PKG_CHECK_MODULES: Check if $pkg_cv_[]$1[]_LIBS works

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/

	PR binutils/26301
	* pkg.m4 (PKG_CHECK_MODULES): Add AC_TRY_LINK to check if
	$pkg_cv_[]$1[]_LIBS works.

binutils/

	PR binutils/26301
	* configure: Regenerated.

gdb/

	PR binutils/26301
	* configure: Regenerated.

ChangeLog

@@ -1,7 +1,5 @@
 2020-07-24  Aaron Merey  <amerey@redhat.com>
 
-	* config/debuginfod.m4: use PKG_CHECK_MODULES.
-	* config/pkg.m4: New file.
 	* configure: Rebuild.
 	* configure.ac: Remove AC_DEBUGINFOD.
 

binutils/ChangeLog

@@ -1,3 +1,8 @@
+2020-07-28  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR binutils/26301
+	* configure: Regenerated.
+
 2020-07-27  Alan Modra  <amodra@gmail.com>
 
 	* objdump.c (dump_section): Don't return without calling

binutils/configure

@@ -12439,6 +12439,28 @@ fi
     pkg_failed=untried
 fi
 
+pkg_save_LDFLAGS="$LDFLAGS"
+LDFLAGS="$LDFLAGS $pkg_cv_DEBUGINFOD_LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+return 0;
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  pkg_failed=no
+else
+  pkg_failed=yes
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LDFLAGS=$pkg_save_LDFLAGS
+
 
 
 if test $pkg_failed = yes; then

config/ChangeLog

@@ -1,3 +1,14 @@
+2020-07-28  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR binutils/26301
+	* pkg.m4 (PKG_CHECK_MODULES): Add AC_TRY_LINK to check if
+	$pkg_cv_[]$1[]_LIBS works.
+
+2020-07-24  Aaron Merey  <amerey@redhat.com>
+
+	* debuginfod.m4: use PKG_CHECK_MODULES.
+	* pkg.m4: New file.
+
 2020-07-04  Nick Clifton  <nickc@redhat.com>
 
 	Binutils 2.35 branch created.

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.])

gdb/ChangeLog

@@ -1,3 +1,8 @@
+2020-07-28  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR binutils/26301
+	* configure: Regenerated.
+
 2020-07-28  Andrew Burgess  <andrew.burgess@embecosm.com>
 
 	* python/py-frame.c: Remove 'user-regs.h' include.

gdb/configure

@@ -7037,6 +7037,28 @@ fi
     pkg_failed=untried
 fi
 
+pkg_save_LDFLAGS="$LDFLAGS"
+LDFLAGS="$LDFLAGS $pkg_cv_DEBUGINFOD_LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+return 0;
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  pkg_failed=no
+else
+  pkg_failed=yes
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LDFLAGS=$pkg_save_LDFLAGS
+
 
 
 if test $pkg_failed = yes; then