+#pragma once
+#include <common/compiler.h>
+#include <stdint.h>
+#define MAX_ERRNO 4095
+
+#define IS_ERR_VALUE(x) unlikely((x) >= (uint64_t)-MAX_ERRNO)
+
+/**
+ * @brief 判断返回的指针是否为errno
+ * 
+ * @param ptr 待校验的指针
+ * @return long 1 => 是错误码
+ *              0 => 不是错误码
+ */
+static inline long __must_check IS_ERR(const void* ptr)
+{
+    return IS_ERR_VALUE((uint64_t)ptr);
+}
+
+/**
+ * @brief 判断返回的指针是否为errno或者为空
+ * 
+ * @param ptr 待校验的指针
+ * @return long 1 => 是错误码或NULL
+ *              0 => 不是错误码或NULL
+ */
+static inline long __must_check IS_ERR_OR_NULL(const void* ptr)
+{
+    return !ptr || IS_ERR_VALUE((uint64_t)ptr);
+}