PATCH for system class loader simplification

[Per Bothner <per at bothner dot com>]

The initial trigger for this patch was the use of the system field
without checking it for null.  But I got to thinking things owuld be
cleaner and simpler if we just got rid of the field and used the
VMClassLoader.instance instance field directly instead.

I guess I could see that having ClassLoader.system allows other
kinds of system class loaders.  Perhaps it might be cleaner to
go the other way:  Replace all uses of VMClassLoader.instance
by ClassLoader.system?

Comments?  Should I check this in?

2001-08-30  Per Bothner  <per@bothner.com>

	* java/lang/ClassLoader.java (system):  Remove static field.
	(getSystemClassLoader):  Get gnu.gcj.runtime.VMClassLoader.instance
	directly instead of using it to set the system field.
	(loadClass):  Use VMClassLoader.instance instead of system field.
	(findSystemClass):   Similar.
	* prims.cc (_Jv_RunMain):  Clear VMClassLoader::instance rather
	than ClassLoader::system which no longer exists.
	* java/lang/natClassLoader.java (_Jv_FindClass):  Simplify.

Index: prims.cc
===================================================================
RCS file: /cvs/gcc/gcc/libjava/prims.cc,v
retrieving revision 1.57
diff -u -p -r1.57 prims.cc
--- prims.cc	2001/08/26 11:30:07	1.57
+++ prims.cc	2001/08/30 21:41:16
@@ -64,6 +64,7 @@ details.  */
 #include <java/lang/reflect/Modifier.h>
 #include <java/io/PrintStream.h>
 #include <java/lang/UnsatisfiedLinkError.h>
+#include <gnu/gcj/runtime/VMClassLoader.h>
 
 #ifdef USE_LTDL
 #include <ltdl.h>
@@ -921,7 +922,7 @@ _Jv_RunMain (jclass klass, const char *n
 	  // jar file only.  The easiest way to do this is to lose our
 	  // reference to the previous classloader.
 	  _Jv_Jar_Class_Path = strdup (name);
-	  java::lang::ClassLoader::system = NULL;
+	  gnu::gcj::runtime::VMClassLoader::instance = NULL;
 	}
     }
   catch (java::lang::Throwable *t)
Index: java/lang/ClassLoader.java
===================================================================
RCS file: /cvs/gcc/gcc/libjava/java/lang/ClassLoader.java,v
retrieving revision 1.13
diff -u -p -r1.13 ClassLoader.java
--- ClassLoader.java	2001/05/06 13:42:11	1.13
+++ ClassLoader.java	2001/08/30 21:41:16
@@ -34,7 +34,6 @@
 
 public abstract class ClassLoader
 {
-  static private ClassLoader system;
   private ClassLoader parent;
   private HashMap definedPackages = new HashMap();
 
@@ -46,9 +46,7 @@ public abstract class ClassLoader
 
   public static ClassLoader getSystemClassLoader ()
   {
-    if (system == null)
-      system = gnu.gcj.runtime.VMClassLoader.instance;
-    return system;
+    return gnu.gcj.runtime.VMClassLoader.instance;
   }
 
   /**
@@ -120,7 +118,7 @@ public abstract class ClassLoader
 	  if (parent != null)
 	    return parent.loadClass (name, link);
 	  else
-	    c = system.findClass (name);
+	    c = gnu.gcj.runtime.VMClassLoader.instance.findClass (name);
 	} catch (ClassNotFoundException ex) {
 	  /* ignore, we'll try findClass */;
 	}
@@ -464,7 +462,7 @@ public abstract class ClassLoader
   protected final Class findSystemClass(String name) 
     throws java.lang.ClassNotFoundException
   {
-    return getSystemClassLoader ().loadClass (name);
+    return gnu.gcj.runtime.VMClassLoader.instance.loadClass (name);
   }
 
   /*
Index: java/lang/natClassLoader.cc
===================================================================
RCS file: /cvs/gcc/gcc/libjava/java/lang/natClassLoader.cc,v
retrieving revision 1.33
diff -u -p -r1.33 natClassLoader.cc
--- natClassLoader.cc	2001/08/22 23:10:07	1.33
+++ natClassLoader.cc	2001/08/30 21:41:17
@@ -481,12 +495,8 @@ _Jv_FindClass (_Jv_Utf8Const *name, java
 	}
       else 
 	{
-	  java::lang::ClassLoader *sys = java::lang::ClassLoader::system;
-	  if (sys == NULL)
-	    {
-	      _Jv_InitClass (&ClassLoaderClass);
-	      sys = java::lang::ClassLoader::getSystemClassLoader ();
-	    }
+	  java::lang::ClassLoader *sys
+	    = java::lang::ClassLoader::getSystemClassLoader ();
 
 	  // Load using the bootstrap loader jvmspec 5.3.1.
 	  klass = sys->loadClass (sname, false); 

-- 
	--Per Bothner
per@bothner.com   http://www.bothner.com/per/