re PR fortran/89782 (Can do an internal READ of a character array when it is a…

re PR fortran/89782 (Can do an internal READ of a character array when it is a parameter, but not a scalar character parameter)

2019-06-22  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

	PR fortran/89782
	* io.c (gfc_resolve_dt): Check that internal units are not
	character PARAMETER.

	* gfortran.dg/io_constraints.f90: New test.

From-SVN: r272594

gcc/fortran/ChangeLog

+2019-06-22  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
+
+	PR fortran/89782
+	* io.c (gfc_resolve_dt): Check that internal units are not
+	character PARAMETER.
+
 2019-06-21  Steven G. Kargl  <kargl@gcc.gnu.org>
 
 	PR fortran/67884

gcc/fortran/io.c

@@ -3328,6 +3328,14 @@ gfc_resolve_dt (gfc_dt *dt, locus *loc)
       return false;
     }
 
+  if (e->symtree && e->symtree->n.sym->attr.flavor == FL_PARAMETER
+      && e->ts.type == BT_CHARACTER)
+    {
+      gfc_error ("UNIT specification at %L must "
+      "not be a character PARAMETER", &e->where);
+      return false;
+    }
+
   if (gfc_resolve_expr (e)
       && (e->ts.type != BT_INTEGER
 	  && (e->ts.type != BT_CHARACTER || e->expr_type != EXPR_VARIABLE)))

gcc/testsuite/ChangeLog

+2019-06-22  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
+
+	PR fortran/89782
+	* gfortran.dg/io_constraints.f90: New test.
+
 2019-06-22  Iain Sandoe  <iain@sandoe.co.uk>
 
 	* gcc.target/powerpc/pr64205.c: Require effective target dfp.

gcc/testsuite/gfortran.dg/io_constraints_14.f90

+! { dg-do compile }
+program pr89782
+  character(len=*),parameter :: VALUES(*)=[character(len=10) :: 'NaN','NAN','nan','Inf','INF','inf','Infinity']
+  character(len=*),parameter :: VALUE='NaN'
+  real(4) :: var
+  do i=1,size(VALUES)
+    read(VALUES(i),*) float ! { dg-error "character PARAMETER" }
+    write(VALUES(i),*)float ! { dg-error "character PARAMETER" }
+  enddo
+  read(var,*)float    ! { dg-error "INTEGER expression or a CHARACTER" }
+  read(VALUE,*)float  ! { dg-error "character PARAMETER" }
+  write(VALUE,*)float ! { dg-error "character PARAMETER" }
+end program pr89782