0.pre7.61:

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

diff --git a/src/code/macros.lisp b/src/code/macros.lisp
index e11812d..1976274 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)

@@ -56,68 +56,57 @@
 ;;;
 ;;; 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
 
 (defmacro-mundanely defconstant (name value &optional documentation)
   #!+sb-doc
 \f
 ;;;; DEFCONSTANT
 
 (defmacro-mundanely defconstant (name value &optional documentation)
   #!+sb-doc

-  "For defining global constants. 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 EQL to the init, the code is not portable
-  (undefined behavior). The third argument is an optional documentation
-  string for the variable."
+  "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)))
 
 ;;; the guts of DEFCONSTANT
 (defun sb!c::%defconstant (name value doc)
   `(eval-when (:compile-toplevel :load-toplevel :execute)
      (sb!c::%defconstant ',name ,value ',documentation)))
 
 ;;; the guts of DEFCONSTANT
 (defun sb!c::%defconstant (name value doc)

-  (/show "doing %DEFCONSTANT" name value doc)

   (unless (symbolp name)
   (unless (symbolp name)

-    (error "constant name not a symbol: ~S" name))
+    (error "The constant name is not a symbol: ~S" name))

   (about-to-modify name)
   (about-to-modify 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
   (let ((kind (info :variable :kind name)))
     (case kind
       (:constant

-       ;; Note 1: 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
+       ;; 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."
        (unless (eql value
                    (info :variable :constant-value name))
         (cerror "Go ahead and change the value."

@@ -130,9 +119,65 @@
       (t (warn "redefining ~(~A~) ~S to be a constant" kind name))))
   (when doc
     (setf (fdocumentation name 'variable) doc))
       (t (warn "redefining ~(~A~) ~S to be a constant" kind name))))
   (when doc
     (setf (fdocumentation name 'variable) doc))

-  (setf (symbol-value name) value)
-  (setf (info :variable :kind name) :constant)
-  (setf (info :variable :constant-value name) value)
+
+  ;; 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

@@ -153,16 +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)

@@ -373,7 +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)

@@ -397,29 +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))))