re PR fortran/26277 (false warning about unused label for a warning used in err=)

fortran/
	PR fortran/26277
	* io.c (match_ltag): Mark label as referenced.
testsuite/
	PR fortran/26277
	* gfortran.dg/label_4.f90: New.

From-SVN: r110993

gcc/fortran/ChangeLog

+2006-02-14  Tobias Schlter  <tobias.schlueter@physik.uni-muenchen.de>
+
+	PR fortran/26277
+	* io.c (match_ltag): Mark label as referenced.
+
 2006-02-14  Jakub Jelinek  <jakub@redhat.com>
 	    Richard Henderson  <rth@redhat.com>
 	    Diego Novillo  <dnovillo@redhat.com>

gcc/fortran/io.c

@@ -972,6 +972,10 @@ match_ltag (const io_tag * tag, gfc_st_label ** label)
       return MATCH_ERROR;
     }
 
+  if (m == MATCH_YES 
+      && gfc_reference_st_label (*label, ST_LABEL_TARGET) == FAILURE)
+    return MATCH_ERROR;
+
   return m;
 }
 

gcc/testsuite/ChangeLog

+2006-02-14  Tobias Schlter  <tobias.schlueter@physik.uni-muenchen.de>
+
+	PR fortran/26277
+	* gfortran.dg/label_4.f90: New.
+
 2006-02-14  Jakub Jelinek  <jakub@redhat.com>
 	    Diego Novillo  <dnovillo@redhat.com>
 	    Uros Bizjak  <uros@kss-loka.si>

gcc/testsuite/gfortran.dg/label_4.f90

+! { dg-do compile }
+! { dg-options "-Wunused-labels" }
+! PR 26277
+! We used to give an incorect warning about label 99 not being referenced
+  open(unit=12,err=99)
+99 print *,"could not open file ..."
+98 continue ! { dg-warning "Label 98 .* defined but not used" }
+end