gcj: disabling synchronization

Sat Apr 1 00:00:00 GMT 2000

Jeff Sturm writes:
> I didn't completely understand the tree structure created by
> patch_synchronized_statement. It may be obvious to anyone who
> understands the compiler internals (which I certainly don't).

It basically builds what is documented in the comment found in the
middle of patch_synchronized_statement: surrounding the synchronized
block with a try/catch sequence so that if an exception is thrown
during the execution of the block, the synchronization lock is
released and the exception rethrown.
If you read java-tree.def, you'll find that the SYNCHRONIZED_EXPR
contains two things: first the expression on which we synchronize and
then the synchronized block. I thing something hereafter might work.
./A
Index: parse.y
===================================================================
RCS file: /cvs/gcc/egcs/gcc/java/parse.y,v
retrieving revision 1.133
diff -u -p -r1.133 parse.y

--- parse.y	2000年01月25日 18:29:02	1.133
+++ parse.y	2000年01月29日 20:06:39
@@ -11720,6 +11724,15 @@ patch_synchronized_statement (node, wfl_
 parse_error_context (wfl_operator, "Incompatible type for `synchronized'. Can't convert `%s' to `java.lang.Object'",
 			 lang_printable_name (TREE_TYPE (expr), 0));
 return error_mark_node;
+ }
+
+ /* If we actually don't synchronize. Simply return a compound
+ expression */
+ if (flag_no_synch)
+ {
+ block = java_complete_tree (block);
+ return (block == error_mark_node ?
+	 block : build (COMPOUND_EXPR, void_type_node, expr, block));
 }
 
 if (flag_emit_xref)
