Debugger now treats compiled-return-address frames with history

specially: The stack information for each is printed as if it had
its own reduction since the first reduction corresponds to the
interpreted expression that tail-recursed into the compiled code.

diff --git a/v7/src/runtime/debug.scm b/v7/src/runtime/debug.scm
index 00294c200c8138d3e4ef2228896214aca0630c32..4f76099500012dbb7cf004b1581bb0accae1d84c 100644 (file)
--- a/v7/src/runtime/debug.scm
+++ b/v7/src/runtime/debug.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/runtime/debug.scm,v 14.28 1991/07/16 00:03:00 arthur Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/runtime/debug.scm,v 14.29 1991/08/06 22:10:41 arthur Exp $
 
 Copyright (c) 1988-91 Massachusetts Institute of Technology
 
@@ -597,6 +597,13 @@ MIT in each case. |#
                 (wrap false))
                ((positive? reduction-number)
                 (move-to-reduction! dstate (-1+ reduction-number)))
+               ((special-history-subproblem? dstate)
+                ;; Reset state
+                (set-current-subproblem! dstate
+                                         (dstate/subproblem dstate)
+                                         (dstate/previous-subproblems dstate))
+                (set-dstate/reduction-number! dstate false)
+                (command/print-subproblem dstate))
                (debugger:student-walk?
                 (down))
                (else
@@ -768,15 +775,17 @@ MIT in each case. |#
   (if (eq? 'ENABLED (dstate/history-state dstate))
       (begin
        (set-dstate/history-state! dstate 'NOW)
-       (debugger-message
-        "Now using information from the execution history."))))
+       (if (not (zero? (dstate/number-of-reductions dstate)))
+           (debugger-message
+            "Now using information from the execution history.")))))
 
 (define (maybe-stop-using-history! dstate)
   (if (eq? 'NOW (dstate/history-state dstate))
       (begin
        (set-dstate/history-state! dstate 'ENABLED)
-       (debugger-message
-        "Now ignoring information from the execution history."))))
+       (if (not (zero? (dstate/number-of-reductions dstate)))
+           (debugger-message
+            "Now ignoring information from the execution history.")))))
 
 (define (dstate/using-history? dstate)
   (or (eq? 'ALWAYS (dstate/history-state dstate))
@@ -804,7 +813,8 @@ MIT in each case. |#
 
 (define (finish-move-to-subproblem! dstate)
   (if (and (dstate/using-history? dstate)
-          (positive? (dstate/number-of-reductions dstate)))
+          (positive? (dstate/number-of-reductions dstate))
+          (not (special-history-subproblem? dstate)))
       (move-to-reduction! dstate 0)
       (begin
        (set-dstate/reduction-number! dstate false)
@@ -816,6 +826,10 @@ MIT in each case. |#
    dstate
    (list (reduction-environment (dstate/reduction dstate))))
   (command/print-reduction dstate))
+
+(define (special-history-subproblem? dstate)
+  (eq? (stack-frame/type (dstate/subproblem dstate))
+       stack-frame-type/compiled-return-address))
 \f
 ;;;; Utilities