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Re: C++ patch: Add support for calling Java interfaces
Here is a revised patch. I decided to go the static local with lazy
initialization route to avoid calling builtin_function repeatedly.
OK to commit?
regards
[ bryce ]
2001-03-21 Bryce McKinlay <bryce@albatross.co.nz>
* gjavah.c (process_file): Mark interface definitions with
"__attribute__ ((java_interface))".
2001-03-22 Bryce McKinlay <bryce@albatross.co.nz>
Add support for Java interface method calls.
* cp-tree.h (struct lang_type): Add java_interface flag.
(TYPE_JAVA_INTERFACE): New macro.
* tree.c (cp_valid_lang_attribute): Handle "java_interface" attribute
by setting TYPE_JAVA_INTERFACE.
* call.c (java_iface_lookup_fn): New static.
(build_over_call): If calling a method declared in a
TYPE_JAVA_INTERFACE, call build_java_interface_fn_ref to generate the
expression which resolves the function address.
(build_java_interface_fn_ref): New function.
Index: cp/call.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/call.c,v
retrieving revision 1.255.2.7
diff -u -r1.255.2.7 call.c
--- call.c 2001/03/06 15:37:37 1.255.2.7
+++ call.c 2001/03/22 07:39:07
@@ -45,6 +45,7 @@
static int joust PARAMS ((struct z_candidate *, struct z_candidate *, int));
static int compare_ics PARAMS ((tree, tree));
static tree build_over_call PARAMS ((struct z_candidate *, tree, int));
+static tree build_java_interface_fn_ref PARAMS ((tree, tree));
#define convert_like(CONV, EXPR) convert_like_real (CONV, EXPR, NULL_TREE, 0, 0)
#define convert_like_with_context(CONV, EXPR, FN, ARGNO) convert_like_real (CONV, EXPR, FN, ARGNO, 0)
static tree convert_like_real PARAMS ((tree, tree, tree, int, int));
@@ -4262,7 +4263,10 @@
if (TREE_SIDE_EFFECTS (*p))
*p = save_expr (*p);
t = build_pointer_type (TREE_TYPE (fn));
- fn = build_vfn_ref (p, build_indirect_ref (*p, 0), DECL_VINDEX (fn));
+ if (DECL_CONTEXT (fn) && TYPE_JAVA_INTERFACE (DECL_CONTEXT (fn)))
+ fn = build_java_interface_fn_ref (fn, *p);
+ else
+ fn = build_vfn_ref (p, build_indirect_ref (*p, 0), DECL_VINDEX (fn));
TREE_TYPE (fn) = t;
}
else if (DECL_INLINE (fn))
@@ -4295,6 +4299,71 @@
if (IS_AGGR_TYPE (TREE_TYPE (fn)))
fn = build_cplus_new (TREE_TYPE (fn), fn);
return convert_from_reference (fn);
+}
+
+static tree java_iface_lookup_fn;
+
+/* Make an expression which yields the address of the Java interface
+ method FN. This is achieved by generating a call to libjava's
+ _Jv_LookupInterfaceMethodIdx(). */
+
+static tree
+build_java_interface_fn_ref (fn, instance)
+ tree fn, instance;
+{
+ tree lookup_args, lookup_fn, method, idx;
+ int i;
+
+ if (!java_iface_lookup_fn)
+ {
+ tree endlink = build_void_list_node ();
+ tree t = tree_cons (NULL_TREE, ptr_type_node,
+ tree_cons (NULL_TREE, ptr_type_node,
+ tree_cons (NULL_TREE, java_int_type_node,
+ endlink)));
+ java_iface_lookup_fn
+ = builtin_function ("_Jv_LookupInterfaceMethodIdx",
+ build_function_type (ptr_type_node, t),
+ 0, NOT_BUILT_IN, NULL_PTR);
+ ggc_add_tree_root (&java_iface_lookup_fn, 1);
+ }
+
+ /* Look up the pointer to the runtime java.lang.Class object for `instance'.
