* parser-defs.h (struct exp_descriptor): New definition, containing

language-specific info for printing, prefixifying, dumping, and
evaluating expressions.
(exp_descriptor_standard): Declare new variable.
(print_subexp): Make global and declare here (from expprint.c).
(dump_subexp): Ditto.
(dump_subexp_body_standard): Declare.
(operator_length_standard): Declare.
(op_name_standard): Declare.
(print_subexp): Declare.
(print_subexp_standard): Declare.

* language.h (struct language_defn): Add la_exp_desc field to hold
pointer to table for language-specific operators.
Remove evaluate_exp field, which is now in struct exp_descriptor.

* parse.c (operator_length): Move most code to new
operator_length_standard function.  Use language-specific information.
(operator_length_standard): New function taking most code from
operator_length.
(exp_descriptor_standard): New constant.

* expression.h (enum exp_opcode): Add definitions of OP_EXTENDED0
and OP_EXTENDED_LAST.

* expprint.c (print_subexp): Use language-specific print_subexp.
Make global; remove static declaration.
Move most code to print_subexp_standard.
(print_subexp_standard): New function, containing code formerly in
print_subexp.
(op_name): Add expression to argument signature.
Use langauge-specific op_name.
Move most code to op_name_standard.
(op_name_standard): New function, containing code formerly in op_name.
(dump_subexp): 	Use new version of op_name function.
Use language-specific dump_subexp_body, and move most existing code to
dump_subexp_body_standard.
(dump_raw_expression): Use new op_name interface.
(dump_subexp_body): Move most code to dump_subexp_body_standard.
(dump_subexp_body_standard): New function, containing code formerly
in dump_subexp_body.

* language.c (unknown_language): Add default la_exp_desc field and
remove evaluate_exp field.
(auto_language): Ditto.
(local_language): Ditto.
* f-lang.c (f_language_defn): Ditto.
* c-lang.c (c_language_defn): Ditto.
(cplus_language_defn): Ditto.
(asm_language_defn): Ditto.
(minimal_language_defn): Ditto.
* p-lang.c (pascal_language_defn): Ditto.
* m2-lang.c (m2_language_defn): Ditto.
* objc-lang.c (objc_language_defn): Ditto.

* jv-lang.c (exp_descriptor_java): New variable, containing
Java-specific expression evaluator.
(java_language_defn): Add la_exp_desc field and remove evaluate_exp
field.
* scm-lang.c (exp_descriptor_scm): New variable, containing
Scheme-specific expression evaluator.
(scm_language_defn): Add la_exp_desc field and remove evaluate_exp
field.
* objc-lang.c (print_object_command): Take evaluate_exp from the
la_exp_desc field.

* Makefile.in (eval.o): Add dependency on parser-defs.h.

* eval.c: Include parser-defs.h for the full declaration of
la_exp_desc's type.
(evaluate_subexp): Get evaluate_exp out of la_exp_desc field.

gdb/expression.h

@@ -322,7 +322,27 @@ enum exp_opcode
     OP_EXPRSTRING,
 
     /* An Objective C Foundation Class NSString constant */
-    OP_OBJC_NSSTRING
+    OP_OBJC_NSSTRING,
+
+     /* First extension operator.  Individual language modules define
+        extra operators they need as constants with values 
+        OP_LANGUAGE_SPECIFIC0 + k, for k >= 0, using a separate 
+        enumerated type definition:
+           enum foo_extension_operator {
+             BINOP_MOGRIFY = OP_EXTENDED0,
+ 	     BINOP_FROB,
+ 	     ...
+           };      */
+    OP_EXTENDED0,
+  
+    /* Last possible extension operator.  Defined to provide an
+       explicit and finite number of extended operators. */
+    OP_EXTENDED_LAST = 0xff
+    /* NOTE: Eventually, we expect to convert to an object-oriented 
+       formulation for expression operators that does away with the
+       need for these extension operators, and indeed for this
+       entire enumeration type.  Therefore, consider the OP_EXTENDED
+       definitions to be a temporary measure. */
   };
 
 union exp_element