Use pkg-config to determine where to find the devmapper library

Fedora and Red Hat puts the devmapper library in different locations
compared to Debian, so we use pkg-config.  Unfortunately Debian's
devmapper.pc file is buggy (See Debian Bug #390243), so we have to
work around it.

Historically, e2fsprogs has tried not to depend on pkg-config, since
its answers are so often **wrong** (the Debian bug has been ignored
for over a year), so I'm hoping I'm not going to regret this.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/configure b/configure
index 8ecc41a..074aae1 100755
--- a/configure
+++ b/configure
@@ -693,10 +693,12 @@
 FSCK_MAN
 E2INITRD_PROG
 E2INITRD_MAN
+PKG_CONFIG
 DEVMAPPER_REQ
 DEVMAPPER_PC_LIBS
 DEVMAPPER_LIBS
 STATIC_DEVMAPPER_LIBS
+STATIC_BLKID_DEVMAPPER_LIBS
 UUIDD_CMT
 GETTEXT_PACKAGE
 PACKAGE
@@ -786,7 +788,8 @@
 LDFLAGS
 LIBS
 CPPFLAGS
-CPP'
+CPP
+PKG_CONFIG'
 
 
 # Initialize some variables set by options.
@@ -1407,6 +1410,7 @@
   CPPFLAGS    C/C++/Objective C preprocessor flags, e.g. -I<include dir> if
               you have headers in a nonstandard directory <include dir>
   CPP         C preprocessor
+  PKG_CONFIG  path to pkg-config utility
 
 Use these variables to override the choices made by `configure' or to help
 it to find libraries and programs with nonstandard names/locations.
@@ -3835,6 +3839,7 @@
 fi
 
 
+E2_PKG_CONFIG_STATIC=--static
 # Check whether --enable-elf-shlibs was given.
 if test "${enable_elf_shlibs+set}" = set; then
   enableval=$enable_elf_shlibs; if test "$enableval" = "no"
@@ -3843,6 +3848,7 @@
 	MAKEFILE_ELF=/dev/null
 	echo "Disabling ELF shared libraries"
 else
+	E2_PKG_CONFIG_STATIC=
 	ELF_CMT=
 	MAKEFILE_ELF=$srcdir/lib/Makefile.elf-lib
 	case "$host_os" in
@@ -3872,6 +3878,7 @@
 	MAKEFILE_BSDLIB=/dev/null
 	echo "Disabling BSD shared libraries"
 else
+	E2_PKG_CONFIG_STATIC=
 	BSDLIB_CMT=
 	MAKEFILE_BSDLIB=$srcdir/lib/Makefile.bsd-lib
 	LIB_EXT=.so
@@ -4138,6 +4145,7 @@
 
 
 
+STATIC_BLKID_DEVMAPPER_LIBS=''
 # Check whether --enable-blkid-devmapper was given.
 if test "${enable_blkid_devmapper+set}" = set; then
   enableval=$enable_blkid_devmapper; if test "$enableval" = "no"
@@ -4153,11 +4161,217 @@
 
 	echo "Enabling device-mapper support"
 
-	DEVMAPPER_REQ='libselinux libsepol'
-	DEVMAPPER_PC_LIBS='-ldevmapper'
-	DEVMAPPER_LIBS='-ldevmapper -lselinux -lsepol -lpthread'
-	STATIC_DEVMAPPER_LIBS='/usr/lib/libdevmapper.a /usr/lib/libselinux.a /usr/lib/libsepol.a -lpthread'
 
