0.pre7.71:

[sbcl.git] / src / code / macros.lisp

diff --git a/src/code/macros.lisp b/src/code/macros.lisp
index 362bce1..fe11e84 100644 (file)
--- a/src/code/macros.lisp
+++ b/src/code/macros.lisp
@@ -28,7 +28,7 @@
   #!+sb-doc
   "Signals an error if the value of test-form is nil. Continuing from this
    error using the CONTINUE restart will allow the user to alter the value of
   #!+sb-doc
   "Signals an error if the value of test-form is nil. Continuing from this
    error using the CONTINUE restart will allow the user to alter the value of

-   some locations known to SETF, starting over with test-form. Returns nil."
+   some locations known to SETF, starting over with test-form. Returns NIL."

   `(do () (,test-form)
      (assert-error ',test-form ',places ,datum ,@arguments)
      ,@(mapcar #'(lambda (place)
   `(do () (,test-form)
      (assert-error ',test-form ',places ,datum ,@arguments)
      ,@(mapcar #'(lambda (place)

@@ -56,66 +56,128 @@
 ;;;
 ;;; FIXME: In reality, this restart cruft is needed hardly anywhere in
 ;;; the system. Write NEED and NEED-TYPE to replace ASSERT and
 ;;;
 ;;; FIXME: In reality, this restart cruft is needed hardly anywhere in
 ;;; the system. Write NEED and NEED-TYPE to replace ASSERT and

-;;; CHECK-TYPE inside the system.
+;;; CHECK-TYPE inside the system. (CL:CHECK-TYPE must still be
+;;; defined, since it's specified by ANSI and it is sometimes nice for
+;;; whipping up little things. But as far as I can tell it's not
+;;; usually very helpful deep inside the guts of a complex system like
+;;; SBCL.)

 ;;;
 ;;; CHECK-TYPE-ERROR isn't defined until a later file because it uses
 ;;; the macro RESTART-CASE, which isn't defined until a later file.
 (defmacro-mundanely check-type (place type &optional type-string)
   #!+sb-doc
 ;;;
 ;;; CHECK-TYPE-ERROR isn't defined until a later file because it uses
 ;;; the macro RESTART-CASE, which isn't defined until a later file.
 (defmacro-mundanely check-type (place type &optional type-string)
   #!+sb-doc

-  "Signals a restartable error of type TYPE-ERROR if the value of PLACE is
+  "Signal a restartable error of type TYPE-ERROR if the value of PLACE is

   not of the specified type. If an error is signalled and the restart is
   not of the specified type. If an error is signalled and the restart is

-  used to return, the
-  return if the
-   STORE-VALUE is invoked. It will store into PLACE and start over."
+  used to return, this can only return if the STORE-VALUE restart is
+  invoked. In that case it will store into PLACE and start over."

   (let ((place-value (gensym)))
   (let ((place-value (gensym)))

-    `(do ((,place-value ,place))
+    `(do ((,place-value ,place ,place))

         ((typep ,place-value ',type))
        (setf ,place
             (check-type-error ',place ,place-value ',type ,type-string)))))
         ((typep ,place-value ',type))
        (setf ,place
             (check-type-error ',place ,place-value ',type ,type-string)))))

-
-#!+high-security-support
-(defmacro-mundanely check-type-var (place type-var &optional type-string)
-  #!+sb-doc
-  "Signals an error of type type-error if the contents of place are not of the
-   specified type to which the type-var evaluates. If an error is signaled,
-   this can only return if STORE-VALUE is invoked. It will store into place
-   and start over."
-  (let ((place-value (gensym))
-       (type-value (gensym)))
-    `(do ((,place-value ,place)
-         (,type-value  ,type-var))
-        ((typep ,place-value ,type-value))
-       (setf ,place
-            (check-type-error ',place ,place-value ,type-value ,type-string)))))

 \f
 ;;;; DEFCONSTANT
 
 \f
 ;;;; DEFCONSTANT
 

-(defmacro-mundanely defconstant (var val &optional doc)
+(defmacro-mundanely defconstant (name value &optional documentation)