+ This is the first entry in the vtable. */
+ tree klass_ref = build_vtbl_ref (build_indirect_ref (instance, 0),
+ integer_zero_node);
+
+ /* Get the java.lang.Class pointer for the interface being called. */
+ tree iface = DECL_CONTEXT (fn);
+ tree iface_ref = lookup_field (iface, get_identifier ("class$"), 0, 0);
+ if (!iface_ref || TREE_CODE (iface_ref) != VAR_DECL
+ || DECL_CONTEXT (iface_ref) != iface)
+ {
+ cp_error ("Could not find class$ field in java interface type `%T'",
+ iface);
+ return error_mark_node;
+ }
+ iface_ref = build1 (ADDR_EXPR, build_pointer_type (iface), iface_ref);
+
+ /* Determine the itable index of FN. */
+ i = 1;
+ for (method = TYPE_METHODS (iface); method; method = TREE_CHAIN (method))
+ {
+ if (!DECL_VIRTUAL_P (method))
+ continue;
+ if (fn == method)
+ break;
+ i++;
+ }
+ idx = build_int_2 (i, 0);
+
+ lookup_args = tree_cons (NULL_TREE, klass_ref,
+ tree_cons (NULL_TREE, iface_ref,
+ build_tree_list (NULL_TREE, idx)));
+ lookup_fn = build1 (ADDR_EXPR,
+ build_pointer_type (TREE_TYPE (java_iface_lookup_fn)),
+ java_iface_lookup_fn);
+ return build (CALL_EXPR, ptr_type_node, lookup_fn, lookup_args, NULL_TREE);
}
/* Returns the value to use for the in-charge parameter when making a
Index: cp/tree.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/tree.c,v
retrieving revision 1.232.2.4
diff -u -r1.232.2.4 tree.c
--- tree.c 2001/03/20 22:03:47 1.232.2.4
+++ tree.c 2001/03/22 07:39:10
@@ -2212,6 +2212,19 @@
tree decl ATTRIBUTE_UNUSED;
tree type ATTRIBUTE_UNUSED;
{
+ if (is_attribute_p ("java_interface", attr_name))
+ {
+ if (attr_args != NULL_TREE
+ || decl != NULL_TREE
+ || ! CLASS_TYPE_P (type)
+ || ! TYPE_FOR_JAVA (type))
+ {
+ error ("`java_interface' attribute can only be applied to Java class definitions");
+ return 0;
+ }
+ TYPE_JAVA_INTERFACE (type) = 1;
+ return 1;
+ }
if (is_attribute_p ("com_interface", attr_name))
{
if (! flag_vtable_thunks)
Index: cp/cp-tree.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/cp-tree.h,v
retrieving revision 1.572.2.11
diff -u -r1.572.2.11 cp-tree.h
--- cp-tree.h 2001/03/20 22:03:39 1.572.2.11
+++ cp-tree.h 2001/03/22 07:39:12
@@ -1337,7 +1337,8 @@
/* There are some bits left to fill out a 32-bit word. Keep track
of this by updating the size of this bitfield whenever you add or
remove a flag. */
- unsigned dummy : 8;
+ unsigned java_interface : 1;
+ unsigned dummy : 7;
int vsize;
@@ -1558,6 +1559,10 @@
/* The alignment of NODE, without its virtual bases, in bytes. */
#define CLASSTYPE_ALIGN_UNIT(NODE) \
(CLASSTYPE_ALIGN (NODE) / BITS_PER_UNIT)
+
+/* True if this a Java interface type, declared with
+ '__attribute__ ((java_interface))'. */
+#define TYPE_JAVA_INTERFACE(NODE) (TYPE_LANG_SPECIFIC(NODE)->java_interface)
/* A cons list of virtual functions which cannot be inherited by
derived classes. When deriving from this type, the derived
Index: java/gjavah.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/java/gjavah.c,v
retrieving revision 1.68
diff -u -r1.68 gjavah.c
--- gjavah.c 2001/01/12 17:28:23 1.68
+++ gjavah.c 2001/03/22 07:39:12
@@ -1857,7 +1857,12 @@
generate_access (out, ACC_PUBLIC);
fprintf (out, "\n static ::java::lang::Class class$;\n");
- fputs ("};\n", out);
+ fputs ("}", out);
+
+ if (jcf->access_flags & ACC_INTERFACE)
+ fputs (" __attribute__ ((java_interface))", out);
+
+ fputs (";\n", out);
if (append_count > 0)
fputc ('\n', out);