[gparted] Only check libparted version once and cache the result (#734718)

[Curtis Gedak <gedakc src gnome org>]

commit bb17f44e996c638fa435ccc66aa17ae968e9d5dd
Author: Mike Fleetwood <mike fleetwood googlemail com>
Date:   Sun Aug 10 09:13:22 2014 +0100

    Only check libparted version once and cache the result (#734718)
    
    Configure.ac still builds and runs very similar test executables twice
    to determine in the version of libparted is >= minimum require 1.7.1 and
    2.2 for improved partition re-read code.
    
    Build and run a single test to determine the version of libparted and
    cache the result.  Use this cached version number when testing the
    version of libparted.  Inspired by the version checking for intltool
    from /usr/share/aclocal/intltool.m4.
    
    Bug #734718 - Update Autoconf version specific libparted checks and
                  defines to feature specific ones

 configure.ac |  117 ++++++++++++++++++----------------------------------------
 1 files changed, 36 insertions(+), 81 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index c500def..4ccc5ea 100644
--- a/configure.ac
+++ b/configure.ac
@@ -15,6 +15,7 @@ dnl======================
 AC_PROG_CXX
 AC_PROG_CC
 AC_PROG_LIBTOOL
+AC_PROG_AWK
 
 
 dnl======================
@@ -42,49 +43,40 @@ AC_CHECK_LIB([dl], [dlopen], [], AC_MSG_ERROR([*** dl library (libdl) not found]
 
 
 dnl Check for minimum required libparted version
-LIBPARTED_VERSION=1.7.1
-AC_MSG_CHECKING([for libparted >= $LIBPARTED_VERSION])
+LIBPARTED_REQUIRED_VERSION='1.7.1'
+AC_MSG_CHECKING([for libparted >= $LIBPARTED_REQUIRED_VERSION])
+LIBPARTED_REQUIRED_INT=`echo "$LIBPARTED_REQUIRED_VERSION" |
+       $AWK -F. '{print $1 * 10000 + $2 * 100 + $3}'`
 LIBS_save="$LIBS"
 LIBS="-lparted -luuid -ldl"
 AC_RUN_IFELSE(
        [AC_LANG_SOURCE(
                [[
 #include <stdio.h>
+#include <stdlib.h>
 #include <parted/parted.h>
 
-int main ()
+int main()
 {
-       int min_major = 0;
-       int min_minor = 0;
-       int min_micro = 0;
-       int major = 0;
-       int minor = 0;
-       int micro = 0;
-
-       if ( ( sscanf( "$LIBPARTED_VERSION", "%d.%d.%d", &min_major, &min_minor, &min_micro ) == 3 ) ||
-            ( sscanf( "$LIBPARTED_VERSION", "%d.%d", &min_major, &min_minor ) == 2 ) ||
-            ( sscanf( "$LIBPARTED_VERSION", "%d", &min_major ) == 1 )
-          )
+       const char *version = ped_get_version();
+       if (version == NULL)
        {
-               if ( ( sscanf( ped_get_version(), "%d.%d.%d", &major, &minor, &micro ) == 3 ) ||
-                    ( sscanf( ped_get_version(), "%d.%d", &major, &minor ) == 2 ) ||
-                    ( sscanf( ped_get_version(), "%d", &major ) == 1 )
-                  )
-               {
-                       printf( "Found libparted %s\t", ped_get_version() ) ;
-                       return ! ( (major > min_major) ||
-                                  ( (major == min_major) && (minor > min_minor) ) ||
-                                  ( (major == min_major) && (minor == min_minor) && (micro >= min_micro) )
-                                ) ;
-               }
+               fprintf(stderr, "ERROR: ped_get_version() returned NULL\n");
+               return EXIT_FAILURE;
        }
-
-       return 1 ;
+       printf("%s\n", version);
+       return EXIT_SUCCESS;
 }
                ]]
        )],
-       [AC_MSG_RESULT([OK])],
-       [AC_MSG_ERROR([*** Requires libparted >= $LIBPARTED_VERSION.  Perhaps development header files 
missing?])]
+       dnl Run test program again to cache libparted version.
+       [LIBPARTED_FOUND_VERSION=`./conftest$EXEEXT`
+        LIBPARTED_FOUND_INT=`echo "$LIBPARTED_FOUND_VERSION" |
+               $AWK -F. '{print $1 * 10000 + $2 * 100 + $3}'`
+        test "$LIBPARTED_FOUND_INT" -ge "$LIBPARTED_REQUIRED_INT" ||
+               AC_MSG_ERROR([*** libparted too old.  Require libparted >= $LIBPARTED_REQUIRED_VERSION but 
only found libparted $LIBPARTED_FOUND_VERSION.])
+       ],
+       [AC_MSG_ERROR([*** Error querying libparted version.  Check config.log for details.])]
 )
 LIBS="$LIBS_save"
 
