From d655f87d6f2f59e00401a483f7f824dea25d1bd4 Mon Sep 17 00:00:00 2001
From: Bryce McKinlay <bryce@albatross.co.nz>
Date: Thu, 15 Jun 2000 11:58:18 +0000
Subject: [PATCH] 2000-06-15  Bryce McKinlay  <bryce@albatross.co.nz>

	Fix for PR java.lang/258:
	* prims.cc (_Jv_PrimClass): Set state of primitive class to
	JV_STATE_DONE, to prevent accidental initialization.
	* java/lang/natClass.cc (_Jv_IsAssignableFrom): Call
	_Jv_InterfaceAssignableFrom if target is an interface and source is
	an interface or an abstract class. Remove redundant initializeClass
	calls. Remove duplicate if_idt test.
	* java/lang/Class.h (_Jv_InterfaceAssignableFrom): New function.

From-SVN: r34562
---
 libjava/ChangeLog             | 11 +++++++++
 libjava/java/lang/natClass.cc | 44 +++++++++++++++++++++++------------
 libjava/prims.cc              |  2 +-
 3 files changed, 41 insertions(+), 16 deletions(-)

diff --git a/libjava/ChangeLog b/libjava/ChangeLog
index 7ec5cb1185f..db0639020e1 100644
--- a/libjava/ChangeLog
+++ b/libjava/ChangeLog
@@ -1,3 +1,14 @@
+2000-06-15  Bryce McKinlay  <bryce@albatross.co.nz>
+
+	Fix for PR java.lang/258:
+	* prims.cc (_Jv_PrimClass): Set state of primitive class to 
+	JV_STATE_DONE, to prevent accidental initialization.
+	* java/lang/natClass.cc (_Jv_IsAssignableFrom): Call 
+	_Jv_InterfaceAssignableFrom if target is an interface and source is an
+	interface or an abstract class.	Remove redundant initializeClass calls. 
+	Remove duplicate if_idt test. 
+	* java/lang/Class.h (_Jv_InterfaceAssignableFrom): New function.
+
 2000-05-31  Tom Tromey  <tromey@cygnus.com>
 
 	* prims.cc (DECLARE_PRIM_TYPE): Define a vtable as well.
diff --git a/libjava/java/lang/natClass.cc b/libjava/java/lang/natClass.cc
index dfc3840a6a0..995e631ace5 100644
--- a/libjava/java/lang/natClass.cc
+++ b/libjava/java/lang/natClass.cc
@@ -921,24 +921,16 @@ _Jv_IsAssignableFrom (jclass target, jclass source)
 
   if (target->isInterface())
     {
-      // Abstract classes have no IDTs, so compare superclasses instead.
-      if (java::lang::reflect::Modifier::isAbstract (source->accflags))
-	{
-	  jclass super = source->getSuperclass();
-	  return super ? _Jv_IsAssignableFrom (target, super) : false;
-	}
-
-      if (source->state != JV_STATE_DONE)
-	source->initializeClass ();
-      if (target->state != JV_STATE_DONE)
-	target->initializeClass ();
-
+      // Abstract classes have no IDT, and IDTs provide no way to check
+      // two interfaces for assignability.
+      if (__builtin_expect 
+         (java::lang::reflect::Modifier::isAbstract (source->accflags)
+          || source->isInterface(), false))
+        return _Jv_InterfaceAssignableFrom (target, source);
+	
       _Jv_IDispatchTable *cl_idt = source->idt;
       _Jv_IDispatchTable *if_idt = target->idt;
 
-      if (if_idt == NULL) // The interface has no implementations
-	return false;
-
       if (__builtin_expect ((if_idt == NULL), false))
 	return false; // No class implementing TARGET has been loaded.    
       jshort cl_iindex = cl_idt->cls.iindex;
@@ -954,6 +946,28 @@ _Jv_IsAssignableFrom (jclass target, jclass source)
   return false;
 }
 
+// Interface type checking, the slow way. Returns TRUE if IFACE is a 
+// superinterface of SOURCE. This is used when SOURCE is also an interface,
+// or a class with no interface dispatch table.
+jboolean
+_Jv_InterfaceAssignableFrom (jclass iface, jclass source)
+{
+  for (int i = 0; i < source->interface_count; i++)
+    {
+      jclass interface = source->interfaces[i];
+      if (iface == interface
+          || _Jv_InterfaceAssignableFrom (iface, interface))
+        return true;      
+    }
+    
+  if (!source->isInterface()
+      && source->superclass 
+      && _Jv_InterfaceAssignableFrom (iface, source->superclass))
+    return true;
+        
+  return false;
+}
+
 jboolean
 _Jv_IsInstanceOf(jobject obj, jclass cl)
 {
diff --git a/libjava/prims.cc b/libjava/prims.cc
index 3a022f0380a..c7c764c604f 100644
--- a/libjava/prims.cc
+++ b/libjava/prims.cc
@@ -543,7 +543,7 @@ public:
       interfaces = NULL;
       loader = NULL;
       interface_count = 0;
-      state = JV_STATE_NOTHING;
+      state = JV_STATE_DONE;
       thread = NULL;
 
       // Note that we have to set `methods' to NULL.