deprecate save-stack, stack-saved?

* module/Makefile.am:
* module/ice-9/boot-9.scm:
* module/ice-9/save-stack.scm (stack-saved?, save-stack): Move these
  bindings to their own module.

* module/oop/goops.scm (goops-error):
* module/ice-9/boot-9.scm (error, top-repl): Remove calls to save-stack.

* module/ice-9/deprecated.scm (stack-saved?, save-stack): Add deprecated
  shims.

* module/ice-9/emacs.scm:
* module/ice-9/stack-catch.scm:
* module/ice-9/debugger/command-loop.scm:
* module/ice-9/scm-style-repl.scm: Import (ice-9 save-stack).

module/Makefile.am

@@ -210,6 +210,7 @@ ICE_9_SOURCES = \
   ice-9/rw.scm \
   ice-9/safe-r5rs.scm \
   ice-9/safe.scm \
+  ice-9/save-stack.scm \
   ice-9/scm-style-repl.scm \
   ice-9/session.scm \
   ice-9/slib.scm \

module/ice-9/boot-9.scm

@@ -856,10 +856,8 @@ If there is no handler at all, Guile prints an error and then exits."
 (define error
   (case-lambda
     (()
-     (save-stack)
      (scm-error 'misc-error #f "?" #f #f))
     ((message . args)
-     (save-stack)
      (let ((msg (string-join (cons "~A" (make-list (length args) "~S")))))
        (scm-error 'misc-error #f msg (cons message args) #f)))))
 
@@ -2690,25 +2688,6 @@ module '(ice-9 q) '(make-q q-length))}."
   (restore-signals))
 
 ;;(define the-last-stack (make-fluid)) Defined by scm_init_backtrace ()
-;; FIXME: stack-saved? is broken in the presence of threads.
-(define stack-saved? #f)
-
-(define (save-stack . narrowing)
-  (if (not stack-saved?)
-      (begin
-        (let ((stacks (fluid-ref %stacks)))
-          (fluid-set! the-last-stack
-                      ;; (make-stack obj inner outer inner outer ...)
-                      ;;
-                      ;; In this case, cut away the make-stack frame, the
-                      ;; save-stack frame, and then narrow as specified by the
-                      ;; user, delimited by the nearest start-stack invocation,
-                      ;; if any.
-                      (apply make-stack #t
-                             2
-                             (if (pair? stacks) (cdar stacks) 0)
-                             narrowing)))
-        (set! stack-saved? #t))))
 
 (define (quit . args)
   (apply throw 'quit args))
@@ -3438,7 +3417,6 @@ module '(ice-9 q) '(make-q q-length))}."
           (lambda ()
             (let ((make-handler (lambda (msg)
                                   (lambda (sig)
-                                    (save-stack 2)
                                     (scm-error 'signal
                                                #f
                                                msg

module/ice-9/debugger/command-loop.scm

@@ -21,6 +21,7 @@
   #:use-module (ice-9 debugger)
   #:use-module (ice-9 debugger state)
   #:use-module (ice-9 debugging traps)
+  #:use-module (ice-9 save-stack)
   #:export (debugger-command-loop
 	    debugger-command-loop-error
 	    debugger-command-loop-quit)

module/ice-9/deprecated.scm

@@ -59,7 +59,9 @@
             repl
             pre-unwind-handler-dispatch
             default-pre-unwind-handler
-            handle-system-error)
+            handle-system-error
+            stack-saved?
+            save-stack)
 
   #:replace (module-ref-submodule module-define-submodule!))
 
@@ -637,3 +639,23 @@ the `(system repl common)' module.")
    "`handle-system-error' is deprecated. Use it from 
 `(ice-9 scm-style-repl)' if you need it.")
   (apply (@ (ice-9 scm-style-repl) handle-system-error) key args))
+
+(define-syntax stack-saved?
+  (make-variable-transformer
+   (lambda (x)
+     (issue-deprecation-warning
+      "`stack-saved?' is deprecated. Use it from
+`(ice-9 save-stack)' if you need it.")
+     (syntax-case x (set!)
+       ((set! id val)
+        (identifier? #'id)
+        #'(set! (@ (ice-9 save-stack) stack-saved?) val))
+       (id
+        (identifier? #'id)
+        #'(@ (ice-9 save-stack) stack-saved?))))))
+
+(define (save-stack . args)
+  (issue-deprecation-warning
+   "`save-stack' is deprecated. Use it from `(ice-9 save-stack)' if you need
+it.")
+  (apply (@ (ice-9 save-stack) save-stack) args))

