configure: endianness check for cross compile

[fio.git] / configure

diff --git a/configure b/configure
index d3649710c1703e39374adcbb9e74f2fcea0ea56a..965623d7c2ab0905d975f4d00ab607d5d6bd7f3d 100755 (executable)
--- a/configure
+++ b/configure
@@ -126,6 +126,7 @@ output_sym() {
 targetos=""
 cpu=""
 
+cross_prefix=${cross_prefix-${CROSS_COMPILE}}
 cc="${CC-${cross_prefix}gcc}"
 
 show_help="no"
@@ -173,6 +174,12 @@ else
   targetos=`uname -s`
 fi
 
+echo "# Automatically generated by configure - do not modify" > $config_host_mak
+printf "# Configured with:" >> $config_host_mak
+printf " '%s'" "$0" "$@" >> $config_host_mak
+echo >> $config_host_mak
+echo "CONFIG_TARGET_OS=$targetos" >> $config_host_mak
+
 # Some host OSes need non-standard checks for which CPU to use.
 # Note that these checks are broken for cross-compilation: if you're
 # cross-compiling to one of these OSes then you'll need to specify
@@ -315,10 +322,27 @@ fi
 
 cc="${CC-${cross_prefix}gcc}"
 
+##########################################
+# check cross compile
+
+cross_compile="no"
+cat > $TMPC <<EOF
+int main(void)
+{
+  return 0;
+}
+EOF
+if compile_prog "" "" "cross"; then
+  $TMPE 2>/dev/null || cross_compile="yes"
+else
+  fatal "compile test failed"
+fi
+
 ##########################################
 # check endianness
 bigendian="no"
-cat > $TMPC <<EOF
+if test "$cross_compile" = "no" ; then
+  cat > $TMPC <<EOF
 #include <inttypes.h>
 int main(void)
 {
@@ -326,8 +350,24 @@ int main(void)
   return (*((uint8_t*)(&i))) == 0x67;
 }
 EOF
-if compile_prog "" "" "endian"; then
-  $TMPE && bigendian="yes"
+  if compile_prog "" "" "endian"; then
+    $TMPE && bigendian="yes"
+  fi
+else
+  # If we're cross compiling, try our best to work it out and rely on the
+  # run-time check to fail if we get it wrong.
+  cat > $TMPC <<EOF
+#include <endian.h>
+int main(void)
+{
+#if __BYTE_ORDER != __BIG_ENDIAN
+# error "Unknown endianness"
+#endif
+}
+EOF
+  compile_prog "" "" "endian" && bigendian="yes"
+  check_define "__ARMEB__" && bigendian="yes"
+  check_define "__MIPSEB__" && bigendian="yes"
 fi
 
 
@@ -335,22 +375,27 @@ echo "Operating system              $targetos"
 echo "CPU                           $cpu"
 echo "Big endian                    $bigendian"
 echo "Compiler                      $cc"
+echo "Cross compile                 $cross_compile"
 echo
 
 ##########################################
 # check for wordsize
 wordsize="0"
 cat > $TMPC <<EOF
-#include <stdio.h>
+#include <limits.h>
+#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
 int main(void)
 {
-  unsigned int wsize = sizeof(long) * 8;
-  printf("%d\n", wsize);
+  BUILD_BUG_ON(sizeof(long)*CHAR_BIT != WORDSIZE);
   return 0;
 }
 EOF
-if compile_prog "" "" "wordsize"; then
-  wordsize=`$TMPE`
+if compile_prog "-DWORDSIZE=32" "" "wordsize"; then
+  wordsize="32"
+elif compile_prog "-DWORDSIZE=64" "" "wordsize"; then
+  wordsize="64"
+else
+  fatal "Unknown wordsize"
 fi
 echo "Wordsize                      $wordsize"
 
@@ -929,11 +974,6 @@ echo "RLIMIT_MEMLOCK                $rlimit_memlock"
 
 #############################################################################
 
-echo "# Automatically generated by configure - do not modify" > $config_host_mak
-printf "# Configured with:" >> $config_host_mak
-printf " '%s'" "$0" "$@" >> $config_host_mak
-echo >> $config_host_mak
-
 if test "$wordsize" = "64" ; then
   output_sym "CONFIG_64BIT"
 elif test "$wordsize" = "32" ; then