   #!+sb-doc
   #!+sb-doc

-  "For defining global constants at top level. The DEFCONSTANT says that the
-  value is constant and may be compiled into code. If the variable already has
-  a value, and this is not equal to the init, an error is signalled. The third
-  argument is an optional documentation string for the variable."
-  `(sb!c::%defconstant ',var ,val ',doc))
+  "Define a global constant, saying that the value is constant and may be
+  compiled into code. If the variable already has a value, and this is not
+  EQL to the new value, the code is not portable (undefined behavior). The
+  third argument is an optional documentation string for the variable."
+  `(eval-when (:compile-toplevel :load-toplevel :execute)
+     (sb!c::%defconstant ',name ,value ',documentation)))

 
 

-;;; These are like the other %MUMBLEs except that we currently
-;;; actually do something interesting at load time, namely checking
-;;; whether the constant is being redefined.
+;;; the guts of DEFCONSTANT

 (defun sb!c::%defconstant (name value doc)
 (defun sb!c::%defconstant (name value doc)

-  (sb!c::%%defconstant name value doc))
-#+sb-xc-host (sb!xc:proclaim '(ftype function sb!c::%%defconstant)) ; to avoid
-                                       ; undefined function warnings
-(defun sb!c::%%defconstant (name value doc)
+  (unless (symbolp name)
+    (error "The constant name is not a symbol: ~S" name))
+  (about-to-modify-symbol-value name)
+  (when (looks-like-name-of-special-var-p name)
+    (style-warn "defining ~S as a constant, even though the name follows~@
+the usual naming convention (names like *FOO*) for special variables"
+               name))
+  (let ((kind (info :variable :kind name)))
+    (case kind
+      (:constant
+       ;; Note: This behavior (discouraging any non-EQL modification)
+       ;; is unpopular, but it is specified by ANSI (i.e. ANSI says a
+       ;; non-EQL change has undefined consequences). If people really
+       ;; want bindings which are constant in some sense other than
+       ;; EQL, I suggest either just using DEFVAR (which is usually
+       ;; appropriate, despite the un-mnemonic name), or defining
+       ;; something like SB-INT:DEFCONSTANT-EQX (which is occasionally
+       ;; more appropriate). -- WHN 2000-11-03
+       (unless (eql value
+                   (info :variable :constant-value name))
+        (cerror "Go ahead and change the value."
+                "The constant ~S is being redefined."
+                name)))
+      (:global
+       ;; (This is OK -- undefined variables are of this kind. So we
+       ;; don't warn or error or anything, just fall through.)
+       )
+      (t (warn "redefining ~(~A~) ~S to be a constant" kind name))))

   (when doc
     (setf (fdocumentation name 'variable) doc))
   (when doc
     (setf (fdocumentation name 'variable) doc))