+
+if test "x$ac_cv_env_PKG_CONFIG_set" != "xset"; then
+        if test -n "$ac_tool_prefix"; then
+  # Extract the first word of "${ac_tool_prefix}pkg-config", so it can be a program name with args.
+set dummy ${ac_tool_prefix}pkg-config; ac_word=$2
+{ echo "$as_me:$LINENO: checking for $ac_word" >&5
+echo $ECHO_N "checking for $ac_word... $ECHO_C" >&6; }
+if test "${ac_cv_path_PKG_CONFIG+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  case $PKG_CONFIG in
+  [\\/]* | ?:[\\/]*)
+  ac_cv_path_PKG_CONFIG="$PKG_CONFIG" # Let the user override the test with a path.
+  ;;
+  *)
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+  for ac_exec_ext in '' $ac_executable_extensions; do
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
+    ac_cv_path_PKG_CONFIG="$as_dir/$ac_word$ac_exec_ext"
+    echo "$as_me:$LINENO: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+done
+IFS=$as_save_IFS
+
+  ;;
+esac
+fi
+PKG_CONFIG=$ac_cv_path_PKG_CONFIG
+if test -n "$PKG_CONFIG"; then
+  { echo "$as_me:$LINENO: result: $PKG_CONFIG" >&5
+echo "${ECHO_T}$PKG_CONFIG" >&6; }
+else
+  { echo "$as_me:$LINENO: result: no" >&5
+echo "${ECHO_T}no" >&6; }
+fi
+
+
+fi
+if test -z "$ac_cv_path_PKG_CONFIG"; then
+  ac_pt_PKG_CONFIG=$PKG_CONFIG
+  # Extract the first word of "pkg-config", so it can be a program name with args.
+set dummy pkg-config; ac_word=$2
+{ echo "$as_me:$LINENO: checking for $ac_word" >&5
+echo $ECHO_N "checking for $ac_word... $ECHO_C" >&6; }
+if test "${ac_cv_path_ac_pt_PKG_CONFIG+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  case $ac_pt_PKG_CONFIG in
+  [\\/]* | ?:[\\/]*)
+  ac_cv_path_ac_pt_PKG_CONFIG="$ac_pt_PKG_CONFIG" # Let the user override the test with a path.
+  ;;
+  *)
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+  for ac_exec_ext in '' $ac_executable_extensions; do
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
+    ac_cv_path_ac_pt_PKG_CONFIG="$as_dir/$ac_word$ac_exec_ext"
+    echo "$as_me:$LINENO: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+done
+IFS=$as_save_IFS
+
+  ;;
+esac
+fi
+ac_pt_PKG_CONFIG=$ac_cv_path_ac_pt_PKG_CONFIG
+if test -n "$ac_pt_PKG_CONFIG"; then
+  { echo "$as_me:$LINENO: result: $ac_pt_PKG_CONFIG" >&5
+echo "${ECHO_T}$ac_pt_PKG_CONFIG" >&6; }
+else
+  { echo "$as_me:$LINENO: result: no" >&5
+echo "${ECHO_T}no" >&6; }
+fi
+
+  if test "x$ac_pt_PKG_CONFIG" = x; then
+    PKG_CONFIG=""
+  else
+    case $cross_compiling:$ac_tool_warned in
+yes:)
+{ echo "$as_me:$LINENO: WARNING: In the future, Autoconf will not detect cross-tools
+whose name does not start with the host triplet.  If you think this
+configuration is useful to you, please write to autoconf@gnu.org." >&5
+echo "$as_me: WARNING: In the future, Autoconf will not detect cross-tools
+whose name does not start with the host triplet.  If you think this
+configuration is useful to you, please write to autoconf@gnu.org." >&2;}
+ac_tool_warned=yes ;;
+esac
+    PKG_CONFIG=$ac_pt_PKG_CONFIG
+  fi
+else
+  PKG_CONFIG="$ac_cv_path_PKG_CONFIG"
+fi
+
+fi
+if test -n "$PKG_CONFIG"; then
+        _pkg_min_version=0.9.0
+        { echo "$as_me:$LINENO: checking pkg-config is at least version $_pkg_min_version" >&5
+echo $ECHO_N "checking pkg-config is at least version $_pkg_min_version... $ECHO_C" >&6; }
+        if $PKG_CONFIG --atleast-pkgconfig-version $_pkg_min_version; then
+                { echo "$as_me:$LINENO: result: yes" >&5
+echo "${ECHO_T}yes" >&6; }
+        else
+                { echo "$as_me:$LINENO: result: no" >&5
+echo "${ECHO_T}no" >&6; }
+                PKG_CONFIG=""
+        fi
+
+fi
+
+	if test -z "$PKG_CONFIG"; then
+		echo "pkg-config not installed; please install it."
+		exit 1;
+	fi
+
+	{ echo "$as_me:$LINENO: checking for dm_tree_create in -ldevmapper" >&5
+echo $ECHO_N "checking for dm_tree_create in -ldevmapper... $ECHO_C" >&6; }
+if test "${ac_cv_lib_devmapper_dm_tree_create+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-ldevmapper $DEVMAPPER_LIBS $LIBS"
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char dm_tree_create ();
+int
+main ()
+{
+return dm_tree_create ();
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (ac_try="$ac_link"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_link") 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } && {
+	 test -z "$ac_c_werror_flag" ||
+	 test ! -s conftest.err
+       } && test -s conftest$ac_exeext &&
+       $as_test_x conftest$ac_exeext; then
+  ac_cv_lib_devmapper_dm_tree_create=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+	ac_cv_lib_devmapper_dm_tree_create=no
+fi
+
+rm -f core conftest.err conftest.$ac_objext conftest_ipa8_conftest.oo \
+      conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ echo "$as_me:$LINENO: result: $ac_cv_lib_devmapper_dm_tree_create" >&5
+echo "${ECHO_T}$ac_cv_lib_devmapper_dm_tree_create" >&6; }
+if test $ac_cv_lib_devmapper_dm_tree_create = yes; then
+  DEVMAPPER_LIBS=`$PKG_CONFIG --libs devmapper`;
+		 STATIC_DEVMAPPER_LIBS=`$PKG_CONFIG --static --libs devmapper`;
+		 DEVMAPPER_REQ="devmapper";
+		 DEVMAPPER_PC_LIBS="-ldevmapper"
+else
+  { { echo "$as_me:$LINENO: error: device-mapper library not found" >&5
+echo "$as_me: error: device-mapper library not found" >&2;}
+   { (exit 1); exit 1; }; }
+fi
+
+	# work around stupid devmapper.pc bug in Debian
+	case "$STATIC_DEVMAPPER_LIBS" in
+	*pthread*)
+	    ;;
+	*)
+	    echo "Working around Debian bug #390243..."
+	    STATIC_DEVMAPPER_LIBS="-pthread $STATIC_DEVMAPPER_LIBS"
+	    ;;
+	esac
+	if test "$E2_PKG_CONFIG_STATIC" = "--static"; then
+	    DEVMAPPER_LIBS="$STATIC_DEVMAPPER_LIBS"
+	    STATIC_BLKID_DEVMAPPER_LIBS="$STATIC_DEVMAPPER_LIBS"
+	fi
 fi
 
