re PR testsuite/65116 (ERROR: can't read additional_sources: no such variable)

Fix PR testsuite/65116

	PR testsuite/65116
	* lib/target-supports.exp (check_compile): Check whether
	additional_sources is defined before using it.

From-SVN: r220822

gcc/testsuite/ChangeLog

+2015-02-19  Maxim Kuvyrkov  <maxim.kuvyrkov@linaro.org>
+
+	PR testsuite/65116
+	* lib/target-supports.exp (check_compile): Check whether
+	additional_sources is defined before using it.
+
 2015-02-19  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/65074

gcc/testsuite/lib/target-supports.exp

@@ -44,8 +44,10 @@ proc check_compile {basename type contents args} {
     # Save additional_sources to avoid compiling testsuite's sources
     # against check_compile's source.
     global additional_sources
-    set tmp_additional_sources "$additional_sources"
-    set additional_sources ""
+    if [info exists additional_sources] {
+	set tmp_additional_sources "$additional_sources"
+	set additional_sources ""
+    }
 
     if { [llength $args] > 0 } {
 	set options [list "additional_flags=[lindex $args 0]"]
@@ -93,7 +95,9 @@ proc check_compile {basename type contents args} {
     }
 
     # Restore additional_sources.
-    set additional_sources "$tmp_additional_sources"
+    if [info exists additional_sources] {
+	set additional_sources "$tmp_additional_sources"
+    }
 
     return [list $lines $scan_output]
 }