[PATCH] Use vague linkage for Java methods

[Julian Brown <julian at codesourcery dot com>]

Hi,

This patch causes Java methods to be output with once-only ("vague") 
linkage (so long as they are non-abstract, non-private and non-static, 
which seem like the right conditions, but I'd be prepared to believe 
aren't perfect). This helps when using CNI to interface with C++, 
especially on platforms with COMDAT groups.

It allows my previous patch to work again:

http://gcc.gnu.org/ml/gcc-patches/2005-02/msg01624.html

The problem was that gcjh-produced header files sometimes output full 
methods in simple cases, which are then put into COMDAT groups by the 
C++ front-end. Java methods are currently output with weak linkage due 
to the definition of MAKE_DECL_ONE_ONLY, so this works, apparently 
somewhat accidentally.

If MAKE_DECL_ONE_ONLY is altered to not use weak linkage, multiple 
definitions occur when mixing Java with CNI code.

This patch has been tested independently (with c,c++,java) on 
i686-pc-linux-gnu.

ChangeLog:

    * gcc/java/decl.c (finish_method): Give methods once-only linkage.
Index: gcc/java/decl.c
===================================================================
RCS file: /home/gcc/repos/gcc/gcc/gcc/java/decl.c,v
retrieving revision 1.209
diff -c -p -r1.209 decl.c
*** gcc/java/decl.c	14 Feb 2005 14:58:22 -0000	1.209
--- gcc/java/decl.c	6 Mar 2005 23:55:51 -0000
*************** finish_method (tree fndecl)
*** 2036,2041 ****
--- 2036,2050 ----
  		    build2 (TRY_FINALLY_EXPR, void_type_node, *tp, exit));
      }
  
+   /* Ensure non-abstract non-static non-private members are defined only once
+      when linking. This is an issue when using CNI to interface with C++ object
+      files.  */
+   if (! METHOD_STATIC (fndecl) && ! METHOD_PRIVATE (fndecl)
+       && ! METHOD_ABSTRACT (fndecl))
+     {
+       make_decl_one_only (fndecl);
+     }
+ 
    /* Prepend class initialization for static methods reachable from
       other classes.  */
    if (METHOD_STATIC (fndecl) && ! METHOD_PRIVATE (fndecl)