 else
@@ -4169,6 +4383,7 @@
 
 
 
+
 # Check whether --enable-tls was given.
 if test "${enable_tls+set}" = set; then
   enableval=$enable_tls; if test "$enableval" = "no"
@@ -15899,10 +16114,12 @@
 FSCK_MAN!$FSCK_MAN$ac_delim
 E2INITRD_PROG!$E2INITRD_PROG$ac_delim
 E2INITRD_MAN!$E2INITRD_MAN$ac_delim
+PKG_CONFIG!$PKG_CONFIG$ac_delim
 DEVMAPPER_REQ!$DEVMAPPER_REQ$ac_delim
 DEVMAPPER_PC_LIBS!$DEVMAPPER_PC_LIBS$ac_delim
 DEVMAPPER_LIBS!$DEVMAPPER_LIBS$ac_delim
 STATIC_DEVMAPPER_LIBS!$STATIC_DEVMAPPER_LIBS$ac_delim
+STATIC_BLKID_DEVMAPPER_LIBS!$STATIC_BLKID_DEVMAPPER_LIBS$ac_delim
 UUIDD_CMT!$UUIDD_CMT$ac_delim
 GETTEXT_PACKAGE!$GETTEXT_PACKAGE$ac_delim
 PACKAGE!$PACKAGE$ac_delim
@@ -15979,7 +16196,7 @@
 LTLIBOBJS!$LTLIBOBJS$ac_delim
 _ACEOF
 
-  if test `sed -n "s/.*$ac_delim\$/X/p" conf$$subs.sed | grep -c X` = 82; then
+  if test `sed -n "s/.*$ac_delim\$/X/p" conf$$subs.sed | grep -c X` = 84; then
     break
   elif $ac_last_try; then
     { { echo "$as_me:$LINENO: error: could not make $CONFIG_STATUS" >&5