This patch fixes PR96624.

2020-08-28  Paul Thomas  <pault@gcc.gnu.org>

gcc/fortran
	PR fortran/96624
	* simplify.c (gfc_simplify_reshape): Detect zero shape and
	clear index if found.

gcc/testsuite/
	PR fortran/96624
	* gfortran.dg/reshape_8.f90 : New test.

2 files changed, 26 insertions, 2 deletions

diff --git a/gcc/fortran/simplify.c b/gcc/fortran/simplify.c
index 074b50c..8e0d2f9 100644
--- a/gcc/fortran/simplify.c
+++ b/gcc/fortran/simplify.c
@@ -6398,7 +6398,7 @@ gfc_simplify_is_contiguous (gfc_expr *array)
 
   if (gfc_is_not_contiguous (array))
     return gfc_get_logical_expr (gfc_default_logical_kind, &array->where, 0);
-    
+
   return NULL;
 }
 
@@ -6725,6 +6725,7 @@ gfc_simplify_reshape (gfc_expr *source, gfc_expr *shape_exp,
   unsigned long j;
   size_t nsource;
   gfc_expr *e, *result;
+  bool zerosize = false;
 
   /* Check that argument expression types are OK.  */
   if (!is_constant_array_expr (source)
@@ -6847,7 +6848,14 @@ gfc_simplify_reshape (gfc_expr *source, gfc_expr *shape_exp,
   result->rank = rank;
   result->shape = gfc_get_shape (rank);
   for (i = 0; i < rank; i++)
-    mpz_init_set_ui (result->shape[i], shape[i]);
+    {
+      mpz_init_set_ui (result->shape[i], shape[i]);
+      if (shape[i] == 0)
+	zerosize = true;
+    }
+
+  if (zerosize)
+    goto sizezero;
 
   while (nsource > 0 || npad > 0)
     {
@@ -6897,6 +6905,8 @@ inc:
       break;
     }
 
+sizezero:
+
   mpz_clear (index);
 
   return result;
diff --git a/gcc/testsuite/gfortran.dg/reshape_8.f90 b/gcc/testsuite/gfortran.dg/reshape_8.f90
new file mode 100644
index 0000000..01799ac
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/reshape_8.f90
@@ -0,0 +1,14 @@
+! { dg-do compile }
+! { dg-options "-fdump-tree-original" }
+!
+! Test the fix for PR96624 in which an attempt was made to assign
+! to the zero length temporary created by reshape, resulting in a segfault.
+!
+! Contributed by Dong Shenpo  <shenpo.dong@compiler-dev.com>
+!
+program test
+  integer :: a(2,0)
+  a = reshape([1,2,3,4], [2,0])
+  print *, a
+end
+! { dg-final { scan-tree-dump-times "data" 4 "original" } }

path: root/gdb/testsuite/gdb.cp/pass-by-ref.cc

/* This testcase is part of GDB, the GNU debugger.

   Copyright 2007-2015 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

class Obj {
public:
  Obj ();
  Obj (const Obj &);
  ~Obj ();
  int var[2];
};

int foo (Obj arg)
{
  return arg.var[0] + arg.var[1];
}

Obj::Obj ()
{
  var[0] = 1;
  var[1] = 2;
}

Obj::Obj (const Obj &obj)
{
  var[0] = obj.var[0];
  var[1] = obj.var[1];
}

Obj::~Obj ()
{

}

struct Derived : public Obj
{
  int other;
};

int blap (Derived arg)
{
  return foo (arg);
}

struct Container
{
  Obj obj;
};

int blip (Container arg)
{
  return foo (arg.obj);
}

Obj global_obj;
Derived global_derived;
Container global_container;

int
main ()
{
  int bar = foo (global_obj);
  blap (global_derived);
  blip (global_container);
  return bar;
}