[PATCH] PR fortran/87992 -- trivially stupid patch, but ...

[Steve Kargl <sgk@troutmask.apl.washington.edu>]

The following patch removes the ICE reported in PR fortran/87992,
and restores the behavior observed with gfortran 7 and 8 (ie,
code compiles).

The PR marks the code with ice-on-invalid-code.  I don't use
CLASS in any of code and have never read the standard nor a
Fortran book about CLASS.  If the code is invalid, is gfortran
required by a constraint to reject the code.  If yes, someone
with CLASS will need to address this PR; otherwise, I will
commit the patch and close it as FIXED.

PS: the patch simply checks for a non-NULL pointer.

Index: gcc/fortran/resolve.c
===================================================================
--- gcc/fortran/resolve.c	(revision 267190)
+++ gcc/fortran/resolve.c	(working copy)
@@ -12313,7 +12313,11 @@ resolve_fl_variable (gfc_symbol *sym, int mp_flag)
     {
       /* Make sure that character string variables with assumed length are
 	 dummy arguments.  */
-      e = sym->ts.u.cl->length;
+      if (sym->ts.u.cl)
+	e = sym->ts.u.cl->length;
+      else
+	return false;
+
       if (e == NULL && !sym->attr.dummy && !sym->attr.result
 	  && !sym->ts.deferred && !sym->attr.select_type_temporary
 	  && !sym->attr.omp_udr_artificial_var)
Index: gcc/testsuite/gfortran.dg/pr87992.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr87992.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr87992.f90	(working copy)
@@ -0,0 +1,5 @@
+! { dg-do compile }
+subroutine s(x)
+   class(*), allocatable :: x
+   x = ''
+end

-- 
Steve