[gcc r13-6651] New testcase

[Richard Biener <rguenth@gcc.gnu.org>]

https://gcc.gnu.org/g:e17936f842d2885447b6b8b82c2fb9cbf2679d7e

commit r13-6651-ge17936f842d2885447b6b8b82c2fb9cbf2679d7e
Author: Richard Biener <rguenther@suse.de>
Date:   Tue Mar 14 08:25:52 2023 +0100

    New testcase
    
    This is a reduced testcase for an issue I ran into when trying to
    improve PTA compile-time further, there wasn't any C family runfail
    in the testsuite for this.
    
            * g++.dg/torture/20230313.C: New testcase.

Diff:
---
 gcc/testsuite/g++.dg/torture/20230313.C | 109 ++++++++++++++++++++++++++++++++
 1 file changed, 109 insertions(+)

diff --git a/gcc/testsuite/g++.dg/torture/20230313.C b/gcc/testsuite/g++.dg/torture/20230313.C
new file mode 100644
index 00000000000..d1f348003bd
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/20230313.C
@@ -0,0 +1,109 @@
+/* { dg-do run } */
+/* { dg-additional-options "-fno-exceptions -fno-rtti" } */
+
+extern "C" void free (void *);
+void fancy_abort () { __builtin_abort (); }
+struct vec_prefix
+{
+  unsigned m_alloc : 1;
+  unsigned m_using_auto_storage : 1;
+  unsigned m_num;
+};
+struct vl_ptr
+;
+struct va_heap
+{
+  typedef vl_ptr default_layout;
+};
+template<typename ,
+         typename A ,
+         typename = typename A::default_layout>
+struct vec
+;
+template<typename T, typename A>
+struct vec<T, A, int>
+{
+  T & operator[] (unsigned ix)
+    {
+      int *__trans_tmp_2;
+      !m_vecpfx.m_num ? fancy_abort (), 0 : 0;
+      __trans_tmp_2 =  reinterpret_cast <T *> (this + 1);
+      return __trans_tmp_2[ix];
+    }
+  bool iterate (unsigned , T *ptr) {
+      *ptr = 0;
+      return false;
+  }
+  void embedded_init (unsigned , unsigned num, unsigned aut)
+    {
+      m_vecpfx.m_alloc =
+	  m_vecpfx.m_using_auto_storage = aut;
+      m_vecpfx.m_num = num;
+    }
+  void quick_grow (unsigned len)
+    {
+      !m_vecpfx.m_alloc ? fancy_abort (), 0 : m_vecpfx.m_num = len;
+    }
+  vec_prefix m_vecpfx;
+};
+template<typename T, int N >
+struct auto_vec : vec<T, va_heap>
+{
+  auto_vec ()
+  {
+    m_auto.embedded_init (N, 0, 1);
+    long off = (char *) &m_auto - (char *) this;
+    this->m_vec = (vec<T, va_heap, int> *) ((char *) this + off);
+  }
+  ~auto_vec ()
+  {
+    this->release ();
+  }
+  vec<T, va_heap, int> m_auto;
+  char m_data;
+};
+template<typename T>
+struct vec<T, va_heap>
+{
+void
+release ()
+{
+  bool __trans_tmp_1 =  m_vec ? m_vec->m_vecpfx.m_using_auto_storage : false;
+  if (__trans_tmp_1)
+      return;
+  vec<int, va_heap, int> *&v = m_vec;
+    free (m_vec);
+    v = nullptr;
+}
+T &operator[] (unsigned ix) { return (*m_vec)[ix]; }
+bool
+iterate (unsigned ix, T *ptr) {
+    m_vec->iterate (ix, ptr);
+    return false;
+}
+void
+quick_grow (unsigned len)
+{
+  m_vec->quick_grow (len);
+}
+  vec<T, va_heap, int> *m_vec;
+};
+void test_auto_alias ()
+{
+  volatile int i = 1;
+  auto_vec<int, 8> v;
+  v.quick_grow (2);
+  v[0] = 1;
+  v[1] = 2;
+  int val;
+  for (int ix = i; v.iterate (ix, &val); ix++)
+    if (val != 2)
+      __builtin_abort ();
+  if (val != 0)
+    __builtin_abort ();
+}
+int main()
+{
+  test_auto_alias ();
+  return 0;
+}