re PR java/20056 ('verification failed: incompatible type on stack' with --indirect-dispatch)

PR java/20056:
	* include/jvm.h (_Jv_Linker::has_field_p): Declare.
	* link.cc (has_field_p): New function.
	* verify.cc (check_field_constant): Added 'putfield' argument.
	(verify_instructions_0): Updated.
	(type::equals): New method.

From-SVN: r95259

libjava/ChangeLog

@@ -1,3 +1,12 @@
+2005-02-18  Tom Tromey  <tromey@redhat.com>
+
+	PR java/20056:
+	* include/jvm.h (_Jv_Linker::has_field_p): Declare.
+	* link.cc (has_field_p): New function.
+	* verify.cc (check_field_constant): Added 'putfield' argument.
+	(verify_instructions_0): Updated.
+	(type::equals): New method.
+
 2005-02-18  Anthony Green  <green@redhat.com>
 
 	* NEWS: Draft of libgcj NEWS for 4.0.

libjava/include/jvm.h

@@ -278,6 +278,7 @@ private:
 
 public:
 
+  static bool has_field_p (jclass, _Jv_Utf8Const *);
   static void print_class_loaded (jclass);
   static void resolve_class_ref (jclass, jclass *);
   static void wait_for_state(jclass, int);

libjava/link.cc

@@ -131,6 +131,18 @@ _Jv_Linker::find_field_helper (jclass search, _Jv_Utf8Const *name,
   return NULL;
 }
 
+bool
+_Jv_Linker::has_field_p (jclass search, _Jv_Utf8Const *field_name)
+{
+  for (int i = 0; i < search->field_count; ++i)
+    {
+      _Jv_Field *field = &search->fields[i];
+      if (_Jv_equalUtf8Consts (field->name, field_name))
+	return true;
+    }
+  return false;
+}
+
 // Find a field.
 // KLASS is the class that is requesting the field.
 // OWNER is the class in which the field should be found.

libjava/verify.cc

@@ -1,6 +1,6 @@
 // verify.cc - verify bytecode
 
-/* Copyright (C) 2001, 2002, 2003, 2004  Free Software Foundation
+/* Copyright (C) 2001, 2002, 2003, 2004, 2005  Free Software Foundation
 
    This file is part of libgcj.
 
@@ -751,6 +751,20 @@ private:
       return klass->compatible(k.klass, verifier);
     }
 
+    bool equals (const type &other, _Jv_BytecodeVerifier *vfy)
+    {
+      // Only works for reference types.
+      if (key != reference_type
+	  || key != uninitialized_reference_type
+	  || other.key != reference_type
+	  || other.key != uninitialized_reference_type)
+	return false;
+      // Only for single-valued types.
+      if (klass->ref_next || other.klass->ref_next)
+	return false;
+      return klass->equals (other.klass, vfy);
+    }
+
     bool isvoid () const
     {
       return key == void_type;
@@ -1963,7 +1977,9 @@ private:
   }
 
   // Return field's type, compute class' type if requested.
-  type check_field_constant (int index, type *class_type = NULL)
+  // If PUTFIELD is true, use the special 'putfield' semantics.
+  type check_field_constant (int index, type *class_type = NULL,
+			     bool putfield = false)
   {
     _Jv_Utf8Const *name, *field_type;
     type ct = handle_field_or_method (index,
@@ -1971,9 +1987,25 @@ private:
 				      &name, &field_type);
     if (class_type)
       *class_type = ct;
+    type result;
     if (field_type->first() == '[' || field_type->first() == 'L')
-      return type (field_type, this);
-    return get_type_val_for_signature (field_type->first());
+      result = type (field_type, this);
+    else
+      result = get_type_val_for_signature (field_type->first());
+
+    // We have an obscure special case here: we can use `putfield' on
+    // a field declared in this class, even if `this' has not yet been
+    // initialized.
+    if (putfield
+	&& ! current_state->this_type.isinitialized ()
+	&& current_state->this_type.pc == type::SELF
+	&& current_state->this_type.equals (ct, this)
+	// We don't look at the signature, figuring that if it is
+	// wrong we will fail during linking.  FIXME?
+	&& _Jv_Linker::has_field_p (current_class, name))
+      class_type->set_uninitialized (type::SELF, this);
+
+    return result;
   }
 
   type check_method_constant (int index, bool is_interface,
@@ -2783,15 +2815,8 @@ private:
 	  case op_putfield:
 	    {
 	      type klass;
-	      type field = check_field_constant (get_ushort (), &klass);
+	      type field = check_field_constant (get_ushort (), &klass, true);
 	      pop_type (field);
-
-	      // We have an obscure special case here: we can use
-	      // `putfield' on a field declared in this class, even if
-	      // `this' has not yet been initialized.
-	      if (! current_state->this_type.isinitialized ()
-		  && current_state->this_type.pc == type::SELF)
-		klass.set_uninitialized (type::SELF, this);
 	      pop_type (klass);
 	    }
 	    break;