[gcc r13-4107] Fortran: error recovery after reference to bad CLASS variable [PR107681]

[gcc r13-4107] Fortran: error recovery after reference to bad CLASS variable [PR107681]

[Harald Anlauf]

https://gcc.gnu.org/g:96e4244ef3ccf4867ca4e37fbc6800e64ef30af6

commit r13-4107-g96e4244ef3ccf4867ca4e37fbc6800e64ef30af6
Author: Harald Anlauf <anlauf@gmx.de>
Date:   Wed Nov 16 21:41:19 2022 +0100

    Fortran: error recovery after reference to bad CLASS variable [PR107681]
    
    gcc/fortran/ChangeLog:
    
            PR fortran/107681
            * resolve.cc (resolve_fl_var_and_proc): Prevent NULL pointer
            dereference with reference to bad CLASS variable.
    
    gcc/testsuite/ChangeLog:
    
            PR fortran/107681
            * gfortran.dg/pr107681.f90: New test.

Diff:
---
 gcc/fortran/resolve.cc                 |  1 +
 gcc/testsuite/gfortran.dg/pr107681.f90 | 13 +++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/gcc/fortran/resolve.cc b/gcc/fortran/resolve.cc
index 5ff1cd070ac..24e5aa03556 100644
--- a/gcc/fortran/resolve.cc
+++ b/gcc/fortran/resolve.cc
@@ -12967,6 +12967,7 @@ resolve_fl_var_and_proc (gfc_symbol *sym, int mp_flag)
 	  && sym->ts.u.derived
 	  && !sym->attr.select_type_temporary
 	  && !UNLIMITED_POLY (sym)
+	  && CLASS_DATA (sym)->ts.u.derived
 	  && !gfc_type_is_extensible (CLASS_DATA (sym)->ts.u.derived))
 	{
 	  gfc_error ("Type %qs of CLASS variable %qs at %L is not extensible",
diff --git a/gcc/testsuite/gfortran.dg/pr107681.f90 b/gcc/testsuite/gfortran.dg/pr107681.f90
new file mode 100644
index 00000000000..0999ad92649
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr107681.f90
@@ -0,0 +1,13 @@
+! { dg-do compile }
+! { dg-options "-fcoarray=lib" }
+! PR fortran/107681 - ICE in gfc_type_is_extensible
+! Contributed by G.Steinmetz
+
+program p
+  type t
+     integer, allocatable :: a
+  end type
+  class(t) :: x[*]   ! { dg-error "must be dummy, allocatable or pointer" }
+  associate (y => x) ! { dg-error "Invalid array reference" }
+  end associate
+end