From dfe7f1a06d78f6319ad81f5774dc43fe52e37f45 Mon Sep 17 00:00:00 2001
From: Harald Anlauf <anlauf@gmx.de>
Date: Sat, 3 Dec 2022 19:21:07 +0100
Subject: [PATCH] Fortran: error recovery handling invalid CLASS variable
 [PR107899]

gcc/fortran/ChangeLog:

	PR fortran/107899
	* resolve.cc (resolve_deallocate_expr): Avoid NULL pointer dereference
	on invalid CLASS variable.

gcc/testsuite/ChangeLog:

	PR fortran/107899
	* gfortran.dg/pr107899.f90: New test.
---
 gcc/fortran/resolve.cc                 |  2 +-
 gcc/testsuite/gfortran.dg/pr107899.f90 | 13 +++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gfortran.dg/pr107899.f90

diff --git a/gcc/fortran/resolve.cc b/gcc/fortran/resolve.cc
index 3396c6ce4a7..75dc4b59105 100644
--- a/gcc/fortran/resolve.cc
+++ b/gcc/fortran/resolve.cc
@@ -7570,7 +7570,7 @@ resolve_deallocate_expr (gfc_expr *e)
   sym = e->symtree->n.sym;
   unlimited = UNLIMITED_POLY(sym);

-  if (sym->ts.type == BT_CLASS)
+  if (sym->ts.type == BT_CLASS && sym->attr.class_ok && CLASS_DATA (sym))
     {
       allocatable = CLASS_DATA (sym)->attr.allocatable;
       pointer = CLASS_DATA (sym)->attr.class_pointer;
diff --git a/gcc/testsuite/gfortran.dg/pr107899.f90 b/gcc/testsuite/gfortran.dg/pr107899.f90
new file mode 100644
index 00000000000..e47b57b7b91
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr107899.f90
@@ -0,0 +1,13 @@
+! { dg-do compile }
+! { dg-options "-fcoarray=single" }
+! PR fortran/107899 - ICE in resolve_deallocate_expr
+! Contributed by G.Steinmetz
+
+program p
+  type t
+  end type
+  class(t), target :: x[:] ! { dg-error "deferred shape" }
+  if (allocated (x)) then  ! { dg-error "must be ALLOCATABLE" }
+     deallocate (x)        ! { dg-error "must be ALLOCATABLE or a POINTER" }
+  end if
+end
--
2.35.3