-  (when (boundp name)
-    (unless (equalp (symbol-value name) value)
-      (cerror "Go ahead and change the value."
-             "The constant ~S is being redefined."
-             name)))
-  (setf (symbol-value name) value)
-  (setf (info :variable :kind name) :constant)
-  (clear-info :variable :constant-value name)
+
+  ;; We want to set the cross-compilation host's symbol value, not just
+  ;; the cross-compiler's (INFO :VARIABLE :CONSTANT-VALUE NAME), so
+  ;; that code like
+  ;;   (defconstant max-entries 61)
+  ;;   (deftype entry-index () `(mod ,max-entries))
+  ;; will be cross-compiled correctly.
+  #-sb-xc-host (setf (symbol-value name) value)
+  #+sb-xc-host (progn
+                ;; Redefining our cross-compilation host's CL symbols
+                ;; would be poor form.
+                ;;
+                ;; FIXME: Having to check this and then not treat it
+                ;; as a fatal error seems like a symptom of things
+                ;; being pretty broken. It's also a problem in and of
+                ;; itself, since it makes it too easy for cases of
+                ;; using the cross-compilation host Lisp's CL
+                ;; constant values in the target Lisp to slip by. I
+                ;; got backed into this because the cross-compiler
+                ;; translates DEFCONSTANT SB!XC:FOO into DEFCONSTANT
+                ;; CL:FOO. It would be good to unscrew the
+                ;; cross-compilation package hacks so that that
+                ;; translation doesn't happen. Perhaps:
+                ;;   * Replace SB-XC with SB-CL. SB-CL exports all the 
+                ;;     symbols which ANSI requires to be exported from CL.
+                ;;   * Make a nickname SB!CL which behaves like SB!XC.
+                ;;   * Go through the loaded-on-the-host code making
+                ;;     every target definition be in SB-CL. E.g.
+                ;;     DEFMACRO-MUNDANELY DEFCONSTANT becomes
+                ;;     DEFMACRO-MUNDANELY SB!CL:DEFCONSTANT.
+                ;;   * Make IN-TARGET-COMPILATION-MODE do 
+                ;;     UNUSE-PACKAGE CL and USE-PACKAGE SB-CL in each
+                ;;     of the target packages (then undo it on exit).
+                ;;   * Make the cross-compiler's implementation of
+                ;;     EVAL-WHEN (:COMPILE-TOPLEVEL) do UNCROSS.
+                ;;     (This may not require any change.)
+                ;;   * Hack GENESIS as necessary so that it outputs
+                ;;     SB-CL stuff as COMMON-LISP stuff.
+                ;;   * Now the code here can assert that the symbol
+                ;;     being defined isn't in the cross-compilation
+                ;;     host's CL package.
+                (unless (eql (find-symbol (symbol-name name) :cl) name)
+                  ;; KLUDGE: In the cross-compiler, we use the
+                  ;; cross-compilation host's DEFCONSTANT macro
+                  ;; instead of just (SETF SYMBOL-VALUE), in order to
+                  ;; get whatever blessing the cross-compilation host
+                  ;; may expect for a global (SETF SYMBOL-VALUE).
+                  ;; (CMU CL, at least around 2.4.19, generated full
+                  ;; WARNINGs for code -- e.g. DEFTYPE expanders --
+                  ;; which referred to symbols which had been set by
+                  ;; (SETF SYMBOL-VALUE). I doubt such warnings are
+                  ;; ANSI-compliant, but I'm not sure, so I've
+                  ;; written this in a way that CMU CL will tolerate
+                  ;; and which ought to work elsewhere too.) -- WHN
+                  ;; 2001-03-24
+                  (eval `(defconstant ,name ',value))))
+
+  (setf (info :variable :kind name) :constant
+       (info :variable :constant-value name) value)

   name)
 \f
 ;;;; DEFINE-COMPILER-MACRO
   name)
 \f
 ;;;; DEFINE-COMPILER-MACRO

@@ -136,16 +198,11 @@
                        :environment environment)
       (let ((def `(lambda (,whole ,environment)
                    ,@local-decs
                        :environment environment)
       (let ((def `(lambda (,whole ,environment)
                    ,@local-decs

-                   (block ,(function-name-block-name name)
+                   (block ,(fun-name-block-name name)

                      ,body))))
        `(sb!c::%define-compiler-macro ',name #',def ',lambda-list ,doc)))))
 (defun sb!c::%define-compiler-macro (name definition lambda-list doc)
                      ,body))))
        `(sb!c::%define-compiler-macro ',name #',def ',lambda-list ,doc)))))
 (defun sb!c::%define-compiler-macro (name definition lambda-list doc)

-  ;; FIXME: Why does this have to be an interpreted function? Shouldn't
-  ;; it get compiled?
-  (assert (sb!eval:interpreted-function-p definition))
-  (setf (sb!eval:interpreted-function-name definition)
-       (format nil "DEFINE-COMPILER-MACRO ~S" name))
-  (setf (sb!eval:interpreted-function-arglist definition) lambda-list)
+  (declare (ignore lambda-list))

   (sb!c::%%define-compiler-macro name definition doc))
 (defun sb!c::%%define-compiler-macro (name definition doc)
   (setf (sb!xc:compiler-macro-function name) definition)
   (sb!c::%%define-compiler-macro name definition doc))
 (defun sb!c::%%define-compiler-macro (name definition doc)
   (setf (sb!xc:compiler-macro-function name) definition)

@@ -160,19 +217,17 @@
 
 (eval-when (:compile-toplevel :load-toplevel :execute)
 
 
 (eval-when (:compile-toplevel :load-toplevel :execute)
 

-;;; CASE-BODY (interface)
-;;;
-;;; CASE-BODY returns code for all the standard "case" macros. Name is
-;;; the macro name, and keyform is the thing to case on. Multi-p
+;;; CASE-BODY returns code for all the standard "case" macros. NAME is
+;;; the macro name, and KEYFORM is the thing to case on. MULTI-P

 ;;; indicates whether a branch may fire off a list of keys; otherwise,
 ;;; a key that is a list is interpreted in some way as a single key.
 ;;; indicates whether a branch may fire off a list of keys; otherwise,
 ;;; a key that is a list is interpreted in some way as a single key.

