From: Tomi Ollila Date: Wed, 27 Nov 2013 08:04:24 +0000 (+0200) Subject: Re: [PATCH v2] util: detect byte order X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=c91f2beb7e11b2c3710776734c57f2b43b745de7;p=notmuch-archives.git Re: [PATCH v2] util: detect byte order --- diff --git a/20/d993038e916430f62033992e4a22964f6ab363 b/20/d993038e916430f62033992e4a22964f6ab363 new file mode 100644 index 000000000..18277aa67 --- /dev/null +++ b/20/d993038e916430f62033992e4a22964f6ab363 @@ -0,0 +1,230 @@ +Return-Path: +X-Original-To: notmuch@notmuchmail.org +Delivered-To: notmuch@notmuchmail.org +Received: from localhost (localhost [127.0.0.1]) + by olra.theworths.org (Postfix) with ESMTP id 20B43431FC2 + for ; Wed, 27 Nov 2013 00:04:40 -0800 (PST) +X-Virus-Scanned: Debian amavisd-new at olra.theworths.org +X-Spam-Flag: NO +X-Spam-Score: 0 +X-Spam-Level: +X-Spam-Status: No, score=0 tagged_above=-999 required=5 tests=[none] + autolearn=disabled +Received: from olra.theworths.org ([127.0.0.1]) + by localhost (olra.theworths.org [127.0.0.1]) (amavisd-new, port 10024) + with ESMTP id InslMOSToKUO for ; + Wed, 27 Nov 2013 00:04:30 -0800 (PST) +Received: from guru.guru-group.fi (guru.guru-group.fi [46.183.73.34]) + by olra.theworths.org (Postfix) with ESMTP id 598B7431FAE + for ; Wed, 27 Nov 2013 00:04:30 -0800 (PST) +Received: from guru.guru-group.fi (localhost [IPv6:::1]) + by guru.guru-group.fi (Postfix) with ESMTP id 76F9810005E; + Wed, 27 Nov 2013 10:04:24 +0200 (EET) +From: Tomi Ollila +To: david@tethera.net, notmuch@notmuchmail.org +Subject: Re: [PATCH v2] util: detect byte order +In-Reply-To: <1385512694-32526-1-git-send-email-david@tethera.net> +References: + <1385512694-32526-1-git-send-email-david@tethera.net> +User-Agent: Notmuch/0.16+175~g19e97d6 (http://notmuchmail.org) Emacs/24.3.1 + (x86_64-unknown-linux-gnu) +X-Face: HhBM'cA~ +MIME-Version: 1.0 +Content-Type: text/plain +X-BeenThere: notmuch@notmuchmail.org +X-Mailman-Version: 2.1.13 +Precedence: list +List-Id: "Use and development of the notmuch mail system." + +List-Unsubscribe: , + +List-Archive: +List-Post: +List-Help: +List-Subscribe: , + +X-List-Received-Date: Wed, 27 Nov 2013 08:04:40 -0000 + +On Wed, Nov 27 2013, david@tethera.net wrote: + +> From: David Bremner +> +> Unfortunately old versions of GCC and clang do not provide byte order +> macros, so we re-invent them. +> +> If UTIL_BYTE_ORDER is not defined or defined to 0, we fall back to +> macros supported by recent versions of GCC and clang +> --- +> +> I think I got all of Tomi's comments, including the most serious one +> about the test in endian-utils.h (LITTLE twice instead of BIG, +> LITTLE). + +Agreed. LGTM. + +You may want to amend the '#' out of the line + ++#rm -f _byteorder _byteorder.c + +before pushing ? + +Tomi + + +> +> configure | 24 ++++++++++++++++++++++-- +> lib/libsha1.c | 21 +++++++-------------- +> util/endian-util.h | 38 ++++++++++++++++++++++++++++++++++++++ +> 3 files changed, 67 insertions(+), 16 deletions(-) +> create mode 100644 util/endian-util.h +> +> diff --git a/configure b/configure +> index 1a8e939..a0c6771 100755 +> --- a/configure +> +++ b/configure +> @@ -441,6 +441,19 @@ else +> EOF +> fi +> +> +printf "Checking byte order... " +> +cat> _byteorder.c < +#include +> +#include +> +uint32_t test = 0x34333231; +> +int main() { printf("%.4s\n", (const char*)&test); return 0; } +> +EOF +> +${CC} ${CFLAGS} _byteorder.c -o _byteorder > /dev/null 2>&1 +> +util_byte_order=$(./_byteorder) +> +echo $util_byte_order +> + +> +#rm -f _byteorder _byteorder.c +> + +> if [ $errors -gt 0 ]; then +> cat < +> @@ -702,6 +715,9 @@ prefix = ${PREFIX} +> # LIBDIR_IN_LDCONFIG value below is still set correctly. +> libdir = ${LIBDIR:=\$(prefix)/lib} +> +> +# byte order within a 32 bit word. 1234 = little, 4321 = big, 0 = guess +> +UTIL_BYTE_ORDER = ${util_byte_order} +> + +> # Whether