[PATCH 20/24] PKG_CHECK_MODULES: Check if $pkg_cv_[]$1[]_LIBS works

[Arsen Arsenović via Gcc-patches]

From: "H.J. Lu" <hjl.to...@gmail.com>

It is quite normal to have headers without library on multilib OSes.
Add AC_TRY_LINK to PKG_CHECK_MODULES to check if $pkg_cv_[]$1[]_LIBS
works.

config/ChangeLog:

        * pkg.m4 (PKG_CHECK_MODULES): Add AC_TRY_LINK to check if
        $pkg_cv_[]$1[]_LIBS works.
---
 config/pkg.m4 | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/config/pkg.m4 b/config/pkg.m4
index 13a88901786..45587e97c8b 100644
--- a/config/pkg.m4
+++ b/config/pkg.m4
@@ -147,6 +147,12 @@ AC_MSG_CHECKING([for $2])
 _PKG_CONFIG([$1][_CFLAGS], [cflags], [$2])
 _PKG_CONFIG([$1][_LIBS], [libs], [$2])
 
+dnl Check whether $pkg_cv_[]$1[]_LIBS works.
+pkg_save_LDFLAGS="$LDFLAGS"
+LDFLAGS="$LDFLAGS $pkg_cv_[]$1[]_LIBS"
+AC_TRY_LINK([],[return 0;], [pkg_failed=no], [pkg_failed=yes])
+LDFLAGS=$pkg_save_LDFLAGS
+
 m4_define([_PKG_TEXT], [Alternatively, you may set the environment variables 
$1[]_CFLAGS
 and $1[]_LIBS to avoid the need to call pkg-config.
 See the pkg-config man page for more details.])
-- 
2.41.0