From f575ddaffe838c611359430946fe26b80808a35a Mon Sep 17 00:00:00 2001
From: Nikodemus Siivola <nikodemus@random-state.net>
Date: Thu, 18 Nov 2010 17:19:50 +0200
Subject: [PATCH] support for deprecating special variables

  Use DEFINE-DEPRECATED-VARIABLE to deprecate them.
---
 package-data-list.lisp-expr    |    3 +++
 src/code/early-extensions.lisp |   15 +++++++++++++++
 src/code/symbol.lisp           |    8 ++++++++
 src/compiler/globaldb.lisp     |    6 ++++++
 src/compiler/ir1tran.lisp      |    2 ++
 5 files changed, 34 insertions(+)

diff --git a/package-data-list.lisp-expr b/package-data-list.lisp-expr
index bfab9b1..8560e0b 100644
--- a/package-data-list.lisp-expr
+++ b/package-data-list.lisp-expr
@@ -1033,6 +1033,9 @@ possibly temporariliy, because it might be used internally."
 
                ;; Deprecating stuff
                "DEFINE-DEPRECATED-FUNCTION"
+               "DEFINE-DEPRECATED-VARIABLE"
+               "DEPRECATED-VARIABLE"
+               "CHECK-DEPRECATED-VARIABLE"
                "EARLY-DEPRECATION-WARNING"
                "LATE-DEPRECATION-WARNING"
                "FINAL-DEPRECATION-WARNING"
diff --git a/src/code/early-extensions.lisp b/src/code/early-extensions.lisp
index 52ab419..6e077f1 100644
--- a/src/code/early-extensions.lisp
+++ b/src/code/early-extensions.lisp
@@ -1191,6 +1191,21 @@
        (setf (compiler-macro-function ',name)
              (deprecation-compiler-macro ,state ,since ',name ',replacements)))))
 
+(defun check-deprecated-variable (name)
+  (let ((info (info :variable :deprecated name)))
+    (when info
+      (deprecation-warning (car info) (cdr info) name nil))))
+
+(defmacro define-deprecated-variable (state since name &key (value nil valuep) replacement)
+  `(progn
+     (setf (info :variable :deprecated ',name) (cons ,state ,since))
+     ,@(when (member state '(:early :late))
+         `((defvar ,name ,@(when valuep (list value))
+             ,(let ((*package* (find-package :keyword)))
+                (format nil
+                        "~@<~S has been deprecated as of SBCL ~A~@[, use ~S instead~].~:>"
+                        name since replacement)))))))
+
 ;;; Anaphoric macros
 (defmacro awhen (test &body body)
   `(let ((it ,test))
diff --git a/src/code/symbol.lisp b/src/code/symbol.lisp
index 7dcfe23..5ef0d7b 100644
--- a/src/code/symbol.lisp
+++ b/src/code/symbol.lisp
@@ -23,6 +23,14 @@
   (declare (optimize (safety 1)))
   (symbol-value symbol))
 
+#-sb-xc-host
+(define-compiler-macro symbol-value (&whole form symbol &environment env)
+  (when (sb!xc:constantp symbol env)
+    (let ((name (constant-form-value symbol env)))
+      (when (symbolp name)
+        (check-deprecated-variable name))))
+  form)
+
 (defun boundp (symbol)
   #!+sb-doc
   "Return non-NIL if SYMBOL is bound to a value."
diff --git a/src/compiler/globaldb.lisp b/src/compiler/globaldb.lisp
index a0d4872..aa9f8b8 100644
--- a/src/compiler/globaldb.lisp
+++ b/src/compiler/globaldb.lisp
@@ -1000,6 +1000,12 @@
   :type-spec boolean
   :default nil)
 
+(define-info-type
+  :class :variable
+  :type :deprecated
+  :type-spec t
+  :default nil)
+
 ;;; the declared type for this variable
 (define-info-type
   :class :variable
diff --git a/src/compiler/ir1tran.lisp b/src/compiler/ir1tran.lisp
index 5a448fd..8bb36fb 100644
--- a/src/compiler/ir1tran.lisp
+++ b/src/compiler/ir1tran.lisp
@@ -682,6 +682,8 @@
                ;; processing our own code, though.
                #+sb-xc-host
                (warn "reading an ignored variable: ~S" name)))
+           (when (global-var-p var)
+             (check-deprecated-variable name))
            (reference-leaf start next result var name))
           (cons
            (aver (eq (car var) 'macro))
-- 
1.7.10.4