cross-compilation guesses (7)

[Bruno Haible]

When cross-compiling, I also see this wrong guess:

  checking whether gettimeofday clobbers localtime buffer... yes

This proposed patch should improve it. OK to apply, Jim & Paul?


2012-05-01  Bruno Haible  <address@hidden>

        gettimeofday: Avoid bad guess when cross-compiling to glibc systems.
        * m4/gettimeofday.m4 (gl_FUNC_GETTIMEOFDAY_CLOBBER): Require
        AC_CANONICAL_HOST. When cross-compiling, guess no on glibc platforms.

--- m4/gettimeofday.m4.orig     Wed May  2 00:04:14 2012
+++ m4/gettimeofday.m4  Wed May  2 00:04:11 2012
@@ -1,4 +1,4 @@
-# serial 18
+# serial 19
 
 # Copyright (C) 2001-2003, 2005, 2007, 2009-2012 Free Software Foundation, Inc.
 # This file is free software; the Free Software Foundation
@@ -82,6 +82,7 @@
 AC_DEFUN([gl_FUNC_GETTIMEOFDAY_CLOBBER],
 [
  AC_REQUIRE([gl_HEADER_SYS_TIME_H])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
 
  AC_CACHE_CHECK([whether gettimeofday clobbers localtime buffer],
   [gl_cv_func_gettimeofday_clobber],
@@ -104,15 +105,23 @@
         ]])],
      [gl_cv_func_gettimeofday_clobber=no],
      [gl_cv_func_gettimeofday_clobber=yes],
-     dnl When crosscompiling, assume it is broken.
-     [gl_cv_func_gettimeofday_clobber=yes])])
-
- if test $gl_cv_func_gettimeofday_clobber = yes; then
-   REPLACE_GETTIMEOFDAY=1
-   gl_GETTIMEOFDAY_REPLACE_LOCALTIME
-   AC_DEFINE([GETTIMEOFDAY_CLOBBERS_LOCALTIME], [1],
-     [Define if gettimeofday clobbers the localtime buffer.])
- fi
+     [# When cross-compiling:
+      case "$host_os" in
+                # Guess all is fine on glibc systems.
+        *-gnu*) gl_cv_func_gettimeofday_clobber="guessing no" ;;
+                # If we don't know, assume the worst.
+        *)      gl_cv_func_gettimeofday_clobber="guessing yes" ;;
+      esac
+     ])])
+
+ case "$gl_cv_func_gettimeofday_clobber" in
+   *yes)
+     REPLACE_GETTIMEOFDAY=1
+     gl_GETTIMEOFDAY_REPLACE_LOCALTIME
+     AC_DEFINE([GETTIMEOFDAY_CLOBBERS_LOCALTIME], [1],
+       [Define if gettimeofday clobbers the localtime buffer.])
+     ;;
+ esac
 ])
 
 AC_DEFUN([gl_GETTIMEOFDAY_REPLACE_LOCALTIME], [