[svn-r26083] Changed the default for building the direct VFD to 'no'.

Updated the direct VFD help string to make it more clear where
it is suported.

Part of HDFFV-7566 and HDFFV-7567

Tested on: jam (configure only)

3 files changed, 16 insertions, 13 deletions

diff --git a/configure b/configure
index 0222f2a..dc12ef5 100755
--- a/configure
+++ b/configure
@@ -1574,7 +1574,7 @@ Optional Features:
   --enable-fortran2003    Compile the Fortran 2003 interface, must also
                           specify --enable-fortran [default=no]
   --enable-cxx            Compile the C++ interface [default=no]
-  --enable-hl             Enable the high level library [default=yes]
+  --enable-hl             Enable the high-level library [default=yes]
   --enable-shared[=PKGS]  build shared libraries [default=yes]
   --enable-static[=PKGS]  build static libraries [default=yes]
   --enable-fast-install[=PKGS]
@@ -1613,8 +1613,9 @@ Optional Features:
                           picky about it's memory operations and also disables
                           the library's free space manager code. Default=no.
   --enable-parallel       Search for MPI-IO and MPI support files
-  --enable-direct-vfd     Build the Direct I/O Virtual File Driver
-                          [default=yes]
+  --enable-direct-vfd     Build the direct I/O virtual file driver (VFD). This
+                          is based on the POSIX (sec2) VFD and requires the
+                          open() call to take the O_DIRECT flag. [default=no]
   --enable-dconv-exception
                           if exception handling functions is checked during
                           data conversions [default=yes]
@@ -28274,14 +28275,14 @@ fi
 ## Check if Direct I/O driver is enabled by --enable-direct-vfd
 ##
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for Direct Virtual File Driver support" >&5
-$as_echo_n "checking for Direct Virtual File Driver support... " >&6; }
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for direct virtual file driver (VFD) support" >&5
+$as_echo_n "checking for direct virtual file driver (VFD) support... " >&6; }
 
 # Check whether --enable-direct-vfd was given.
 if test "${enable_direct_vfd+set}" = set; then :
   enableval=$enable_direct_vfd; DIRECT_VFD=$enableval
 else
-  DIRECT_VFD=yes
+  DIRECT_VFD=no
 fi
 
 
diff --git a/configure.ac b/configure.ac
index 8dc0790..3a14090 100644
--- a/configure.ac
+++ b/configure.ac
@@ -540,7 +540,7 @@ AC_SUBST(HL_FOR) HL_FOR=""
 AC_MSG_CHECKING([if high level library is enabled])
 AC_ARG_ENABLE([hl],
      [AS_HELP_STRING([--enable-hl],
-                     [Enable the high level library [default=yes]])],
+                     [Enable the high-level library [default=yes]])],
      [HDF5_HL=$enableval],
      [HDF5_HL=yes])
 
@@ -2521,13 +2521,15 @@ fi
 ## Check if Direct I/O driver is enabled by --enable-direct-vfd
 ##
 
-AC_MSG_CHECKING([for Direct Virtual File Driver support])
+AC_MSG_CHECKING([for direct virtual file driver (VFD) support])
 
 AC_ARG_ENABLE([direct-vfd],
               [AS_HELP_STRING([--enable-direct-vfd],
-                              [Build the Direct I/O Virtual File Driver
-                               [default=yes]])],
-              [DIRECT_VFD=$enableval], [DIRECT_VFD=yes])
+                              [Build the direct I/O virtual file driver (VFD).
+                               This is based on the POSIX (sec2) VFD and
+                               requires the open() call to take the O_DIRECT
+                               flag. [default=no]])],
+              [DIRECT_VFD=$enableval], [DIRECT_VFD=no])
 
 if test "$DIRECT_VFD" = "yes"; then
    AC_CACHE_VAL([hdf5_cv_direct_io],
@@ -2548,7 +2550,7 @@ if test "$DIRECT_VFD" = "yes"; then
    if test ${hdf5_cv_direct_io} = "yes"; then
       AC_MSG_RESULT([yes])
       AC_DEFINE([HAVE_DIRECT], [1],
-                [Define if the direct I/O virtual file driver should be compiled])
+                [Define if the direct I/O virtual file driver (VFD) should be compiled])
    else
       AC_MSG_RESULT([no])
       DIRECT_VFD=no
diff --git a/src/H5config.h.in b/src/H5config.h.in
index 5a3159e..5de3a9e 100644
--- a/src/H5config.h.in
+++ b/src/H5config.h.in
@@ -77,7 +77,7 @@
 /* Define to 1 if you have the `difftime' function. */
 #undef HAVE_DIFFTIME
 
-/* Define if the direct I/O virtual file driver should be compiled */
+/* Define if the direct I/O virtual file driver (VFD) should be compiled */
 #undef HAVE_DIRECT
 
 /* Define to 1 if you have the <dirent.h> header file. */