Ocfs2-test: Port header-checker macro and api-compat mechanism from o…

…cfs2 to better use system call.

This patch adds OCFS2_CHECK_HEADERS macro in the build infrastructure
to allow us to search for symbols in userspace headers.

Signed-off-by: Tristan Ye <[email protected]>
Signed-off-by: Sunil Mushran <[email protected]>

Config.make.in

@@ -29,6 +29,8 @@ TESTDIR = $(libdir)/ocfs2-test
 
 top_builddir = .
 
+EXTRA_CFLAGS += @API_COMPAT_CFLAGS@
+
 INSTALL = @INSTALL@
 INSTALL_PROGRAM = @INSTALL_PROGRAM@
 INSTALL_LIBRARY = @INSTALL_PROGRAM@

Makefile

@@ -26,6 +26,7 @@ SUBDIRS = programs utilities tests suites
 
 SUBDIRS += vendor
 
+API_COMPAT_FILES =
 
 DIST_FILES = \
 	COPYING					\

aclocal.m4

@@ -1,3 +1,4 @@
 m4_include([pkg.m4])
 m4_include([runlog.m4])
 m4_include([python.m4])
+m4_include([kfeature.m4])

configure.in

@@ -127,6 +127,11 @@ AC_MSG_RESULT($enable_third_party)
 dnl check for Python
 AM_PATH_PYTHON(2.3, , AC_MSG_ERROR([could not find Python 2.3 or higher.]))
 
+API_COMPAT_HEADERS=""
+API_COMPAT_CFLAGS=""
+
+AC_SUBST(API_COMPAT_CFLAGS)
+
 AC_CONFIG_FILES([
 Config.make
 vendor/common/ocfs2-test.spec-generic

kfeature.m4

@@ -0,0 +1,17 @@
+AC_DEFUN([OCFS2_CHECK_HEADERS],
+  [AC_MSG_CHECKING([for $1])
+   kernel_check_regexp="m4_default([$5], [\<$1(])"
+
+   kernel_check_headers=
+   for kfile in $2; do
+     kernel_check_headers="$kernel_check_headers /usr/include/$kfile"
+   done
+
+   if grep "$kernel_check_regexp" $kernel_check_headers >/dev/null 2>&1 ; then
+     m4_default([$3], :)
+     AC_MSG_RESULT(yes)
+   else
+     m4_default([$4], :)
+     AC_MSG_RESULT(no)
+   fi
+])# OCFS2_CHECK_HEADERS