re PR fortran/85521 (ICE in gfc_resolve_character_array_constructor, at fortran/array.c:2049)

2018-05-10  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/85521
	* array.c (gfc_resolve_character_array_constructor): Substrings
	with upper bound smaller than lower bound are zero length strings.

2018-05-10  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/85521
	* gfortran.dg/pr85521_1.f90: New test.
	* gfortran.dg/pr85521_2.f90: New test.

From-SVN: r260139

gcc/fortran/ChangeLog

 2018-05-10  Steven G. Kargl  <kargl@gcc.gnu.org>
 
+	PR fortran/85521
+	* array.c (gfc_resolve_character_array_constructor): Substrings
+	with upper bound smaller than lower bound are zero length strings.
+
+2018-05-10  Steven G. Kargl  <kargl@gcc.gnu.org>
+
 	PR fortran/70870
 	* data.c (gfc_assign_data_value): Check that a data object does
 	not also have default initialization.

gcc/fortran/array.c

@@ -2046,7 +2046,8 @@ got_charlen:
 	  else
 	    return true;
 
-	  gcc_assert (current_length != -1);
+	  if (current_length < 0)
+	    current_length = 0;
 
 	  if (found_length == -1)
 	    found_length = current_length;

gcc/testsuite/ChangeLog

 2018-05-10  Steven G. Kargl  <kargl@gcc.gnu.org>
 
+	PR fortran/85521
+	* gfortran.dg/pr85521_1.f90: New test.
+	* gfortran.dg/pr85521_2.f90: New test.
+
+2018-05-10  Steven G. Kargl  <kargl@gcc.gnu.org>
+
 	PR fortran/70870
 	* gfortran.dg/pr70870_1.f90: New test.
 

gcc/testsuite/gfortran.dg/pr85521_1.f90

+! { dg-do compile }
+! PR fortran/85521
+program p
+   character(3) :: c = 'abc'
+   character(3) :: z(1)
+   z = [ c(:-1) ]
+   print *, z
+end

gcc/testsuite/gfortran.dg/pr85521_2.f90

+! { dg-do compile }
+! PR fortran/85521
+program p
+   character(3) :: c = 'abc'
+   character(3) :: z(1)
+   z = [ c(:-2) ]
+   print *, z
+end