lib/ld-lib.exp (check_sysroot_available): New proc.

ld/testsuite/ChangeLog

@@ -1,3 +1,7 @@
+2014-10-15  Hans-Peter Nilsson  <hp@axis.com>
+
+	* lib/ld-lib.exp (check_sysroot_available): New proc.
+
 2014-10-04  Alan Modra  <amodra@gmail.com>
 
 	* ld-elf/eh1.s: Don't create FDEs with zero address ranges.

ld/testsuite/lib/ld-lib.exp

@@ -1669,6 +1669,24 @@ proc check_plugin_api_available { } {
     return $plugin_api_available_saved
 }
 
+# Returns true if the target ld supports sysroot.
+proc check_sysroot_available { } {
+    global ld_sysroot_available_saved
+    global ld
+    if {![info exists ld_sysroot_available_saved]} {
+	# Check if ld supports --sysroot *other* than empty
+	# (non-sysroot linkers don't emit errors for --sysroot="").
+	# The help-text by itself is no indication as it always lists --sysroot.
+	set status [remote_exec host $ld "--sysroot=ldxyzzy --help >/dev/null"]
+	if { [lindex $status 0] != 0 } {
+	    set ld_sysroot_available_saved 0
+	} else {
+	    set ld_sysroot_available_saved 1
+	}
+    }
+    return $ld_sysroot_available_saved
+}
+
 # Returns true if the target compiler supports LTO
 proc check_lto_available { } {
     global lto_available_saved