module/ice-9/emacs.scm

@@ -1,4 +1,4 @@
-;;;; 	Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2006, 2009 Free Software Foundation, Inc.
+;;;; 	Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2006, 2009, 2010 Free Software Foundation, Inc.
 ;;;; 
 ;;;; This library is free software; you can redistribute it and/or
 ;;;; modify it under the terms of the GNU Lesser General Public
@@ -32,6 +32,7 @@
   :use-module (ice-9 debug)
   :use-module (ice-9 threads)
   :use-module (ice-9 session)
+  :use-module (ice-9 save-stack)
   :no-backtrace)
 
 (define emacs-escape-character #\sub)

module/ice-9/save-stack.scm

@@ -0,0 +1,55 @@
+;;; -*- mode: scheme; coding: utf-8; -*-
+
+;;;; Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004,2005,2006,2007,2008,2009,2010
+;;;; Free Software Foundation, Inc.
+;;;;
+;;;; This library is free software; you can redistribute it and/or
+;;;; modify it under the terms of the GNU Lesser General Public
+;;;; License as published by the Free Software Foundation; either
+;;;; version 3 of the License, or (at your option) any later version.
+;;;; 
+;;;; This library is distributed in the hope that it will be useful,
+;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+;;;; Lesser General Public License for more details.
+;;;; 
+;;;; You should have received a copy of the GNU Lesser General Public
+;;;; License along with this library; if not, write to the Free Software
+;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+;;;;
+
+
+
+;;; Commentary:
+
+;;; An older approack to debugging, in which the user installs a pre-unwind
+;;; handler that saves the stack at the time of the error. The last stack can
+;;; then be debugged later.
+;;;
+
+;;; Code:
+
+(define-module (ice-9 save-stack)
+  ;; Replace deprecated root-module bindings, if present.
+  #:replace (stack-saved?
+             save-stack))
+
+;; FIXME: stack-saved? is broken in the presence of threads.
+(define stack-saved? #f)
+
+(define (save-stack . narrowing)
+  (if (not stack-saved?)
+      (begin
+        (let ((stacks (fluid-ref %stacks)))
+          (fluid-set! the-last-stack
+                      ;; (make-stack obj inner outer inner outer ...)
+                      ;;
+                      ;; In this case, cut away the make-stack frame, the
+                      ;; save-stack frame, and then narrow as specified by the
+                      ;; user, delimited by the nearest start-stack invocation,
+                      ;; if any.
+                      (apply make-stack #t
+                             2
+                             (if (pair? stacks) (cdar stacks) 0)
+                             narrowing)))
+        (set! stack-saved? #t))))

module/ice-9/scm-style-repl.scm

@@ -17,6 +17,8 @@
 ;;;;
 
 (define-module (ice-9 scm-style-repl)
+  #:use-module (ice-9 save-stack)
+
   #:export (scm-repl-silent
             scm-repl-print-unspecified
             scm-repl-verbose

module/ice-9/stack-catch.scm

@@ -18,6 +18,7 @@
 ;;;; 
 
 (define-module (ice-9 stack-catch)
+  #:use-module (ice-9 save-stack)
   #:export (stack-catch))
 
 (define (stack-catch key thunk handler)

module/oop/goops.scm

@@ -1,6 +1,6 @@
 ;;; installed-scm-file
 
-;;;; Copyright (C) 1998,1999,2000,2001,2002, 2003, 2006, 2009 Free Software Foundation, Inc.
+;;;; Copyright (C) 1998,1999,2000,2001,2002, 2003, 2006, 2009, 2010 Free Software Foundation, Inc.
 ;;;; 
 ;;;; This library is free software; you can redistribute it and/or
 ;;;; modify it under the terms of the GNU Lesser General Public
@@ -105,7 +105,6 @@
 ;; goops-error
 ;;
 (define (goops-error format-string . args)
-  (save-stack)
   (scm-error 'goops-error #f format-string args '()))
 
 ;;