shada,config: Use CMake to determine endianess and be64toh existence

config/CMakeLists.txt

@@ -2,6 +2,7 @@ include(CheckTypeSize)
 include(CheckSymbolExists)
 include(CheckFunctionExists)
 include(CheckIncludeFiles)
+include(CheckCSourceRuns)
 
 check_type_size("int" SIZEOF_INT)
 check_type_size("long" SIZEOF_LONG)
@@ -71,6 +72,35 @@ if(HAVE_LANGINFO_H)
   check_symbol_exists(CODESET "langinfo.h" HAVE_NL_LANGINFO_CODESET)
 endif()
 
+set(SI "#include <stdint.h>\n")
+set(MS "int main(int argc,char**argv)\n{\n  uint64_t i=0x0102030405060708ULL;")
+set(ME "}")
+check_c_source_runs("
+  ${SI}
+  ${MS}
+    char *s = (char *) &i;
+    return (
+      s[0] == 0x01
+      && s[1] == 0x02
+      && s[2] == 0x03
+      && s[3] == 0x04
+      && s[4] == 0x05
+      && s[5] == 0x06
+      && s[6] == 0x07
+      && s[7] == 0x08) ? 0 : 1;
+  ${ME}"
+  ORDER_BIG_ENDIAN)
+check_c_source_runs("
+  #define _BSD_SOURCE 1
+  #define _DEFAULT_SOURCE 1
+  ${SI}
+  #include <endian.h>
+  ${MS}
+    uint64_t j = be64toh(i);
+    return (j == 0);  // Must not be zero
+  ${ME}"
+  HAVE_BE64TOH)
+
 # generate configuration header and update include directories
 configure_file (
   "${PROJECT_SOURCE_DIR}/config/config.h.in"

config/config.h.in

@@ -61,4 +61,7 @@
 #cmakedefine HAVE_JEMALLOC
 #endif
 
+#cmakedefine HAVE_BE64TOH
+#cmakedefine ORDER_BIG_ENDIAN
+
 #endif  // AUTO_CONFIG_H

src/nvim/shada.c

@@ -1,3 +1,8 @@
+#ifdef HAVE_BE64TOH
+# define _BSD_SOURCE 1
+# define _DEFAULT_SOURCE 1
+# include <endian.h>
+#endif
 #include <stdlib.h>
 #include <stddef.h>
 #include <stdbool.h>
@@ -7,15 +12,6 @@
 #include <errno.h>
 #include <unistd.h>
 #include <assert.h>
-#if defined (__GLIBC__)
-# ifndef _BSD_SOURCE
-#  define _BSD_SOURCE 1
-# endif
-# ifndef _DEFAULT_SOURCE
-#  define _DEFAULT_SOURCE 1
-# endif
-# include <endian.h>
-#endif
 
 #include <msgpack.h>
 
@@ -88,43 +84,6 @@ KHASH_SET_INIT_STR(strset)
 #define regtilde(s, m) ((char *) regtilde((char_u *) s, m))
 #define path_tail_with_sep(f) ((char *) path_tail_with_sep((char_u *)f))
 
-// From http://www.boost.org/doc/libs/1_43_0/boost/detail/endian.hpp + some
-// additional checks done after examining `{compiler} -dM -E - < /dev/null`
-// output.
-#if defined (__GLIBC__)
-# if (__BYTE_ORDER == __BIG_ENDIAN)
-#  define SHADA_BIG_ENDIAN
-# endif
-#elif defined(_BIG_ENDIAN) || defined(_LITTLE_ENDIAN)
-# if defined(_BIG_ENDIAN) && !defined(_LITTLE_ENDIAN)
-#  define SHADA_BIG_ENDIAN
-# endif
-// clang-specific
-#elif defined(__BIG_ENDIAN__) || defined(__LITTLE_ENDIAN__)
-# if defined(_BIG_ENDIAN) && !defined(_LITTLE_ENDIAN)
-#  define SHADA_BIG_ENDIAN
-# endif
-// pcc-, gcc- and clang-specific
-#elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__)
-# if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
-#  define SHADA_BIG_ENDIAN
-# endif
-#elif defined(__sparc) || defined(__sparc__) \
-  || defined(_POWER) || defined(__powerpc__) \
-  || defined(__ppc__) || defined(__hpux) || defined(__hppa) \
-  || defined(_MIPSEB) || defined(_POWER) \
-  || defined(__s390__)
-# define SHADA_BIG_ENDIAN
-#elif defined(__i386__) || defined(__alpha__) \
-  || defined(__ia64) || defined(__ia64__) \
-  || defined(_M_IX86) || defined(_M_IA64) \
-  || defined(_M_ALPHA) || defined(__amd64) \
-  || defined(__amd64__) || defined(_M_AMD64) \
-  || defined(__x86_64) || defined(__x86_64__) \
-  || defined(_M_X64) || defined(__bfin__)
-// Define nothing
-#endif
-
 #define SEARCH_KEY_MAGIC "sm"
 #define SEARCH_KEY_SMARTCASE "sc"
 #define SEARCH_KEY_HAS_LINE_OFFSET "sl"
@@ -3176,10 +3135,10 @@ static void shada_free_shada_entry(ShadaEntry *const entry)
   }
 }
 
-#ifndef __GLIBC__
+#ifndef HAVE_BE64TOH
 static inline uint64_t be64toh(uint64_t big_endian_64_bits)
 {
-#ifdef SHADA_BIG_ENDIAN
+#ifdef ORDER_BIG_ENDIAN
   return big_endian_64_bits;
 #else
   uint8_t *buf = (uint8_t *) &big_endian_64_bits;