Patch: JNI method invocation

[Tom Tromey <tromey at cygnus dot com>]

This patch gives libgcj the ability to call JNI functions for
otherwise interpreted classes.  JNI functions for compiled classes are
still unimplemented (this requires compiler changes).  JNI function
lookup isn't done, so JNI still doesn't work.  We aren't too far away
from testing, though.

2000-02-01  Tom Tromey  <tromey@cygnus.com>

	* include/java-interp.h (_Jv_JNI_conversion_call): Declare.
	* resolve.cc (ncode): Use _Jv_JNI_conversion_call when
	constructing the closure if the function is native.
	* jni.cc (_Jv_JNI_conversion_call): Now returns `void'.  No longer
	a template function, #if'd out, or static.
	Include <java-interp.h>.

Tom

Index: jni.cc
===================================================================
RCS file: /cvs/java/libgcj/libjava/jni.cc,v
retrieving revision 1.8
diff -u -r1.8 jni.cc
--- jni.cc	2000/02/01 17:36:05	1.8
+++ jni.cc	2000/02/02 01:49:01
@@ -45,6 +45,8 @@
 #include <gcj/method.h>
 #include <gcj/field.h>
 
+#include <java-interp.h>
+
 #define ClassClass _CL_Q34java4lang5Class
 extern java::lang::Class ClassClass;
 #define ObjectClass _CL_Q34java4lang6Object
@@ -1204,11 +1206,14 @@
 
 // This function is the stub which is used to turn an ordinary (CNI)
 // method call into a JNI call.
-#if 0
-template<typename T>
-static T
-_Jv_JNI_conversion_call (fixme)
+void
+_Jv_JNI_conversion_call (ffi_cif *cif,
+			 void *ret,
+			 ffi_raw *args,
+			 void *__this)
 {
+  _Jv_InterpMethod* _this = (_Jv_InterpMethod*)__this;
+
   JNIEnv env;
   _Jv_JNI_LocalFrame *frame
     = (_Jv_JNI_LocalFrame *) alloca (sizeof (_Jv_JNI_LocalFrame)
@@ -1216,7 +1221,7 @@
 
   env.p = &_Jv_JNIFunctions;
   env.ex = NULL;
-  env.klass = FIXME;
+  env.klass = _this->defining_class;
   env.locals = frame;
 
   frame->marker = true;
@@ -1225,20 +1230,24 @@
   for (int i = 0; i < frame->size; ++i)
     frame->vec[i] = NULL;
 
-  T result = FIXME_ffi_call (args);
+  // FIXME: we should mark every reference parameter as a local.  For
+  // now we assume a conservative GC, and we assume that the
+  // references are on the stack somewhere.
+
+  ffi_raw_call (cif,
+		NULL, // FIXME: function pointer.
+		ret,
+		args);
 
   do
     {
-      _Jv_JNI_PopLocalFrame (&env, result);
+      _Jv_JNI_PopLocalFrame (&env, NULL);
     }
   while (env.locals != frame);
 
   if (env.ex)
     JvThrow (env.ex);
-
-  return T;
 }
-#endif
 
 
 
Index: resolve.cc
===================================================================
RCS file: /cvs/java/libgcj/libjava/resolve.cc,v
retrieving revision 1.10
diff -u -r1.10 resolve.cc
--- resolve.cc	2000/01/26 23:44:40	1.10
+++ resolve.cc	2000/02/02 01:49:09
@@ -1022,7 +1022,13 @@
 
   args_raw_size = ffi_raw_size (&closure->cif);
 
-  if ((self->accflags & Modifier::SYNCHRONIZED) != 0)
+  if ((self->accflags & Modifier::NATIVE) != 0)
+    {
+      // FIXME: for now we assume that all native methods for
+      // interpreted code use JNI.
+      fun = (ffi_closure_fun) &_Jv_JNI_conversion_call;
+    }
+  else if ((self->accflags & Modifier::SYNCHRONIZED) != 0)
     {
       if (staticp)
 	fun = (ffi_closure_fun)&_Jv_InterpMethod::run_synch_class;
Index: include/java-interp.h
===================================================================
RCS file: /cvs/java/libgcj/libjava/include/java-interp.h,v
retrieving revision 1.4
diff -u -r1.4 java-interp.h
--- java-interp.h	2000/01/19 18:39:25	1.4
+++ java-interp.h	2000/02/02 01:49:13
@@ -1,6 +1,6 @@
 // java-interp.h - Header file for the bytecode interpreter.  -*- c++ -*-
 
-/* Copyright (C) 1999  Red Hat, Inc.
+/* Copyright (C) 1999, 2000  Red Hat, Inc.
 
    This file is part of libgcj.
 
@@ -121,6 +121,9 @@
   friend class gnu::gcj::runtime::MethodInvocation;
 
   friend void _Jv_PrepareClass(jclass);
+
+  // This function is used when making a JNI call from the interpreter.
+  friend void _Jv_JNI_conversion_call (ffi_cif *, void *, ffi_raw *, void *);
 };
 
 class _Jv_InterpMethodInvocation {
Index: include/jvm.h
===================================================================
RCS file: /cvs/java/libgcj/libjava/include/jvm.h,v
retrieving revision 1.13
diff -u -r1.13 jvm.h
--- jvm.h	2000/02/01 06:14:26	1.13
+++ jvm.h	2000/02/02 01:49:13
@@ -204,5 +204,4 @@
 /* Initialize JNI.  */
 extern void _Jv_JNI_Init (void);
 
-
 #endif /* __JAVA_JVM_H__ */