X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/7deed8c9bfb5aec2b461b2b112c9efb0cd538f8d..b426ab51d0598242a4c2b57d563341db66d71f7b:/src/method-proto.lisp

diff --git a/src/method-proto.lisp b/src/method-proto.lisp
index 8b3822a..78429ef 100644
--- a/src/method-proto.lisp
+++ b/src/method-proto.lisp
@@ -85,14 +85,16 @@
    (chain-head :initarg :chain-head :type sod-class
 	       :reader method-entry-chain-head)
    (chain-tail :initarg :chain-tail :type sod-class
-	       :reader method-entry-chain-tail))
+	       :reader method-entry-chain-tail)
+   (role :initarg :role :type (or :keyword null) :reader method-entry-role))
   (:documentation
    "An entry point into an effective method.
 
-   Specifically, this is the entry point to the effective method METHOD
-   invoked via the vtable for the chain headed by CHAIN-HEAD.  The CHAIN-TAIL
-   is the most specific class on this chain; this is useful because we can
-   reuse the types of method entries from superclasses on non-primary chains.
+   Specifically, this is the entry point to the effective METHOD invoked via
+   the vtable for the chain headed by CHAIN-HEAD, and serving the given ROLE.
+   The CHAIN-TAIL is the most specific class on this chain; this is useful
+   because we can reuse the types of method entries from superclasses on
+   non-primary chains.
 
    Each effective method may have several different method entries, because
    an effective method can be called via vtables attached to different
@@ -101,16 +103,22 @@
    job of the method entry to adjust the instance pointers correctly for the
    rest of the effective method.
 
+   A vtable can contain more than one entry for the same message.  Such
+   entries are distinguished by their roles.  A message always has an entry
+   with the `nil role.  No other roles are currently defined, though they may
+   be introduced by extensions.
+
    The boundaries between a method entry and the effective method
    is (intentionally) somewhat fuzzy.  In extreme cases, the effective method
    may not exist at all as a distinct entity in the output because its
    content is duplicated in all of the method entry functions.  This is left
    up to the effective method protocol."))
 
-(export 'make-method-entry)
-(defgeneric make-method-entry (effective-method chain-head chain-tail)
+(export 'make-method-entries)
+(defgeneric make-method-entries (effective-method chain-head chain-tail)
   (:documentation
-   "Return a METHOD-ENTRY for an EFFECTIVE-METHOD called via CHAIN-HEAD.
+   "Return a list of `method-entry' objects for an EFFECTIVE-METHOD called
+   via CHAIN-HEAD.
 
    There is no default method for this function.  (Maybe when the
    effective-method/method-entry output protocol has settled down I'll know
@@ -180,6 +188,17 @@
   (:documentation
    "Return the C function type for a method entry."))
 
+(export 'method-entry-slot-name)
+(defgeneric method-entry-slot-name (entry)
+  (:documentation
+   "Return the `vtmsgs' slot name for a method entry.
+
+   The default method indirects through `method-entry-slot-name-by-role'."))
+
+(defgeneric method-entry-slot-name-by-role (entry role name)
+  (:documentation "Easier implementation for `method-entry-slot-name'.")
+  (:method ((entry method-entry) (role (eql nil)) name) name))
+
 (export 'effective-method-basic-argument-names)
 (defgeneric effective-method-basic-argument-names (method)
   (:documentation
@@ -312,7 +331,8 @@
 	 (return-type (c-type-subtype message-type))
 	 (raw-args (sod-message-argument-tail message))
 	 (arguments (if (varargs-message-p message)
-			(cons (make-argument *sod-ap* (c-type va-list))
+			(cons (make-argument *sod-ap*
+					     (c-type va-list))
 			      (butlast raw-args))
 			raw-args)))
     (codegen-push codegen)
@@ -332,13 +352,13 @@
    "Returns the function name of an effective method."))
 
 (export 'method-entry-function-name)
-(defgeneric method-entry-function-name (method chain-head)
+(defgeneric method-entry-function-name (method chain-head role)
   (:documentation
    "Returns the function name of a method entry.
 
-   The method entry is given as an effective method/chain-head pair, rather
-   than as a method entry object because we want the function name before
-   we've made the entry object."))
+   The method entry is given as an effective method/chain-head/role triple,
+   rather than as a method entry object because we want the function name
+   before we've made the entry object."))
 
 (export 'compute-method-entry-functions)
 (defgeneric compute-method-entry-functions (method)