-;;; When multi-p, test is applied to the value of keyform and each key
-;;; for a given branch; otherwise, test is applied to the value of
-;;; keyform and the entire first element, instead of each part, of the
-;;; case branch. When errorp, no t or otherwise branch is permitted,
-;;; and an ERROR form is generated. When proceedp, it is an error to
-;;; omit errorp, and the ERROR form generated is executed within a
-;;; RESTART-CASE allowing keyform to be set and retested.
+;;; When MULTI-P, TEST is applied to the value of KEYFORM and each key
+;;; for a given branch; otherwise, TEST is applied to the value of
+;;; KEYFORM and the entire first element, instead of each part, of the
+;;; case branch. When ERRORP, no T or OTHERWISE branch is permitted,
+;;; and an ERROR form is generated. When PROCEEDP, it is an error to
+;;; omit ERRORP, and the ERROR form generated is executed within a
+;;; RESTART-CASE allowing KEYFORM to be set and retested.

 (defun case-body (name keyform cases multi-p test errorp proceedp needcasesp)
   (unless (or cases (not needcasesp))
     (warn "no clauses in ~S" name))
 (defun case-body (name keyform cases multi-p test errorp proceedp needcasesp)
   (unless (or cases (not needcasesp))
     (warn "no clauses in ~S" name))

@@ -180,105 +235,33 @@
        (clauses ())
        (keys ()))
     (dolist (case cases)
        (clauses ())
        (keys ()))
     (dolist (case cases)

-      (cond ((atom case)
-            (error "~S -- Bad clause in ~S." case name))
-           ((memq (car case) '(t otherwise))
-            (if errorp
-                (error 'simple-program-error
-                       :format-control "No default clause is allowed in ~S: ~S"
-                       :format-arguments (list name case))
-                (push `(t nil ,@(rest case)) clauses)))
-           ((and multi-p (listp (first case)))
-            (setf keys (append (first case) keys))
-            (push `((or ,@(mapcar #'(lambda (key)
+      (unless (list-of-length-at-least-p case 1)
+       (error "~S -- bad clause in ~S" case name))
+      (destructuring-bind (keyoid &rest forms) case
+       (cond ((memq keyoid '(t otherwise))
+              (if errorp
+                  (error 'simple-program-error
+                         :format-control
+                         "No default clause is allowed in ~S: ~S"
+                         :format-arguments (list name case))
+                  (push `(t nil ,@forms) clauses)))
+             ((and multi-p (listp keyoid))
+              (setf keys (append keyoid keys))
+              (push `((or ,@(mapcar (lambda (key)

                                       `(,test ,keyform-value ',key))
                                       `(,test ,keyform-value ',key))

-                                  (first case)))
-                    nil ,@(rest case))
-                  clauses))
-           (t
-            (push (first case) keys)
-            (push `((,test ,keyform-value
-                           ',(first case)) nil ,@(rest case)) clauses))))
+                                    keyoid))
+                      nil
+                      ,@forms)
+                    clauses))
+             (t
+              (push keyoid keys)
+              (push `((,test ,keyform-value ',keyoid)
+                      nil
+                      ,@forms)
+                    clauses)))))

     (case-body-aux name keyform keyform-value clauses keys errorp proceedp
                   `(,(if multi-p 'member 'or) ,@keys))))
 
     (case-body-aux name keyform keyform-value clauses keys errorp proceedp
                   `(,(if multi-p 'member 'or) ,@keys))))
 