@@ -92,58 +84,21 @@ LIBS="$LIBS_save"
 dnl Check for libparted >= 2.2 for improved informing the kernel to
 dnl re-read the partition table code and support of larger sector sizes
 dnl (> 512 bytes).
-LIBPARTED_VERSION=2.2
-AC_MSG_CHECKING([if libparted >= $LIBPARTED_VERSION (has improved pt re-read)])
-LIBS_save="$LIBS"
-LIBS="-lparted -luuid -ldl"
-AC_RUN_IFELSE(
-       [AC_LANG_SOURCE(
-               [[
-#include <stdio.h>
-#include <parted/parted.h>
-
-int main ()
-{
-       int min_major = 0;
-       int min_minor = 0;
-       int min_micro = 0;
-       int major = 0;
-       int minor = 0;
-       int micro = 0;
-
-       if ( ( sscanf( "$LIBPARTED_VERSION", "%d.%d.%d", &min_major, &min_minor, &min_micro ) == 3 ) ||
-            ( sscanf( "$LIBPARTED_VERSION", "%d.%d", &min_major, &min_minor ) == 2 ) ||
-            ( sscanf( "$LIBPARTED_VERSION", "%d", &min_major ) == 1 )
-          )
-       {
-               if ( ( sscanf( ped_get_version(), "%d.%d.%d", &major, &minor, &micro ) == 3 ) ||
-                    ( sscanf( ped_get_version(), "%d.%d", &major, &minor ) == 2 ) ||
-                    ( sscanf( ped_get_version(), "%d", &major ) == 1 )
-                  )
-               {
-                       return ! ( (major > min_major) ||
-                                  ( (major == min_major) && (minor > min_minor) ) ||
-                                  ( (major == min_major) && (minor == min_minor) && (micro >= min_micro) )
-                                ) ;
-               }
-       }
-
-       return 1 ;
-}
-               ]]
-       )],
-       [AC_DEFINE([USE_LIBPARTED_LARGE_SECTOR_SUPPORT], 1,
-                  [Define to 1 to use libparted large sector support])
-        need_pt_reread_workaround=no; support_large_sector_sizes=yes
-        AC_MSG_RESULT([yes])
-       ],
-       [AC_DEFINE([ENABLE_PT_REREAD_WORKAROUND], 1,
-                  [Define to 1 to enable partition re-read workaround])
-        need_pt_reread_workaround=yes; support_large_sector_sizes=no
-        AC_MSG_RESULT([no])
-       ]
-)
-LIBS="$LIBS_save"
+LIBPARTED_WANTED_VERSION='2.2'
+AC_MSG_CHECKING([for libparted >= $LIBPARTED_WANTED_VERSION (improved pt re-read)])
+LIBPARTED_WANTED_INT=`echo "$LIBPARTED_WANTED_VERSION" |
+       $AWK -F. '{print $1 * 10000 + $2 * 100 + $3}'`
+if test "$LIBPARTED_FOUND_INT" -ge "$LIBPARTED_WANTED_INT"; then
+       AC_DEFINE([USE_LIBPARTED_LARGE_SECTOR_SUPPORT], 1,
+                 [Define to 1 to use libparted large sector support])
+       need_pt_reread_workaround=no; support_large_sector_sizes=yes
+       AC_MSG_RESULT([(cached) yes])
+else
+       AC_DEFINE([ENABLE_PT_REREAD_WORKAROUND], 1,
+                 [Define to 1 to enable partition re-read workaround])
+       need_pt_reread_workaround=yes; support_large_sector_sizes=no
+       AC_MSG_RESULT([(cached) no])
+fi
 
 
 dnl Check for ped_file_system_resize() function to determine the existence