re PR tree-optimization/47541 (For integer pointers, the value of ++*p is not writte...

2011-02-01  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/47541
	* tree-ssa-structalias.c (push_fields_onto_fieldstack): Make
	sure to have a field at offset zero.

	* g++.dg/torture/pr47541.C: New testcase.

From-SVN: r169468

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 90e4c78..e5ed1d8 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2011-02-01  Richard Guenther  <rguenther@suse.de>
+
+       PR tree-optimization/47541
+       * tree-ssa-structalias.c (push_fields_onto_fieldstack): Make
+       sure to have a field at offset zero.
+
 2011-01-31  Joseph Myers  <joseph@codesourcery.com>
 
        * config/arc/arc.opt (EB, EL): New Driver options.

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 17bb107..8164cf4 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2011-02-01  Richard Guenther  <rguenther@suse.de>
+
+       PR tree-optimization/47541
+       * g++.dg/torture/pr47541.C: New testcase.
+
 2011-01-31  Janus Weil  <janus@gcc.gnu.org>
 
        PR fortran/47455

diff --git a/gcc/testsuite/g++.dg/torture/pr47541.C b/gcc/testsuite/g++.dg/torture/pr47541.C
new file mode 100644 (file)
index 0000000..350a051
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr47541.C
@@ -0,0 +1,27 @@
+/* { dg-do run } */
+
+struct Dummy {};
+struct RefCount : public Dummy {
+    ~RefCount(); /* Has to be non-pod.  */
+    int *a;
+    int *b;
+};
+RefCount::~RefCount(){}
+struct Wrapper : public Dummy { RefCount ref; };
+void __attribute__((noinline,noclone))
+Push(Wrapper ptr)
+{
+  *ptr.ref.b = 0;
+}
+extern "C" void abort (void);
+int main()
+{
+  int a = 1, b = 1;
+  Wrapper x;
+  x.ref.a = &a;
+  x.ref.b = &b;
+  Push(x);
+  if (b != 0)
+    abort ();
+  return 0;
+}

diff --git a/gcc/tree-ssa-structalias.c b/gcc/tree-ssa-structalias.c
index cf1e817..97719ff 100644 (file)
--- a/gcc/tree-ssa-structalias.c
+++ b/gcc/tree-ssa-structalias.c
@@ -5083,6 +5083,19 @@ push_fields_onto_fieldstack (tree type, VEC(fieldoff_s,heap) **fieldstack,
            if (!VEC_empty (fieldoff_s, *fieldstack))
              pair = VEC_last (fieldoff_s, *fieldstack);
 
+           /* If there isn't anything at offset zero, create sth.  */
+           if (!pair
+               && offset + foff != 0)
+             {
+               pair = VEC_safe_push (fieldoff_s, heap, *fieldstack, NULL);
+               pair->offset = 0;
+               pair->size = offset + foff;
+               pair->has_unknown_size = false;
+               pair->must_have_pointers = false;
+               pair->may_have_pointers = false;
+               pair->only_restrict_pointers = false;
+             }
+
            if (!DECL_SIZE (field)
                || !host_integerp (DECL_SIZE (field), 1))
              has_unknown_size = true;