rewrite endian header to not interfere with the endian system header.

the system header is inconsistently available across platforms.
This header provides the same functionality for less of the cost,
overriding the system macros.

src/dat/nbt.c

@@ -1,9 +1,9 @@
 #include "nbt.h"
 
-#include <endian.h>
 #include <stddef.h>
 #include <string.h>
 
+#include "../util/compat/endian.h"
 #include "../util/types.h"
 
 /* returns the string length from a specific location in the buffer */

src/util/compat/endian.h

@@ -2,53 +2,36 @@
 // Licensed under the MIT Licence. See LICENSE for details
 #pragma once
 
-#include <stdint.h>
-
-#include "../atrb.h"
-#include "../types.h"
-
-/* little endian */
-atrb_const static inline u16 le16ton(u16); // converts little-endian (LE) encoding to native for a 16 bit integer. (NOOP if native is LE)
-atrb_const static inline u32 le32ton(u32); // converts little-endian (LE) encoding to native for a 32 bit integer. (NOOP if native is LE)
-atrb_const static inline u64 le64ton(u64); // converts little-endian (LE) encoding to native for a 64 bit integer. (NOOP if native is LE)
-atrb_const static inline u16 ntole16(u16); // converts native encoding to little-endian (LE) for a 16 bit integer. (NOOP if native is LE)
-atrb_const static inline u32 ntole32(u32); // converts native encoding to little-endian (LE) for a 32 bit integer. (NOOP if native is LE)
-atrb_const static inline u64 ntole64(u64); // converts native encoding to little-endian (LE) for a 64 bit integer. (NOOP if native is LE)
-
-/* big endian */
-atrb_const static inline u16 be16ton(u16); // converts big-endian (BE) encoding to native for a 16 bit integer. (NOOP if native is BE)
-atrb_const static inline u32 be32ton(u32); // converts big-endian (BE) encoding to native for a 32 bit integer. (NOOP if native is BE)
-atrb_const static inline u64 be64ton(u64); // converts big-endian (BE) encoding to native for a 64 bit integer. (NOOP if native is BE)
-atrb_const static inline u16 ntobe16(u16); // converts native encoding to big-endian (BE) for a 16 bit integer. (NOOP if native is BE)
-atrb_const static inline u32 ntobe32(u32); // converts native encoding to big-endian (BE) for a 32 bit integer. (NOOP if native is BE)
-atrb_const static inline u64 ntobe64(u64); // converts native encoding to big-endian (BE) for a 64 bit integer. (NOOP if native is BE)
-
+#if __has_include(<endian.h>)
+#include <endian.h>
+#else
 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
-u16 le16ton(u16 x) { return x; }
-u32 le32ton(u32 x) { return x; }
-u64 le64ton(u64 x) { return x; }
-u16 ntole16(u16 x) { return x; }
-u32 ntole32(u32 x) { return x; }
-u64 ntole64(u64 x) { return x; }
-u16 be16ton(u16 x) { return __builtin_bswap16(x); }
-u32 be32ton(u32 x) { return __builtin_bswap32(x); }
-u64 be64ton(u64 x) { return __builtin_bswap64(x); }
-u16 ntobe16(u16 x) { return __builtin_bswap16(x); }
-u32 ntobe32(u32 x) { return __builtin_bswap32(x); }
-u64 ntobe64(u64 x) { return __builtin_bswap64(x); }
+#define le16toh(x) __uint16_identity(x)
+#define le32toh(x) __uint32_identity(x)
+#define le64toh(x) __uint64_identity(x)
+#define htole16(x) __uint16_identity(x)
+#define htole32(x) __uint32_identity(x)
+#define htole64(x) __uint64_identity(x)
+#define be16toh(x) __builtin_bswap16(x)
+#define be32toh(x) __builtin_bswap32(x)
+#define be64toh(x) __builtin_bswap64(x)
+#define htobe16(x) __builtin_bswap16(x)
+#define htobe32(x) __builtin_bswap32(x)
+#define htobe64(x) __builtin_bswap64(x)
 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
-u16 le16ton(u16 x) { __builtin_bswap16(x); }
-u32 le32ton(u32 x) { __builtin_bswap32(x); }
-u64 le64ton(u64 x) { __builtin_bswap64(x); }
-u16 ntole16(u16 x) { __builtin_bswap16(x); }
-u32 ntole32(u32 x) { __builtin_bswap32(x); }
-u64 ntole64(u64 x) { __builtin_bswap64(x); }
-u16 be16ton(u16 x) { return x; }
-u32 be32ton(u32 x) { return x; }
-u64 be64ton(u64 x) { return x; }
-u16 ntobe16(u16 x) { return x; }
-u32 ntobe32(u32 x) { return x; }
-u64 ntobe64(u64 x) { return x; }
+#define le16toh(x) __builtin_bswap16(x)
+#define le32toh(x) __builtin_bswap32(x)
+#define le64toh(x) __builtin_bswap64(x)
+#define htole16(x) __builtin_bswap16(x)
+#define htole32(x) __builtin_bswap32(x)
+#define htole64(x) __builtin_bswap64(x)
+#define be16toh(x) __uint16_identity(x)
+#define be32toh(x) __uint32_identity(x)
+#define be64toh(x) __uint64_identity(x)
+#define htobe16(x) __uint16_identity(x)
+#define htobe32(x) __uint32_identity(x)
+#define htobe64(x) __uint64_identity(x)
 #else
 #error machine architecture unsupported! Expected either big-endian or little-endian, make sure to use a compiler which defines __BYTE_ORDER__ (like clang or gcc)
 #endif
+#endif