[WIP] [PATCH v0.0-20200229 01/11] ez: add basic source files

[Gao Xiang via Linux-erofs <linux-erofs@lists.ozlabs.org>]

Add common headers to provide basic definitions and
helpers. Open source license is included as well.

Signed-off-by: Gao Xiang <hsiangkao@aol.com>
---
 include/ez/defs.h | 76 +++++++++++++++++++++++++++++++++++++++++++++++
 include/ez/util.h | 25 ++++++++++++++++
 2 files changed, 101 insertions(+)
 create mode 100644 include/ez/defs.h
 create mode 100644 include/ez/util.h

diff --git a/include/ez/defs.h b/include/ez/defs.h
new file mode 100644
index 0000000..d5acccf
--- /dev/null
+++ b/include/ez/defs.h
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: Apache-2.0 */
+/*
+ * ez/include/ez/defs.h
+ *
+ * Copyright (C) 2019-2020 Gao Xiang <hsiangkao@aol.com>
+ */
+#ifndef __EZ_DEFS_H
+#define __EZ_DEFS_H
+
+#include <stdint.h>
+#include <assert.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <string.h>
+#include <errno.h>
+
+#define DIV_ROUND_UP(n, d)	(((n) + (d) - 1) / (d))
+
+#define min(x, y) ({				\
+	typeof(x) _min1 = (x);			\
+	typeof(y) _min2 = (y);			\
+	(void) (&_min1 == &_min2);		\
+	_min1 < _min2 ? _min1 : _min2; })
+
+#define max(x, y) ({				\
+	typeof(x) _max1 = (x);			\
+	typeof(y) _max2 = (y);			\
+	(void) (&_max1 == &_max2);		\
+	_max1 > _max2 ? _max1 : _max2; })
+
+/*
+ * ..and if you can't take the strict types, you can specify one yourself.
+ * Or don't use min/max at all, of course.
+ */
+#define min_t(type, x, y) ({			\
+	type __min1 = (x);			\
+	type __min2 = (y);			\
+	__min1 < __min2 ? __min1: __min2; })
+
+#define max_t(type, x, y) ({			\
+	type __max1 = (x);			\
+	type __max2 = (y);			\
+	__max1 > __max2 ? __max1: __max2; })
+
+#define ARRAY_SIZE(arr)	(sizeof(arr) / sizeof((arr)[0]))
+
+#ifndef __OPTIMIZE__
+#define BUILD_BUG_ON(condition)	((void)sizeof(char[1 - 2 * !!(condition)]))
+#else
+#define BUILD_BUG_ON(condition)	assert(condition)
+#endif
+
+#define BUG_ON(cond)	assert(!(cond))
+
+#ifdef NDEBUG
+#define DBG_BUGON(condition)	((void)(condition))
+#else
+#define DBG_BUGON(condition)	BUG_ON(condition)
+#endif
+
+#ifndef __maybe_unused
+#define __maybe_unused		__attribute__((__unused__))
+#endif
+
+#define ARRAY_SIZE(arr)		(sizeof(arr) / sizeof((arr)[0]))
+
+#ifndef likely
+#define likely(x)	__builtin_expect(!!(x), 1)
+#endif
+
+#ifndef unlikely
+#define unlikely(x)	__builtin_expect(!!(x), 0)
+#endif
+
+#endif
+
diff --git a/include/ez/util.h b/include/ez/util.h
new file mode 100644
index 0000000..9cb6e62
--- /dev/null
+++ b/include/ez/util.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: Apache-2.0 */
+/*
+ * ez/include/ez/util.h
+ *
+ * Copyright (C) 2019-2020 Gao Xiang <hsiangkao@aol.com>
+ */
+#ifndef __EZ_UTIL_H
+#define __EZ_UTIL_H
+
+#include "defs.h"
+
+static inline const uint8_t *ez_memcmp(const void *ptr1, const void *ptr2,
+				       const void *buf1end)
+{
+	const uint8_t *buf1 = ptr1;
+	const uint8_t *buf2 = ptr2;
+
+	for (; buf1 != buf1end; ++buf1, ++buf2)
+		if (*buf1 != *buf2)
+			break;
+	return buf1;
+}
+
+#endif
+
-- 
2.20.1