From 97d35a552ec5b6ddf7923dd2f9a8eb973526acea Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Thu, 17 Oct 2019 15:40:16 -0400 Subject: move __BYTE_ORDER definition to alltypes.h this change is motivated by the intersection of several factors. presently, despite being a nonstandard header, endian.h is exposing the unprefixed byte order macros and functions only if _BSD_SOURCE or _GNU_SOURCE is defined. this is to accommodate use of endian.h from other headers, including bits headers, which need to define structure layout in terms of endianness. with time64 switch-over, even more headers will need to do this. at the same time, the resolution of Austin Group issue 162 makes endian.h a standard header for POSIX-future, requiring that it expose the unprefixed macros and the functions even in standards-conforming profiles. changes to meet this new requirement would break existing internal usage of endian.h by causing it to violate namespace where it's used. instead, have the arch's alltypes.h define __BYTE_ORDER, either as a fixed constant or depending on the right arch-specific predefined macros for determining endianness. explicit literals 1234 and 4321 are used instead of __LITTLE_ENDIAN and __BIG_ENDIAN so that there's no danger of getting the wrong result if a macro is undefined and implicitly evaluates to 0 at the preprocessor level. the powerpc (32-bit) bits/endian.h being removed had logic for varying endianness, but our powerpc arch has never supported that and has always been big-endian-only. this logic is not carried over to the new __BYTE_ORDER definition in alltypes.h. --- include/alltypes.h.in | 3 +++ include/endian.h | 8 +------- 2 files changed, 4 insertions(+), 7 deletions(-) (limited to 'include') diff --git a/include/alltypes.h.in b/include/alltypes.h.in index 8e76c839..1ab40395 100644 --- a/include/alltypes.h.in +++ b/include/alltypes.h.in @@ -1,3 +1,6 @@ +#define __LITTLE_ENDIAN 1234 +#define __BIG_ENDIAN 4321 + TYPEDEF unsigned _Addr size_t; TYPEDEF unsigned _Addr uintptr_t; TYPEDEF _Addr ptrdiff_t; diff --git a/include/endian.h b/include/endian.h index 1bd44451..2c2ad5f4 100644 --- a/include/endian.h +++ b/include/endian.h @@ -3,15 +3,9 @@ #include -#define __LITTLE_ENDIAN 1234 -#define __BIG_ENDIAN 4321 #define __PDP_ENDIAN 3412 -#if defined(__GNUC__) && defined(__BYTE_ORDER__) -#define __BYTE_ORDER __BYTE_ORDER__ -#else -#include -#endif +#include #if defined(_GNU_SOURCE) || defined(_BSD_SOURCE) -- cgit v1.2.1