From: Guillermo J. Rozas <edu/mit/csail/zurich/gjr>
Date: Wed, 28 Mar 1990 06:11:39 +0000 (+0000)
Subject: Add new method for finding variable that is used by stack-overwrite
X-Git-Tag: 20090517-FFI~11488
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=979f50d97fb7aa67db9dd902f49e7940effbe8db;p=mit-scheme.git

Add new method for finding variable that is used by stack-overwrite
mechanism.  This new method does not use any tricks like variable
indirection to find the value, but produces a locative for that
particular variable.
---

diff --git a/v7/src/compiler/rtlgen/fndvar.scm b/v7/src/compiler/rtlgen/fndvar.scm
index 135b81d83..e9d9b32a7 100644
--- a/v7/src/compiler/rtlgen/fndvar.scm
+++ b/v7/src/compiler/rtlgen/fndvar.scm
@@ -1,8 +1,8 @@
 #| -*-Scheme-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/rtlgen/fndvar.scm,v 1.3 1989/10/26 07:38:52 cph Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/rtlgen/fndvar.scm,v 1.4 1990/03/28 06:11:14 jinx Exp $
 
-Copyright (c) 1988 Massachusetts Institute of Technology
+Copyright (c) 1988, 1990 Massachusetts Institute of Technology
 
 This material was developed by the Scheme project at the Massachusetts
 Institute of Technology, Department of Electrical Engineering and
@@ -76,6 +76,15 @@ MIT in each case. |#
       block locative
       (error "Closure variable in IC frame" variable))))
 
+(define (find-stack-overwrite-variable context variable)
+  (find-variable-no-tricks context variable
+    (lambda (variable locative)
+      variable
+      locative)
+    (lambda (variable block locative)
+      block locative
+      (error "Stack overwrite slot in IC frame" variable))))
+
 (define (find-variable-internal context variable if-compiler if-ic)
   (let ((rvalue (lvalue-known-value variable)))
     (if (and rvalue
@@ -101,16 +110,18 @@ MIT in each case. |#
 		(let ((register (variable/register variable)))
 		  (if register
 		      (if-compiler variable (register-locative register))
-		      (find-block/variable context variable
-			(lambda (offset-locative)
-			  (lambda (block locative)
-			    (if-compiler
-			     variable
-			     (offset-locative
-			      locative
-			      (variable-offset block variable)))))
-			(lambda (block locative)
-			  (if-ic variable block locative)))))))))))
+		      (find-variable-no-tricks context variable
+					       if-compiler if-ic)))))))))
+
+(define (find-variable-no-tricks context variable if-compiler if-ic)
+  (find-block/variable context variable
+    (lambda (offset-locative)
+      (lambda (block locative)
+	(if-compiler variable
+		     (offset-locative locative
+				      (variable-offset block variable)))))
+    (lambda (block locative)
+      (if-ic variable block locative))))
 
 (define (find-definition-variable context lvalue)
   (find-block/variable context lvalue
diff --git a/v7/src/compiler/rtlgen/rgstmt.scm b/v7/src/compiler/rtlgen/rgstmt.scm
index 3fc74805f..e4b8bbc6f 100644
--- a/v7/src/compiler/rtlgen/rgstmt.scm
+++ b/v7/src/compiler/rtlgen/rgstmt.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/rtlgen/rgstmt.scm,v 4.13 1990/03/21 02:12:01 cph Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/rtlgen/rgstmt.scm,v 4.14 1990/03/28 06:11:39 jinx Exp $
 
 Copyright (c) 1988, 1990 Massachusetts Institute of Technology
 
@@ -234,7 +234,7 @@ MIT in each case. |#
 
 (define (stack-overwrite-locative context target)
   (cond ((variable? target)
-	 (find-closure-variable context target))
+	 (find-stack-overwrite-variable context target))
 	((block? target)
 	 (block-ancestor-or-self->locative
 	  context