[PATCH v2] util: detect byte order

2013-11-27 Thread Tomi Ollila
On Wed, Nov 27 2013, david at 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*)); 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..4eb 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 000..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() { 

[PATCH v2] util: detect byte order

2013-11-27 Thread David Bremner
Tomi Ollila  writes:
>
> You may want to amend the '#' out of the line
>
> +#rm -f _byteorder _byteorder.c
>

done and pushed.

d


Re: [PATCH v2] util: detect byte order

2013-11-27 Thread Tomi Ollila
On Wed, Nov 27 2013, da...@tethera.net wrote:

 From: David Bremner da...@tethera.net

 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 EOF
 +#include stdio.h
 +#include stdint.h
 +uint32_t test = 0x34333231;
 +int main() { printf(%.4s\n, (const char*)test); return 0; }
 +EOF
 +${CC} ${CFLAGS} _byteorder.c -o _byteorder  /dev/null 21
 +util_byte_order=$(./_byteorder)
 +echo $util_byte_order
 +
 +#rm -f _byteorder _byteorder.c
 +
  if [ $errors -gt 0 ]; then
  cat EOF
  
 @@ -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..4eb 100644
 --- a/lib/libsha1.c
 +++ b/lib/libsha1.c
 @@ -34,7 +34,7 @@
  */
  
  #include string.h /* 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 000..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 stdio.h
 +#include stdint.h
 +uint32_t test = 0x34333231;
 +int main() { printf(%.4s\n, (const char*)test); return 0; }
 +#endif
 +
 +#define UTIL_ORDER_BIG_ENDIAN  4321
 

Re: [PATCH v2] util: detect byte order

2013-11-27 Thread David Bremner
Tomi Ollila tomi.oll...@iki.fi writes:

 You may want to amend the '#' out of the line

 +#rm -f _byteorder _byteorder.c


done and pushed.

d
___
notmuch mailing list
notmuch@notmuchmail.org
http://notmuchmail.org/mailman/listinfo/notmuch


[PATCH v2] util: detect byte order

2013-11-26 Thread da...@tethera.net
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).

 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 
+uint32_t test = 0x34333231;
+int main() { printf("%.4s\n", (const char*)); 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 < /* 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 000..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*)); return 0; }
+#endif
+
+#define UTIL_ORDER_BIG_ENDIAN4321
+#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



[PATCH v2] util: detect byte order

2013-11-26 Thread david
From: David Bremner da...@tethera.net

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).

 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 EOF
+#include stdio.h
+#include stdint.h
+uint32_t test = 0x34333231;
+int main() { printf(%.4s\n, (const char*)test); return 0; }
+EOF
+${CC} ${CFLAGS} _byteorder.c -o _byteorder  /dev/null 21
+util_byte_order=$(./_byteorder)
+echo $util_byte_order
+
+#rm -f _byteorder _byteorder.c
+
 if [ $errors -gt 0 ]; then
 cat EOF
 
@@ -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..4eb 100644
--- a/lib/libsha1.c
+++ b/lib/libsha1.c
@@ -34,7 +34,7 @@
 */
 
 #include string.h /* 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 000..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 stdio.h
+#include stdint.h
+uint32_t test = 0x34333231;
+int main() { printf(%.4s\n, (const char*)test); return 0; }
+#endif
+
+#define UTIL_ORDER_BIG_ENDIAN4321
+#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__ ==