diff --git a/libutils/include/utils/ByteOrder.h b/libutils/include/utils/ByteOrder.h index 44ea13df8..9b940e6e0 100644 --- a/libutils/include/utils/ByteOrder.h +++ b/libutils/include/utils/ByteOrder.h @@ -14,10 +14,17 @@ * limitations under the License. */ -// +#pragma once -#ifndef _LIBS_UTILS_BYTE_ORDER_H -#define _LIBS_UTILS_BYTE_ORDER_H +/* + * If you're looking for a portable that's available on Android, + * Linux, macOS, and Windows, see instead. + * + * Nothing in this file is useful because all supported Android ABIs are + * little-endian and all our code that runs on the host assumes that the host is + * also little-endian. What pretense at big-endian support exists is completely + * untested and unlikely to actually work. + */ #include #include @@ -27,55 +34,12 @@ #include #endif -/* - * These macros are like the hton/ntoh byte swapping macros, - * except they allow you to swap to and from the "device" byte - * order. The device byte order is the endianness of the target - * device -- for the ARM CPUs we use today, this is little endian. - * - * Note that the byte swapping functions have not been optimized - * much; performance is currently not an issue for them since the - * intent is to allow us to avoid byte swapping on the device. - */ +/* TODO: move this cruft to frameworks/. */ -static inline uint32_t android_swap_long(uint32_t v) -{ - return (v<<24) | ((v<<8)&0x00FF0000) | ((v>>8)&0x0000FF00) | (v>>24); -} +#define dtohl(x) (x) +#define dtohs(x) (x) +#define htodl(x) (x) +#define htods(x) (x) -static inline uint16_t android_swap_short(uint16_t v) -{ - return (v<<8) | (v>>8); -} - -#define DEVICE_BYTE_ORDER LITTLE_ENDIAN - -#if BYTE_ORDER == DEVICE_BYTE_ORDER - -#define dtohl(x) (x) -#define dtohs(x) (x) -#define htodl(x) (x) -#define htods(x) (x) - -#else - -#define dtohl(x) (android_swap_long(x)) -#define dtohs(x) (android_swap_short(x)) -#define htodl(x) (android_swap_long(x)) -#define htods(x) (android_swap_short(x)) - -#endif - -#if BYTE_ORDER == LITTLE_ENDIAN #define fromlel(x) (x) -#define fromles(x) (x) #define tolel(x) (x) -#define toles(x) (x) -#else -#define fromlel(x) (android_swap_long(x)) -#define fromles(x) (android_swap_short(x)) -#define tolel(x) (android_swap_long(x)) -#define toles(x) (android_swap_short(x)) -#endif - -#endif // _LIBS_UTILS_BYTE_ORDER_H