From: Mark Wooding <mdw@distorted.org.uk>
Date: Sun, 30 Aug 2015 09:58:38 +0000 (+0100)
Subject: src/: Tweak handling of `va_list' pointers in generated functions.
X-Git-Tag: 0.2.0~20
X-Git-Url: https://git.distorted.org.uk/~mdw/sod/commitdiff_plain/2bbe0f1d36d39db51085bf88612055e0b5743ffb?ds=sidebyside

src/: Tweak handling of `va_list' pointers in generated functions.

In method entries, effective method bodies, and delegation trampolines,
the `va_list' argument is named `sod__ap', and a copy is made for
invoking direct methods into a temporary called `sod__tmp_ap'.  The name
`sod__master_ap' is now only used in direct method argument lists and
the `CALL_NEXT_METHOD' machinery.

This reduces the amount of mangling of argument lists which needs to be
done.  It will also make some future changes a little easier.
---

diff --git a/src/codegen-proto.lisp b/src/codegen-proto.lisp
index f6cd4bd..e947a72 100644
--- a/src/codegen-proto.lisp
+++ b/src/codegen-proto.lisp
@@ -74,6 +74,8 @@
   (make-instance 'temporary-name :tag "sod__ap"))
 (defparameter *sod-master-ap*
   (make-instance 'temporary-name :tag "sod__master_ap"))
+(defparameter *sod-tmp-ap*
+  (make-instance 'temporary-name :tag "sod__tmp_ap"))
 
 ;;;--------------------------------------------------------------------------
 ;;; Instructions.
diff --git a/src/method-impl.lisp b/src/method-impl.lisp
index 6508f57..e6368e7 100644
--- a/src/method-impl.lisp
+++ b/src/method-impl.lisp
@@ -419,15 +419,10 @@
 	 ;; Effective method function details.
 	 (emf-name (effective-method-function-name method))
 	 (ilayout-type (c-type (* (struct (ilayout-struct-tag class)))))
-	 (emf-arg-tail (mapcar (lambda (arg)
-				 (if (eq (argument-name arg) *sod-ap*)
-				     (make-argument *sod-master-ap*
-						    (c-type va-list))
-				     arg))
-			       (sod-message-no-varargs-tail message)))
+	 (emf-arg-tail (sod-message-no-varargs-tail message))
 	 (emf-type (c-type (fun (lisp return-type)
 				("sod__obj" (lisp ilayout-type))
-				. (sod-message-no-varargs-tail message))))
+				. emf-arg-tail)))
 
 	 ;; Method entry details.
 	 (chain-tails (remove-if-not (lambda (super)
@@ -450,12 +445,12 @@
 			   (make-convert-to-ilayout-inst class
 							 head "me"))))
 	   (varargs-prologue ()
-	     (ensure-var codegen *sod-master-ap* (c-type va-list))
+	     (ensure-var codegen *sod-ap* (c-type va-list))
 	     (emit-inst codegen
-			(make-va-start-inst *sod-master-ap*
+			(make-va-start-inst *sod-ap*
 					    (argument-name parm-n))))
 	   (varargs-epilogue ()
-	     (emit-inst codegen (make-va-end-inst *sod-master-ap*)))
+	     (emit-inst codegen (make-va-end-inst *sod-ap*)))
 	   (finish-entry (tail)
 	     (let* ((head (sod-class-chain-head tail))
 		    (name (method-entry-function-name method head))
diff --git a/src/method-proto.lisp b/src/method-proto.lisp
index 17db6e9..8b3822a 100644
--- a/src/method-proto.lisp
+++ b/src/method-proto.lisp
@@ -252,8 +252,7 @@
    CLASS where CLASS is the class on which the method was defined.
 
    If the message accepts a variable-length argument list then a copy of the
-   prevailing master argument pointer is provided in place of the
-   `:ellipsis'."
+   prevailing argument pointer is provided in place of the `:ellipsis'."
 
   (let* ((message (sod-method-message direct-method))
 	 (class (sod-method-class direct-method))
@@ -267,14 +266,14 @@
 	(convert-stmts codegen target
 		       (c-type-subtype (sod-method-type direct-method))
 		       (lambda (var)
-			 (ensure-var codegen *sod-ap* (c-type va-list))
+			 (ensure-var codegen *sod-tmp-ap* (c-type va-list))
 			 (emit-inst codegen
-				    (make-va-copy-inst *sod-ap*
-						       *sod-master-ap*))
+				    (make-va-copy-inst *sod-tmp-ap*
+						       *sod-ap*))
 			 (deliver-expr codegen var
 				       (make-call-inst function arguments))
 			 (emit-inst codegen
-				    (make-va-end-inst *sod-ap*))))
+				    (make-va-end-inst *sod-tmp-ap*))))
 	(deliver-expr codegen target (make-call-inst function arguments)))))
 
 (export 'ensure-ilayout-var)
@@ -313,8 +312,7 @@
 	 (return-type (c-type-subtype message-type))
 	 (raw-args (sod-message-argument-tail message))
 	 (arguments (if (varargs-message-p message)
-			(cons (make-argument *sod-master-ap*
-					     (c-type va-list))
+			(cons (make-argument *sod-ap* (c-type va-list))
 			      (butlast raw-args))
 			raw-args)))
     (codegen-push codegen)
@@ -378,7 +376,7 @@
 
   (let* ((message (codegen-message codegen))
 	 (argument-tail (if (varargs-message-p message)
-			    (cons *sod-master-ap* basic-tail)
+			    (cons *sod-tmp-ap* basic-tail)
 			    basic-tail)))
     (labels ((next-trampoline (method chain)
 	       (if (or kernel chain)