[Box Backup-commit] COMMIT r1453 - box/chris/general/infrastructure/m4

[boxbackup-dev@fluffy.co.uk]

Author: chris
Date: 2007-03-24 14:55:46 +0000 (Sat, 24 Mar 2007)
New Revision: 1453

Added:
   box/chris/general/infrastructure/m4/ax_check_llong_minmax.m4
Log:
Merge new m4 from chris/merge


Added: box/chris/general/infrastructure/m4/ax_check_llong_minmax.m4
===================================================================
--- box/chris/general/infrastructure/m4/ax_check_llong_minmax.m4	                        (rev 0)
+++ box/chris/general/infrastructure/m4/ax_check_llong_minmax.m4	2007-03-24 14:55:46 UTC (rev 1453)
@@ -0,0 +1,76 @@
+dnl @synopsis AX_CHECK_LLONG_MINMAX
+dnl
+dnl This macro will fix up LLONG_MIN and LLONG_MAX as appropriate. I'm finding
+dnl it quite difficult to believe that so many hoops are necessary. The world
+dnl seems to have gone quite mad.
+dnl
+dnl This gem is adapted from the OpenSSH configure script so here's
+dnl the original copyright notice:
+dnl
+dnl Copyright (c) 1999-2004 Damien Miller
+dnl
+dnl Permission to use, copy, modify, and distribute this software for any
+dnl purpose with or without fee is hereby granted, provided that the above
+dnl copyright notice and this permission notice appear in all copies.
+dnl
+dnl @category C
+dnl @author Martin Ebourne and Damien Miller
+dnl @version 2005/07/07
+
+AC_DEFUN([AX_CHECK_LLONG_MINMAX], [
+  AC_CHECK_DECL([LLONG_MAX], [have_llong_max=1], , [[#include <limits.h>]])
+  if test -z "$have_llong_max"; then
+    AC_MSG_CHECKING([[for max value of long long]])
+    AC_RUN_IFELSE([AC_LANG_SOURCE([[
+      #include <stdio.h>
+      /* Why is this so damn hard? */
+      #undef __GNUC__
+      #undef __USE_ISOC99
+      #define __USE_ISOC99
+      #include <limits.h>
+      #define DATA "conftest.llminmax"
+      int main(void) {
+        FILE *f;
+        long long i, llmin, llmax = 0;
+
+        if((f = fopen(DATA,"w")) == NULL)
+          exit(1);
+
+        #if defined(LLONG_MIN) && defined(LLONG_MAX)
+        fprintf(stderr, "Using system header for LLONG_MIN and LLONG_MAX\n");
+        llmin = LLONG_MIN;
+        llmax = LLONG_MAX;
+        #else
+        fprintf(stderr, "Calculating LLONG_MIN and LLONG_MAX\n");
+        /* This will work on one's complement and two's complement */
+        for (i = 1; i > llmax; i <<= 1, i++)
+          llmax = i;
+        llmin = llmax + 1LL;    /* wrap */
+        #endif
+
+        /* Sanity check */
+        if (llmin + 1 < llmin || llmin - 1 < llmin || llmax + 1 > llmax || llmax - 1 > llmax) {
+          fprintf(f, "unknown unknown\n");
+          exit(2);
+        }
+
+        if (fprintf(f ,"%lld %lld", llmin, llmax) < 0)
+          exit(3);
+
+        exit(0);
+      }
+      ]])], [
+      read llong_min llong_max < conftest.llminmax
+      AC_MSG_RESULT([$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]])]
+      )
+    fi
+  ])dnl