AUTOTOOLS: Use pkg-config to detect libraries.

We used pkg-config only as a fallback if header files was not found,
but detection of library failed in case of available header file and
linking problem (missing -Ldir).

This patch prefers pkg-config.

1 files changed, 13 insertions, 6 deletions

diff --git a/src/external/libcares.m4 b/src/external/libcares.m4
index 5b8a35875..e2a56f157 100644
--- a/src/external/libcares.m4
+++ b/src/external/libcares.m4
@@ -2,9 +2,17 @@ AC_SUBST(CARES_OBJ)
 AC_SUBST(CARES_LIBS)
 AC_SUBST(CARES_CFLAGS)
 
-AC_CHECK_HEADERS(ares.h,
-    [AC_CHECK_LIB([cares], [ares_init], [ CARES_LIBS="-lcares" ], [AC_MSG_ERROR([No usable c-ares library found])])],
-    [AC_MSG_ERROR([c-ares header files are not installed])]
+PKG_CHECK_MODULES([CARES], [libcares], [found_libcares=yes], [found_libcares=no])
+
+SSS_AC_EXPAND_LIB_DIR()
+AS_IF([test x"$found_libcares" != xyes],
+    [AC_CHECK_HEADERS([ares.h],
+        [AC_CHECK_LIB([cares],
+                      [ares_init],
+                      [CARES_LIBS="-L$sss_extra_libdir -lcares"],
+                      [AC_MSG_ERROR([No usable c-ares library found])],
+                      [-L$sss_extra_libdir])],
+        [AC_MSG_ERROR([c-ares header files are not installed])])]
 )
 
 dnl Check if this particular version of c-ares supports the generic ares_free_data function
@@ -12,9 +20,8 @@ AC_CHECK_LIB([cares],
              [ares_free_data],
              [AC_DEFINE([HAVE_ARES_DATA], 1, [Does c-ares have ares_free_data()?])
              ],
-             [
-                ares_data=1
-             ]
+             [ares_data=1],
+             [$CARES_LIBS]
 )
 
 AM_CONDITIONAL(BUILD_ARES_DATA, test x$ares_data = x1)