re PR tree-optimization/45580 (Building WebKit fails with compiler catching SIGSEGV in gimple_fold_obj_type_ref_known_binfo())

2010-09-21  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/45580
	* tree-ssa-propagate.c (substitute_and_fold): Always replace
	regular uses.
	* gimple-fold.c (gimple_fold_obj_type_ref): For a BINFO without
	virtuals fold the call into a regular indirect one.

	* g++.dg/torture/pr45580.C: New testcase.

From-SVN: r164474

5 files changed, 70 insertions, 4 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 3b8d418..7585ee6 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2010-09-21  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/45580
+	* tree-ssa-propagate.c (substitute_and_fold): Always replace
+	regular uses.
+	* gimple-fold.c (gimple_fold_obj_type_ref): For a BINFO without
+	virtuals fold the call into a regular indirect one.
+
 2010-09-20  Eric Botcazou  <ebotcazou@adacore.com>
 
 	PR rtl-optimization/42775
diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
index 8faadcc..896f508 100644
--- a/gcc/gimple-fold.c
+++ b/gcc/gimple-fold.c
@@ -1471,6 +1471,9 @@ gimple_fold_obj_type_ref (tree ref, tree known_type)
   if (binfo)
     {
       HOST_WIDE_INT token = tree_low_cst (OBJ_TYPE_REF_TOKEN (ref), 1);
+      /* If there is no virtual methods fold this to an indirect call.  */
+      if (!BINFO_VIRTUALS (binfo))
+	return OBJ_TYPE_REF_EXPR (ref);
       return gimple_fold_obj_type_ref_known_binfo (token, binfo);
     }
   else
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index ac22fff..b00b891 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2010-09-21  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/45580
+	* g++.dg/torture/pr45580.C: New testcase.
+
 2010-09-21  Uros Bizjak  <ubizjak@gmail.com>
 
 	* lib/gcc-dg.exp (clanup-stack-usage): Really remove .su files.
diff --git a/gcc/testsuite/g++.dg/torture/pr45580.C b/gcc/testsuite/g++.dg/torture/pr45580.C
new file mode 100644
index 0000000..c3af491
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr45580.C
@@ -0,0 +1,50 @@
+// { dg-do compile }
+
+namespace std {
+    typedef __SIZE_TYPE__ size_t;
+}
+inline void* operator new(std::size_t, void* __p) throw() {
+    return __p;
+}
+class Noncopyable  { };
+struct CollectorCell { };
+template<typename T> class PassRefPtr {
+public:
+    T* releaseRef() const { }
+};
+template <typename T> class NonNullPassRefPtr {
+public:
+    template <class U> NonNullPassRefPtr(const PassRefPtr<U>& o)
+	: m_ptr(o.releaseRef()) { }
+    mutable T* m_ptr;
+};
+struct ClassInfo;
+class JSValue { };
+JSValue jsNull();
+class Structure;
+class JSGlobalData {
+    static void storeVPtrs();
+};
+class JSCell : public Noncopyable {
+    friend class JSObject;
+    friend class JSGlobalData;
+    virtual ~JSCell();
+};
+class JSObject : public JSCell {
+public:
+    explicit JSObject(NonNullPassRefPtr<Structure>);
+    static PassRefPtr<Structure> createStructure(JSValue prototype) { }
+};
+class JSByteArray : public JSObject {
+    friend class JSGlobalData;
+    enum VPtrStealingHackType { VPtrStealingHack };
+    JSByteArray(VPtrStealingHackType)
+	: JSObject(createStructure(jsNull())), m_classInfo(0) { }
+    const ClassInfo* m_classInfo;
+};
+void JSGlobalData::storeVPtrs() {
+    CollectorCell cell;
+    void* storage = &cell;
+    JSCell* jsByteArray = new (storage) JSByteArray(JSByteArray::VPtrStealingHack);
+    jsByteArray->~JSCell();
+}
diff --git a/gcc/tree-ssa-propagate.c b/gcc/tree-ssa-propagate.c
index e08d2e7..c97960c 100644
--- a/gcc/tree-ssa-propagate.c
+++ b/gcc/tree-ssa-propagate.c
@@ -1122,12 +1122,12 @@ substitute_and_fold (ssa_prop_get_value_fn get_value_fn,
 	    {
 	      did_replace = true;
 	      prop_stats.num_stmts_folded++;
+	      stmt = gsi_stmt (oldi);
+	      update_stmt (stmt);
 	    }
 
-	  /* Only replace real uses if we couldn't fold the
-	     statement using value range information.  */
-	  if (get_value_fn
-	      && !did_replace)
+	  /* Replace real uses in the statement.  */
+	  if (get_value_fn)
 	    did_replace |= replace_uses_in (stmt, get_value_fn);
 
 	  /* If we made a replacement, fold the statement.  */