[PATCH] fsusage: avoid needless check on GNU/Linux

[Paul Eggert]

I installed this as an obvious minor tuneup.

* m4/fsusage.m4 (gl_FILE_SYSTEM_USAGE): Omit STAT_STATFS3_OSF1 check
on GNU/Linux systems, since it can't possibly work.
---
 ChangeLog     |    6 ++++++
 m4/fsusage.m4 |   53 +++++++++++++++++++++++++++--------------------------
 2 files changed, 33 insertions(+), 26 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index a505f6d..fda733e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2012-07-02  Paul Eggert  <address@hidden>
+
+       fsusage: avoid needless check on GNU/Linux
+       * m4/fsusage.m4 (gl_FILE_SYSTEM_USAGE): Omit STAT_STATFS3_OSF1 check
+       on GNU/Linux systems, since it can't possibly work.
+
 2012-07-01  Bruno Haible  <address@hidden>
 
        log: Fix an autoconf >= 2.64 warning.
diff --git a/m4/fsusage.m4 b/m4/fsusage.m4
index 1549e05..55e123f 100644
--- a/m4/fsusage.m4
+++ b/m4/fsusage.m4
@@ -102,32 +102,6 @@ int check_f_blocks_size[sizeof fsd.f_blocks * CHAR_BIT <= 
32 ? -1 : 1];
   fi
 fi
 
-if test $ac_fsusage_space = no; then
-  # DEC Alpha running OSF/1
-  AC_MSG_CHECKING([for 3-argument statfs function (DEC OSF/1)])
-  AC_CACHE_VAL([fu_cv_sys_stat_statfs3_osf1],
-  [AC_RUN_IFELSE([AC_LANG_SOURCE([[
-#include <sys/param.h>
-#include <sys/types.h>
-#include <sys/mount.h>
-  int
-  main ()
-  {
-    struct statfs fsd;
-    fsd.f_fsize = 0;
-    return statfs (".", &fsd, sizeof (struct statfs)) != 0;
-  }]])],
-    [fu_cv_sys_stat_statfs3_osf1=yes],
-    [fu_cv_sys_stat_statfs3_osf1=no],
-    [fu_cv_sys_stat_statfs3_osf1=no])])
-  AC_MSG_RESULT([$fu_cv_sys_stat_statfs3_osf1])
-  if test $fu_cv_sys_stat_statfs3_osf1 = yes; then
-    ac_fsusage_space=yes
-    AC_DEFINE([STAT_STATFS3_OSF1], [1],
-              [   Define if  statfs takes 3 args.  (DEC Alpha running OSF/1)])
-  fi
-fi
-
 # Check for this unconditionally so we have a
 # good fallback on glibc/Linux > 2.6 < 2.6.36
 AC_MSG_CHECKING([for two-argument statfs with statfs.f_frsize member])
@@ -154,12 +128,39 @@ AC_CACHE_VAL([fu_cv_sys_stat_statfs2_frsize],
   [fu_cv_sys_stat_statfs2_frsize=no])])
 AC_MSG_RESULT([$fu_cv_sys_stat_statfs2_frsize])
 if test $fu_cv_sys_stat_statfs2_frsize = yes; then
+    ac_fsusage_space=yes
     AC_DEFINE([STAT_STATFS2_FRSIZE], [1],
 [  Define if statfs takes 2 args and struct statfs has a field named f_frsize.
    (glibc/Linux > 2.6)])
 fi
 
 if test $ac_fsusage_space = no; then
+  # DEC Alpha running OSF/1
+  AC_MSG_CHECKING([for 3-argument statfs function (DEC OSF/1)])
+  AC_CACHE_VAL([fu_cv_sys_stat_statfs3_osf1],
+  [AC_RUN_IFELSE([AC_LANG_SOURCE([[
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/mount.h>
+  int
+  main ()
+  {
+    struct statfs fsd;
+    fsd.f_fsize = 0;
+    return statfs (".", &fsd, sizeof (struct statfs)) != 0;
+  }]])],
+    [fu_cv_sys_stat_statfs3_osf1=yes],
+    [fu_cv_sys_stat_statfs3_osf1=no],
+    [fu_cv_sys_stat_statfs3_osf1=no])])
+  AC_MSG_RESULT([$fu_cv_sys_stat_statfs3_osf1])
+  if test $fu_cv_sys_stat_statfs3_osf1 = yes; then
+    ac_fsusage_space=yes
+    AC_DEFINE([STAT_STATFS3_OSF1], [1],
+              [   Define if  statfs takes 3 args.  (DEC Alpha running OSF/1)])
+  fi
+fi
+
+if test $ac_fsusage_space = no; then
   # glibc/Linux, Mac OS X, FreeBSD < 5.0, NetBSD < 3.0, OpenBSD < 4.4.
   # (glibc/{Hurd,kFreeBSD}, FreeBSD >= 5.0, NetBSD >= 3.0,
   # OpenBSD >= 4.4, AIX, HP-UX, OSF/1, Cygwin already handled above.)
-- 
1.7.6.5