Do not use a header-file names endian.h, embed declarations

ChangeLog

@@ -2,8 +2,8 @@
 
 	* DESCRIPTION (Version, Date): Roll micro version and date
 
-	* src/endian.h: Use endian-ness definition from Rconfig.h
-	* src/digest.c (is_big_endian): Define one-line helper
+	* src/digest.c (is_big_endian): Use endian-ness definition from
+	Rconfig.h and define one-line helper
 
 	* inst/tinytest/test_digest.R: Skip spookyhash test on big endian
 

src/digest.c

@@ -39,7 +39,6 @@
 #include "pmurhash.h"
 #include "blake3.h"
 #include "crc32c.h"
-#include "endian.h"
 
 #ifdef _WIN32
 #include <Windows.h>
@@ -622,6 +621,28 @@ SEXP vdigest(SEXP Txt, SEXP Algo, SEXP Length, SEXP Skip, SEXP Leave_raw, SEXP S
     return ans;
 }
 
+
+// Also already used in sha2.h
+//
+// We can rely on WORDS_BIGENDIAN only be defined on big endian systems thanks to Rconfig.
+//
+// A number of other #define based tests are in other source files here for different hash
+// algorithm implementations notably crc32c, pmurhash, sha2 and xxhash
+//
+// A small and elegant test is also in package qs based on https://stackoverflow.com/a/1001373
+
+// edd 02 Dec 2013  use Rconfig.h to define BYTE_ORDER, unless already defined
+#ifndef BYTE_ORDER
+    // see sha2.c comments, and on the internet at large
+    #define LITTLE_ENDIAN 1234
+    #define BIG_ENDIAN    4321
+#ifdef WORDS_BIGENDIAN
+    #define BYTE_ORDER  BIG_ENDIAN
+#else
+    #define BYTE_ORDER  LITTLE_ENDIAN
+#endif
+#endif
+
 SEXP is_big_endian() {
     return Rf_ScalarLogical(BYTE_ORDER == BIG_ENDIAN);
 }