re PR c++/89698 (Run-time error due to optimization of field access after cast at...

2019-03-14  Richard Biener  <rguenther@suse.de>

	PR middle-end/89698
	* fold-const.c (operand_equal_p): For INDIRECT_REF check
	that the access types are similar.

	* g++.dg/torture/pr89698.C: New testcase.

From-SVN: r269677

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8c3a6b966f2b2447e1ca4c9471db13c627a2b45d..2d2495cba2710e239e8cd9306e218d9885d6db5a 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2019-03-14  Richard Biener  <rguenther@suse.de>
+
+       PR middle-end/89698
+       * fold-const.c (operand_equal_p): For INDIRECT_REF check
+       that the access types are similar.
+
 2019-03-14  Jakub Jelinek  <jakub@redhat.com>
 
        PR tree-optimization/89703

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 571566aa6bca91e20153d7bfa4d6cfcd897cd97b..dbc96798e656fafd613b92d3e7a9d901edd416b6 100644 (file)
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -3220,10 +3220,16 @@ operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
       switch (TREE_CODE (arg0))
        {
        case INDIRECT_REF:
-         if (!(flags & OEP_ADDRESS_OF)
-             && (TYPE_ALIGN (TREE_TYPE (arg0))
-                 != TYPE_ALIGN (TREE_TYPE (arg1))))
-           return 0;
+         if (!(flags & OEP_ADDRESS_OF))
+           {
+             if (TYPE_ALIGN (TREE_TYPE (arg0))
+                 != TYPE_ALIGN (TREE_TYPE (arg1)))
+               return 0;
+             /* Verify that the access types are compatible.  */
+             if (TYPE_MAIN_VARIANT (TREE_TYPE (arg0))
+                 != TYPE_MAIN_VARIANT (TREE_TYPE (arg1)))
+               return 0;
+           }
          flags &= ~OEP_ADDRESS_OF;
          return OP_SAME (0);
 

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index db45dc4fdfc14428d3bbd5dadf5753255f1fcc8d..b0f9efa63fe63145fe4f52359f9c0437b31eb0a3 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2019-03-14  Richard Biener  <rguenther@suse.de>
+
+       PR middle-end/89698
+       * g++.dg/torture/pr89698.C: New testcase.
+
 2019-03-14  Jakub Jelinek  <jakub@redhat.com>
 
        PR tree-optimization/89703

diff --git a/gcc/testsuite/g++.dg/torture/pr89698.C b/gcc/testsuite/g++.dg/torture/pr89698.C
new file mode 100644 (file)
index 0000000..fbeb797
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr89698.C
@@ -0,0 +1,28 @@
+/* { dg-do run } */
+
+extern "C" void abort (void);
+
+class A {
+    virtual void f(){};
+public:
+    int x;
+    A(int in): x(in) {};
+};
+
+class B: public A {
+public:
+    int y;
+    B(int in):A(in-1), y(in) {};
+};
+
+int test(void)
+{
+  int res;
+  B b(2);
+  A* bp = &b;
+  void* vp = dynamic_cast<void*>(bp);
+  if (((A*)vp)->x == 1 && ((B*)vp)->y == 2)
+    return 1;
+  return 0;
+}
+int main() { if (test() != 1) abort (); return 0; }