From: Taylor R Campbell <campbell@mumble.net>
Date: Wed, 28 Nov 2018 03:01:22 +0000 (+0000)
Subject: Fix miscompilation of default optional parameters.
X-Git-Tag: mit-scheme-pucked-10.1.7~3^2~164
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=cc65b1e8919f7d951cba55d6b70741b6931dd176;p=mit-scheme.git

Fix miscompilation of default optional parameters.

Holdover from days when optional parameters were filled with
unassigned reference traps -- LIAR never got the memo.
---

diff --git a/src/compiler/fgopt/simapp.scm b/src/compiler/fgopt/simapp.scm
index ff285216f..ed7d006a6 100644
--- a/src/compiler/fgopt/simapp.scm
+++ b/src/compiler/fgopt/simapp.scm
@@ -96,7 +96,7 @@ USA.
 		    (operands operands))
 		 (if (not (null? parameters))
 		     (if (null? operands)
-			 (for-each lvalue-unassigned! parameters)
+			 (for-each lvalue-defaulted! parameters)
 			 (begin
 			   (lvalue-connect! (car parameters) (car operands))
 			   (loop (cdr parameters) (cdr operands)))))))
@@ -135,8 +135,8 @@ USA.
     (eq-set-union* (lvalue-initial-values (car lvalues))
 		   (map lvalue-initial-values (cdr lvalues)))))
 
-(define (lvalue-unassigned! lvalue)
-  (lvalue-connect! lvalue (make-constant (make-unassigned-reference-trap))))
+(define (lvalue-defaulted! lvalue)
+  (lvalue-connect! lvalue (make-constant (default-object))))
 
 (define-integrable (lvalue-connect! lvalue rvalue)
   (if (rvalue/reference? rvalue)
diff --git a/tests/runtime/test-optional.scm b/tests/runtime/test-optional.scm
index ffb6a7b75..2a1c52478 100644
--- a/tests/runtime/test-optional.scm
+++ b/tests/runtime/test-optional.scm
@@ -37,8 +37,4 @@ USA.
       (define (local #!optional arg)
         (assert-eqv (fixit arg) #!default))
       (local))
-    ;; Compiler incorrectly passes unassigned reference trap if
-    ;; argument is never passed.
-    (if (compiled-procedure? test)
-        (expect-failure test)
-        (test))))
+    (test)))