-
-;;; MNA: typecase-implicit-declarations patch
-
-;;; TYPECASE-BODY (interface)
-;;;
-;;; TYPECASE-BODY returns code for all the standard "typecase" macros.
-;;; Name is the macro name, and keyform is the thing to case on.
-;;; test is applied to the value of keyform and the entire first element,
-;;; instead of each part, of the case branch.
-;;; When errorp, no t or otherwise branch is permitted,
-;;; and an ERROR form is generated. When proceedp, it is an error to
-;;; omit errorp, and the ERROR form generated is executed within a
-;;; RESTART-CASE allowing keyform to be set and retested.
-(defun typecase-body (name keyform cases test errorp proceedp needcasesp)
-  (unless (or cases (not needcasesp))
-    (warn "no clauses in ~S" name))
-  (let* ((keyform-symbol-p (symbolp keyform))
-         (keyform-value (unless keyform-symbol-p                         
-                          (gensym)))
-         (clauses ())
-         (keys ()))
-    (dolist (case cases)
-      (cond ((atom case)
-            (error "~S -- Bad clause in ~S." case name))
-           ((memq (car case) '(t otherwise))
-            (if errorp
-                (error 'simple-program-error
-                       :format-control "No default clause is allowed in ~S: ~S"
-                       :format-arguments (list name case))
-               (push `(t nil ,@(rest case)) clauses)))
-           (t
-              (push (first case) keys)
-              (push (if keyform-symbol-p
-                      `((,test ,keyform ',(first case)) nil
-                        (locally
-                          ;; this will cause a compiler-warning ... disabled
-                          ;; for now.
-                          ;; (declare (type ,(first case) ,keyform))
-                          ,@(rest case)))
-                      `((,test ,keyform-value ',(first case)) nil
-                        ,@(rest case)))
-                    clauses))))
-    (if keyform-symbol-p
-      (typecase-symbol-body-aux name keyform clauses keys errorp proceedp
-                                (cons 'or keys))
-      (case-body-aux name keyform keyform-value clauses keys errorp proceedp
-                     (cons 'or keys)))))
-
-;;; TYPECASE-SYMBOL-BODY-AUX provides the expansion once CASE-BODY has groveled
-;;; all the cases, iff keyform is a symbol.
-(defun typecase-symbol-body-aux (name keyform clauses keys
-                                      errorp proceedp expected-type)
-  (if proceedp
-      (let ((block (gensym))
-           (again (gensym)))
-        `(block ,block
-          (tagbody
-            ,again
-            (return-from
-              ,block
-              (cond ,@(nreverse clauses)
-                    (t
-                      (setf ,keyform
-                              (case-body-error
-                               ',name ',keyform ,keyform
-                               ',expected-type ',keys)))
-                    (go ,again))))))
-    `(progn
-      (cond
-        ,@(nreverse clauses)
-        ,@(if errorp
-              `((t (error 'sb!conditions::case-failure
-                    :name ',name
-                    :datum ,keyform
-                    :expected-type ',expected-type
-                    :possibilities ',keys))))))))
-

 ;;; CASE-BODY-AUX provides the expansion once CASE-BODY has groveled
 ;;; all the cases. Note: it is not necessary that the resulting code
 ;;; signal case-failure conditions, but that's what KMP's prototype
 ;;; CASE-BODY-AUX provides the expansion once CASE-BODY has groveled
 ;;; all the cases. Note: it is not necessary that the resulting code
 ;;; signal case-failure conditions, but that's what KMP's prototype

@@ -313,7 +296,7 @@
         (cond
          ,@(nreverse clauses)
          ,@(if errorp
         (cond
          ,@(nreverse clauses)
          ,@(if errorp

-               `((t (error 'sb!conditions::case-failure
+               `((t (error 'case-failure

                            :name ',name
                            :datum ,keyform-value
                            :expected-type ',expected-type
                            :name ',name
                            :datum ,keyform-value
                            :expected-type ',expected-type

@@ -347,21 +330,21 @@
   "TYPECASE Keyform {(Type Form*)}*
   Evaluates the Forms in the first clause for which TYPEP of Keyform and Type
   is true."
   "TYPECASE Keyform {(Type Form*)}*
   Evaluates the Forms in the first clause for which TYPEP of Keyform and Type
   is true."

-  (typecase-body 'typecase keyform cases 'typep nil nil nil))
+  (case-body 'typecase keyform cases nil 'typep nil nil nil))

 
 (defmacro-mundanely ctypecase (keyform &body cases)
   #!+sb-doc
   "CTYPECASE Keyform {(Type Form*)}*
   Evaluates the Forms in the first clause for which TYPEP of Keyform and Type
   is true. If no form is satisfied then a correctable error is signalled."
 