libdir is in a path configured into ldconfig +> LIBDIR_IN_LDCONFIG = ${libdir_in_ldconfig} +> +> @@ -807,7 +823,9 @@ CONFIGURE_CFLAGS = -DHAVE_GETLINE=\$(HAVE_GETLINE) \$(GMIME_CFLAGS) \\ +> -DHAVE_STRSEP=\$(HAVE_STRSEP) \\ +> -DSTD_GETPWUID=\$(STD_GETPWUID) \\ +> -DSTD_ASCTIME=\$(STD_ASCTIME) \\ +> - -DHAVE_XAPIAN_COMPACT=\$(HAVE_XAPIAN_COMPACT) +> + -DHAVE_XAPIAN_COMPACT=\$(HAVE_XAPIAN_COMPACT) \\ +> + -DUTIL_BYTE_ORDER=\$(UTIL_BYTE_ORDER) +> + +> CONFIGURE_CXXFLAGS = -DHAVE_GETLINE=\$(HAVE_GETLINE) \$(GMIME_CFLAGS) \\ +> \$(TALLOC_CFLAGS) -DHAVE_VALGRIND=\$(HAVE_VALGRIND) \\ +> \$(VALGRIND_CFLAGS) \$(XAPIAN_CXXFLAGS) \\ +> @@ -815,6 +833,8 @@ CONFIGURE_CXXFLAGS = -DHAVE_GETLINE=\$(HAVE_GETLINE) \$(GMIME_CFLAGS) \\ +> -DHAVE_STRSEP=\$(HAVE_STRSEP) \\ +> -DSTD_GETPWUID=\$(STD_GETPWUID) \\ +> -DSTD_ASCTIME=\$(STD_ASCTIME) \\ +> - -DHAVE_XAPIAN_COMPACT=\$(HAVE_XAPIAN_COMPACT) +> + -DHAVE_XAPIAN_COMPACT=\$(HAVE_XAPIAN_COMPACT) \\ +> + -DUTIL_BYTE_ORDER=\$(UTIL_BYTE_ORDER) +> + +> CONFIGURE_LDFLAGS = \$(GMIME_LDFLAGS) \$(TALLOC_LDFLAGS) \$(XAPIAN_LDFLAGS) +> EOF +> diff --git a/lib/libsha1.c b/lib/libsha1.c +> index 87c7c52..aaaa4eb 100644 +> --- a/lib/libsha1.c +> +++ b/lib/libsha1.c +> @@ -34,7 +34,7 @@ +> */ +> +> #include /* for memcpy() etc. */ +> - +> +#include "endian-util.h" +> #include "libsha1.h" +> +> #if defined(__cplusplus) +> @@ -49,20 +49,13 @@ extern "C" +> +> #define bswap_32(x) ((rotr32((x), 24) & 0x00ff00ff) | (rotr32((x), 8) & 0xff00ff00)) +> +> -/* The macros __BYTE_ORDER__ and __ORDER_*_ENDIAN__ are GNU C +> - * extensions. They are also supported by clang as of v3.2 */ +> - +> -#ifdef __BYTE_ORDER__ +> -# if (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) +> -# define bsw_32(p,n) \ +> - { int _i = (n); while(_i--) ((uint32_t*)p)[_i] = bswap_32(((uint32_t*)p)[_i]); } +> -# elif (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) +> -# define bsw_32(p,n) +> -# else +> -# error "unknown byte order" +> -# endif +> +#if (UTIL_BYTE_ORDER == UTIL_ORDER_LITTLE_ENDIAN) +> +# define bsw_32(p,n) \ +> + { int _i = (n); while(_i--) ((uint32_t*)p)[_i] = bswap_32(((uint32_t*)p)[_i]); } +> +#elif (UTIL_BYTE_ORDER == UTIL_ORDER_BIG_ENDIAN) +> +# define bsw_32(p,n) +> #else +> -# error "macro __BYTE_ORDER__ is not defined" +> +# error "Unsupported byte order" +> #endif +> +> #define SHA1_MASK (SHA1_BLOCK_SIZE - 1) +> diff --git a/util/endian-util.h b/util/endian-util.h +> new file mode 100644 +> index 0000000..bc80c40 +> --- /dev/null +> +++ b/util/endian-util.h +> @@ -0,0 +1,38 @@ +> +/* this file mimics the macros present in recent GCC and CLANG */ +> + +> +#ifndef _ENDIAN_UTIL_H +> +#define _ENDIAN_UTIL_H +> + +> +/* This are prefixed with UTIL to avoid collisions +> + * +> + * You can use something like the following to define UTIL_BYTE_ORDER +> + * in a configure script. +> + */ +> +#if 0 +> +#include +> +#include +> +uint32_t test = 0x34333231; +> +int main() { printf("%.4s\n", (const char*)&test); return 0; } +> +#endif +> + +> +#define UTIL_ORDER_BIG_ENDIAN 4321 +> +#define UTIL_ORDER_LITTLE_ENDIAN 1234 +> + +> + +> +#if !defined(UTIL_BYTE_ORDER) || ((UTIL_BYTE_ORDER != UTIL_ORDER_BIG_ENDIAN) && \ +> + (UTIL_BYTE_ORDER != UTIL_ORDER_LITTLE_ENDIAN)) +> +#undef UTIL_BYTE_ORDER +> +#ifdef __BYTE_ORDER__ +> +# if (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) +> +# define UTIL_BYTE_ORDER UTIL_ORDER_LITTLE_ENDIAN +> +# elif (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) +> +# define UTIL_BYTE_ORDER UTIL_ORDER_BIG_ENDIAN +> +# else +> +# error "Unsupported __BYTE_ORDER__" +> +# endif +> +#else +> +# error "UTIL_BYTE_ORDER not correctly defined and __BYTE_ORDER__ not defined." +> +#endif +> +#endif +> + +> +#endif +> -- +> 1.8.4.2 +> +> _______________________________________________ +> notmuch mailing list +> notmuch@notmuchmail.org +> http://notmuchmail.org/mailman/listinfo/notmuch