+ CFLAGS="$CFLAGS -Wsign-compare"
+
+ if test -z "$have_llong_max"; then
+ # retry LLONG_MAX with -std=gnu99, needed on some Linuxes
+ unset ac_cv_have_decl_LLONG_MAX
+ saved_CFLAGS="$CFLAGS"
+ CFLAGS="$CFLAGS -std=gnu99"
+ AC_CHECK_DECL(LLONG_MAX,
+ [have_llong_max=1],
+ [CFLAGS="$saved_CFLAGS"],
+ [#include <limits.h>]
+ )
+ fi
+fi
+
+if test -z "$have_llong_max"; then
+ AC_MSG_CHECKING([for max value of long long])
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+#include <stdio.h>
+/* Why is this so damn hard? */
+#ifdef __GNUC__
+# undef __GNUC__
+#endif
+#define __USE_ISOC99
+#include <limits.h>
+#define DATA "conftest.llminmax"
+int main(void) {
+ FILE *f;
+ long long i, llmin, llmax = 0;
+
+ if((f = fopen(DATA,"w")) == NULL)
+ exit(1);
+
+#if defined(LLONG_MIN) && defined(LLONG_MAX)
+ fprintf(stderr, "Using system header for LLONG_MIN and LLONG_MAX\n");
+ llmin = LLONG_MIN;
+ llmax = LLONG_MAX;
+#else
+ fprintf(stderr, "Calculating LLONG_MIN and LLONG_MAX\n");
+ /* This will work on one's complement and two's complement */
+ for (i = 1; i > llmax; i <<= 1, i++)
+ llmax = i;
+ llmin = llmax + 1LL; /* wrap */
+#endif
+
+ /* Sanity check */
+ if (llmin + 1 < llmin || llmin - 1 < llmin || llmax + 1 > llmax
+ || llmax - 1 > llmax) {
+ fprintf(f, "unknown unknown\n");
+ exit(2);
+ }
+
+ if (fprintf(f ,"%lld %lld", llmin, llmax) < 0)
+ exit(3);
+
+ exit(0);
+}
+ ]])],
+ [
+ llong_min=`$AWK '{print $1}' conftest.llminmax`
+ llong_max=`$AWK '{print $2}' conftest.llminmax`
+ AC_MSG_RESULT($llong_max)
+ AC_DEFINE_UNQUOTED(LLONG_MAX, [${llong_max}LL],
+ [max value of long long calculated by configure])
+ AC_MSG_CHECKING([for min value of long long])
+ AC_MSG_RESULT($llong_min)
+ AC_DEFINE_UNQUOTED(LLONG_MIN, [${llong_min}LL],
+ [min value of long long calculated by configure])
+ ],
+ [
+ AC_MSG_RESULT(not found)
+ ],
+ [
+ AC_MSG_WARN([cross compiling: not checking])
+ ]
+ )