 (defmacro-mundanely ctypecase (keyform &body cases)
   #!+sb-doc
   "CTYPECASE Keyform {(Type Form*)}*
   Evaluates the Forms in the first clause for which TYPEP of Keyform and Type
   is true. If no form is satisfied then a correctable error is signalled."

-  (typecase-body 'ctypecase keyform cases 'typep t t t))
+  (case-body 'ctypecase keyform cases nil 'typep t t t))

 
 (defmacro-mundanely etypecase (keyform &body cases)
   #!+sb-doc
   "ETYPECASE Keyform {(Type Form*)}*
   Evaluates the Forms in the first clause for which TYPEP of Keyform and Type
   is true. If no form is satisfied then an error is signalled."
 
 (defmacro-mundanely etypecase (keyform &body cases)
   #!+sb-doc
   "ETYPECASE Keyform {(Type Form*)}*
   Evaluates the Forms in the first clause for which TYPEP of Keyform and Type
   is true. If no form is satisfied then an error is signalled."

-  (typecase-body 'etypecase keyform cases 'typep t nil t))
+  (case-body 'etypecase keyform cases nil 'typep t nil t))

 \f
 ;;;; WITH-FOO i/o-related macros
 
 \f
 ;;;; WITH-FOO i/o-related macros
 

@@ -430,7 +413,7 @@
 
 (defmacro-mundanely nth-value (n form)
   #!+sb-doc
 
 (defmacro-mundanely nth-value (n form)
   #!+sb-doc

-  "Evaluates FORM and returns the Nth value (zero based). This involves no
+  "Evaluate FORM and return the Nth value (zero based). This involves no

   consing when N is a trivial constant integer."
   (if (integerp n)
       (let ((dummy-list nil)
   consing when N is a trivial constant integer."
   (if (integerp n)
       (let ((dummy-list nil)

@@ -454,29 +437,23 @@
   #!+sb-doc
   "DECLAIM Declaration*
   Do a declaration or declarations for the global environment."
   #!+sb-doc
   "DECLAIM Declaration*
   Do a declaration or declarations for the global environment."

-  #-sb-xc-host

   `(eval-when (:compile-toplevel :load-toplevel :execute)
   `(eval-when (:compile-toplevel :load-toplevel :execute)

-     ,@(mapcar #'(lambda (x)
-                  `(sb!xc:proclaim ',x))
-              specs))
-  ;; KLUDGE: The definition above doesn't work in the cross-compiler,
-  ;; because UNCROSS translates SB!XC:PROCLAIM into CL:PROCLAIM before
-  ;; the form gets executed. Instead, we have to explicitly do the
-  ;; proclamation at macroexpansion time. -- WHN ca. 19990810
-  ;;
-  ;; FIXME: Maybe we don't need this special treatment any more now
-  ;; that we're using DEFMACRO-MUNDANELY instead of DEFMACRO?
-  #+sb-xc-host (progn
-                (mapcar #'sb!xc:proclaim specs)
-                `(progn
-                   ,@(mapcar #'(lambda (x)
-                                 `(sb!xc:proclaim ',x))
-                             specs))))
+     ,@(mapcar (lambda (spec) `(sb!xc:proclaim ',spec))
+              specs)))

 
 

-(defmacro-mundanely print-unreadable-object ((object stream
-                                             &key type identity)
+(defmacro-mundanely print-unreadable-object ((object stream &key type identity)

                                             &body body)
                                             &body body)

+  "Output OBJECT to STREAM with \"#<\" prefix, \">\" suffix, optionally
+  with object-type prefix and object-identity suffix, and executing the
+  code in BODY to provide possible further output."

   `(%print-unreadable-object ,object ,stream ,type ,identity
                             ,(if body
                                  `#'(lambda () ,@body)
                                  nil)))
   `(%print-unreadable-object ,object ,stream ,type ,identity
                             ,(if body
                                  `#'(lambda () ,@body)
                                  nil)))

+
+(defmacro-mundanely ignore-errors (&rest forms)
+  #!+sb-doc
+  "Execute FORMS handling ERROR conditions, returning the result of the last
+  form, or (VALUES NIL the-ERROR-that-was-caught) if an ERROR was handled."
+  `(handler-case (progn ,@forms)
+     (error (condition) (values nil condition))))