Re: jni and static libgcj and friends? (Finally success!)

[Martin Kahlert <martin dot kahlert at infineon dot com>]

Hi Alexandre and Jeff!

Thanks a lot for all your help.

To make that all work was a bit more effort than i thought.
It is *not* enough to add -prefer-pic to the --mode=compile commands
in libjava but in all needed packages (boehm-gc, zlib, libffi...).
I finally put it into every Makefile.in i found.

Then the only way to make that work was with --disable-shared
When i tried --enable-shared=libstdc++ instead, something went amok:
Error messages were like this: no rule to make target java/i
Seems like some sed scripts would need improvements here.

In order to make my application work correctly on Solaris i used the appended patch.
(Originally from the mailing list but i had to update it for void support)

How is the libffi issue handled, now? I saw Tom suggested some fix and probably
did something in libffi, but does it work now?
gcc-20020218 was the last snapshot, which worked for me. So i cannot tell
about the actual state.

Thanks a lot again,
Martin.


diff -ur gcc-20020218.old/libjava/java/lang/reflect/natMethod.cc gcc-20020218/libjava/java/lang/reflect/natMethod.cc
--- gcc-20020218.old/libjava/java/lang/reflect/natMethod.cc	Tue Jan  8 21:00:50 2002
+++ gcc-20020218/libjava/java/lang/reflect/natMethod.cc	Tue Feb 19 11:51:27 2002
@@ -145,6 +145,39 @@
 
   return r;
 }
+
+static inline ffi_type *
+get_ffi_return_type (jclass klass)
+{
+  // A special case.
+  if (klass == NULL)
+    return &ffi_type_pointer;
+
+  ffi_type *r;
+  if (klass == JvPrimClass (byte))
+    r = &ffi_type_sint32;
+  else if (klass == JvPrimClass (short))
+    r = &ffi_type_sint32;
+  else if (klass == JvPrimClass (int))
+    r = &ffi_type_sint32;
+  else if (klass == JvPrimClass (long))
+    r = &ffi_type_sint64;
+  else if (klass == JvPrimClass (float))
+    r = &ffi_type_float;
+  else if (klass == JvPrimClass (double))
+    r = &ffi_type_double;
+  else if (klass == JvPrimClass (boolean))
+    r = &ffi_type_sint32;
+  else if (klass == JvPrimClass (char))
+    r = &ffi_type_uint32;
+  else
+    {
+      JvAssert (! klass->isPrimitive());
+      r = &ffi_type_pointer;
+    }
+
+  return r;
+}
 #endif // USE_LIBFFI
 
 jobject
@@ -343,7 +376,9 @@
   if (is_constructor || return_type == JvPrimClass (void))
     rtype = &ffi_type_void;
   else
-    rtype = get_ffi_type (return_type);
+    // Return type must be at least one word, so get_ffi_return_type
+    // guarantees this.
+    rtype = get_ffi_return_type (return_type);
   ffi_type **argtypes = (ffi_type **) __builtin_alloca (param_count
 							* sizeof (ffi_type *));
 
@@ -416,6 +451,8 @@
       p += tsize;
     }
 
+  jvalue result_word;
+
   // FIXME: initialize class here.
 
   using namespace java::lang;
@@ -425,7 +462,7 @@
 
   try
     {
-      ffi_call (&cif, (void (*)()) meth->ncode, result, values);
+      ffi_call (&cif, (void (*)()) meth->ncode, &result_word, values);
     }
   catch (Throwable *ex2)
     {
@@ -436,8 +473,20 @@
       ex = new InvocationTargetException (ex2);
     }
 
+  // Handle return type.  Constructor return values are faked, and
+  // subword return types must be narrowed to the proper jvalue element.
   if (is_constructor)
     result->l = obj;
+  else if (return_type == JvPrimClass (byte))
+    result->b = (jbyte)result_word.i;
+  else if (return_type == JvPrimClass (short))
+    result->s = (jshort)result_word.i;
+  else if (return_type == JvPrimClass (boolean))
+    result->z = (jboolean)result_word.i;
+  else if (return_type == JvPrimClass (char))
+    result->c = (jchar)result_word.i;
+  else if (return_type != JvPrimClass(void))
+    memcpy (result, &result_word, sizeof (jvalue));
 
   return ex;
 #else


-- 
The early bird catches the worm. If you want something else for       
breakfast, get up later.